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BUILDING CODE
CITY OF BOSTON

2 'I C

July 1, 1970

KEVIN H. WHITE

Mayor

RICHARD R. THUMA, JR.

Building Commissioner

Building Department City Hall Boston, Massachusetts 02201

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Gov Va6$

BOSTON PUBLIC LIBRARY

CONTENTS

PART I

PART II
Article

Administration

1 General Provisions

2 Definitions and Classifications

3 General Building Limitations

4 Special Use and Occupancy Requirements

5 Light, Heat, Ventilation and Noise Control

6 Means of Egress

7 Structural and Foundation Loads and Stresses
8A Materials and Tests
8B Steel, Masonry, Concrete, Gypsum and Lumber

Construction

8C Building Enclosures, Walls and Wall Thickness
9 Fireresistive Construction Requirements

10 Chimneys, Flues and Vent Pipes

11 Heating Equipment and Appliances Mounting,
Clearances and Connections

12 Fire Protection and Fire-Extinguishing Equipment

13 Precautions During Building Operations

14 Signs and Outdoor Display Structures

15 Electrical Wiring and Equipment

16 Elevator, Dumbwaiter and Conveyor Equipment
Installation and Maintenance

17 Plumbing, Drainage and Gas Piping

18 Air Conditioning, Refrigeration and Mechanical
Ventilation

19 Prefabricated Construction

20 Light Transmitting Plastic Materials

[APPENDIX A Accredited Authoritative Agencies Listed

in Reference Standards
\PPENDIX B Code Revision Proposal Form

\PPENDIX C Permit Application Procedure and List of Application
Forms
Alphabetical
Principal Regulations by Occupancy Group

NDEX A
NDEX B

THE COMMONWEALTH OF MASSACHUSETTS
ACTS OF 1938, CHAPTER 479

AN ACT FOR CODIFICATION, REVISION AND
AMENDMENT OF THE LAWS RELATIVE TO THE
CONSTRUCTION, ALTERATION AND MAINTENANCE
OF BUILDINGS AND OTHER STRUCTURES IN THE
CITY OF BOSTON.

PART I.
ADMINISTRATION

101-Title.
102-Repeals.
103-Pending Actions.
104-Other Statutes.
105 -Effective Date.
[105A-Amendment by Ordinance.]
106-Meaning of Certain Words.
107-Scope.
108-Maintenance.
109-Organization.
110-Application for Permit.
Ill-Permits.
112-Fees.
113-Inspection.
114-Posting Floor Loads.
115-Annual Report.

116-Powers and Duties of Building Commissioner.
117-Board of Appeal.
11 8- Appeals.

119-Decisions of the Board of Appeal.
120-Board of Examiners.
121 -Omitted.
122-Penalties.

123-Enforcement Jurisdiction.
124-132-Omitted.
133-Change of Occupancy.

Sect. 101. Title. — This act shall be known and may be
cited as the Boston Building Code and is hereinafter referred to
as this code.

Sect. 102. Repeals. — Except as provided in section one
hundred and three, the following acts and parts of acts, as
severally amended, are hereby repealed; — chapter two hundred
and sixty-five of the acts of eighteen hundred and ninety-seven;
the two paragraphs added to section four of chapter three hun-
dred and eighty-three of the acts of nineteen hundred and five
by section one of chapter one hundred and fifty-six of the
Special Acts of nineteen hundred and nineteen; chapter five
hundred and fifty of the acts of nineteen hundred and seven,
except section one hundred and twenty-eight thereof; chapter
three hundred and forty-two of the acts of nineteen hundred
and eleven; chapter seven hundred and twenty-nine of the acts
of nineteen hundred and thirteen; chapter seven hundred and
eighty-two of the acts of nineteen hundred and fourteen; sec-
tions one to five, inclusive of chapter one hundred and sixty-
three of the Special Acts of nineteen hundred and nineteen;
chapter two hundred and seventy-eight of the acts of nineteen
hundred and twenty-three; chapter one hundred and eighty-two
of the acts of nineteen hundred and twenty-six; and chapter
forty-two of the acts of nineteen hundred and twenty-seven.

Sect. 103. Pending Actions. — All actions and proceedings,
at law or in equity, and all prosecutions, pending on the effec-
tive date of this code, whether commenced for the purpose of
enforcing any of the provisions of the acts, or parts, thereof,
repealed by the preceding section or brought upon any com-
plaint or indictment for the violation of any of such provisions,
or for the violation of any ordinance, rule or regulation estab-
lished thereunder for the violation of which a penalty of a fine
or imprisonment, or otherwise, is provided therein, may be
prosecuted and enforced to the same extent as if said acts, or
parts thereof, were still in force and effect.

Sect. 104. Other Statutes. —All statutes applicable generally
to departments of the city of Boston, including the provisions
of section five of chapter four hundred and eighty-six of the
acts of nineteen hundred and nine, as most recently amended by
chapter two hundred and twenty-seven of the acts of nineteen
hundred and thirty-four, and any pertinent action taken there-
under whether before or after the effective date of this code,

101-107

shall apply to the building department and to the boards estab-
lished under sections one hundred and nine, one hundred and
seventeen, one hundred and twenty and one hundred and twenty-
one hereof.

*Sect. 105. Effective Date. — This code shall take full effect
upon its acceptance by vote of the city council of the city of
Boston, subject to the provisions of its charter. If an applica-
tion for a permit is filed before said effective date, and a per-
mit is issued thereon and the work is actually commenced within
ninety days after the issuance of the permit, the applicant not-
withstanding any provision to the contrary in section one hun-
dred and seven, may elect to be governed in the entire operation
covered by the permit either by the building laws as they existed
when the application was filed or by this code.

\*As amended by Ord. 1943, ch. 2]

t Sect. 105A. [Amendment by Ordinance.] — The city of
Boston, for the purposes of the prevention of fire and preserva-
tion of life, health and morals, or for any of such purposes,
may from time to time, by ordinance and upon the written
recommendation of the building commissioner or the board of

I L appeal, regulate the inspection, materials, construction, altera-
tion, repair, height, area, location and use of buildings and
I other structures in said city, except such buildings or structures
j as are excluded from the operation of this code by sub-section
(a) of section one hundred and seven, and for any or all of
j said purposes may from time to time, by ordinance upon like
written recommendation, alter, amend, extend or render ineffec-
! tive any provision or provisions of this code regulating building
and other structures as aforesaid.

| t As inserted by Stat. 1939, ch. 217]

Sect. 106. Meaning of Certain Words. —

"Approved", approved by the building commissioner of the

city of Boston.

"Commissioner", the building commissioner of the city of

Boston.

"Department", the building department of the city of Boston.

*Sect. 107. Scope. — (a) The provisions of this code shall
apply to every building or structure hereafter erected in the city
of Boston, except public highway, railroad or railway bridges

or trestles, quays or wharves, buildings owned and occupied by
the United States or the commonwealth, railroad structures and
stations used primarily for railroad purposes, subway and ele-
vated railway structures and stations used primarily for railway
purposes, voting booths erected and maintained by the board of
election commissioners, prefabricated metal tanks of less than
five thousand gallons capacity and tanks exceeding ten thousand
gallons capacity for liquids other than water, tunnels constructed
and maintained by a public authority, tents covering an area
less than one hundred square feet, fences less than six feet high,
signs or billboards upon the ground and signs less than one
square foot in area, upon or attached to the outside of a
structure and flagpoles less than twenty feet in length.

(b) The provisions of sections one hundred and eight, one
hundred and fourteen, one hundred and sixteen, one hundred
and eighteen, one hundred and nineteen, one hundred and
twenty-two, and one hundred and twenty-three shall apply to
pre-code buildings.

(c) A pre-code building may be altered, repaired, enlarged,
moved, or converted to other uses, only in conformity with the
following provisions of this section and subject to permit as
hereinafter provided.

(d) A pre-code building which is altered or repaired within
any period of twelve months, said alterations or repairs costing
in excess of fifty per cent of its physical value, shall be made
to conform to the requirements of this code for post-code build-
ings. A pre-code building damaged by fire or otherwise in excess
of fifty per cent of its physical value before such damage shall
be made to conform to such requirements, if repaired. If the
cost of such alterations or repairs or the amount of such damage
is more than twenty-five but not more than fifty per cent of
the physical value of the building it shall be made to conform
to such requirements in the portions so altered or repaired to
such extent as the commissioner may determine. For the pur-
poses of this paragraph physical value shall mean the repro-
duction cost of the building less physical deterioration as deter-
mined by the building commissioner.

(e) When occupancy of a pre-code building, or portions
thereof separated from the remainder as required in part II,
is so changed that the hazard is increased, the commissioner

107

may require that said pre-code building or said portions thereof
be made to conform with the provisions of this code, which
will specifically eliminate said increased hazard.

1. All buildings altered or repaired shall, in the opinion of
the building commissioner, provide structural safety, adequate
resistance to the spread of fire, and safe egress in the event of
fire to the occupants.

2. Structural safety shall be construed to mean that a build-
ing or parts thereof shall sustain twice the loads and stresses
subjected therein or thereupon by actual normal use. Owners,
if directed to do so by the building commissioner, shall demon-
strate such structural safety by actual load tests made as directed
by him.

3. Adequate resistance to the spread of fire shall be con-
strued to mean protection to adjacent properties and protection
to egress enclosures keeping them free from fire long enough
to permit the occupants to evacuate the building. The resistance
of various materials and constructions to fire shall be assumed
to be as stated in this code or as otherwise satisfactorily demon-
strated to the commissioner.

4. Safe egresses not less than two in number shall be con-
strued to mean egress facilities sufficient to evacuate the build-
ing in three minutes. Owners of buildings shall, if directed by
the building commissioner, demonstrate the time required to
evacuate the occupants by actual test conducted under the
direction of the commissioner.

5. An electrical fire alarm system shall be installed, if it is
necessary in the opinion of the commissioner to meet the above
egress requirements.

(f) A pre-code building which is enlarged in floor area or
in number of stories shall be made to conform throughout the
entire building to the requirements of this code in respect to
egress and fire protection.

(g) A pre-code building to which repairs and alterations are
made which are not covered by the preceding paragraphs of this
section, may be repaired or altered with the same kind of ma-
terials as those of which the building is constructed, providing
such alterations or repairs will not increase an existing non-

conformity or hazard; but not more than twenty-five per cent
of the roof covering of a building shall be replaced in any
period of twelve months unless the entire roof covering is made
to conform with the requirements of this code for post-code
buildings. New roofing meeting the requirements of this code
may be placed over existing roofing providing that it be properly
supported and securely fastened.

(h) A pre-code building when moved to another location
shall conform to the requirements of this code relative to the
fire limits, to location on the lot and to exterior walls.

(i) Except as otherwise provided in this section, no provision
of this code shall be held to deprive the health department, the
police commissioner, the board of street commissioners, the
licensing board, the fire commissioner or the park department of
the city of Boston either of any power or authority which it,
he or they had on the effective date of this act or of any
remedy then existing for the enforcement of its, his or their
orders.

(j) Provisions of this code relating to buildings shall also
apply to structures other than buildings to such extent as they
are pertinent.

[*As amended by Ord. 1943, ch. 2]

tSect. 108. Maintenance. — All buildings or structures, and all
parts thereof, shall be maintained in a safe condition. All de-
vices or safeguards which are required by this code in a building
when erected, altered or repaired, shall be maintained in good
working order, except as otherwise provided in section twenty-
seven A of chapter one hundred and forty-eight of the General
Laws. Except as otherwise provided in paragraph (d) of section
one hundred and six, the owner shall be responsible for the
maintenance of all buildings and structures. This section shall
apply to pre-code as well as to post-code buildings.
[ f As amended by Ord. 1943, ch. 2}

Sect. 109. Organization. — (a) There is hereby established in
the city of Boston a department to be called the building de-
partment, which shall be in charge of the building commissioner.

(b) The commissioner shall have had at least ten years'
experience as an architect, builder or civil engineer, and shall

107-109

be appointed by the mayor for a term of five years. He shall
receive such salary as shall be fixed by the city council, with
the approval of the mayor.

(c) Upon the effective date of this code the building com-
missioner of the building department, as constituted immediately
prior thereto, shall become the building commissioner of the
building department established by paragraph (a) of this section,
the members of the board of appeal, as constituted immediately
prior thereto, shall become the members of the board of appeal
established by paragraph (a) of section one hundred and seven-
teen, the members of the board of examiners, as constituted
immediately prior thereto, shall become the members of the
board of examiners established by paragraph (a) of section one
hundred and twenty, and the licensed master gasfitter member
of the board of examiners of gasfitters, as constituted imme-
diately prior thereto, shall become the licensed master gasfitter
member of the board of examiners of gasfitters extablished by
paragraph (a) of section one hundred and twenty-one, and each
of said persons shall thereafter hold his respective position until
the expiration of such period of time as shall be equal to the
remainder of the term for which he was appointed, unless
sooner removed or discharged according to law; and all of the
employees of the building department, as constituted immediately
prior thereto, who are subject to the civil service laws shall be
reappointed to similar positions in the building department or
the several boards established by this code with the same status
and compensation held and received by them, respectively, im-
mediately prior thereto in the building department and the
several boards established by this code, without civil service
examination or registration; and the said building commissioner,
and all such employees upon such reappointment, shall retain
or would thereafter accrue to them, and their services shall be
deemed to have been -rontinuous to the same extent as if this
code had not been passed.

(d) The commissioner, with the approval of the mayor,
may appoint such number of officers, inspectors, assistants and
other employees as the city council shall from time to time
determine. No person shall be appointed as inspector of con-
struction who has not had at least five years' experience as a
builder, civil engineer or architect, or as a superintendent, fore-
man or competent mechanic in charge of construction.

(e) The commissioner may appoint as his deputy an officer
or other employee in the department who shall, during the ab-
sence or disability of the commissioner, exercise all the powers
of the commissioner.

(f) No officer or employee connected with the department,
except one whose only connection is as a member of a board,
shall be financially interested in furnishing of labor, material or
appliances for the construction, alteration or maintenance of a
building, or in the making of plans or of specifications therefor,
unless he is the owner of such building. No such officer or em-
ployee shall engage in any work which is inconsistent with the
duties or with the interests of the department. The provisions of
this paragraph shall not apply to the members of boards estab-
lished by this code.

(g) The commissioner shall keep a record of the business of
the department. The records of the department shall be open to
public inspection. The commissioner shall not, however, be re-
quired to allow inspection of the plans of buildings except upon
request of the owner. If such request is made more than two
months after completion of the work described in the plans, the
commissioner shall allow such inspection only upon payment of
such fees as the commissioner, with the approval of the major,
may establish.

*Sect. 110. Application for Permit. — (a) Whoever desires in
the city of Boston to erect, enlarge , alter, substantially repair,
move, demolish or change the occupancy of a building or
structure, or to install, alter or substantially repair plumbing,
gasfitting, fire extinguishing apparatus or elevators, or to install
a steam boiler, furnace, heater, or other heat producing appar-
atus the installation of which is regulated by this code, or to
install an engine or dynamo, or to cause any such work to be
done, shall first make application to the building commissioner
and obtain a permit therefor.

(b) Each application for a permit with the required fee shall
be filed with the commissioner on a form furnished by him and
shall contain a general description of the proposed work and its
location. It shall be signed by the owner or his authorized
agent, and before a permit is issued such application shall also
be signed by the person who is to perform or take charge of
the work covered by such permit.

109-110

(c) Each application hereunder shall indicate the proposed
occupancy of all parts of the building and of that portion of
the lot, if any, not covered by the building, and shall contain
such other information as may be required by the commissioner.

(d) The commissioner may require the material facts con-
tained in each such application to be certified by the applicant
under oath.

(e) When required by the commissioner, copies of plans
drawn with sufficient clarity and detail to indicate the nature
and character of the work shall accompany every such applica-
tion, and shall be filed in duplicate with the commissioner. Such
plans shall contain information, in the form of notes or other-
wise, as to the quality of materials where quality is essential to
conformity with this code. Such information shall be specific,
and this code shall not be cited as a whole or in part, nor
shall the term "legal" or its equivalent be used, as a substitute
for specific information.

(f) The commissioner may require details, computations,
stress diagrams and other data necessary to describe the con-
struction and basis of calculations. He may also require plans
showing the location of the proposed building and of every
existing building on the lot. He may require structural plans
and computations to bear the signature of the architect or
engineer in charge of the structural design, and plot plans to
bear the signature of an approved surveyor.

(g) An application for a permit for any proposed work shall
be deemed to have been abandoned six months after the date
of filing, unless within such time a permit shall have been is-
sued; provided, that for cause one or more extensions of time
for periods of not exceeding ninety days each may be allowed
in writing by the commissioner.

(h) The commissioner shall examine each application for
permit and the plans and computations filed therewith and
shall ascertain by examination whether the construction indi-
cated and described is in accordance with the requirements of
this code and of all other pertinent laws or ordinances.

(i) The commissioner may accept an application for a permit
accompanied by plans and computations and an affidavit filed
therewith by a competent architect or engineer to the effect that

said plans and computations are in accordance with the require-
ments of this code and of all other pertinent laws- or ordinances.
[*As amended by Ord. 1943, ch. 2]

t Sect. 111. Permits. — (a) If the commissioner is satisfied
that the work described in an application for permit conforms
to the requirements of this code and other pertinent laws and
ordinances, and if the person designated by signature on the
application as the person who will perform or take charge of
the work is duly licensed, the commissioner shall issue a permit
therefor to the applicant; provided, that if the work to be done,
in the opinion of the commissioner, is of minor importance, and
of such simple character that its execution by an unlicensed
person will not endanger the public or any workman engaged
thereon, the commissioner need not require the signature to be
that of a licensed person but may issue the permit applied for
after entering upon the application his reason for waiving such
requirement.

(b) If the application for a permit and the plans filed there-
with describe work which does not conform to the requirements
of this code or other pertinent laws or ordinances, the com-
missioner shall not issue a permit, but shall return the plans to
the applicant with his refusal to issue such permit. Such refusal
when requested shall be in writing and shall contain the reasons
therefor.

(c) Permits for ordinary repairs, for minor alterations not
involving vital structural changes, may be issued upon presenta-
tion of an application on a special form, to be furnished by the
commissioner, and payment of the required fee.

(d) When application for permit to erect or enlarge a build-
ing has been filed, and pending issuance of such permit, the
commissioner may, in his discretion, upon payment of the re-
quired fee, issue a special permit for the foundations of such
building. The holder of such a special permit shall proceed only
at his own risk and without assurance that a permit for the
superstructure will be granted.

(e) The commissioner shall act upon an application for a
permit with plans as filed, or as amended, without unreasonable
or unnecessary delay. A permit issued shall be construed to be
a license to proceed with the work and shall not be construed
as authority to violate, cancel, alter or set aside any of the pro-

110-111

visions of this code, nor shall such issuance of a permit prevent

the commissioner from thereafter requiring correction of errors
in plans or in construction or of violations of this code. Any
permit issued shall become invalid unless the work authorized
by it shall have been commenced within six months after its
issuance; provided, that for cause one or more extensions of
time, for periods not exceeding three months each, may be
allowed in writing by the commissioner, except that in no event
shall the time for commencing the work be extended beyond
eighteen months after the issuance of the permit. Any permit
issued may be revoked by the commissioner at any time after
notice and hearing if there is a false statement or misrepresenta-
tion of a material fact in the application for the permit or in
the plans or computations filed therewith, or if the work author-
ized by the permit violates any provision of this code or other
provision of law or the permit is otherwise issued in error, or
if in the course of the work there is any violation of any pro-
vision of this code or other provision of law, or if after com-
mencement of the work there is unreasonable delay in completing
the work, or if there is other good cause for revocation of the
permit.

(f) When the commissioner issues a permit he shall endorse
in writing, or stamp, duplicate sets of plans "Approved". One
set of plans so approved shall be retained by the commissioner
and the other set shall be returned to the applicant, shall be
kept at the site of work and shall be open to inspection at all
reasonable times by the commissioner or his authorized repre-
sentative.

(g) An architect, engineer or builder who is preparing plans
for a building or structure in the city of Boston may make
written request of the commissioner for an interpretation of this
code as specifically applicable to such building or structure. The
request shall be made on a form furnished by the commissioner,
shall indicate the specific provision of this code as to which
interpretation is so desired, shall be accompanied by the re-
quired fee, and shall contain or be accompanied by a descrip-
tion of the proposed work with plans sufficient to enable the
commissioner to form an opinion. The commissioner shall make
reply in writing within thirty days after receipt of the request
either than the description of the proposed work is inadequate
to form the basis of an opinion, or that he discerns no reason

under the indicated provision of this code for disallowing the
proposed construction, or that his interpretation of such pro-
vision will not allow the proposed construction for reasons which
he shall state. If the commissioner shall interpret such provision
as not allowing the proposed construction, such interpretation
shall be deemed a disallowance thereof and any person deeming
himself aggrieved thereby may appeal from such disallowance
as provided in section one hundred and eighteen.

(h) Whenever a permit is to be issued in reliance upon an
affidavit as provided in paragraph (i) of section one hundred
and ten or whenever the work to be covered by a permit in-
volves construction under conditions which, in the opinion of
the commissioner, are hazardous or complex, the commissioner
shall require that the architect or engineer who signed the affi-
davit or made the plans or computations shall supervise such
work, be responsible for its conformity with the approved plans,
and forthwith upon its completion make and file with the com-
missioner written affidavit that the work has been done in
conformity with the approved plans and with the structural
provisions of this code. In the event that such architect or en-
gineer is not available a competent person whose qualifications
are approved by the commissioner shall be employed by the
owner in his stead.

[ t As amended by Ord. 1943, ch. 2 and Ord. 1953, ch. 7]

* Sect. 112. Fees. — (a) Whoever applies for a permit shall
pay, at the time of filing his application, the fee established
under authority of chapter two hundred and ninety-seven of the
acts of nineteen hundred and thirty-one as amended by Chapter
173 of the acts of nineteen hundred and thirty-nine.

(b) The commissioner, with the approval of the mayor, may
establish and from time to time alter or amend fees —

(1) For producing for inspection the plans of buildings, as
provided in section one hundred and nine.

(2) For issuance of a special foundation permit, as provided
in paragraph (d) of section one hundred and eleven.

(3) For written interpretation of his code given for the pur-
pose of an appeal from a disallowance as provided in paragraph
(g) of said section one hundred and eleven.

111-114

(c) No fee paid in connection with an application for a
permit shall be returned, whether or not the permit is granted.
[ $As amended by Ord. 1943, ch. 2]

Note — Chapter 297 of the Acts of 1931 was affected by Stat.
1949, ch. 222, which gave to the City of Boston authority to
fix certain fees and charges.

Sect. 113. Inspection. — (a) The commissioner shall examine
each site, application for permit to erect or enlarge a building
or structure upon which has been received, and shall examine
all buildings, applications for permit to enlarge, alter, repair,
move, demolish or change the occupancy of which has been
received. He shall inspect all such buildings and structures from
time to time during and finally upon the completion of their
erection, enlargement, alteration, repair, moving or demolition.
He shall make a record of every such examination and inspec-
tion and of all violations of this code. The publication of such
records shall be privileged.

(b) No building operation requiring a permit shall be com-
menced until the permit holder or his authorized agent shall
have posted a building permit card in a conspicuous place
protected from the weather on the front of the premises and
in such a position as to permit the commissioner to make the
required entries thereon respecting inspection of the work. Such
card shall be preserved and shall remain posted until the com-
pletion of the work.

*Sect. 114. Posting Floor Loads. — No pre-code or post-code
building shall be occupied for any purpose which will cause the
floors thereof to be loaded beyond their safe capacity as speci-
fied in this code; provided, that the commissioner may permit
occupancy of a building for mercantile, commercial or industrial
purposes, by a specific business, when he is satisfied that such
safe capacity will not thereby be exceeded, even though the
class of occupancy of such business, under this code, requires a
greater load capacity. In every such case the safe floor loads,
as determined by the commissioner, shall be marked on metal
plates of approved design which shall be supplied and securely
affixed by the owner of the building in a conspicuous place in
each story to which they relate. Such plates shall not be re-
moved or defaced, and if lost, removed or defaced shall be
replaced by such owner. No such owner shall place or permit

to be placed, or to remain on any floor of a building a greater
load than the safe load so determined and posted.
\*As amended by Ord. 1943, ch. 2]

t Sect. 115. Annual Report. — The commissioner shall an-
nually, not later than May first, submit a report to the mayor,
covering the work of the department during the preceding cal-
endar year, and shall incorporate in said report a summary of
the decisions of the board of appeal, a summary of the pro-
ceedings of the board of examiners and of the board of ex-
aminers of gas fitters, during said year, and his recommendations
as to desirable amendments of this code.

[ t As amended by Ord. 1943, ch. 2]

$ Sect. 116. Powers and Duties of Building Commissioner.—

(a) The commissioner and the health commissioner shall sever-
ally enforce the provisions of this code relative to his powers
and duties and they may, themselves or by their respective duly
authorized representatives, enter any building or premises in
said city to perform any duty imposed upon them, respectively,
by this code.

(b) Upon notice from the commissioner that work on any
building or structure is being done contrary to the provisions of
this code or in a dangerous or unsafe manner, such work shall
be immediately stopped. Such notice shall be in writing and
given to the owner of the property, or his agent, or the licensed
builder or mechanic doing the work, and shall state the condi-
tions under which work may be resumed.

(c) Whoever hinders or prevents, or attempts to hinder or
prevent, the commissioner or his authorized representative from
entering a building, structure or enclosure, or part thereof, in
the performance of his duty in the enforcement of any provi-
sion of this code shall be punished by a fine of not less than
fifty nor more than one hundred dollars. Each day during any
portion of which such hindering continues shall be considered a
separate offense.

(d) Every building of which the exits are insufficient shall be
provided with exits satisfactory to the commissioner; and every
building which is dangerous or unsafe shall be made safe or
removed; or every such building shall be vacated forthwith on
order of the commissioner, with the approval of the mayor. Such

114-116

order shall be in writing and shall be addressed and delivered,
or mailed, postage prepaid, to the owner or tenant, if he is
known and can be found, or otherwise by posting an attested
copy of the order in a conspicuous place upon an external wall
of the building, and shall state the conditions under which the
building may again be used or occupied. An attested copy so
posted shall not be defaced or removed without the approval
of the commissioner. If in the opinion of the commissioner the
public safety so requires the commissioner, with the approval of
the mayor, may at once enter the building or other structure
which he finds unsafe or dangerous, or land on which it stands,
or the abutting land or buildings, with such assistance as he
may require, and make safe or remove said unsafe or dangerous
building or other structure and may protect the public by a
proper fence or otherwise as may be necessary, and for this
purpose may close a public or private way.

*(e) A claim for the expense incurred by the commissioner
under paragraph (d) shall constitute a debt due the city upon
completion of the work and rendering to the owner of an ac-
count therefor and recoverable from the owner in an action of
contract. Said debt, together with interest thereon at the rate of
six per cent per annum from the date upon which said debt
became due, shall constitute a lien upon the real estate on which
the expense was incurred in the manner hereafter provided. Such
lien shall take effect upon the filing, within ninety days after
the debt became due, for record in the registry of deeds for
Suffolk county, or in the case of registered land with the assis-
tant recorder for the Suffolk district, of a statement of the
claim, signed by the commissioner, setting forth the amount
claimed without interest. Such lien shall continue for two years
from the first day of October next following the date of filing
said statement. Such lien may be dissolved by filing for record
in such registry of deeds or with said assistant recorder as the
case may be, a certificate from the collector-treasurer that the
debt for which such lien attached, together with interest and
costs thereon, has been paid or legally abated. The collector-
treasurer shall have the same powers and be subject to the same
duties with respect to such claim as in the case of the annual
taxes upon real estate; and the provisions of law relative to the
collection of such annual taxes, the sale or taking of land for
the non-payment thereof, and the redemption of land so sold or
taken shall apply.

(f) The owner of the real estate to which a lien has attached,
as provided in paragraph (e) within ninety days after the state-
ment of said lien was filed in the registry of deeds or with said
assistant recorder, as the case may be, may appeal to the muni-
cipal court of the city of Boston, which shall hear and deter-
mine after a hearing whether the amount of the claim is more
than the amount actually expended to make safe or remove the
building or structure, if amount is more, said court may reduce
the amount of the claim to the amount so actually expended.

(g) Any requirement necessary for the strength or stability
of a pre-code or proposed structure or for the safety of the
occupants thereof, not specifically covered by this code, shall
be determined by the commissioner subject to appeal to the
board of appeal.

(h) The commissioner shall examine every building reported
as dangerous or damaged, and shall make a written record of
such examination, stating the nature and estimated amount of
the damage, and the purpose for which the building was used,
and in case of fire the probable origin thereof.

(i) The owners of buildings in Boston shall comply with,
and all materials used and work performed in gas fitting in
Boston shall be in accordance with, the rules and regulations
from time to time in effect under the provisions of section
twelve H of chapter twenty-five of the General Laws, except as
such rules and regulations may be varied under the provisions
of sections one hundred and seventeen, one hundred and eighteen
and one hundred and nineteen of this code. The commissioner
and the health commissioner of the city of Boston shall severally
have power to inspect from time to time gas fixtures and appli-
ances in any and all buildings in Boston and to compel com-
pliance in Boston with the rules and regulations aforesaid.

(j) The commissioner shall make and issue rules and regula-
tions governing the tearing down of buildings.

(k) The provisions of this section shall apply to pre-code as
well as post-code buildings.

**(1) Whoever desires to substitute for the materials or
methods covered by this code, materials or methods of construc-
tion or maintenance not covered thereby, shall present to the
commissioner plans, methods of analysis, and tests or other
information substantiating the analysis of the system or qualities
of the material and shall make such additional tests or present

116-117

satisfactory evidence of such tests as the commissioner may
require. The costs of any tests required to determine acceptability
of substitute materials or methods shall be paid by the applicant.
When the strength of any construction cannot be satisfactorily
determined by the application of accepted engineering principles,
its safe strength shall be determined as one sixth of the ultimate
strength evidenced by test of full size units or assemblies thereof
of such construction so loaded as to produce critical stresses.
Such materials or methods of construction shall not be used
until after the commissioner has issued regulations fixing the
practices to be followed, but no such regulation shall have the
effect of altering the working stresses for any material herein
mentioned or of reducing the fire-resistive and fire-protective
requirements of this code; provided, that any such regulation
fixing the practices to be followed in the use of any such material
may reduce the fire-resistive or fire-protective requirements of
this code if in promulgating such regulation the commissioner
certifies, on the basis of reports on file in his office as to tests
of such material made in accordance with standard specifications
of the American Society for Testing Materials, that in his opinion
such material used in accordance with such regulation will pro-
vide substantially as much safety from fire as material meeting
such fire-resistive and fire-protective requirements.

(t As amended by Ord. 1943, ch. 2 and ch. 737 of 1960]

[*As amended by ch. 234, Acts 1958]

[**As amended Ord. 1957, ch. 11]

*Sect. 117. Board of Appeal. — (a) There is hereby established
in the city of Boston a board, to be called the board of appeal,
and to consist of five members appointed by the mayor in the
following manner: — One member from two candidates, one to
be nominated by the Boston Real Estate Exchange and one by
the Massachusetts Real Estate Exchange; one member from two
candidates, one to be nominated by the Boston Society of
Architects and one by the Boston Society of Civil Engineers;
one member from three candidates, one to be nominated by the
Master Builders Association, one by the Building Trades Em-
ployers' Association and one by the Building Contractors
Association of Massachusetts, Inc.; one member from two
candidates to be nominated by the Building Trades Council of
Boston and Vicinity; and one member selected by the mayor.

(b) Upon the expiration of the term of office of a member
of said board in office on the effective date of this code his

successor shall be appointed for the term of five years; and
subsequent appointments to said board shall be for terms of
five years each. Vacancies shall be filled for an unexpired term
in the manner in which original appointments are required to be
made. Each member of the board of appeal shall receive for
every day or part thereof of actual service twenty dollars or
such other sum as may from time to time be fixed by the city
council with the approval of the mayor; but no member shall
so receive in any one year more than fifteen hundred dollars
or such other sum as may from time to time be fixed by the
city council with the approval of the mayor. No member shall
act in a case in which he has a personal interest, and when a
member is so disqualified, or absent, the remaining members
shall designate a substitute.

Note — Chapter 3 of the Ordinances of 1961 provides: "Each
member of the board of appeal shall receive for every day or
part thereof of actual service thirty-five dollars, but in no event
shall any member of said board receive in any one year more
than forty-two hundred dollars in the aggregate for services
rendered by him under the building code and the zoning law. ."
Effective January 1, 1953.

(d) Said board shall cause to be made a detailed record of
all its proceedings, which shall set forth the reasons for its de-
cisions, the vote of each member participating therein, the ab-
sence of a member, the name of his substitute and any failure
of a member to vote.

(e) The board shall establish rules and regulations for its
own procedure not inconsistent with this code.

\*As amended by Stat. 1949, ch. 201, and Stat. 1952, ch. 212]

Sect. 118. Appeals. — (a) A person whose application for a
permit has been refused by the commissioner may appeal to
said board of appeal within ninety days thereafter. A person
who has been ordered by the commissioner to incur expense may
so appeal therefrom within thirty days of the date of such order,
except that, in case of a building or structure, which, in the

117-119

opinion of the commissioner, is unsafe or dangerous, the com-
missioner may in his order limit the time for such appeal to
a shorter period. A person aggrieved by an adverse interpreta-
tion of this code and a disallowance by the commissioner of
proposed construction thereunder, as provided in section one
hundred and eleven, may so appeal from such disallowance with-
in thirty days after the date thereof. Appeals hereunder shall
be on forms provided by the commissioner and shall be ac-
companied by such fee as may be established by the commis-
sioner, with the approval of the mayor.

(b) The commissioner may refer without fee to the board of
appeal for its decision such cases as, in his opinion, justice
requires.

t Sect. 119, Decisions of the Board of Appeal. — (a) The

board of appeal, when so appealed to and after a hearing, may
vary the application of any provision of this code to any parti-
cular case when in its opinion the enforcement thereof would do
manifest injustice, provided that the decision of the board shall
not conflict with the spirit of any provision of this code.

(b) Every decision of said board shall be in writing, shall
indicate the vote of each member upon the decision, and if it is
to vary the application of any provision of this code or modify
an order of the commissioner, shall require the assent of at
least four members. Every decision shall promptly be filed in
the office of the commissioner, and shall be open to public
inspection; a certified copy shall be sent by mail or otherwise
to the appellant and a copy shall be kept publicly posted in
the office of the commissioner for two weeks after filing.

(c) A decision of said board to vary the application of any
provision of this code or modify an order of the commissioner
shall specify in what manner such variation or modification,
respectively, is made, the conditions upon which it is made
and the reasons therefor.

(d) Said board shall in every case reach a decision without
unreasonable or unnecessary delay.

(e) If the refusal, order or disallowance of the commissioner
is reversed or modified, or the application of any provision of

this code is varied by a decision of said board, the commissioner
shall immediately take action in accordance with such decision;
but no decision of said board shall be regarded as establishing
a precedent or be held to amend this code or the commissioner's
interpretation thereof.

(f) A person aggrieved by a decision of said board, whether
previously a party to the proceeding or not, or a municipal of-
ficer or board, may, within fifteen days after the filing of such
decision in the office of the commissioner, bring a petition in
the supreme judicial court for the couty of Suffolk for a writ
of certiorari to correct errors of law in such decision, and the
provisions of section four of chapter two hundred and forty-
nine of the General Laws shall, except as hereinbefore provided,
apply to such petition.

The person filing the petition shall file a bond with sufficient
surety, to be approved by the court, for such sum as shall be
fixed by the court, to indemnify and save harmless the person
or persons in whose favor the decision was rendered from all
damages and costs which they may sustain in case the decision
of said board is affirmed. In case the decision of the board is
affirmed the court, on motion, shall assess damages, and execu-
tion shall issue therefor.

| \As amended by Ord. 1943, ch. 2]

JSect. 120. Board of Examiners. — (a) There is herebv
established in the City of Boston a Board of Examiners to con-
sist of three members appointed by the Mayor. The Board shall
consist of an engineer or architect with at least five years' ex-
perience in the City of Boston, a contractor or person well
qualified in the supervision of construction work with at least
five years' experience in the City of Boston, and a lawyer or
other person with proper legal qualifications. Said Board shall
exercise the powers and perform the duty herein provided. Upon
the expiration of the term of office of a member of said Board
in office on the effective date of this code, his successor shall
be appointed for the term of three years; and subsequent ap-
pointments to said Board shall be for terms of three years each.
Vacancies shall be filled by appointments by the Mayor for the
remainder of the unexpired term. Each member of the board
of examiners shall receive for every day or part thereof of actual
service ten dollars or such other sum as may from time to time

119-120

be fixed by the city council with the approval of the mayor; but
no member shall so receive in any one year more than one
thousand dollars or such other sum as may from time to time
be fixed by the city council with the approval of the mayor.

Note — Section 3 of the Ordinances of 1961 provides: "Each
member of the board of examiners, and the appointive member
Of the board of examiners of gasfitters, shall receive for every
day or part thereof of actual service twenty-five dollars, but in
no event more than two thousand dollars in any one year."

(b) *The board of examiners shall hold examinations, under
rules and regulations adopted by it, of persons desiring to be
registered as qualified to have charge or control of the con-
struction, alteration, removal or tearing down of buildings or
structures. Due notice of the time and place for such examina-
tions shall be posted in the office of the building department
and published in the City Record.

Note — Stat. 1945, Chap. 626, provides that the licensing of
elevator and escalator mechanics shall be under the jurisdiction
of the State Department of Public Safety.

(c) Said board shall establish various classes of persons to
be registered, shall determine the qualifications required for
each class, and after examination shall register in each class
the persons found to possess the requisite qualifications therefor.
The name and address of each person so found to be qualified,
with the designation of the class in which he is registered, shall
thereupon be certified by said board to the commissioner, who
shall make a record thereof, which shall be open to public
inspection.

(d) Except as otherwise provided in section one hundred and
eleven, all work of erecting, enlarging, altering, repairing, mo\ing
and demolishing of buildings or structures and installing and
repairing of elevators and escalators in the city of Boston shall
be under the charge, control and personal supervision of a
licensed builder or mechanic, qualified by education, training
and experience for the performance of that duty in a manner
which shall preserve the public safety and conform to this code
and all other pertinent laws and ordinances.

(e) Any person who shall by affidavit, together with such
other evidence as may be required by said board, show to it

that he has had charge or control of such work in the class in
which he applies to be registered, and shall satisfy the board
that he is qualified by education, training and experience to
have charge or control of such work, may, without other ex-
amination, be registered in such class and be certified to the
commissioner as a person qualified within such class.

(f) Said board, upon payment of the required fee, shall issue
a license to each person so certified by it to the commissioner.
Each license shall expire one year from the date of its issuance.
Said board shall renew a license, upon the expiration thereof
and upon payment of the required fee therefor, for the further
period of one year from the date of renewal. The fees to be
paid to said board for such licenses and renewals shall be as
provided in chapter two hundred and ninety-seven of the acts
of nineteen hundred and thirty-one, as amended by Chapter 173
of the acts of nineteen hundred and thirty-nine.

(g) Any person who is duly licensed as aforesaid shall be
entitled to have charge or control of any work described in this
section, in the class in which he is registered, until his license
is revoked or suspended by the commissioner, upon the order
of said board. No such license shall be revoked or suspended
except upon proof, satisfactory to said board, or specific charges,
filed with said board by the commissioner or other person, that
the licensee has been careless or negligent in the performance of
his duty in connection with work under his charge or control, or
has caused or permitted a violation of this code in connection
therewith, or that this code has been violated in connection with
such work and that the licensee, being in charge of such work,
knew, or, in the exercise of due diligence, should have known,
of such violation. Upon learning of such carelessness, neglect
of duty or violation of this code, the commissioner shall file
charges with said board and prosecute them. Upon the filing
thereof by the commissioner or other person, said board shall
give to the licensee notice of a hearing thereon, which hearing
shall be held by said board not less than seven days after date
of said notice. Such notice shall be served upon the licensee
either by service in hand or by registered mail, shall state the
time and place of the hearing and shall contain a copy of the
charges. At such hearing the licensee may be represented by
counsel, and the commissioner may be assisted by a representa-
tive of the law department of the city.

120-123

(h) If, for any cause, a person licensed as herein provided
shall cease to have charge or control of work described in this
section before such work is finished, the work shall stop until
another person duly licensed for the doing of such work has
been placed in charge thereof.

(i) Whoever violates any provision of this section shall be
punished by a fine of not more than fifty dollars.
[ * As amended by Stat. 1952, ch. 212 and Ord. 1943, ch. 2]
\*As amended by ch. 227 , Acts of 1959]

Sect. 121. Omitted

Sect. 122. Penalties. — (a) A building or structure which is
erected or maintained in violation of any provision of this code
shall be deemed a common nuisance without other proof thereof
than proof of the unlawful construction or maintenance, and the
commissioner may abate and remove it in the same manner in
which boards of health may remove nuisances under sections
one hundred and twenty-three to one hundred and twenty-five,
inclusive, of chapter one hundred and eleven of the General
Laws.

(b) Except as otherwise provided in this code, whoever vio-
lates any provision thereof, or whoever builds, alters, or main-
tains a structure or a part thereof in violation of any provision
thereof, shall be punished by a fine of not exceeding five hun-
dred dollars. Each day during any portion of which such viola-
tion is allowed to continue, or is permitted by the owner, shall
be considered a separate offense.

Sect. 123. Enforcement Jurisdiction. — (a) Any court having
jurisdiction in equity, or any justice thereof, may, upon the
application of the city by its attorney —

(1) Restrain the construction, alteration, repair, maintenance,
use or occupation of any building or structure constructed,
maintained, used or occupied in violation of any provision of
this code, and order its removal or abatement as a nuisance;

(2) Restrain the further construction, alteration, repair,
maintenance, use or occupation of any building or structure
which is unsafe or dangerous;

(3) Restrain the unlawful construction, alteration, repair,
maintenance, use or occupation of any building or structure;

(4) Compel compliance with the provisions of this code;

(5) Order the removal by the owner of a building or structure
unlawfully existing and authorize the commissioner, with the!
written approval of the mayor, in default of such removal by
the owner, to remove it at the owner's expense.

(b) The municipal court of the city of Boston, concurrently
with the superior court, shall have jurisdiction throughout the
city of prosecutions and proceedings at law under the provisions
of this code, and all other pertinent laws and ordinances.

(c) Upon the entry of any case brought under any provision
of this code the court shall, at the request of either party, ad-
vance the case, so that it may be heard and determined with as
little delay as possible.

Sees. 124 to 132 inclusive — Omitted

tSect. 133. Change of Occupancy. — The occupancy of a
building shall not be changed unless such building conforms or
is made to conform with the requirements of this code for the
group in which it is to be classified, except that the occupancy
of a pre-code building may be changed as provided in section
one hundred and seven.

1 1 As amended by Ord. 1943, ch. 2]

ARTICLE
PART II

GENERAL PROVISIONS

100.0

Scope

103.0

Demolition of Buildings

101.0

Minor Alterations— Ordinary

104.0

Fee Computation

Repairs

105.0

Certificate of Use and Occu-

102.0

Installation of Service Equip-
ment

pancy

SECTION 100.0. SCOPE

100.1. Continuity. — The provisions of Part II, Article 1, are
supplementary to the provisions contained in Part I, Adminis-
tration, and both shall apply to the construction, alteration,
repair, demolition, removal, maintenance, occupancy and use
of new and existing buildings in the City of Boston.

100.2. Building Official. — Wherever used in this Code, the term
"building official" shall mean the building commissioner of the
City of Boston, or his authorized representative.

100.3. Matters Not Provided For. — Any requirement essential
for structural, fire or sanitary safety of an existing or proposed
building or structure or essential for the safety of the occupants
thereof and which is not specifically covered by this Code, shall
be determined by the building official.

100.4. Continuation of Unlawful Use. — The continuation of
occupancy or use of a building or structure, or of a part there-
of, contrary to the provisions of this Code, shall be deemed a
violation and subject to the penalties prescribed in Part I, Sec-
tion 122.

100.5. Zoning Restrictions. — When the provisions herein speci-
fied for structural, fire and sanitary safety are more restrictive
than the zoning law, this Code shall control the erection or
alteration of buildings in respect to location, use, permissible
area and height; but in any case the most rigid requirements
of either the building code or the zoning law shall apply when-
ever they may be in conflict.

SECTION 101.0. MINOR ALTERATIONS- ORDINARY
REPAIRS

Minor alterations or ordinary repairs to buildings may be made
without application or notice to the building official as follows:

101.1. Minor Alterations. — For the purposes of this code, thee
term "minor alterations" shall mean minor changes or modi-
fications in a building or any part thereof, excluding additions
thereto, that do not in any way affect the fire or structural
safety of the building. Minor alterations shall not include any
of the work described or referred to in section 101.3, or any
other work for which a permit is required under Part I, Sec-
tion 110.

101.2. Ordinary Repairs. — For the purposes of this code, the
term "ordinary repairs" shall mean replacements or renewal of
existing work in a building, or of parts of the service equip-
ment therein, with the same or equivalent materials or equip-
ment parts, that are made in the ordinary course of maintenance
and that do not in any way affect the fire or structural safety
of the building or the safe use and operation of the service
equipment therein. Ordinary repairs shall not include any of the
work described or referred to in section 101.3, or any other
work for which a permit is required under the provisions of
Part I, Section 110.

101.3. Work not Minor Alterations or Ordinary Repairs. — For

the purposes of this code, minor alterations or ordinary repairs
shall not include the cutting away of any wall, floor, or roof
construction, or any portion thereof; or the removal, cutting, or
modification of any beams or structural supports; or the re-
moval, change, or closing ot any required means ot egress; or
the rearrangement or relocation of any parts of the building
affecting loading or exit requirements, or light, heat, ventilation,
or elevator requirements; nor shall minor alterations or ordinary
repairs, include additions to, alterations of, or rearrangement,
relocation, or removal of any standpipe or sprinkler piping,
water distribution piping, house sewer, private sewer or drainage
system, including leaders, or any soil, waste, or vent pipe, or
any gas distribution system, or any other work affecting the
fire or structural safety of the building.

101-103
SECTION 102.0. INSTALLATION OF SERVICE
EQUIPMENT

When the installation, extension, alteration or repair of an ele-
vator, moving stairway, mechanical equipment, refrigerating,
air conditioning or ventilating apparatus, plumbing, gas piping,
electric wiring, heating system or any other equipment is speci-
fically controlled by the provisions of this Code or the approved
rules, it shall be unlawful to use such equipment until a certifi-
cate of approval has been issued therefor by the building official.

SECTION 103.0. DEMOLITION OF BUILDINGS

103.1. Service Connections. — Before a building can be demolished
or removed, the owner or agent shall notify all utilities having
service connections within the building such as water, electric,
gas, sewer and other connections. A permit to demolish or re-
move a building shall not be issued until a release is obtained
from the utilities, stating that their respective service connections
and appurtenant equipment, such as meters and regulators, have
been removed or sealed and plugged in a safe manner.

103.2. State Laws and Bonds. — Before the issue of any permit
for the demolition or removal of a building or structure situated
at a site for which no building permit for re-use of the land has
been issued, the applicant therefore shall file a bond running
to the City, and with sureties satisfactory to the building official
issuing such permit, in such penal sum as he shall determine
to be twice the cost of leveling the lot, all as provided for by
Chapter 143, Section 3, of the General Laws of the Common-
wealth of Massachusetts.

103.3. Lot Regulation. — Whenever a building is demolished or
removed, the premises shall be maintained free from all unsafe
or hazardous conditions by the proper regulation of the lot,
restoration of established grades and the erection of the neces-
sary retaining walls and fences in accordance with the provisions
of Article 13.

103.4. Pest Control. — Before a building can be demolished or
removed, the owner or agent shall carry out effective measures
for rodent extermination over the entire premises. The method
of extermination employed shall be one in successful use locally
and shall meet with the approval of the building official.

SECTION 104.0. FEE COMPUTATION

For the determination of permit fees as required under Part I]
Section 1 12, the square footage of the building or structure
shall be computed as follows:

104.1. Architectural Area of Buildings. — The architectural area
of a building is the sum of the areas of the several floors of
the building, including basements, mezzanine and intermediate
floored tiers and penthouses of headroom height, measured from
the exterior faces of exterior walls or from the center line of
walls separating buildings.

104.1.1. Other Areas. — Covered walkways, open roofed-over
areas that are paved, porches and similar spaces shall have
the architectural area multiplied by an area factor of 0.50.

104.1.2. Not Included. — The architectural area does not include
such features as pipe trenches, exterior terraces or steps, chim-
neys, roof overhangs, etc.

104.2. Cost Computation. — When required, the current edition
of Building Construction Cost Data published by Robert Snow
Means Company, Inc. may be used as a guide in establishing
the cost of a building or structure.

104.2.1. Costs Excluded. — Exclude all architectural and engi-
neering fees, cost of land, paving, walks, landscaping, movable
furnishings and equipment.

SECTION 105.0. CERTIFICATE OF USE AND OCCUPANCY

105.1. New Buildings. — No building hereafter erected shall be
used or occupied in whole or in part until the certificate of use
and occupancy shall have been issued by the building official.

105.2. Buildings Hereafter Altered. — No building hereafter en-
larged, extended or altered to change from one use group to
another, in whole or in part, and no building hereafter altered
for which a certificate of use and occupancy has not been here-
tofore issued, shall be occupied or used until the certificate shall
have been issued by the building official, certifying that the
work has been completed in accordance with the provisions of
the approved permit; except that any use or occupancy, which
was not discontinued during the work of alteration, shall be
discontinued within thirty (30) days after the completion of the
alteration unless the required certificate is secured from the
building official.

104-105

105.3. Existing Buildings. — Upon written request from the owner
}f an existing building, the building official shall issue a certifi-
cate of use and occupancy, provided there are no violations of
aw or orders of the building official pending, and it is estab-
ished after inspection and investigation that the alleged use of

(:he building has heretofore existed. Nothing in this Code shall
■equire the removal, alteration or abandonment of, or prevent
he continuance of the use and occupancy of a lawfully existing
ouilding, unless such use is deemed to endanger public safety
and welfare.

105.4. Changes in Use and Occupancy. — After a change of use
las been made in a building, the reestablishment of a prior use
:hat would not have been legal in a new building of the same
type of construction is prohibited unless all the applicable provi-
sions of this Code are complied with. A change from one pro-
hibited use, for which a permit has been granted, to another
prohibited use shall be deemed a violation of this Code.

105.5. Temporary Occupancy. — Upon the request of a holder of
k permit, the building official may issue a temporary certificate
{of occupancy for a building or structure, or part thereof, before
the entire work covered by the permit shall have been completed,
(provided such portion or portions may be occupied safely prior
to full completion of the building without endangering life or
public welfare.

105.6. Contents of Certificate. — When a building or structure
is entitled thereto, the building official shall issue a certificate of
use and occupancy within ten (10) days after written application.
The certificate shall certify compliance with the provisions of this
Code and the purpose for which the building or structure may
be used in its several parts. The certificate of use and occupancy
shall specify: the use group, in accordance with the provision of
article 2, the fire grading as defined in article 2 and table 9-4,

{the maximum live load on all floors as prescribed in article 7,
the occupancy load in the building and all parts thereof as
defined in article 2 and article 6, and any special stipulations
and conditions of the building permit.

ARTICLE

DEFINITIONS AND CLASSIFICATIONS

200.0
201.0
202.0

:203.0

1204.0

i 205.0

206.0

207.0

208.0

209.0
210.0

TABLES

Scope

Definitions

Occupancy Group Classifica-
tion

Occupancy Group A — High
Hazard Building

Occupancy Group B — Stor-
age Buildings

Occupancy Group C — Mer-
cantile Buildings

Occupancy Group D — In-
dustrial Buildings

Occupancy Group E — Busi-
ness Buildings

Occupancy Groups F and G
— Assembly and School
Buildings

Occupancy Group H — Insti-
tutional Buildings

Occupancy Group L — Resi-
dential Buildings

211.0

212.0
213.0

214.0
215.0

216.0

217.0

218.0
219.0
220.0
221.0

RS-2

Occupancy Group M — Mis-
cellaneous
Doubtful Occupancies

Mixed and /or Multiple Oc-
cupancy

Construction Classification

Type 1 — Fireproof Construc-
tion

Type 2 — Noncombustible
Construction

Type 3 — Exterior Masonry

Wall Construction
Type 4 — Frame Construction
Subdivision of Attic Spaces
Temporary Structures
Fire Resistance Rating and

General Height and Area

Limitations
Reference Standards

2-1

2-2

221.1.
221.2.

Fire Resistance Rating of Structural Elements in Hours
General Height and Area Limitations of One Story Buildings
Facing on One Street or Public Space Not Less than 30 Feet
Wide

SECTION 200.0. SCOPE

The provisions of this article shall control the classification of
all buildings as to occupancy group and type of construction;
and the definition of all terms relating thereto in the City of
Boston, Massachusetts.

200.1. Application of Terms. — The terms herein defined shall be
used to interpret all the applicable provisions of this code.

200.2. Application of Other Laws. — Nothing herein contained
shall be deemed to nullify any provisions of the zoning law or
any other statute of the City of Boston, Massachusetts pertaining
to the location, occupancy or type of construction of buildings,
except as may be specifically required by the provisions of this
code.

SECTION 201.0. DEFINITIONS

Unless otherwise expressly stated, the following terms shall, for
the purpose of this code, have the meaning indicated in this 1
section.

201.1. Tense, Gender and Number. — Words used in the present
tense include the future; words used in the masculine gender
include the feminine and neuter; the singular number includes
the plural and the plural the singular.

201.2. Terms Not Defined. — Where terms are not defined, they
shall have their ordinarily accepted meanings or such as the
context may imply.

abut. Touch, be continguous. A building abuts upon a stree
when some part of the building touches or extends to the
street line. A building shall be construed to abut upon a
street if it is nearer at any point than ten (10) feet from the
street line or when the space between the building and the
street line is used wholly or chiefly for the purposes of a
street or sidewalk.

accepted engineering practice. That which conforms to accepted
principles, tests or standards as specifically cited in the refer-
ence standards of this code.

accessory building. A structure devoted exclusively to an occu-
pancy accessory to a main occupancy of the lot.

accessory occupancy, (accessory use). An occupancy custom-
arily incident to, and on the same lot as, a main occupancy.

access stair. A stair between two (2) floors, which does not
serve as a required means of egress.

addition. An alteration which is an extension or increase in'
floor area or height of a building that increases its exterior
dimensions.

air conditioning. The process by which the temperature, humi-
dity, movement, cleanliness, and odor of air circulated
through a space is controlled.

air duct. A tube or conduit, or an enclosed space or corridor
within a wall or structure used for conveying air.

201
airplane hangar, private. A hangar for the storage of four (4)
or less single engine planes and in which no volatile or
flammable oil is handled, stored or kept other than that con-
tained in the fuel storage tank of the plane.

— public. A building for the storage, care or repair of private or
commercial airplanes not included in the term private airplane
hangar.

aisle. A clear and unobstructed passageway through a room.

alley. A secondary thoroughfare less than thirty (30) feet in
width dedicated or deeded for the public use of vehicles
and/or pedestrians affording access to abutting property.

alteration. As applied to a building or structure or service
equipment thereof means a change or rearrangement in the
structural parts or in the exitway facilities; or an addition,
whether by extending on a side or increasing in height; or
the moving from one (1) location or position to another; or
any change or modification in construction or occupancy.

apartment. A room or suite of rooms occupied by one (1)
person or one (1) family for living and sleeping purposes.

apartment hotel. A building primarily for persons who have
their residence therein, containing four (4) or more apartments
which do not have kitchens.

apartment house. Any building, or portion thereof, which is
designed, built, rented, leased, let or hired out to be occupied,
or which is occupied as the home or residence of more than
two (2) families living independently of each other and doing
their own cooking in the said building, and shall include
flats and apartments.

approved. Approved by the Building Official.

approved (rules). The legally adopted rule of the Building
Official (or of a cited reference standard).

appurtenant structure. A device or structure attached to the
exterior or erected on the roof of a building designed to
support service equipment or used in connection therewith,
or for advertising or display purposes, or other similar uses.

architect. A person registered by the Commonwealth of Mas-
sachusetts to practice the profession of architecture.

architectural terra cotta. Plain or ornamental hard-burned \
plastic clay units normally larger in size than brick, with,
glazed or unglazed ceramic finish.

area (building). The maximum horizontal projected area of the
building at or above grade, including all extensions.

area of refuge. A floor area to which egress is made through
an exitway.

area (surface measurement). See "Floor Area (Gross)".

areaway. A space below grade, adjacent to a building, open to
the outer air and enclosed by walls.

ashlar facing. Facing of solid rectangular units larger in size
than brick, burned clay or shale natural or cast stone, with
sawed, dressed and squared beds and mortar joints.

ashlar masonry. Masonry composed of bonded, rectangular
units, larger in size than brick, with sawed, dressed or
squared beds and mortar joints.

assembly (assembly space). Any part of a place of assembly,
exclusive of a stage, that is occupied by numbers of persons
during the major period of occupancy. Every balcony tier of
seating shall be considered a separate assembly space.

assembly hall. A hall or room, including the balconies thereof,
if any, in which persons may assemble in a manner as per-
mitted in occupancy group F.

attic. Finished or unfinished story situated within a sloping
roof, the area of which at a height of four (4) feet above
the level of its finished floor does not exceed two-thirds
(2/3) of the area of the story immediately below it. There
shall be only one (1) attic in any building, and it shall be
considered as a half story.

— habitable attic. A habitable attic is an attic which has a
stairway as a means of access and egress and in which the
ceiling area at a height of seven and one-third (7-1/3) feet
above the attic floor is not more than one-third (1/3) the
area of the floor next below.

automatic. As applied to an opening protective, shall mean a
door, window, damper, or other device, and its assembly,
which is normally open and is designed to close automatically

201

when subjected to a predetermined temperature, rate of tem-
perature rise, or abnormal smoke condition.

automatic collapsible revolving door. A door which is designed,
supported and constructed so that the wings will release and
fold back in the direction of egress under pressure exerted by
persons under panic conditions, providing a legal passageway
on both sides of the door pivot.

automatic dry pipe sprinkler system. A sprinkler system in
which the piping up to the sprinkler heads is filled with
compressed air, with the water supply controlled by a dry
pipe valve.

automatic dry standpipe system. A standpipe system in which
all piping is filled with compressed air. Water enters the sys-
tem through a control valve actuated either automatically by
the reduction of air pressure within the system or by the
manual activation of a remote control located at each hose
station.

automatic fire alarm system. A system which automatically
detects a fire condition and actuates a fire alarm signal de-
vice audible to the public into a central signal system service
center.

automatic fire door. A fire door equipped with a heat actuated
closing device which will operate at a predetermined tempera-
ture of not more than one hundred and sixty-five (165)
degrees F. or equipped with a rate of rise of temperature
operating device.

automatic fire pump. A pump that maintains a required water
pressure in a fire extinguishing system and which is actuated
by a starting device adjusted to cause the pump to operate
when the pressure in the system drops below a predetermined
pressure, and to stop the pump when the pressure is restored.

automatic sprinkler head. A device connected to a water supply
system that opens automatically at a predetermined fixed
temperature and disperses a stream or spray of water.

automatic sprinkler system. A system of piping supplied with
water under pressure with devices for releasing under the
influence of heat and spraying the water on ceilings, walls
and floors.

automatic water supply source. Water supplied through a.
gravity or pressure tank, or automatically operated fire
pumps, or from a direct connection to an approved city
water main.

automatic wet pipe sprinkler system. A sprinkler system in
which all piping and sprinkler heads are at all times filled
with water under pressure, which is immediately discharged
when a sprinkler head operates, with the water continuing
to flow until the system is shut off.

automotive lift. See "Special Hoisting and Conveying Equip-
ment."

backup. That part of a masonry wall behind the facing.

balcony. Within an auditorium, is a floor, inclined, stepped,
or level, above the main floor, the open side or sides of
which shall be protected by a rail or railings. Where a bal-
cony of an auditorium has means of egress at two (2) or
more levels opening into separate foyers, one above another,
each portion thereof served by such a foyer shall be con-
sidered a separate balcony for the purpose of this code.

balloon frame. Light timber construction in which the exterior
walls consist of studs that are either continuous through
floors or interrupted only by thickness of plates.

basement. A portion of a building below the first story.

bay. (Part of a structure). The space between two (2) adjacent
piers or mullions or between two (2) adjacent lines of
columns.

bay window. A window projecting beyond the wall line of the
building and extending down to the foundations.

bearing. (See Bearing Wall.)

block. The lot or lots fronting on the same side of the street
between two (2) streets intersecting such street on such side
with no other such intersecting street intervening.

board of appeal. The board of appeal in the building depart-
ment of the City of Boston.

boarder, (roomer, lodger). An individual not within the second
degree of kindred to the person conducting the boarding

201

house living within a household who pays a consideration for
such residence and does not occupy such space as an incident
of employment therein.

boarding house. Any dwelling (other than a hotel, motel,
apartment hotel, dormitory, fraternity or sorority house) in
which board is provided to five (5) or more persons who are
not within the second degree of kinship.

breezeway. A structure open to the outdoors consisting of a
roof, roof supports, and floor, connecting a garage or other
accessory building with a dwelling.

brick. A masonry unit, not less than seventy-five (75) per cent
solid, having a shape approximating a rectangular prism,
made from burned clay or shale, or mixture thereof. Brick
may be composed of other materials when so designated, as
for example, "concrete brick" and "sand-lime brick."

building. A structure forming a shelter for persons, animals or
property and having a roof, exclusive, however, of such
frameworks and tents as are customarily used exclusively for
outdoor carnivals, lawn parties, or like activities. Where the
context allows, the word "building" shall be construed as
though followed by the words "or part thereof."

building commissioner. The building commissioner of the City
of Boston.

building line. The line established by law, beyond which a
building shall not extend, except as specifically provided
by law.

building official. The building commissioner in the department
of building inspection of the City of Boston, or his duly
authorized representative.

building, post-code. A building erected after the effective date
of this code and subject to the provisions thereof.

building, pre-code. A building already erected on the effective
date of this code, or thereafter erected, under permit for its
construction subject to the provisions of law in effect prior
to such effective date.

building section. A room, floor, group of floors, wing, or
any other portion of a building contained within type A
fire divisions.

building service equipment. The mechanical, electrical, and
elevator equipment, including piping, wiring, fixtures and
other accessories, which provide sanitation, lighting, heating,
ventilation, fire-fighting and transportation facilities essential
for the habitable occupancy of the building or structure for
its designated use and occupancy.

building site. The area occupied by a building or structure,
including the yards and courts required for light and ven-
tilation, and such areas that are prescribed for access to the
street.

bulkhead. The raised portion of a floor or roof, raised for
the passage of persons, materials, light or air, through
the side of such raised portion, or for other purposes.

buttress. A projecting part of a wall integrated therewith to
furnish lateral stability.

casing-off. The elimination of the frictional forces between a]
portion of a pile and the surrounding soil by use of a sleeve
between the pile and the soil.

cellar. See Basement.

central station system. An automatic sprinkler or fire alarm
system in which all equipment is supervised by a central or
proprietary station to which all alarm signals are transmitted
and relayed to the fire department.

certificate of use and occupancy. The certificate issued by the
building official which permits the use of a building in ac-
cordance with the approved plans and specifications and
which certifies compliance with the provisions of law for the
use and occupancy of the building in its several parts together
with any special stipulations or conditions of the building
permit.

change of occupancy. A change in the occupancy group of a
building heretofore existing to a new occupancy group which
imposes other special provisions of law governing building
construction, equipment, exitways or zoning.

charging chute (incinerator). An enclosed vertical passage
through which refuse is fed to an incinerator.

201

charging gate (incinerator). A gate in an incinerator used to
control the flow of combustion gases into the charging chute
and the entry of refuse into the combustion chamber.

chimney. A vertical shaft of masonry, reinforced concrete, or
other approved noncombustible, heat resisting material en-
closing one (1) or more flues, for the purpose of removing
products of combustion from solid, liquid, or gas fuel.

chimney connector. A pipe or metal breeching that connects
combustion equipment to a chimney.

city. The City of Boston, Massachusetts.

clay masonry unit. A building unit composed of burned clay,
shale, fireclay or mixtures thereof.

clinic. A place for the medical or similar examination and
treatment of persons as out patients.

coatings, fire-retardant. A material applied to the surface of
a building material to reduce its flame spread.

code. This code, the Boston Building Code, consisting of this
act and the regulations established thereunder.

collecting safe area. A safe area that receives occupants from
the assembly space it serves, as well as from other safe areas.

combustible material. A material which cannot be classified as
noncombustible in accordance with that definition.

concentrated load. A conventional representation of an element
of dead or live load whereby the entire load is assumed to
act at a point.

concrete. A mixture of cement, aggregates and water, of such
proportions and manipulation as to meet specific requirements.

concrete masonry unit. A building unit or block made of ce-
ment and suitable aggregates.

concurrent loads. Two (2) or more elements of dead or live
load that, for purposes of design, are considered to act simul-
taneously.

conflagration hazard. The fire risk involved in the spread of
fire by exterior exposure to and from adjoining buildings and
structures.

construction. Any or all work or operations necessary or inci-
dental to the erection, demolition, assembling, installing, or
equipping of buildings, or any alterations and operations
incidental thereto. The term "construction" shall include land
clearing, grading, excavating, and filling. It shall also mean
the finished product of any such work or operations.

construction classification (type). The category in which a
building or space is classified by the provisions of Article 2
based on the fireresistance ratings of its construction elements.

construction equipment. The construction machinery, tools,
derricks, hoists, scaffolds, platforms, runways, ladders and
all material handling equipment safeguards and protective
devices used in construction operations.

contractor. A person undertaking construction.

controlled construction. The construction of a building or struc-
ture or a specific part therof which has been designed and
erected under the supervision of a registered engineer or
architect using controlled materials as herein defined in com-
pliance with the provisions of the code.

controlled materials. Materials which are certified by an ap-
proved authoritative agency as meeting standards for quality
and as provided in sections 722 and 800 and the reference
standards.

conveyors. See Special Hoisting and Conveying Equipment.

corridor. An enclosed passage or passageway contributing to
the means of egress from rooms or spaces.

court. An open, uncovered unoccupied space partially or
wholly surrounded by the walls of a structure.

_ enclosed or inner. A court surrounded on all sides by the
exterior walls of a structure or by such walls and an interior
lot line.

— outer court. A court having at least one (1) side thereof
opening on to a street, alley, or yard or other permanent
open space.

cross over aisle. An aisle in a place of assembly usually parallel
to rows of seats, connecting other aisles or an aisle and an
exitway.

201
curb level. The elevation of the street curb as established in
accordance with law.

dead end egress. A portion of a corridor in which the means
of egress is in one (1) direction only.

dead load. See Loads.

deluge sprinkler system. An open head sprinkler system without
water in the system piping, with the water supply controlled
by an automatic valve operated by smoke or heat-responsive
devices installed throughout the sprinklered area, and in-
dependent of the sprinkler heads.

demolition. The dismantling or razing of all or part of a
building, including all operations incidental thereto.

department. The department of building inspection of the City
of Boston.

door, wood, solid core bonded. Shall be a door conforming
to Architectural Woodwork Institute, 1966 edition, 2nd re-
vision, designation "A" with surface treatment complying
with the applicable requirements of section 922. An approved
marking and/or certification meeting the approval of the
building official shall be affixed thereon.

dormitory. Any dwelling (other than a fraternity or sorority
house) occupied primarily as a place of temporary abode by
persons attending educational institutions.

draft hood. A device placed in and made part of a chimney,
vent connector, or combustion equipment, to (1) insure the
ready escape of the products of combustion in the event of
no draft, back-draft, or stoppage beyond the draft hood,
(2) prevent a back-draft from entering the equipment, or (3)
neutralize the effect of excessive stack action of the chimney
flue upon the operation of the equipment.

draft regulator. A device which functions to maintain a desired
draft in the appliance by automatically reducing the draft to
the desired value.

dry pipe system. A system employing automatic sprinklers at-
tached to a piping system containing air under pressure, the
release of which as from the opening of sprinklers permits
the water pressure to open a valve known as a "dry-pipe

valve." The water then flows into the piping system and outo
the opened sprinklers.

duct. A tube, pipe, conduit, shaft or continuous enclosed
passageway used for the conveying of air, gases or vapors.

dumbwaiter. See section 1601.

dwelling. A building or structure used in whole or in part for
human habitation.

— dwelling, detached. A dwelling which is designed to be and

is substantially separate from any other structure or structures
except accessory buildings.

— dwelling, multi-family. A building containing three (3) or

more dwelling units, but not including a motel.

— dwelling, semi-detached. A dwelling having a party wall in

common with another dwelling but which otherwise is de-
signed to be and is substantially separate from any other
structure or structures except accessory buildings.

— dwelling unit. A room or group of rooms forming a habitable

unit for one (1) family with facilities used or intended to be
used for living, sleeping, cooking and eating.

egress. See "Means of Egress."

electrical. See Form FPR 1 1 Massachusetts Electrical Code for
all definitions of electrical equipment.

elevator. See section 1601.

— freight elevator. See section 1601.

— hand elevator. See section 1601.

— hydraulic elevator. See section 1601.

— passenger elevator. See section 1601.

— power elevator. See section 1601.
-sidewalk elevator. See section 1601.

elevator repairs. All work necessary to maintain present elevator
equipment in a safe and serviceable condition and to adjust
or replace defective, broken or worn parts, with parts made
of equivalent material, strength and design, and only where
the replacing part performs the same function as the replaced
part.

201
engineer. A person registered by the Commonwealth of Massa-
chusetts to practice the profession of engineering.

equivalent uniform load. A conventional representation of an
element of dead or live load, used for the purposes of design
in lieu of the actual dead or live load.

erect. To construct or reconstruct or excavate, fill, drain, or
conduct physical operations of any kind in preparation for or
in pursuance of construction or reconstruction, or to move
a building or structure.

escalator. A power driven, inclined, continuous stairway used
for raising or lowering passengers. (See section 1601.)

existing building. A building erected prior to the adoption of
this code, or one for which a legal building permit has
been issued.

existing equipment. Any equipment covered by this article
which was installed prior to the effective date of this code
or for which an application for permit to install was filed
with the building official prior thereto.

exit. See "Exitway."

exitway. That portion of a means of egress which is separated
from the area of the building from which escape is to be
made by walls, floors, doors, or other means which provide
the protected path necessary for the occupants to proceed
with reasonable safety to the exterior of the building.

exitway access. That portion of a means of egress which leads
to an entrance to an exitway.

exitway discharge. That portion of a means of egress between
the termination of the exitway at the exterior of the building
and ground level.

exitway discharge court. An exterior unoccupied space which
is open to the sky for its entire area, located on the same
lot with a theatre or other assembly building which it serves
exclusively as an unobstructed path to the street or other
public space from an exitway discharge.

extend. To increase in area or volume.

exterior separation. The shortest distance across an unobstructed
outdoor space measured from the furthest projection of the

exterior wall of a building to an interior lot line or to a line
halfway between the wall and that of any other building on
the same lot, or to the centerline of an adjacent street or
other public space.

family. One (1) or more persons occupying a dwelling unit
and living as a single, non-profit housekeeping unit; provided
that a group of five (5) or more persons who are not within
the second degree of kinship shall not be deemed to consti-
tute a family.

fire area. A floor area enclosed by Type A fire division and/or
exterior walls.

fire canopy. A solid horizontal projection, extending beyond
the exterior face of a building wall, located over a wall
opening so as to retard the spread of fire through openings
from one story to another.

fire damper. An approved automatic or self-closing noncombus-
tible barrier designed to prevent the passage of air, gases,
smoke or fire through an opening, a duct or plenum chamber.

fire districts. The territories defined and limited by the pro-
visions of this code for the restriction of types of construction.

fire division. A vertical, horizontal or other construction that
segregates a building or buildings into completely separate
areas, spaces, parts or sections.

— Type A, fire division. One having a fireresistance rating and

structural stability under fire conditions to provide a fire
barrier between adjoining buildings or between adjoining or
superimposed fire areas or building sections within the same
building.

— Type B, fire division. (Fire separation). One having a fire-

resistance rating to provide a fire barrier between adjoining
rooms or spaces within a building, building section or fire
area.

fire door. A self-closing door and its assembly, including
frame, trim, hardware, so constructed and assembled in place
as to retard the passage of fire.

fire extinguisher. A portable device the contents of which are
used for extinguishing a fire.

201

fire grading. The posted fire hazard classification of a building

or structure in hours or fractions of an hour as established

for its occupancy group in section 902.4, tables 9-1 and 9-2.

fire hazard. The potential degree of fire severity existing in the
use and occupancy of a building and classified as high,
moderate, or low.

— high. All occupancies which involve the storage, sale, manu-

facture or processing of highly combustible, volatile flam-
mable or explosive products which are likely to burn with
extreme rapidity or produce large volumes of smoke, poison-
ous fumes, gases or explosions in the event of fire.

— moderate. All occupancies which involve the storage, sale,

manufacture or processing of materials which are likely to
burn with moderate rapidity and a considerable volume of
smoke, but which do not produce either poisonous fumes or
explosions in the event of fire.

— low. All occupancies which involve the storage, sale or manu-

facture of materials that do not ordinarily burn rapidly, nor
produce excessive smoke, poisonous fumes, or explosions in
the event of fire.

fire prevention. The preventive measures which provide for the
safe conduct and operation of hazardous processes, storage
of highly combustible and flammable materials, conduct of
fire drills, and the maintenance of fire detecting and fire-
extinguishing service equipment and good housekeeping con-
ditions.

fire protection. The provisions of safeguards in construction
and of egress facilities; and the installation of fire alarm,
fire-detecting and fire-extinguishing service equipment to re-
duce the fire risk and the conflagration hazard.

fire protection rating. The time in hours or fractions thereof
that an opening protective and its assembly will withstand fire
exposure as determined by a fire test conducted in compliance
with reference standards or as determined by approved exten-
sion or approved interpretation of information derived there-
from.

fireresistance. That property of materials or their assemblies
which prevents or retards the passage of excessive heat, hot
gases or flames under conditions of use.

fireresistance rating. The time in hours or fractions thereof
that materials or their assemblies will withstand fire exposure
as determined by a fire test conducted in compliance with
reference standards or as determined by approved extension or
approved interpretation of information derived therefrom.

fireresistive partition. A partition other than a fire partition
which is required to subdivide the floor area of a fireresistive
building for the purpose of restricting the spread of fire.

fireretardant lumber. Wood so treated by a recognized im-
pregnation process as to reduce its combustibility to limits
set by reference standards noted in this code.

fire safety. The measure of protection of a building or struc-
ture against interior and exposure fire hazards through fire-
resistive construction and the provision of safe exitways and
fire-detecting and extinguishing equipment.

fire separation (material). See Fire Division.

fire wall. A vertical Type A Fire Division in the form of a
wall.

fire window. An opening protective in the form of a window
and its assembly.

flammable. Capable of being easily ignited when exposed to
flame, and which burns intensely, or has a rapid rate of
flamespread.

flame resistance. The property of materials or combinations
of component materials which restricts the spread of flame as
determined by the flame resistance tests specified in this code.

flame spread. The propagation of flame over a surface.

flame spread rating. The measurement of flame spread on the
surface of materials or their assemblies as determined by tests
conducted in compliance with approved reference standards
noted in this code.

floor area (gross). For zoning purposes the sum of the areas
of the several floors of the structure as measured by the ex-
terior faces of the walls, including fully enclosed porches and
the like as measured by the exterior limits thereof, but ex-
cluding (a) areas used for accessory garage purposes, (b)

201

basement and cellar areas devoted to uses accessory to the
operation of the structure, and (c) areas elsewhere in the
structure devoted to housing mechanical equipment custom-
arily located in the basement or cellar such as heating and
air conditioning equipment, plumbing, electrical equipment,
laundry facilities, and storage facilities.

floor area (gross). For the purposes of classification of oc-
cupancy, gross floor area shall be the projected horizontal
area enclosed inside of walls, partitions or other enclosing
construction of the building or part thereof under considera-
tion with no deductions for hallways, stairs, closets, thickness
of walls, columns or other features. When the term area is
used elsewhere in this code, it shall be understood to be gross
area unless otherwise specified.

floor area (net). The horizontal occupiable area within the
space, excluding the thickness of walls, and partitions, col-
umns, furred-in spaces, equipment, and accessory spaces such
as closets, machine and equipment rooms, toilets, stairs, halls,
corridors, elevators and similar unoccupied spaces.

floor area ratio. The ratio of gross floor area, as defined for
zoning purposes, of a structure to the total area of the lot.

floor fill. The fill between the structural floor arch or slab and
the finished flooring.

floor finish. The finish placed on top of the floor arch, slab or
other structural floor element.

flue. An enclosed passageway in a chimney to carry products
of combustion to the outer air.

formed steel construction. That type of construction used in
floor and roof systems consisting of integrated units of sheet
or strip steel plates which are shaped into parallel steel ribs
or beams with a continuous connecting flange deck; generally
attached to and supported on the primary or secondary
members of a structural steel or reinforced concrete frame.

foundation (building). A construction that transfers building
loads to the supporting soil.

foundation pier. A foundation element consisting of a column
embedded into the soil below the lowest floor to the top of
a footing or pile cap. Where a pier bears directly on the

soil without intermediate footings or pile caps, the entire
length of the column below the lowest floor level shall be
considered as a foundation pier. Foundation piers shall be
limited to piers so constructed that the entire surface of the
sides of the pier and the bearing material under the lower
end of the pier can be visually inspected prior to or during
construction, but which will be concealed in the final work.
Piers below the lowest floor or basement level that will be
exposed and open to inspection in the final work shall be
considered as columns. Types of construction wherein the
sides cannot be visually inspected shall be considered as piling
or caissons.

foundation wall. A wall entending below grade.

foyer. A foyer, lobby, corridor or passageway, one (1) or more
in combination, adjacent to the auditorium of a theatre or
assembly hall at the level of the main floor or a balcony
thereof and into which one (1) or more exitways therefrom
open, in the path of normal egress from the building.

frame construction. See section 218,0.

front. A building or wall fronts upon a street when a wall of
the building or the wall faces the street and is parallel there-
to or makes an angle of less than forty-five (45) degrees
therewith.

frontage. As applied to building location on a lot, shall mean
the distance between lines drawn through the most remote
points of the building perimeter, projected at right angles to
a street; or an open space outside of a building, not less than
thirty (30) feet in any dimension, that is accessible from a
street by a driveway, lane, or alley at least twenty (20) feet
in width, and that is permanently maintained free of all ob-
structions that might interfere with its use by the fire depart-
ment.

fuel oil. A liquid mixture or compound derived from petroleum
which does not emit flammable vapor below a temperature
of one hundred and twenty-five (125) degrees F. in a Tag
closed-cup tester.

garage, private. A building or enclosed space used for the
parking or storage of not more than four (4) motor vehicles
having fuel storage tanks of twenty (20) gallon capacity or

201

less and in which no repair, body work, or painting of vehi-
cles is conducted, and in which no gasoline, oil, or similar
products are dispensed.

garage, public. A building or structure for the storage, parking,
care or repair of five (5) or more motor vehicles not included
in the term garage private. Public garages shall be classified
according to their specific use in one of the following groups:

— group 1. Buildings or spaces used for the parking of vehicles

having fuel storage tanks in excess of twenty (20) gallon
capacity; or used for the parking of vehicles of any size, and
in which mechanical repair, body work, or painting of
vehicles is conducted, or in which gasoline, oil, or similar
products are dispensed. Group 1 public garages shall be
classified in storage occupancy group B-l.

— group 2. Buildings or spaces used exclusively for the parking

of vehicles having fuel storage tanks of twenty (20) gallon
capacity or less, and in which no repair, body work or
painting of vehicles is conducted, and in which no gasoline,
oil, or similar products are dispensed. Group 2 public garages
shall be classified in storage occupancy group B-2.

grade. An elevation with reference to Boston city base, namely,
a horizontal plane of reference established and used by the
City of Boston. The reference is the Mean Low Water at the
U.S. Navy Yard in Charlestown, Boston, Massachusetts.

grade (building height). In cases where all walls of the principal
building are more than five (5) feet from the nearest street
line, the mean elevation of the ground adjoining the building
on all sides; and in all other cases, the mean elevation of the
nearest sidewalk.

habitable room. A room or enclosed floor space arranged for
living, eating, or sleeping purposes (not including bathrooms,
water closet compartments, laundries, pantries, foyers, hall-
ways and other accessory floor spaces) which has a clear
height from finished floor to finished ceiling of not less than
seven and one-half (7-1/2) feet, except that in attics and top
half-stories the height shall be not less than one-third (1/3)
the area of the floor when used for sleeping, study or similar
activity; and has a minimum dimension of seven (7) feet and
a minimum area of seventy (70) square feet, between enclosing
walls or partitions, exclusive of closet and storage spaces.

height, building. The vertical distance of the highest point of
the roof, excluding penthouses and roof structures, above the
mean grade of the sidewalk at the line of the street or streets
on which the building abuts, or, in the case of a building not
abutting on a street, above the mean grade of the ground be-
tween the building and whichever of the following is nearer,
namely, a line twenty (20) feet from the building or the lot
line; but in no event shall the mean grade of such ground be
taken to be more than five (5) feet above or below the mean
grade of the ground immediately contiguous to the building.

— story. The vertical distance from top to top of two (2)

successive tiers of beams or finished floor surfaces; and, for
the topmost story, from the top of the floor finish to the
top of the ceiling joists, or, where there is no ceiling, to
the top of the roof rafters.

— story, first. The lowest story of which sixty-five (65) per

cent or more of the height is above the mean grade from
which the height of the building is measured.

— wall. The vertical distance from the mean elevation of the

ground adjoining the wall on all sides.

hereafter. After the time that this code becomes effective.

heretofore. Before the time that this code became effective.

high pressure boiler. A closed vessel in which steam or other
vapor to be used externally to itself, is generated at a
pressure of more than fifteen (15) pounds per square inch
gage by the direct application of heat.

hollow masonry unit. A masonry unit whose net cross-sectional
area in any plane parallel to the bearing surface is less than
seventy-five (75) per cent of its gross cross-sectional area
measured in the same plane.

hood. A canopy or similar device connected to a duct for the
removal of heat, fumes or gases.

hotel. A building (other than a dormitory) containing four (4)
or more apartments without kitchens, or containing sleeping
accommodations for ten (10) or more persons, primarily the
temporary abode of persons who have their residences
elsewhere.

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impact load. See "Loads"

incombustible materials. Synonymous with "Noncombustible
Material."

independent. In reference to two (2) or more exitways, removed
or distant from one another in such manner that a person in
any place served by such exitways may choose either of two
(2) directions in a path toward an exitway and in such manner
that a single fire could not, in its early stages, block both
paths toward an exitway.

industrial lift. See "Special Hoisting and Conveying Equip-
ment".

inflammable. Synonymous with flammable.

inner court. See "Court."

interior lot line. Any lot line other than one adjoining a
street or public space.

kitchen. A room used or adapted for cooking and containing
a stove, range, hot-plate or other cooking apparatus, which
burns coal, oil, gas or other fuel or is heated by electricity,
except electric appliances consuming less than eighteen
hundred (1800) watts.

lagging (pile). Pieces of timber or other material attached to
the sides of piles to increase resistance to penetration through
soil.

light gage steel construction. That type of construction in
which the structural frame consists of studs, floor joists,
arch ribs, rafters, steel decks and other structural elements
which are composed and fabricated of cold-formed sheets.

live load. See "Loads".

load.

— dead load. The weight of all permanent construction including

walls, floors, roofs, partitions, stairways and of fixed service
equipment.

— impact load. The load resulting from moving machinery,

elevators, craneways, vehicles, and other similar forces and
kinetic loads.

— lateral soil load. The lateral pressure in pounds per square

foot due to the weight of the adjacent soil, including due
allowance for hydrostatic pressure.

— live load. The weight superimposed by the use and occupancy

of the building, including snow load, not including the wind
load, or dead load.

— wind load. The lateral pressure on the building or structure

in pounds per square foot due to wind blowing in any
direction.

load-bearing. See "Bearing".

loading ramp. A hinged, non-portable device, either mechanical
or hydraulic, hand or power operated, used for spanning
gaps or adjusting heights between loading surface and carrier
or between loading surface and loading surface.

lobby. The enclosed vestibule between the principal entrance
to the building and the doors to the main floor of the
auditorium or assembly room of a theatre or place of
assembly or to the main floor corridor of a business building.

lodging house. Any dwelling (other than a boarding house,
dormitory, fraternity, sorority house, hotel, motel or apart-
ment hotel) in which living space, without kitchen facilities,
is let to five (5) or more persons who are not within the
second degree of kinship.

lot. A parcel of land including land under water, whether or
not platted, in single ownership, and not divided by a street.

— area. The horizontal area of the lot exclusive (a) of any area

in a street or private way open to public use, and (b) of any
fresh-water area more than ten (10) feet from the shoreline,
and (c) of any salt-water area below the mean high tide line.

— corner. A lot with boundaries abutting on, and meeting at

the intersection of, two (2) streets when the lines of such
boundaries form within such lot at such intersection an
angle of not more than one hundred thirty-five (135) degrees.
In the case of a curved boundary, the tangent to such curved
boundary at its point of intersection with another boundary
of the lot shall be deemed to be the line of such boundary
for the purposes of this definition.

201

— depth. The horizontal distance between the front and rear

lot lines measured by the length, within the lot, of a straight
line connecting the midpoint of a straight line between the
foremost points of the side lot lines with the midpoint of a
straight line between the rearmost points of the side lot lines.

— line, front. The line separating the lot from the street. The

owner of a lot abutting on two (2) or more streets may
designate as the front lot line whichever of the two (2)
widest streets he chooses.

— line, rear. The line which most nearly qualifies as the line

most distant and opposite from the front lot line; where the
lot is irregularly shaped, a line perpendicular to the mean
direction of the side lot lines, and at least ten (10) feet in
length within the lot.

— width. The shortest horizontal distance between the side lot

lines measured perpendicular to the mean direction of two (2)
straight lines, one (1) between the foremost and rearmost
points of one (1) side lot line, and the other between the
foremost and rearmost points of the other side lot line.

low pressure boiler. A steel or cast iron heating boiler in
which the maximum allowable gage working pressure is
limited to fifteen (15) pounds per square inch.

manlifts. See "Special Hoisting and Conveying Equipment. "

manual fire alarm system. An interior alarm system composed
of sending stations and signaling devices in a building,
operated on an electric circuit, so arranged that the opera-
tion of any one (1) station will ring all signals throughout
the building or at one (1) or more approved locations.
Signals may be either non-coded or coded to indicate the
floor area in which the signal originated and may be trans-
mitted to an outside central station.

marquee sign. A display sign attached to or hung from a
marquee canopy or other covered structure projecting from
and supported by the building and extending beyond the
building wall, building line or street lot line.

masonry. A built-up construction or combination of building
units or materials of clay, shale, concrete, glass, gypsum,

stone or other approved units; or monolithic concrete. Re-
inforced concrete is not classed as masonry.

masonry solid. Masonry consisting of solid masonry units laid
contiguously with the joints between the units filled with
mortar, or consisting of plain concrete.

masonry unit solid. A masonry unit whose net cross-sectional
area in every plane parallel to the bearing surface is seventy-
five (75) per cent or more of its gross cross-sectional area
measured in the same plane.

material lift. See "Special Hoisting and Conveying Equipment."

material platform hoist. A power or manually operated sus-
pended platform conveyance operating in guide rails for
the exclusive raising or lowering of materials, which is
operated and controlled from a point outside the conveyance.

may. A term giving permission but not, except in the nega-
tive, making a requirement. "May" is used in this code to
emphasize that specified construction is not prohibited by
the code when such prohibition might otherwise be implied
or construed; or to limit the scope of a prohibition by
excepting specified construction from its effect. A permission
so expressed in this code in specific terms shall not be
construed as a prohibition of other construction. "May
not" is prohibitive.

means of egress. A means of egress is a continuous path of
travel from any point in a building or structure to the
open air outside at ground level and consists of three (3)
separate and distinct parts: (a) the exitway access, (b) the
exitway and (c) the exitway discharge. A means of egress
comprises the vertical and horizontal means of travel and
may include the room space, doorway, corridor, hallway,
passageway, stairs, ramp, lobby and other paths of travel.

mechanical ventilation. The process of introducing outdoor
air into, or removing vitiated air from a building by mechan-
ical means. A mechanical ventilating system may include air
heating, air cooling, or air conditioning components.

mezzanine floor. A floor within a story between the floor and
ceiling thereof, having an area not over thirty-three and
one-third (33 x h ) per cent of the area of the building at

201

the level at which the mezzanine floor occurs. A floor of
larger area separates two (2) stories.

mortar. A plastic mixture of approved cementitious materials,
fine aggregates and water used to bond masonry or other
structural units.

motel. A hotel primarily for transients traveling by automo-
bile, with a parking space on the lot for each lodging unit,
and with access to each such unit directly from the outside.

motor fuel service station. A structure, building or premise
or any portion thereof where a flammable fluid is stored,
housed or sold for supply to motor vehicles.

motor vehicle. A conveyance propelled by an internal com-
bustion engine and having a fuel storage tank capacity of
more than two (2) gallons.

motor vehicle repair shop. A building, structure or enclo-
sure in which the general business of repairing motor ve-
hicles is conducted including a public garage.

moving stairway. See Escalator.

moving walk. A type of passenger-carrying device on which
passengers stand or walk, and in which the passenger-
carrying surface remains parallel to its direction of motion
and is uninterrupted.

nominal dimension.

_ lumber. A dimension that may vary from actual dimensions
as provided in this code including the reference standards.

_ masonry. A dimension that may vary from actual masonry
dimensions by the thickness of a mortar joint but not to
exceed one-half (':) inch.

nonautomatie sprinkler system. A sprinkler system in which
all pipes and sprinkler heads are maintained dry and which
is supplied with water through a fire department Siamese
connection.

nonautomatie standpipe system. A standpipe system in which
all piping is maintained dry, and which is supplied with
water through a fire department Siamese connection.

nonbearing. As applied to a wall or partition, shall mean
one that supports no vertical load other than its own weight.

noncombustible (material). This is a general, relative term.
Its precise meaning is defined in this code in article 903.7.1.

non-corrodible metal. A metal which, under the conditions of
its use, may reasonably be expected, without unusual or
excessive maintenance, to serve its purpose throughout the
probable life of the structure in which it is used as deter-
mined by the building official.

nonconcurrent loads. Two (2) or more elements of dead or
live load which, for purposes of design, are considered not
to act simultaneously.

nonloadbearing. See nonbearing.

occupancy. The purpose or activity for which a building or
space is used or is designed or intended to be used.

occupancy group. The category in which a building or space
is classified by the provisions of article 2, based on its
occupancy or use.

occupancy load. The number of individuals normally occu-
pying the building or part thereof, or for which the egress
facilities have been designed.

occupancy, unit of. That portion of one (1) building within
separations within which the occupancy, whether of one (1)
or more tenants, falls in a single group as classified in
article 2.

occupied. As applied to a building, shall be construed as
though followed by the words "or intended, arranged or
designed to be occupied."

one-source sprinkler system. An automatic sprinkler system
which is supplied from one (1) of the approved automatic
sources of water supply.

open exterior space. A street or other public space; or a
yard, court, or plaza open on one (1) or more sides and
unroofed or open on all sides, which provides egress to
a street or public space.

opening protective. An assembly of materials and accessories,
including frames and hardware installed in an opening in a

201
wall, partition, floor, ceiling or roof to prevent, resist, or
retard the passage of flame, smoke or hot gases.

or. Providing an alternative at the option, unless the con-
trary is clearly indicated, of the applicant for a permit.

ordinary materials. Materials which do not conform to the
requirements of this code for controlled materials.

ordinary repairs. See section 102.2.

. oriel window. A window projected beyond and suspended
from the wall of the building or cantilevered therefrom.

! outer court. See "Court."

owner. The owner of the land as recorded in the registry of
deeds for Suffolk county, or as registered in the land court,
except that nothing in this code shall be held to prevent the
owner of land from transferring to another his rights and
responsibilities under this code by means of a lease or other
suitable agreement. The building official may recognize the
person to whom such a transfer by operation of law or
otherwise has been made as the possessor of such rights and
responsibilities and to such extent as the owner in receiving
applications, issuing permits and otherwise in enforcing this
code.

panel. (Part of a structure.) The section of a floor or wall
comprised between the supporting frame of two (2) adjacent
rows of columns and girders or column bands of floor
construction.

panel wall. See Wall-skeleton or Panel.

parapet. See Wall-parapet.

parking lot, open. A lot, or portion thereof, used for the
storage or sale of more than four (4) motor vehicles, but
not used for the repair or servicing of such vehicles.

partial sprinkler system. An automatic sprinkler system con-
sisting of a limited number of automatic sprinkler heads
serviced from the building water supplies with one (1) or
more fire department Siamese connections as required, for
use in egress facilities and isolated hazardous locations when
approved by the building official.

partition. An interior vertical unit or assembly of materials
that separates one space from another within any story of
a building.

party wall. See Wall-party.

penthouse. An enclosed occupiable structure above the roof
of a building, other than a roof structure, extending not
more than twelve (12) feet above the roof, and occupying
not more than thirty-three and one-third (33 l A ) per cent
of the roof area.

person. An individual, partnership, corporation, or other legal
entity.

pier. A vertical body of masonry used as a column, the
portion of a masonry wall between thinner portions or be-
tween openings when the horizontal dimensions parallel to
the wall does not exceed four (4) times the thickness.

place of assembly. An enclosed room or space in which
seventy-five (75) or more persons gather for any of the
following purposes: religious, recreational, educational, po-
litical, social, consumption of food and drink or for similar
group activities.

plan or plans. The word plan or plans shall be construed to
mean drawing or drawings illustrating the work involved.

plastic. A material that contains as an essential ingredient an
organic substance of large molecular weight, is solid in its
finished state and, at some stage in its manufacture or its
processing into finished articles, can be shaped by flow.

_ approved combustible. A plastic which meets the require-
ments of section 1409.5.2.

_ approved light transmitting. A plastic which meets the re-
quirements of section 2000.1.

platform frame. Light timber construction in which the ex-
terior walls and bearing walls consist of studs which are
interrupted at floors by the entire thickness of the floor
construction.

plenum chamber. A compartment or chamber to which one (1)
or more ducts are connected and which form a part of
either the supply or return air system.

201

pole footing. A type of construction in which a pole em-
bedded in the ground and extending upward to form a
column is used for both column and footing.

ponding. The retention of rainwater on roofs.

posted occupancy. The posted classification of a building in
respect to use, fire grading, floor load and occupancy load.

posted sign. The tablet, card, or plate which defines the use,
occupancy, fire grading and floor loads of each story, floor
or parts thereof for which the building or part thereof has
been approved.

prefabricated. Construction materials or assembled units fabri-
cated prior to erection or installation in a building or struc-
ture.

prefabricated building. The completely assembled and erected
building or structure, including the service equipment, of
which the structural parts consist of prefabricated individual
units or subassemblies using ordinary or controlled materials;
and in which the service equipment may be either prefab-
ricated or at-site construction.

prefabricated subassembly. A built-up combination of several
structural elements designed and fabricated as an assembled
section of wall, ceiling, floor or roof to be incorporated into
the structure by field erection of two (2) or more such
subassemblies.

prefabricated unit. A built-up section forming an individual
structural element of the building, such as a beam, girder,
plank, strut, column or truss, the integrated parts of which
are prefabricated prior to incorporation into the structure,
including the necessary means for erection and connection
at the site to complete the structural frame.

prefabricated unit service equipment. A prefabricated assembly
of mechanical units, fixtures and accessories comprising a
complete service unit of mechanical equipment, including
bathroom and kitchen plumbing assemblies, unit heating and
air-conditioning systems and loop-wiring assemblies of electric
circuits.

private garages. (See garages)

professional engineer or architect. (See architect or engineer.)

projection room. A room in a theatre or assembly hall con-
taining a projector of moving pictures.

protected construction. That in which all structural members
are constructed, chemically treated, covered or protected so
that the individual unit or the combined assemblage of all
such units has the required fireresistance rating specified for
its particular use or application in section 221.1 table 2-1,
and includes protected-frame, protected-ordinary and pro-
tected-noncombustible construction.

public garage. See Garage, public.

public open space. An open space in public ownership de-
voted or to be devoted to a public use with only minor
accessory buildings, if any. No structure that exceeds
twenty (20) feet in height or two thousand (2000) square
feet in gro'ss floor area shall be considered to be a part
of such public open space. "Public open space" shall be
construed to include a street.

pyroxylin plastic. Any nitro-cellulose product or compound
soluble in a volatile, flammable liquid, including such sub-
stances as celluloid, pyroxylin, fiberloid and other cellulose
nitrates (other than nitro-cellulose film) which are susceptible
to explosion from rapid ignition of the gases emitted there-
from.

ramp. See Runway.

reference standard. An approved recognized authoritative source
reference for specific use within this code and limited to
that use.

refrigerant. The medium used to produce cooling or refrigera-
tion by the process of expansion or vaporization.

refrigeration. The mechanical process of removing heat from
the air in an enclosed space of a building or structure.

reinforced concrete. Concrete in which reinforcement other
than that provided for shrinkage or temperature changes
is combined in such manner that the two (2) materials may
act together in resisting forces.

201
emote. See Independent.

equired. Shall be construed to be mandatory by provisions
of this code.

etaining wall. See Wall.

oof. The topmost slab or deck of a building, either flat or
sloping, with its supporting members not including vertical
supports.

■oof covering. The covering applied to the exterior surface of
a roof for weather resistance, fireresistance, wear, and/or
appearance, but not including insulation.

oof structure. A structure above the roof of any part of a
building constructed for use with a stairway, tank, elevator
machinery or ventilating apparatus, or such part of a shaft
as extends above the roof.

ubble.

- coursed rubble. Masonry composed of roughly shaped stones

fitting approximately on level beds and well bonded.

random rubble. Masonry composed of roughly-shaped stones
laid without regularity of coursing but well bonded and
fitted together to form well defined joints.

rough or ordinary rubble. Masonry composed of unsquared
field stones laid without regularity of coursing but well
bonded.

- rubble masonry. Masonry composed of roughly shaped stones.

runway. Any aisle or walkway constructed or maintained as
a passageway for pedestrians or vehicles.

rupture member. A mechanical device that will rupture at a
predetermined pressure to control automatically the com-
pressor or maximum pressure of operation of the refrigerant.

safe area. An interior or exterior space that serves as a part
of a means of egress by providing a transitional area from,
and that also serves as a normal means of entry to, an
assembly space.

scenery and scenic elements. Any or all of those devices
ordinarily used on a stage in the presentation of a theatrical

performance, such as back drops, side tabs, teasers, border
or scrim, rigid flats, set pieces, and all properties, but no
including costumes.

school. Any building or premises in which a regular course '
of public or private instruction is afforded to not less than
ten (10) pupils at one time, exclusive of rooms in buildings
separate from or attached to churches used for the primary
purpose of religious instruction.

seating section. An area of seating bounded on all sides by .
aisles, cross over aisles, walls or partitions.

self-closing. As applied to an opening protective shall mean
a door, window, damper, or other device, and its assembly
that is normally kept in a closed position and that is
equipped with an approved device to insure immediate closing
after having been opened for use.

service equipment. See building service equipment.

shaft. An enclosure of a vertical opening in two (2) or more
stories.

— covered. A shaft enclosed at the top.

— open. A shaft open to the outdoor air at the top.

shall. As used in this code is always to be construed as man-
datory.

Siamese connection. A fitting connected to a fire extinguishing
system and installed on the outside of a building, with two
(2) hose inlets for use of the fire department, to furnish or
supplement the water supply to the system.

sidewalk shed. A construction over a public sidewalk, used to
protect pedestrians from falling objects.

sign. An outdoor structure, banner or other device, designed
or used as an advertisement or announcement for the infor-
mation or attraction of the public; consisting of the frame-
work and all letters, words, numerals, illustrations, illumina-
tion, decorations, trade marks, emblems, symbols or other
figures or characters.

— billboard, (poster panel). A board, panel or tablet used for
the display of printed or painted advertising matter.

201

— closed sign. A display sign in which the entire area is solid

or tightly enclosed or covered.

— display sign. A structure that is arranged, intended, designed

or used as an advertisement, announcement or direction; and
includes a sign, sign screen, billboard, poster panel and ad-
vertising devices of every kind.

— ground sign. A display sign supported by uprights or braces

in or upon the ground surface.

— open sign. A display sign in which at least fifty (50) per

cent of the enclosed area is uncovered, or open to the trans-
mission of wind.

— poster panel. See Billboard.

— projecting sign. A display sign which is attached directly to

the building wall and which extends more than fifteen (15)
inches from the faces of the wall.

— roof sign. A display sign which is erected, constructed and

maintained above the roof of the building.

— temporary sign. A display sign, banner or other advertising

device constructed of cloth, canvas, fabric or other light tem-
porary material, with or without a structural frame, intended
for a limited period of display; including decorative displays
for holidays or public demonstrations.

— wall sign. A display sign which is painted on or attached

directly to the building wall and which extends not more than
fifteen (15) inches from the face of the wall.

slow-burning plastic. See plastic, approved.

smoke damper. A damper arranged to seal off air flow auto-
matically through a part of an air duct system, so as to
restrict passage of smoke. A smoke damper may be a stan-
dard louvered damper serving other control functions if its
location lends itself to the dual purpose. A smoke damper
does not need to meet all the requirements of a fire damper.

smokepipe. See chimney connector.

smokestack. See chimney.

smoke screen. A door or set of doors and assembly placed in
a corridor to restrict the spread of smoke and to retard the
spread of fire by reducing draft.

soil. The softer matter mostly inorganic composing part of the
surface of the earth in distinction from firm rock; including
gravel, clay, loam and the like and filling materials of similar
nature.

space heater. (Room heater). An above-the-floor device for
direct heating of the space in and adjacent to that in which j
the device is located without external heating pipes or ducts.

special hoisting and conveying equipment. Manually or power-
operated hoisting, lowering or conveying mechanisms, other
than elevators, moving stairways or dumbwaiters for the
transport of persons or freight in a vertical, inclined or hori-
zontal direction on one floor or in successive floors.

— automotive lift. A fixed mechanical device for raising an

entire motor vehicle above the floor level but not through
successive floors of the building or structure.

— conveyors. A system of machinery and manual or mechanized

devices other than elevator and dumbwaiter equipment con-
sisting of belts, chains, rollers, buckets, aprons, slides and
chutes and other miscellaneous equipment for hoisting, low-
ering and transporting materials and merchandise in packages
or in bulk in any direction in a building or structure.

— manlifts. A power-operated belt device with steps and hand-

holds for transporting persons in a vertical position through
successive floors or levels of the building or structure.

— material lift. A power-operated rising or lowering device for

transporting freight vertically, operating entirely within one
(1) story of the building or structure.

sprinkler alarm — (water gong). An apparatus constructed and
installed so that a flow of water through the sprinkler sys-
tem equal to, or greater than, that required for a single
automatic sprinkler head will cause an alarm to be given.

sprinklers. See Automatic sprinklers.

sprinkler system. A system of piping and sprinkler heads con-
nected to one (1) or more sources of water supply.

sprinkler system, chemical. A system of automatic sprinklers
controlled by thermostatic operating devices for the diffusion
of approved fire-extinguishing chemicals or gases.

201
prinkler system, dry pipe. A system in which all pipes and
sprinkler heads are filled with air under pressure and the
water supply is controlled by an approved automatic dry-
pipe valve in the event of fire, actuated either by the release
of air or by thermostatic electric control.

prinkler system, supervised. A system in which all water sup-
ply, valves and accessory equipment is provided with electrical
contact devices to transmit signals to an outside central
supervisory station.

sprinkler system, thermostatic. An open or closed head sprinkler
system operated through an auxiliary thermostatic device
which functions at a predetermined rate of temperature rise.

•prinkler system, wet pipe. A system of automatic sprinklers
in which all pipes are filled with water at all times.

iprinklered. Equipped with an approved automatic sprinkler
system properly maintained.

itage. A raised portion of floor for staging purposes exceeding
eighteen (18) feet or more in depth behind the curtain line.

itair, rise of. The vertical distance between successive treads or
steps measured always from the same relative position thereon.

itair, tread of. The horizontal distance from one riser to the
next or from one nosing to the next.

itairway. One or more flights of stairs and the necessary
landings and platforms connecting them to form a continuous
and uninterupted passage from one floor to another.

standard fire test. The standard controlled furnace test for-
mulated under the procedure outlined in reference standard
RS9-2.

standpipe, dry. A standpipe fire line without permanent or
automatic water supply equipped with a Siamese connection
for use of the fire department.

standpipe system. A system of piping, for fire-fighting purposes,
consisting of connections to one (1) or more sources of water
supply, and serving one (1) or more hose outlets.

standpipe, wet. A standpipe fire line having a primary water
supply constantly available at every hose outlet, or made

available by opening the hose outlet or by automatic func-
tioning of a control station.

steel joist. Any secondary steel member of a building or struc-
ture made of hot or cold-formed solid or open-web sections,
or riveted or welded bar, strip or sheet-steel members or
slotted and expanded or otherwise deformed rolled sections.

story. That portion of a building included between the top
surface of a floor and the top surface of the next floor or
roof above.

street. A public way, alley, lane, court, sidewalk and such
parts of public squares and public places as form travelled
parts of highways.

street line. The line separating a street from a lot.

structural steel member. Any member of a building or structure
consisting of rolled steel structural shapes other than formed
steel, light gage steel or steel joist members.

structure. A combination of materials assembled at a fixed
location to give support or shelter, such as a building, bridge,
trestle, tower, framework, retaining wall, tank, tunnel, tent,
stadium, reviewing stand, platform, bin, fence, sign, flagpole,
or the like. The word "structure" shall be construed, where
the context allows, as though followed by the words "or
part thereof."

thermoplastic material. A solid plastic material which is cap-
able of being repeatedly softened by increase of temperature
and hardened by decrease of temperature.

thermosetting material. A solid plastic material which is cap-
able of being changed into a substantially infusible and insol-
uble product when cured under the application of heat or by
mechanical means.

ton of refrigeration. The unit of capacity of refrigeration
equivalent to the removal of heat at the rate of twelve
thousand (12,000) B.T.U. per hour.

two-source system. An automatic sprinkler system which is
supplied from a combination of any two (2) of the approved
automatic sources of water supply, or from two (2) pressure
tanks, or by direct connections to the municipal water supply

201

on two (2) streets in which the water mains are separately
controlled.

Linfired pressure vessel. A closed metal vessel which contains
air, steam, gas or liquid pressure in excess of fifty (50)
pounds per square inch gage which is supplied from an
external source.

uniformly distributed load. A conventional representation of
an element of dead or live load as a load of uniform inten-
sity, distributed over an area.

unit heater. An appliance which consists of an integral com-
bination of heating element and fan within a common en-
closure and which is located within or adjacent to the space
to be heated.

use. (used). As a verb, shall be construed as if followed by
the words "or is intended, arranged, designed, built, altered,
converted, rented or leased to be used."

use group. See occupancy group.

ventilation. The process of supplying or removing air by natural
or mechanical means to or from any space. Such air may or
may not have been conditioned.

vestibule. An enclosed space, with doors or opening protectives,
to provide protected passage between the exterior and interior
of a building, or between spaces within a building.

wall.

— r.pron wall. That portion of a skeleton wall below the sill

of a window.

— bearing wall. A wall which supports any vertical load in

addition to its own weight.

— cavity wall. A wall built of masonry units or of plain con-

crete, or a combination of these materials, arranged to pro-
vide an air space within the wall, and in which the inner
and outer parts of the wall are tied together with metal ties.

— composite wall. A wall built of a combination of two (2) or

more masonry units of different materials bonded together,
one (1) forming the back-up and the other the facing elements.

— curtain wall. A nonbearing enclosure wall not necessarily

supported at each story.

— enclosure wall. A wall, bearing or nonbearing, which en-

closes a stairway, elevator shaft or other vertical opening. !

— faced wall. A wall in which the masonry facing and backing

are so bonded as to exert common action under load.

— fire wall. A vertical type A fire division in the form of a

wall.

— hollow wall. A wall built of units so arranged as to provide

an air space within the wall, and in which the facing and
backing of the wall are bonded together.

— nonbearing wall. A wall which supports no vertical load

other than its own weight.

— panel wall. See skeleton.

— parapet wall. That part of any wall entirely above the roof

line.

— party wall. A wall on an interior lot line used or adapted

for joint service between two (2) buildings.

— retaining wall. A wall designed to resist lateral pressure.

— skeleton or panel wall. A nonbearing wall supported at each

story on a skeleton frame.

— spandrel wall. That portion of a skeleton wall above the

head of a window or door.

— veneered wall. A wall having a facing of masonry or other

weather-resisting noncombustible materials securely attached
to the backing, but not so bonded as to exert common ac-
tion under load.

wall heater. A unit heater which is supported from or recessed
in the wall of the room or space to be heated.

warm air furnace. A solid, liquid, gas-fired, or electric ap-
pliance for heating air to be distributed with or without
duct systems to the space to be heated.

201

■varm air furnace, mechanical. A warm air furnace equipped
with a fan to circulate the air.

■vater curtain. A system of approved open or closed sprinkler
heads or perforated pipes installed on the exterior of a build-
ing at eaves, cornices, window openings, and on mansard or
peak roofs with water supply under manual control; or in-
stalled around openings in floors or walls of a building with
water supply under thermostatic control.

width.

— inner court. As applied to an inner court, means its least

horizontal dimension.

— outer court. As applied to an outer court, means the shortest

horizontal dimension measured in a direction substantially
parallel with the principal open end of such court.

workmen's hoist. A hoisting and lowering mechanism equipped
with a car that moves in guides in a substantially vertical
direction and that is used primarily for raising and lowering
workmen to the working levels.

writing. The term shall be construed to include handwriting,
typewriting, printing, photo-offset or any other form of re-
production in legible symbols or characters.

written notice. A notification in writing delivered in person
to the individual or to the parties intended or delivered at
or sent by certified or registered mail to the last business
address known to the party giving the notice.

yard, front. An open space extending across the full width of
the lot and lying between the front lot line and the nearest
building.

yard, rear. An open space immediately behind the rearmost
main building on the lot and extending across the full width
of the lot.

yard, side. An open space along the side line of a lot, extend-
ing from the front yard line to the rear yard line; in the
case of a side yard abutting on a street, extending to the rear
lot line.

zoning. The reservation of certain specified areas within the
City of Boston for building and structures, or use of land,'
for certain purposes with other limitations such as height,
lot coverage and other stipulated requirements.

SECTION 202.0. OCCUPANCY GROUP CLASSIFICATION^

Every building, structure and all spaces therein shall be classi-
fied with respect to use or occupancy in accordance with the
provisions of section 203 through 213 according to the occupancy
or use of the building and spaces therein. The list of repres-
sentative occupancies in reference standard RS2-1 shall be used
for this purpose.

202.1. Fire Grading of Buildings. — All buildings and structures
shall be graded in accordance with the degree of fire hazard of
their occupancy in terms of hours and fractions of an hour
and as regulated in section 902.

202.2. New Occupancies. — The building official shall establish
by approved rules the degree of hazard involved and the fire!
grading of any occupancy not specifically provided for in this;
code.

SECTION 203.0. OCCUPANCY GROUP A — HIGH
HAZARD BUILDING

Buildings and spaces shall be classified in the high hazard
occupancy group when they are used for storing, manufacturing,
or processing potentially explosive products or materials, or
highly-combustible or high-flammable products or materials that
are likely to burn with extreme rapidity. The high hazard group
shall also include: occupancies that involve storing, processing,
or handling any materials that produce explosive dust, or that
result in the division of matter into fine particles subject to
spontaneous ignition; occupancies that employ solids or sub-
stances that ignite or produce flammable gases on contact with
water; and any other occupancies that constitute a high fire
hazard because of the form, character, or volume of the mater-
ials involved. The storage and use of flammables are subject
to rules and regulations of the City of Boston Licensing Board.
203.1. Typical Material Contents. — Acetylene gas and gases
under pressure of fifteen (15) psi or more and in quantities
greater than twenty-five hundred (2,500) cubic feet, including
hydrogen, illuminating gas, natural gas, and all other gases

201-204

ubject to explosion; celluloid and celluloid products; cotton
>atting; kerosene, fuel, or other oils having a flash point under
wo hundred (200) degrees F. (Tag. closed cup) except five
lundred and fifty (550) gallons or less in one and two-family
Iwellings; refrigerating systems using high hazard refrigerants
is defined in article 18.

103.2. Typical Occupant Activities. — Artificial flower and syn-
hetic leather manufacture; ammunition, and explosives manu-
acture, sales or storage; dry cleaning or dyeing using or storing
gasoline or other combustible solvents as outlined in section
U3.0; feather renovating; fruit ripening processes; hydrogenation
jrocesses; match manufacture or storage; metal enamelling or
apanning; paint and varnish manufacture; paint spraying or
lipping, as specified in section 412.0 derivation of petroleum
products by application of heat, processing of paper or card-
board in loose form; pyroxylin products manufacture and stor-
ige; rag sorting and storage; shoe polish manufacture; straw
*oods manufacture or broom corn storage; tar, pitch, or resin
Drocessing; waste paper sorting, shredding, storage, or baling;
;otton waste processes.

103.3. Representative Occupancies. — PaintShop and storerooms;
■ndustrial smoke houses; grain elevators; tanneries with enamel-
ing or japanning; distilleries; sugar, starch, cereal, feed, flour,
and grist mills.

SECTION 204.0. OCCUPANCY GROUP B — STORAGE
BUILDINGS

Buildings and spaces shall be classified in the storage occu-
pancy group when they are used primarily for storing goods.
However, limited storage incidental to the display, sale, or
manufacture of such goods is excepted. When the goods stored
are highly combustible, flammable, or potentially explosive, the
building or space sha!' meet the requirements for high hazard
occupancies when the latter are more restrictive than the corres-
ponding requirements for the storage classification. The storage
occupancy group consists of sub-groups B-l and B-2.
204.1. Occupancy Group B-l. — Shall include buildings and
spaces used for storing any flammable or combustible materials
that are likely to permit the development and propogation of
fire with moderate hazard but which do not produce either
poisonous gases, fumes or explosives.

204.1.1. Typical Material Contents. — Bags (cloth, burlap, anc I
paper); bamboo and rattan; baskets; belting (canvas and leather) |
books and paper in rolls or packs; buttons, including cloth j
covered, pearl, or bone; boots and shoes; cardboard and card- I
board boxes; wearing apparel; cordage; furniture; furs; glue I
mucilage, paste, and size; horn and combs other than celluloid
linoleum; livestock; lumber; photo-engraving supplies; silk, soap;
sugar; tobacco; cigars, cigarettes, and snuff; upholstery and (
mattresses; wax candles.

204.1.2. Typical Occupant Activities. — Photo engraving; leather
enamelling or japanning.

204.1.3. Representative Occupancies. — Warehouses, storeroom,
freight depots, stables, coal pockets, lumber yards, group 1 —
public garages; petroleum warehouses for storage of lubricating
oils with a flash point of three hundred (300) degrees F or
higher (see section 905.3).

204.2. Occupancy Group B-2. — Shall include buildings and
spaces used for storing non-combustible materials and materials
that do not ordinarily burn rapidly.

204.2.1. Typical Material Contents. — Asbestos, chalk and cra-
yons, food products, glass, ivory, metals, porcelain and pottery,
talc and soapstones.

204.2.2. Typical Occupant Activities. — Wholesaling.

204.2.3. Representative Occupancies. — Warehouses; storerooms;
private garages; greenhouses; group 2 — public garages.

SECTION 205.0. OCCUPANCY GROUP C — MERCANTILE
BUILDINGS

Buildings and spaces shall be classified in the mercantile oc-
cupancy group when they are used for display and sales of goods
accessible to public inspection. Highly combustible or flammable
goods, such as those made of pyroxylin products shall be limited
to small quantities that do not constitute a high hazard; if not
so limited, the occupancy shall meet the requirements for high
hazard occupancies when the latter are more restrictive than
the corresponding requirements for the mercantile classification.
205.1. Representative Occupancies. — Retail stores; shops; sales-
rooms; markets; public auction rooms.

204-206
SECTION 206.0. OCCUPANCY GROUP D —
INDUSTRIAL BUILDINGS

Buildings and spaces shall be classified in the industrial oc-
cupancy group when they are used for fabricating, assembling,
manufacturing, or processing products, materials, or energy, ex-
cept that when any products or materials, or other products or
materials used in their manufacture are highly combustible,
flammable, or explosive, the occupancy shall meet the require-
ments for high hazard occupancies when the latter are more
restrictive than the corresponding requirements for the industrial
classification. The industrial occupancy group consists of sub-
groups D-l and D-2.

206.1. Occupancy Group D-l. — Shall include buildings and spaces
in which the fabrication, assembly, manufacturing, or processing
represents a moderate fire hazard due to the extent and nature
of such operations, or to the materials involved.

206.1.1. Typical Occupant Activities. — Canning, including food
products and condensed and powdered milk manufacturer; dry
cleaning or dyeing using or storing solvents having a flash point
between one hundred (100) degrees F and one hundred thirty-
eight and two-tenths (138.2) degrees F (Tag. closed-cup); elec-
trolytic processes; glass manufacture, leather tanning and treat-
ing, excluding enamelling or japanning; sugar refining; textile
milling, including canvas, cotton, cloth, bagging, burlap, carpets,

>'and rugs; upholstering; woodworking; cotton dressmaking; and
manufacturing or processing materials such as those outlined in
section 204.1.1.

206.1.2. Representative Occupancies. — Baking plants, breweries;
motor vehicle repair shops; foundries; heliports; scenery shops.

1 206.2. Occupancy Group D-2. — This group shall include build-
ings and spaces in which the fabrication, assembly, manufac-
turing, or processing represents a low fire hazard.
206.2.1. Representative Occupancies. — Mechanical and electrical
equipment rooms; commercial laundries; vocational training
shops; laboratories; boiler and furnace rooms; nonresidential

; kitchens; power plants.

1206.3. Special Industrial Uses. — All buildings and structures

: designed to house low hazard industrial processes, including

; among others the production and distribution of electric, gas
or steam power and rolling mills and foundries, requiring large
areas and unusual heights to accommodate craneways or special

I machinery and equipment shall be exempt from the height and

iarea limitations of section 221.2 table 2-2.

206.3.1. Construction. — Buildings and structures for such special
industrial uses shall comply with the requirements of section
309.0 except as to height and when constructed of non-combus-
tible (type 2-C) construction may have balconies and mezzanine
floors which do not exceed two-thirds (2/3) the area of the main
floor in any one tier.

206.3.2. Enclosure Walls. — The enclosure walls of buildings of
such low hazard industrial uses shall be constructed of approved
non-combustible and weather resisting materials and when located
with a fire separation of less than thirty (30) feet from interior
lot lines of any other building shall be protected or constructed
to provide a fire resistance rating of not less than two (2) hours.

206.3.3. Firefighting and Extinguishing Equipment. — Special use
industrial buildings as herein defined shall comply with the re-
quirements of article 12 for auxiliary fire extinguishing equip-
ment; except that the provisions of section 309.0 for automatic
sprinkler equipment in unlimited area buildings may be waived
by the building official when such installations would be detri-
mental or dangerous to the specific use and occupancy.

SECTION 207.0. OCCUPANCY GROUP E — BUSINESS
BUILDINGS

Buildings and spaces shall be classified in the business occupancy
group when they are occupied for transacting business; for ren-
dering professional services, or for performing other commercial
services that may incidentally involve the storage of limited
quantities of stocks of goods for office use or purposes. Build-
ing and spaces used for prosecuting public or civic services shall
also be classified in this group.

207.1. Representative Occupancies. — Office buildings; banks;
civic administration buildings; radio and television stations;
telephone exchanges; barber and beauty shops; automotive
service stations.

SECTION 208.0. OCCUPANCY GROUPS F AND G
ASSEMBLY AND SCHOOL BUILDINGS

Buildings and spaces shall be classified in the assembly oc-
cupancy group when they are used or designed as places of
assembly as defined in article 2. The assembly occupancy group
consists of sub-groups F-l through F-5.

206-208

208.1. Occupancy Group F-l. — Shall include those indoor
places of assembly in which, during the major period of occu-
pancy, the persons assembled comprise a seated or otherwise
passive audience to a performance or presentation, and have
their attention focused in a common direction or at a common
subject. Occupancy group F-l consists of two (2) subdivisions
F-la and F-lb.

208.1.1. Occupancy Group F-la. — Includes all F-l places of
assembly using scenery and scenic elements including such repre-
sentative occupancies as theaters, playhouses, opera houses.

208.1.2. Occupancy Group F-lb. — Includes all F-l places of
assembly not using scenery and scenic elements including such
representative occupancies as motion picture theatres, convention
halls, concert halls, sports arenas, planetariums.

208.2. Occupancy Group F-2. — Shall include those indoor places
of assembly in which, during the major period of occupancy,
the persons assembled are physically active and do not have a
common center of attention; entertainment or for similar pur-
poses including all rooms, lobbies and other spaces connected
thereto with a common means of egress.

208.2.1. Representative Occupancies. — Restaurants; night clubs;
cabarets; dance halls; ballrooms; banquet rooms; cafeterias;
snack bars; taverns; coffee houses.

208.3. Occupancy Group F-3. — Shall include those indoor
places of assembly in which, during the major period of occu-
pancy, the persons assemble for amusement, entertainment or
recreation, incidental motion picture, dramatic, theatrical or ed-
ucational presentations, lectures or other similar purposes not
provided for in groups F-l and F-2 and principally used with-
out permanent seating facilities.

208.3.1. Representative Occupancies —Exhibition halls, art gal-
leries, museums, gymnasiums, lecture halls, passenger terminals,
bowling alleys, billiard parlors, skating rinks; recreation centers,
funeral establishments.

208.4. Occupancy Group F-4. — Shall include those buildings and
spaces used as churches or for similar religious purposes.

208.4.1. Representative Occupancies. — Libraries, churches.

208.5. Occupancy Group F-5. — Shall include all outdoor places
of assembly.

208.5.1. Representative Occupancies. — Grandstands, bleachers,
coliseums, stadiums, drive-in theatres, tents and similar structures.

208.5.2. The buildings and structures in this group shall com-
ply with the provisions of this code for special uses and occu-
pancies — see article 4.

208.6. Occupancy Group G. — Shall include those buildings and
spaces or premises in which a regular course of public or private
instruction is afforded to not less than ten (10) pupils at one
time. Rooms in buildings separate from or attached to churches
used for the primary purpose of religious instruction are regu
lated under occupancy group F4.

208.6.1. Representative Occupancies. — Schools; academies; uni
versities; colleges.

SECTION 209.0. OCCUPANCY GROUP H —
INSTITUTIONAL BUILDINGS

Buildings and spaces shall be classified in the institutional occu-
pancy group when persons suffering from physical limitations
because of health or age are harbored therein for care or treat-
ment; when persons are detained therein for penal or correctional
purposes; or when the liberty of the inmates is restricted. The
institutional occupancy group consists of sub-groups H-l and
H-2.

209.1. Occupancy Group H-l. — Shall include buildings and
spaces used for the detention of persons under restraint.
209.1.1. Representative Occupancies. — Jails, prisons, reforma-
tories, mental institutions, cell areas of police stations.

209.2. Occupancy Group H-2. — Shall include buildings and
spaces used for the care or treatment of persons with physical
limitations because of health or age.

209.2.1. Representative Occupancies. — Hospitals; sanitariums;
clinics; nursing homes; orphanages; homes for the aged; day
nurseries.

SECTION 210.0. OCCUPANCY GROUP L —
RESIDENTIAL BUILDINGS

Buildings and spaces shall be classified in the residential occu-
pancy group when families or households dwell therein, or
when sleeping accommodations, with or without dining facilities,
are provided therein for individuals. Excluded from this group
are those buildings and spaces classified under the institutional
occupancy group. The residential occupancy consists of sub-
groups L-l, L-2 and L-3.

208-212

210.1. Occupancy Group L-l. — Shall include buildings and
spaces that are primarily occupied for the shelter and sleeping
accommodation of individuals on a day-to-day or week-to-week
basis.

210.1.1. Representative Occupancies. — Hotels; motels; lodging
houses, rooming houses.

210.2. Occupancy Group L-2. — Shall include buildings with
three or more dwelling units that are primarily occupied for
the shelter and sleeping accommodation of individuals on a
month-to-month or longer-term basis.

210.2.1. Representative Occupancies. — Apartment houses; school
dormitory buildings; college fraternity and sorority houses.

210.3. Occupancy Group L-3. — Shall include buildings occupied
as one-family or two-family dwellings, or as convents or rec-
tories.

210.3.1 . Representative Occupancies. — One-family and two-family
dwellings; rectories; convents.

SECTION 211.0. OCCUPANCY GROUP M —
MISCELLANEOUS

Structures of a temporary character, and minor occupancies
not classified in any other specific occupancy group, shall be
classified in the miscellaneous occupancy group. Such structures
and occupancies shall be constructed, equipped, and maintained
to meet the requirements of this code commensurate with the
fire and life hazard incidental to their use. The miscellaneous
occupancy group includes all accessory structures such as sheds,
fences, and similar constructions.
211.1. Representative Structures. — Sheds, fences, signs.

SECTION 212.0. DOUBTFUL OCCUPANCIES

When a building or space is used for an occupancy not speci-
fically provided for in this code, or when its classification is
otherwise uncertain, such building or space shall be included in
the occupancy group that it most nearly resembles with respect
to the existing or proposed life and fire hazard, and it shall
be so classified by the architect or engineer subject to the ap-
proval of the building official.

208.5.2. The buildings and structures in this group shall com-
ply with the provisions of this code for special uses and occu-
pancies — see article 4.

208.6. Occupancy Group G. — Shall include those buildings and
spaces or premises in which a regular course of public or private
instruction is afforded to not less than ten (10) pupils at one i
time. Rooms in buildings separate from or attached to churches
used for the primary purpose of religious instruction are regu-
lated under occupancy group F4.

208.6.1. Representative Occupancies. — Schools; academies; uni- I
versities; colleges.

SECTION 209.0. OCCUPANCY GROUP H —
INSTITUTIONAL BUILDINGS

209.2. Occupancy Group H-2. — Shall include buildings and
spaces used for the care or treatment of persons with physical
limitations because of health or age.

209.2.1. Representative Occupancies. — Hospitals; sanitariums;
clinics; nursing homes; orphanages; homes for the aged; day
nurseries.

SECTION 210.0. OCCUPANCY GROUP L —
RESIDENTIAL BUILDINGS

208-212

210.1. Occupancy Group L-l. — Shall include buildings and
spaces that are primarily occupied for the shelter and sleeping
accommodation of individuals on a day-to-day or week-to-week
basis.

210.1.1. Representative Occupancies. — Hotels; motels; lodging
houses, rooming houses.

210.2.1. Representative Occupancies. — Apartment houses; school
dormitory buildings; college fraternity and sorority houses.

210.3. Occupancy Group L-3. — Shall include buildings occupied
as one-family or two-family dwellings, or as convents or rec-
tories.

210.3.1. Representative Occupancies. — One-family and two-family
dwellings; rectories; convents.

SECTION 211.0. OCCUPANCY GROUP M —
MISCELLANEOUS

SECTION 212.0. DOUBTFUL OCCUPANCIES

SECTION 213.0. MIXED AND/OR MULTIPLE
OCCUPANCY

213.1. Two or More Occupancies. — In case a building is oc-
cupied for two (2) or more uses not included in the same
occupancy group, the provisions of this code applying to each
occupancy shall be applied as follows:

213.1.1. Multiple Occupancy. — When the building or space is
used for multiple purposes, involving different activities at dif-
ferent times, the building or space shall be given a separate
occupancy group classification for each of the activities involved.
The design and construction of the building or space shall be
in accordance with the most restrictive provisions of this code
that apply to any of the occupancy group classifications utilized.

213.1.2. Mixed Occupancy. — When any space within a building
has an occupancy group classification other than that for which
the building is classified and occupies ten (10) percent or more of
the total net floor area of the building, that space shall be sep-
arated horizontally and vertically from all adjoining occupancies
by construction meeting the fire resistance rating requirements
for Type A-Fire Divisions as provided for in article 9 and
such occupancies shall for the purpose of this code be classified
and treated as separate buildings and referred to as a building
section. When the space in question occupies less than ten (10)
percent of the total net floor area, it shall be separated hori-
zontally and vertically from all adjoining occupancies by con-
struction meeting the fireresistance rating requirements for Type
B-Fire Division as provided for in article 9.

SECTION 214.0. CONSTRUCTION CLASSIFICATION

Every structure, building, room, or space hereafter altered or
erected shall for the purposes of this code be classified in one (1)
or in a combination of the four (4) construction types herein
defined: Type 1, Fireproof Construction; Type 2, Noncombustible
Construction; Type 3, Exterior Masonry Wall Construction; and
Type 4, Frame Construction.

214.1. False Designation. — No building or space shall be desig-
nated a given construction type unless it conforms to the
minimum requirements for that type; and no building or space
shall be posted, used, designated, or advertised as of a given

213-215

construction type unless it complies with the minimum require-
ments of this code for that type.

214.2. Minimum Requirements. — When a superior type of con-
struction is used than the minimum herein required for any
specified use, height and area of the building, nothing in this
code shall be construed to require full compliance with the
specifications for the higher type; but the designated construction
classification of the building shall be that of the lesser require-
ment, unless all the requirements for the higher type are fulfilled.

214.3. Mixed Construction. — When two (2) or more types of
construction occur within the same building, the entire building
shall be subject to the most restrictive occupancy and size limita-
tions for the type of construction involved. However, if the oc-
cupancy within the different classes of construction are completely
separated by construction that meets the fireresistance rating
requirements for Type A fire divisions listed in section 221.1
table 2-1 then each occupancy so separated may, for the pur-
poses of this code, be considered as a separate building ("build-
ing section").

214.3.1. Restrictions. — In buildings of mixed construction, no
structural element shall be supported by construction having a
lower fireresistance rating than that required for the element
being supported.

214.4. Hazardous Occupancies. — For hazardous occupancies
involving an exceptionally high degree of fire risk or an ex-
ceptionally high concentration of combustible or flammable
contents, the building official may increase the requirements
of section 221.1 table 2-1.

SECTION 215.0. TYPE 1 — FIREPROOF CONSTRUCTION

Buildings and structures of fireproof construction are those in
which the walls, partitions, structural elements, floors, ceilings,
and roofs, and the means of egress parts are constructed and
protected with noncombustible materials to afford the fire-
resistance specified in section 221.1 table 2-1, except as otherwise
specifically regulated by the provisions of article 9. Fireproof
buildings shall be further classified as types 1A and IB in which
their bearing walls and other major structural elements are
generally of four (4) hour and three (3) hour fireresistance ratings
respectively. Fire-retardant treated wood may be used as specified
in section 221.1 table 2-1 and section 903.8.

SECTION 216.0. TYPE 2 — NONCOMBUSTIBLE
CONSTRUCTION

Buildings and structures of noncombustible construction are
those in which the walls, partitions, structural elements, floors,
ceilings and roofs, and the means of egress parts are constructed
of approved noncombustible materials meeting the fireresistive
requirements specified in section 221.1 table 2-1, except as modi-
fied by the fire district limitations of article 3, and as further
regulated in article 9. Noncombustible buildings shall be further
classified as types 2A, 2B and 2C in which their bearing walls
and other major structural elements are generally of two (2)
hour fireresistance rating, three-quarter (3/4) hour fireresistance
rating or of no fireresistance rating respectively. Fire-retardant
treated wood may be as specified in section 221.1 table 2-1
and section 903.8.

SECTION 217.0. TYPE 3 — EXTERIOR MASONRY
WALL CONSTRUCTION

Buildings and structures of exterior masonry wall construction
are those in which the exterior, fire and party walls are con-
structed of masonry or other approved noncombustible ma-
terials, of the required fireresistance and structural properties;
and the floors, roofs and interior framing are wholly or partly
of wood or of metal or other approved construction; the fire
and party walls are ground supported; except that girders and
their supports carrying walls of masonry shall be protected to
afford the same degree of fireresistance as the walls supported
thereon; and all structural elements have the required firere-
sistance rating specified in section 221.1 table 2-1. Type 3 build-
ings shall be further classified as types 3A, 3B and 3C to re-
flect the fire resistive properties of their framing components.
217.1. Type 3A. — Buildings and structures of heavy timber
construction are those in which fireresistance is attained by
placing limitations on the minimum sizes of wood structural
members and on minimum thickness and composition of wood
floors and roofs; by the avoidance, or by the proper protection
by firestopping or other acceptable means, of concealed spaces
under floors and roofs; by the use of approved fastenings,
construction details, and adhesives for structural members; and
by providing the required degree of fire resistance in exterior
and interior walls. (See section 854.0 for construction details.)

216-217

217.1.1. Columns. — Wood columns may be sawn or glued lam-
inated and shall be not less than eight (8) inches, nominal, in
any dimension when supporting floor loads and not less than
six (6) inches, nominal, in width and not less than eight (8)
inches, nominal, in depth when supporting roof and ceiling
loads only.

217.1.2. Floor Framing. — Beams and girders of wood may be
sawn or glued laminated and shall be not less than six (6)
inches, nominal, in width and not less then ten (10) inches,
nominal, in depth. Framed or glued laminated arches which
spring from the floor line and support floor loads shall be not
less than eight (8) inches, nominal, in any dimension. Framed
timber trusses supporting floor loads shall have members of not
less than eight (8) inches, nominal, in any dimension.

217.1.3. Roof Framing. — Framed or glued laminated arches for
roof construction which spring from the floor line or from grade
and do not support floor loads shall have members not less than
six (6) inches, nominal, in width and not less than eight (8)
inches, nominal, in depth for the lower half of the height and
not less than six (6) inches, nominal, in depth for the upper
half. Framed or glued laminated arches for roof construction
which spring from the top of walls or wall abutments, framed
timber trusses, and other roof framing which do not support
floor loads, shall have members not less than four (4) inches
nominal, in width and not less than six (6) inches, nominal,
in depth. Spaced members may be composed of two (2) or
more pieces not less than three (3) inches, nominal, in thickness
when blocked solidly throughout their intervening spaces or
when such spaces are tightly closed by a continuous wood
cover plate of not less than two (2) inches, nominal, in thick-
ness, secured to the underside of the members. Splice plates
shall be no less than three (3) inches, nominal, in thickness.
When protected by approved automatic sprinklers under the
roof deck, framing members shall be not less than three (3)
inches, nominal, in width.

217.1.4. Flooring. — Floors shall be without concealed spaces
and shall be of sawn or glued laminated plank, splined, or
tongue-and-groove, of not less than three (3) inches, nominal,
in thickness covered with one (1) inch, nominal, dimension
tongue-and-groove flooring, laid crosswise or diagonally, or of

planks not less than four (4) inches, nominal, in width set on
edge close together and well spiked, and covered with one (1)
inch, nominal, dimension flooring.

217.1.5. Roof Decking. — Roofs shall be without concealed
spaces and roof decks shall be sawn or glued laminated, splined
or tongue-and-groove plank, not less than two (2) inches,
nominal, in thickness, and one and one-eighth (1-1/8) inches
thick interior plywood (exterior glue), or of planks not less
than three (3) inches, nominal, in width, set on edge close to-
gether and laid as required for floors. Other types of decking
may be used if providing equivalent fireresistance and structural
properties.

217.1.6. Bearing Walls. — Bearing portions of exterior and in-
terior walls shall be of approved noncombustible material and
shall have a fireresistance rating of not less than two (2) hours.

217.1.7. Nonbearing Walls. — Nonbearing portions of exterior
walls shall be of approved noncombustible materials except as
otherwise- noted and; where horizontal separation of less than
twenty (20) feet is provided, nonbearing exterior walls shall
have a fire resistance rating of not less than two (2) hours.
Where a horizontal separation of twenty (20) feet to thirty (30)
feet is provided, nonbearing exterior walls shall have a fire re-
sistance rating of not less than one (1) hour. Where a horizontal
separation of thirty (30) feet or more is provided, no fire re-
sistance rating is required. Where a horizontal separation of
twenty (20) feet or more is provided wood columns and arches
conforming to heavy timber sizes may be used externally.

217.2. Type 3-B. — Structures of type 3-B (ordinary protected)
shall include all exterior masonry wall buildings in which the
interior structural elements are wholly or partly of fire-protected
wood of not less than two (2) inch nominal thickness, or of
other approved protected combustible materials, or of metal
protected and insulated to afford three-quarter (3/4) hour fire-
resistance where specified in section 221.1 table 2-1.

217.3. Type 3-C. — Structures of type 3-C (ordinary unprotected)
construction shall include all exterior masonry wall buildings in
which the interior structural members are of wood of not less
than two (2) inch nominal thickness or consist of other com-
bustible or noncombustible materials with protection of less
than three-quarter (3/4) hour fireresistance rating.

217-220
SECTION 218.0. TYPE 4 — FRAME CONSTRUCTION

Buildings and structures of frame construction are those in which
the exterior walls, bearing walls, partitions, floor and roof
construction are constructed wholly or partly of wood stud
and joist assemblies with a minimum nominal dimension of
two (2) inches, or of other approved combustible materials;
with firestopping at all vertical and horizontal draft openings
as regulated in section 877, and in which the structural elements
have the required fireresistance ratings specified in section 221.1
table 2-1. Frame buildings shall be further classified as types
4-A and 4-B in which the exterior walls, bearing walls, floors,
roofs, and interior framing are generally of wood or other
combustible materials having the required fireresistance ratings
or having no fireresistance ratings respectively.

SECTION 219.0. SUBDIVISION OF ATTIC SPACES

The attic spaces of all buildings, except where the roof and
attic are of noncombustible or fireproof construction, shall be
subdivided in accordance with the applicable requirements of
section 921.0 by means of approved fire stops. When doors or
other openings are provided in such subdividing partitions, they
shall be of noncombustible or similarly protected materials and
the construction shall be tightly fitted around all ducts or other
assemblies piercing such partitions.

SECTION 220.0. TEMPORARY STRUCTURES

Pursuant to a variance granted by the board of appeals under
the provisions of Part I section 117, the building official may
issue a permit for temporary construction as approved by the
board of appeals. Such permits shall be limited as to time of
service, but in no case shall such temporary construction be
permitted for more than one (1) year.

220.1. Special Approval. — All temporary construction shall con-
form to structural strength, fire safety, means of egress facilities,
light, ventilation and sanitary requirements of this code necessary
to insure the public health, safety and general welfare.

220.2. Termination of Approval. — The building official is here-
by authorized to terminate such special approval and to order
the demolition of any such construction at his discretion, or
as directed by the decision of the board of appeals.

SECTION 221.0. FIRE RESISTANCE RATING AND
GENERAL HEIGHT AND AREA LIMITATIONS

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221

Notes on Table 2-1

1. The fire separation or fire exposure in feet as herein limited applies to the
distance from other buildings on the site, or from an interior lot line or
from the opposite side of a street or other public space not less than thirty
(30) feet wide to the building wall. (See Definitions, section 201.0.)

2. Protected exteriors shall be required within the fire limits in type 2 con-
struction as follows: high hazard occupancies, two (2) hour fire resistance
with fire separation up to eleven (11) feet.

3. Party walls in type 4 buildings shall be as follows: one- and two-family
dwellings, three-quarter (3 4) hour fireresistance. (See section 907.3) Other
occupancies two (2) hours, but not less than the fire grading of the occu-
pancy group. (See section 902.4 table 9-2.)

4. In all buildings in which the roof framing may be unprotected, roof slabs
and decking may be noncombustible without fireresistance rating except
that in buildings not more than five (5) stories in height, roof decking may
be of mill type construction or of any other materials providing equivalent
fireresistant and structural properties. (See sections 217 and 915.)

5. In Type 3A construction members which are of material other than heavy
timber shall have a fireresistance rating of not less than three-quarter (3/4)
hours.

6. Fire retardant treated wood, complying with section 903.7.2 may be used
as provided in section 903.8.

221

Notes on Table 2-2

1. Church auditoriums of type 3-A construction may be erected to sixty-five
(65) feet in height and of type 4 construction to forty-five (45) feet in height.

2. For exceptions to height and area limitations of high hazard use buildings,
see article 4 governing the specific use. For other special fireresistive re-
quirements governing specific uses, see section 905.

3. In multi-story buildings, the limiting areas specified in section 221.2 table
2-2 shall be reduced as regulated by section 307.2.

4. For exception to area limitations for one-story school buildings of type 2,
3A and 3B construction, see section 309.1.1.

5. For accessory high hazard spaces within these occupancies refer to section
403.3 for sprinkler requirements.

6. Refer to section 415.6 for public garage sprinkler requirements.

7. Refer to sections 308 and 310 for sprinkler requirements.

RS2

not applicable

F-3

F-5

B-2

RS 2-1 Occupancy Classifications for Building and Zoning
Codes

Zoning Code Building Code

Use Item Occupancy Group

Advertising displavs manufacture

including billboards 68 D-2

Airport or other aircraft landing or

service facility (See also: Helicopter

rooftop landing facility)
Amusement park, indoor

Outdoor

Animal

Crematorium

Hospital, kennel, pound

Accessory enclosure for horses,

cows, or similar animals other

than pigs 75 B-l

Accessory enclosure for poultry,

pigeons, rabbits or bees 76 —

Accessory enclosure for animals

incidental to laboratory use 77 —

Apartments (see Residences)

Appliances
Manufacture
Sales

Arenas

Asphalt

Processing and products manufacture 70 A

Athletic equipment

Manufacture 68 D-l

Sales 34 C

Auditoriums See Section 418.0

Commercial 38 F-la with scenery, F-lb no scenery

Community centers 29 F-la or F-lb

(see also Colleges &. universities;
Schools)
Automobiles & other motor vehicles

Gasoline Service Station

Rental agency outdoors

Rental agency within a building

Repair

Repair incidental to auto sales
with limitations

Sales, outdoor

Sales within a building

Wrecking

(see also Parking garages; Parking
lots)

Washing 60

D-l

34 or 35

F-lb indoor

F-5 outdoor

Section 416.0

—

D-

1, Section 417.0

D-l

—

D-2

Awnings manufacture

Baked goods shop

Bakeries

Banks

Banquet halls

Barber shops

in hotels, etc.
Beauty shops
Beverages

bottling

manufacture
alcoholic
less than 0.5% alcohol @ 60°

Bicycle

manufacture

rental or repair conducted
within a building
outdoors
sales
Billiard parlor
Blacksmith shops
Blueprinting, etc., establishments

Boarding house
Boats or ships
building or repair of boats less
than one hundred feet long
building or repair or boats more
than one hundred feet long
Bone distillation
Bowling alleys

Broom or brush manufacture

Building materials

outdoor storage of new materials
outdoor storage of used materials
wholesale business in roofed
structures

Bus terminals or stations

yard for storing buses
Business schools or colleges
Camera & other photo equipment

manufacture except film

sales

Canvas or canvas products

manufacture or repair
Carpet & rug

cleaning establishments

manufacture or repair
Catering for outside consumption

Zoning Code
Use Item

Building Code
Occupancy Group

D-l

34
68
41

D-l

F-2, Section 419

43
78
43

L-2

70
38

54
62

64
18

34 or 35

D-2

D-l

D-2

—

F-3, Section 419

D-l

D-2

L-l

D-l

D-l
D-l
F-3, Section 419.0
D-l

B-l or B-2 no sales, C sales
B-l or B-2 no sales, C sales

C, B-l or B-2 storage

D-l (bus area)

F-3 (passenger area),

D-2
C

D-l

A or D-l depending on nature
of materials involved
D-l

D-2

RS2-1

Cemeteries

crematory in cemetery
extension of existing cemetery
mausoleum, crypt, columbarium
mortuary chapel in cemetery

Ceramic products manufacture
including pottery, small glazed
tile, & similar items

Charcoal, fuel, briquettes, or
lampblack manufacture

Chemicals
packaging

manufacture

Churches or other places of worship
Circuses, temporary
Cleaning (see Drycleaning & Dyeing;
Laundries; Automobiles — washing)
Clothing

Zoning Code

Building Code

Use Item

Occupancy Group

26c

B-2

26a

—

26d

B-2

26b

F-4, Section 419.0

D-2

D-l

A, D-l, or D-2 depending on natu

of materials involved
A, D-l, or D-2 depending on natu

of materials involved
F-4, Section 419
F-la, Section 418

manufacturing

A or

D-l depending on nature

of materials involved

rental establishment

—

retail sales

or 35

tailoring, custom manufacture or

repair

(see also Feathers; Felt; Fur;

Leather)

Clubs

private

E w

thout residence

nightclubs (see eating & drinking

establishments)

Coal, coke or tar products.

manufacture

Colleges & universities

classroom buildings

dormitories

,12,13

L-2 depending on lot

fraternities or sororities

L-2

accessory use with limitations

—

Community centers

F-3,

see Section 419

Convalescent homes (see nursing homes)

Convents

L-3

Cosmetics or toiletries manufacture

D-l

Cotton ginning

Cotton wadding or linters manufacture

Courthouses

Crematoriums

animal

—

B-l

human

26c

B-l

Dance halls

F-2,

Section 419

Zoning Code

Bui

Iding

Use Item

Occupancj

)

11,12,13

L-:

D-l

D-2

F-5

Dental offices (see Medical &. dental)

Department stores

Dormitories

Dressmaking shops, custom

Drinking places (see eating &

drinking establishments)
Drive-in restaurants

Drive-in theaters

Drug stores

Dry cleaning & dyeing

establishment 45 A. D-l or D-2 depending on soil

used, see Section 413

pick up & delivery station 43 C

shop 44 C sales. A, D-l, or D-2 work an

Dwellings (see residences)

Eating or drinking places

lunchrooms, restaurants, cafeterias,

etc. primarily enclosed

drive-in

with entertainment or dancing

accessory to hotel, etc. primarily

for occupants 78 F-2. Section 419

Electric

power or steam generating plants

substation
Electrical appliances, bulbs, wiring
supplies, etc.

manufacture

sales

Electronic components &. supplies

manufacture or repair 68 D-2

Feathers

curing, dyeing, washing or bulk

F-2, Section 419

D-2

F-2, Section 419

D-l

D-2

34 or 35

processing

manufacturing exclusive of above

Felt

curing, dyeing, washing or bulk

processing

D-l

products manufacture, exclusive

of above

D-l

Fertilizers, manufacture

D-l

Film, photographic manufacture

D-l

Storage and Studios

—

A. Section 409

Fire station

garage

dormitory

Fish processing

D-l

Florist shops

34.35 or 51

RS 2-1

Zoning Code Building Code

Use Item Occupane> Group

hood

product processing except meat

& fish 68 D-

retail sales 34 or 35 C

Fraternities or sororities
(see Colleges & universities)

Funeral establishments

Fur

curing, dyeing, finishing, tanning

products manufacture exclusi\e of
above
Garage (see parking Garage)
Garbage incineration or reduction
Garden supplies, produce or flowers

Outdoor sales

Gas

Manufacture

Two thousand cu. ft. a day or less

More than two thousand cu. ft. a
day

Public utility stations for
metering or regulating
Storage

Ten thousand cu. ft. or less

More than ten thousand cu. ft.

Incidental to a lawful use

Gasoline sen ice stations
(see Automobiles)

Gelatin manufacture

Generating plants, electric or steam

Gift shops

Glass products from previously

manufactured
Glue manufacture
Golf

Indoor courses or dri%ing ranges

Outdoor courses or dri\ing ranges
Gvmnasiums
Gypsum manufacture
Grain storage

Hair

Curing, dyeing, washing, bulk

processing
Product manufacture exclusive of
above
Hardware
Manufacture
Retail sales

Hat bodies manufacture

F-3

D-2

D-l

or D-l

D-l

56 or

more the

5" or

—

D-l

or 35

D-:

D-l

F-3.

Section 419

—

F-3

Section 419

D-2

A S

action 41 1

D-:

69
34 or 35

D-:
c

D-l

Helicopter landing facility, rooftop

Zoning Code
Use Item

Home occupations
Homes for the aged
Hosiery manufacture
Hospitals

Including convalescent, nursing or
rest homes, and sanitoriums
provided custodial care is not
provided for drug addicts,
alcoholics, or mentally ill or
mentally deficient
For care of drug addicts, mentally

ill or mentally deficient
Research or teaching laboratories
Limited accessory uses
(see also Animals — Hospitals)
Hotels

Apartment
Transient

Ice manufacture (dry or natural)
Ice skating rinks

Incineration or reduction of garbage,
offal, or dead animals

Industrial uses (see specific items)
Without resulting noise, vibration,

special danger, hazard, dust,

smoke, fumes etc.
Other than above

Ink or inked ribbon manufacture
Kennels (see Animals)
Jewelry

Costume, manufacture by metal
stamping or extrusion

Junk, outdoor storage

Laboratories

Research laboratory not accessory

to school or hospital
Scientific research or teaching

laboratory, non-profit, accessory

to school or hospital subject

to limitations
Animal quarters incidental to

educational or institutional use

Laundries
Hand laundry

Self service; Pick up & delivery
station of laundry or dry cleaner

or 69

58
48

44
43

Building Code
Occupancy Group

D-l, structural, egress, &
fire protection provisions
rel. to building roofs
(Section 415.1.4)

L-2

D-l

H-2

H-l

D-2

—

L-2

L-l

D-2

F-3, Section 419

D-l

D-2

A or D-l depending on natun
of materials involved
D-l

D-2

not applicable

D-2
D-2

A or D-l

D-l

F-4 see Section 419

34 or

D-l

RS2-1

Zoning Code Building Code

Use Item Occupancy Group

Steam laundry, laundries without

limitations 45 D-2

Leather
Curing, dyeing, finishing or

tanning
Product manufacture exclusive of
above
Libraries, non profit
Linoleum or oilcloth manufacture
Liquor sales, package
Luggage manufacture

Lumber (see Wood)
Manufacturing

Depending upon product, processes,

and resulting effects 68,69 or 70 A, D-l or D-2

Manufacturing, assembly or
packaging of products sold on

the lot 81 —

Matches manufacture 70 A

Mattresses manufacture and

renovation 68 A

Meat

Markets 34 or 35 C

Poultry or rabbit slaughtering

or packaging 68 D-l

Slaughtering or packaging 70 D-l

Medical & dental

Offices not accessory to main

use
(see also Laboratories; Orthopedic
and medical appliances; Hospitals)
Meeting halls F-lb, see Section 418

Metals manufacture

Furniture, cabinets, doors,
fencing and like

Products made by stamping or
extrusion

Reduction, refining or smelting
Mobile homes
Monasteries
Motels
Motor freight stations

(see trucking terminals)

Museums

Nonprofit 20 F-3, Section 419

Musical instruments manufacture

Excluding pianos & organs 68 D-2

Including pianos & organs 68 D-l

Newspaper publishing 68 D-l

News stands 34 C

Novelty products manufacture 68 D-l

D-l

or D-2

D-2

—

L-3.

, see Section 425

L-3

L-l.

, see Section 426

Zoning Code

Use Item

Nursing homes

Offices

Building

Agency, real estate, insurance, etc.

Professional (accountant, architect,

attorney, dentist, physician, etc.)

or clinic not accessory to a main

use

Wholesale office, display or sales

space

Oilcloth manufacture

Optical equipment or similar

precision instruments manufacture

Orphanages

Orthopedic or medical appliances

manufacture

Paint, turpentine or varnish

Manufacture

Spraying booths

Paper products manufacture

Parish houses

Park, public

Parking garages

Group 1 (for buses, trucks etc.)

Group 2 (cars)

Private

Accessory for use of occupants.

employees, customers, students,

or visitors

Parking lots

Petroleum or petroleum products

Refining

Storage

Fifteen thousand gallons or less

More than fifteen thousand gallons

Pharmaceutical products manufacture

Photographers studio

Plastics

Products manufacture

Raw, manufacture

Playgrounds

Police Stations

Cells

3.3

Offices

Pool rooms

Post offices

Poultry or rabbit slaughtering

Building Code
Occupancy Group

H-2

E
E

E if storage restricted to samp
A

D-2
L-2

D-1

see Section 412

D-1
F-3, Section 419
not applicable

B-l, Section 415

B-2, Section 415, open Sectiorj

B-2, Section 414

see Section 424

A or B-l
A

A or D-1 depending on nature
of materials involved

see Section 408

F-5

H-l

F-3

, Section
E
D-1

419

RS 2-1

Zoning Code Building Code

Use Item Occupancy Group

Printing

Plant 46 D-l

Printing or newspaper publishing 68 D-l

Prisons & other correctional or

detention institutions 25 H-l

Pumping station or substation,

water or sewage 3 1 D-2

Radio

Sales 34 or 35 C

Studios with audience 48 F-la (scenery) F-lb (no scenery)

Studios without audience 48 E

Railroad

Freight terminal 64 B-l

Passenger station 63 F-3

Recreation

Center, indoor, public 27 F-3 Section 418

Center 1 , outdoor, public 27 F-5

Center for profit (e.g. skating
rink, bowling alley, billiard

parlor) 38 F-3 Section 418

Community center building 29 F-3 Section 418

Private grounds, non profit 28 —

Rectories 21 L-3

Residences

One-family detached 1 L-3

One-family each side of party wall

semi-detached 2 L-3

Attached row house, one family

between party walls 3 L-3

Two-family detached 4 L-3

Semi-detached, not more than two

families each side of party wall 5 L-3

Attached row house, not more than

two families each side of partv

wall 6 L-3

Apartment, apartment hotel (without

accessory uses)
Temporary dwelling structure
Dwelling converted for more

families
Boarding or lodging house
Dormitory accessory to school or

university depending upon lot
Fraternity or sorority
Hotel, motel, apartment hotel with

accessory services 15 L-2

Accessory use in buildings with more

than fifty dwelling units or hotels

with more than fifty sleeping rooms

(e.g. newsstand, barbershop,

dining room, etc. with limitations) 78 L-2

Convents, monasteries, rectories 21 L-3

L-2

L-3

L-2 or L-3

L-l

11,12,

L-2

Zoning Code Building Code

Use Item Occupancy Group

Accessory dwelling for personnel
required to reside on lot for
proper operation of main use 83

Mobile homes —

Research laboratories (see Laboratories)
Restaurant, lunch room, cafeteria or
other establishment primarily
for eating 37

Retail business

Department store, furniture store,

general merchandise mart or other

store serving needs of major

portion of city, with limited

combustible or flammable goods 35

Shop or store primarily serving

local neighborhood, with limited

combustible or flammable goods 34

Stores with combustible or flammable

goods constituting a high hazard 34 or 35

Rubber

Manufacture (natural or synthetic),
including tires, tubes or
similar products 70

Products (exclusive of processing)
including washers, gloves,
footwear, bathing caps and like 68

Salvage storage, outdoor 57

Sanatoriums

Not providing custodial care for
drug addicts, alcoholics or
mentally ill or mentally
deficient
Providing care for above

Scenery construction
Schools

Adult education center
Elementary or secondary
Day nursery, nursery school,

kindergarten
Machine shop or other noisy

activity accessory to school,

college, etc.
Trade or professional
Accessory uses subject to

limitations
(see also Colleges & universities)

Seminaries 16.

Settlement houses

Sewage

Disposal plant

Pumping station

11-13
29

70
31

L-3
L-3, Section 425

F-2, Section 419

C and A

D-l

D-l
not applicable

H-2

H-l

D-l

D-2 and G
G

G, L-2

L-2

D-l
D-2

RS 2-1

Ship or boat building or repair
Boats under one hundred feet long
Boats over one hundred feet long

Shoddy manufacture

Shoes

Manufacture
Repair shop

Silverware, manufacture, plate or
sterling

Size manufacture

Skating rinks

Soaps & detergents

Manufacturing, including fat

rendering
Packaging

Solvent extracting
Sporting or athletic goods

Manufacture

Stores, depending on area served

Stables, accessory use subject to

limitations

(see also: Animals)
Stadiums
Statuary, mannequins, figurines or

religious or church art goods,

exclusive of foundry operations

Storage

Outdoors, new building materials,

equipment, etc.
Outdoors, second-hand building

materials, junk, salvage items
Outdoors or in silos or hoppers of

coal, coke or other solid fuel,

or crushed stone, sand, etc.
Warehouses

Wholesale business including
accessory storage other than
flammable liquids, gases and
explosives, in roofed structures
(see also: Wholesale)

Gases, fifteen thousand gallons or
less of flammable liquids or
ten thousand cu. ft. or less of
gases.

Gases, more than fifteen thousand
gallons of flammable liquids, or
more than ten thousand cu. ft. of
gases.

Stores (see: Retail stores; or
specific items)

Zoning Code
Use Item

Building Code
Occupancy Group

; 68
69
68

D-l
D-l
A

68
43

D-l
D-l

68
68

D-2
D-l

F-3,

Section 419

70
68

A
D-l

68
34 or 35

D-l
C

B-l

F-5,

Section 421

56
56

56 or

57 or 70

D-2

B-l or B-2

A, B-l or B-2 depending on nature
of materials involved

B-l or B-2 depending on nature
of materials involved

A, Section 407

Zoning Code
Use Item

Tailor shops, custom
Tanning (see Leather; Fur)

Taxidermist shops

Telephone exchanges

automatic

Non automatic
Television

Sales 34 or 35

Studios 48

Textiles

Manufacture, including knit goods,
yard goods, thread or cordage;
spinning, weaving, dyeing and
printing
Shoddy, manufacture
Theaters

Tires, manufacture

Tobacco products manufacture

including curing 68

Tools and hardware

Manufacture 68

Sales 34 or 35

Toys

Manufacture 68

Trailer park 54

(see also Mobile homes)

Truck

Repairs 60

Sales, outdoor 51

Sales, indoor 36

Trucking terminals & yards or motor

freight yards 64

Turpentine manufacture 70

Warehouses 56

Waterfreight facilities, including

docks, piers, accessories 65

Water pumping stations 31

Wax products manufacture 68

Wholesale

Office, display or sales space 42

Storage, other than flammable
liquids or gases and explosives,
in roofed structures 54

Storage of coal, coke or other
solid fuel, crushed stone, sand

Building Code
Occupancy Group

F-la with scenery, Section 41i
F-lb no scenery. Section 418
E no audience

D-l

F-la with scenery, Section 418

F-lb no scenery

motion picture, see Section 405

D-l

D-2
C

D-l

D-2

B-l

A, B-l or B-2 depending on m
of materials involved

D-2

E storage restricted to samples

B-l or B-2 depending on natur
of materials involved

or similar materials, gases,
flammable liquids

Zoning Code
Use Item

56 or 57

Building Code
Occupancy Group

RS2-1

Storage outdoors of new building

materials, metals or like
Window shades manufacture

Wood

Distillation
Products manufacture, including
furniture, boxes, crates,
barrels, baskets, pencils and
the like
Pulp or fiber reduction or

processing, including paper mill

operation
Sales, retail
Sawmills
Storage outdoors of new building

materials
Storage outdoors of second hand

building materials
Wool scouring or pulling

Umbrellas, manufacture
Upholstering

Vehicles

Manufacture, children's

including baby carriages, scooters,
wagons, bicycles and like
(see also Automobiles; Parking; Trucks)
Venetian blinds, window shades &
awnings, manufacture 68

A, B-l or B-2 depending on nature
of materials involved

D-l

D-l
D-l
D-l

D-l

A or D-l depending on nature
of materials involved

ARTICLE

GENERAL BUILDING LIMITATIONS

300.0

Scope

309.0

301.0

Fire District Subdivisions

310.0

302.0

General Fire Zone Provisions

311.0

303.0

Restrictions of First Fire
Zone

312.0

304.0

Restrictions of Second Fire
Zone

313.0

305.0

Restrictions Outside Fire
Zones

314.0

306.0

Existing Buildings

315.0

307.0

General Area and Height
Limitations

316.0

308.0

Area Exceptions

RS 3

Unlimited Areas

Height Exceptions

Street Encroachments

Permissible Projections Be-
yond Street lines

Permissible Yard and Court
Encroachments

Special and Temporary Pro-
jections

Awnings and Canopies

Accessibility to Fire Fighting

Reference Standards

SECTION 300.0. SCOPE

The provisions of this article shall control the division of the
City of Boston into fire districts and the general limitations of
height and area of all buildings hereafter erected, and extensions
to existing buildings hereafter altered or enlarged as affected by
the fire and life hazard incident to type of construction, occu-
pancy group, density of development, exterior exposure and
accessibility of buildings and structures to firefighting facilities
and equipment.

300.1. Standards. — The provision of reference standard RS 3
shall be part of this article.

300.2. Definitions. — For definitions to be used in the interpreta-
tion of this article, see section 201.

SECTION 301.0. FIRE DISTRICT SUBDIVISIONS

For the purpose of control of occupancy and construction of
building and structures, there shall be established in the City of
Boston limiting districts designated the first fire zone, the second
fire zone and outside the fire zones.

301.1. First Fire Zone. — The boundaries of the first fire zone
shall be those described in reference standard RS 3-1.

301.2. Second Fire Zone. — The boundaries of the second fire
zone shall be those described in reference standard RS 3-2.

301.3. Outside Fire Zones. — All other areas not included in
First and Second Fire Zones.

SECTION 302.0. GENERAL FIRE ZONE PROVISIONS

302.1. Changes in Zones. — The city council of the City of Boston
may by ordinance from time to time extend either fire zone and
re-establish its boundaries.

302.2. Overlapping Zones. — A building or structure located in
more than one (1) fire zone shall be deemed to be in that one
of the zones which contain the major part of the building area;
and in the event of equal distribution in two (2) or more zones,
the limitations of the most restricted zone shall apply.

302.3. Limitations.

302.3.1. No buildings in those combinations of construction
classes and occupancy groups prohibited by section 221.2 table
2-2, shall neither be erected inside the first and second fire zones
nor shall be moved from outside to inside the fire zones nor
from one lot to another inside the fire zones.

302.3.2. High Hazard Occupancies. — Except as specifically ap-
proved by the building official, all buildings of high hazard use
(occupancy group A) shall be prohibited from location in the
first fire zone. Paint spray, drying rooms and rooms for similar
incidental uses not exceeding one thousand (1000) square feet in
area in industrial buildings shall be permitted when enclosed in
fireresistive construction as specified in article 4 for special uses
and occupancies and when separated by fire divisions of the
required fireresistance specified in this code.

302.3.3. Protected Exteriors. — Within the fire zones, all buildings
of type 2 construction shall have those exterior walls, which are
located within eleven (11) feet of interior lot lines or other
buildings on the same lot constructed of not less than two (2)
hour fireresistance for occupancy group A nor less than three-
quarter (3/4) hour fireresistance for all other occupancies.

302.3.4. No building inside the fire zones may be increased in
area or height to exceed the limitations of section 221.2, table
2-2.

302.4. Deleted.

302.5. Frame Construction. — No building of frame construction
(type 4) shall be erected within the fire districts nor shall such
building or structure be moved from without to within, or from
one (1) lot to another within the fire districts, except as provided

301-303

in sections 303 and 304; and no building of otherwise lawful
construction shall be extended in height or area within the fire
districts by frame construction; except that one- and two-family
frame dwellings may be extended in area by not more than three
hundred (300) square feet and to a height of not more than two
and one-half (2-1/2) stories nor more than thirty-five (35) feet
when permitted by the building official.

302.6. Roof Coverings. — All roof coverings shall be constructed
of Class A, Class B or Class C roofings, complying with the
provisions of article 9.

SECTION 303.0. RESTRICTIONS OF FIRST FIRE ZONE

303.1. General. — All buildings and structures, and all additions
to existing buildings and structures, hereafter erected within the
boundaries of First Fire Zone shall be of fireproof (type 1),
protected noncombustible (type 2-A and 2-B), heavy timber
(type 3-A), or ordinary protected (type 3-B) construction as
defined in article 2 and regulated in section 221.1, table 2-1;
and shall be constructed within the height and area limitations

-of section 221.2, table 2-2; except as herein provided.
Open parking structures may be constructed as permitted under
section 905.2.

303.2. Exemptions.

303.2.1. Fences. — Fences not over six (6) feet high may be
erected of wood or other combustible material.

303.2.2. Storm Enclosures, Bay Windows, Etc. — Storm en-
closures may be erected of frame construction not more than
ten (10) feet in height and not more than three (3) feet wider
than the entrance doors which they serve; provided they do not
project more than six (6) feet beyond the building line.

Bay windows and similar appendages may be constructed of
combustible materials in accordance with the provisions of
section 926.3.2.

303.2.3. Accessory Buildings.

a. Outbuildings and Parking Lot Offices. — Outbuildings and
parking lot offices not more than ten (10) feet in height
and one hundred (100) square feet in area may be erected
of frame (type 4) construction when accessory to one-
or two-family dwellings on the same lot or accessory to
a lot approved for motor vehicle parking, when located
not less than six (6) feet from the lot line or any building.

b. Greenhouses. — Greenhouses may be constructed of com-
bustible materials when accessory to a one- or two-family,
dwelling on the same lot and when located at least 6 ft.
from any lot line or building.

c. Private Garages. — Private garages not more than one
(1) story nor more than fifteen (15) feet in height when
accessory to a one- or two-family dwelling may be
erected of protected frame (type 4- A) construction not
more than seven hundred and fifty (750) square feet in
area, or of frame (type 4-B) construction not more than
five hundred (500) square feet in area, when located not
less than six (6) feet from interior lot lines or any
building.

303.2.4. Temporary Structures. — Temporary structures to be
used in connection with construction work and temporary
reviewing stands, frame-works and tents, as are customarily
used exclusively for outdoor carnivals, lawn parties or like
activities, may be erected in either fire zone and of any type of
construction, subject to the approval of the building official,
and to such conditions and for such time as he may in each
case specify.

303.2.5. Bins, Tanks and Towers. — Coal and material bins,
water towers, tank structures, and trestles may be constructed of
wood planking and timbers of dimensions not less than as
required for type 3A construction when not over thirty-five (35)
feet high and having an exterior separation of at least thirty
(30) feet.

303.2.6. Bulk Storage Buildings and Buildings on Wharves. —
Buildings not over twenty-seven (27) feet high on wharves and
buildings for the storage and handling of coal or grain in bulk
of type 2C, 4A or 4B construction if the exterior thereof is
covered with slate, tin, sheet metal or other equally fireresistive
construction, erected with the approval of the building official
and subject to such conditions as he may in each case specify.

303.2.7. Motor Fuel Service Stations. — Gasoline service stations,
and structures of similar business uses, not including high hazard
uses, may be erected of unprotected noncombustible (type 2-C)
construction within the height and area limits of occupancy group
E of section 221.2, table 2-2 provided they are located not less
than eleven (11) feet from the lot line or any building.

303.2.8. Bus and Passenger Terminals. — Roofs over parking lots,
bus and passenger terminals may be erected one (1) story and

303-304

not over twenty (20) feet in height and not more than eleven
thousand (11,000) square feet in area of noncombustible (type
2-C) construction or of heavy timber mill (type 3-A) construction.

303.2.9. Signs. — Ground signs, wall signs, roof signs, and
temporary signs may be constructed of combustible materials
within the limitations established in article 14.

303.2.10. Store Fronts. — Wood veneers of one (1) inch nominal
thickness or exterior grade plywood not less than three-eighths
(3/8) inch thick or exterior grade particle board not less than
three-eighths (3/8) inch thick may be used on store fronts when
facing public streets; provided the veneer does not exceed one
(1) story in height and is applied to noncombustible backing or
is furred not to exceed one and five eighths (1-5/8) inches and
is firestopped in accordance with sections 877 and 921.2.

SECTION 304.0. RESTRICTIONS OF SECOND FIRE ZONE

304.1. General. — All buildings and structures hereafter erected
within the boundaries of Second Fire Zone shall be fireproof
(type 1), noncombustible (type 2), heavy timber (type 3-A) or
ordinary protected (type 3-B) construction as defined in article 2
and regulated by section 221.1 table 2-1, and shall be constructed
within the height and area limitations of section 221.2 table 2-2;
except that all the variations permitted in the First Fire Zone
shall apply to permissible construction in the Second Fire Zone
with the following additional exceptions:

304.2. Exceptions.

304.2.1. Dwellings. — One- and two-family dwellings (occupancy
group L-3) may be erected or enlarged of protected frame
(type 4- A) construction when not less than three (3) feet from
interior lot lines and of unprotected frame (type 4B) construction
when not less than six (6) feet from interior lot lines within the
height and area limitations of section 221.2 table 2-2 and where
the area of each does not exceed sixty (60) per cent of the area
of the lot on which it is located. The roof of said buildings
shall have roof covering of class a, b or c roofings complying
with the provisions of article 9.

304.2.2. Garages. — Buildings of type 2-C construction may
be erected or enlarged for use as garages in the second fire
zone providing they are equipped with fire windows and are
not within two (2) feet of a lot line or within five (5) feet of a
building of type 4-B construction and the height does not exceed

one (1) story and the area six hundred (600) square feet and
the capacity two (2) cars.

304.2.3. Type 2-C Construction. — Buildings of Type 2-C con-'
struction for other occupancies may be erected providing the
location and the occupancy are approved by the building official.

304.2.4. Boat Houses. — Boat houses not more than two (2)
stories nor more than thirty (30) feet in height nor more than
four thousand (4000) square feet in area may be erected of
frame (type 4-B) construction subject to the approval of the
building official.

304.2.5. Verandas. — Verandas, balconies, entrance porticoes and
similar appurtenant structures on dwellings, not exceeding ten
(10) feet in depth nor projecting more than two (2) feet above
the second story floor beams may be erected of frame (type 4-B)
construction provided they do not extend nearer than five (5)
feet to the lot line. When connected to a similar structure of an
adjoining building, they shall be separated therefrom by walls
of two (2) hour fireresistance.

304.2.6. Exterior Trim. — Wood cornices and half timbering
may be erected on residence (occupancy group L) and business
(occupancy group C, D, and E) buildings.

SECTION 305.0. RESTRICTIONS OUTSIDE FIRE ZONES

Outside the fire zones, all types of construction except as herein
specifically prohibited, or for which special approval is required
in connection with high hazard uses and occupancies in article
4, shall be permitted within the height and area limitations of
section 221.2, table 2-2.

305.1. Lot Line Separation. — In frame construction an exterior
wall erected less than six (6) feet from its adjacent lot line shall
be of three-quarter (3/4) hour fireresistive construction, in-
cluding opening protectives except store fronts; and window and
door openings in one (1) and two (2) family dwellings, but in
no case shall such wall be located less than three (3) feet from
interior lot lines.

SECTION 306.0. EXISTING BUILDINGS

306.1. Alterations.

306.1.1. Limitations. — Nothing in these provisions shall be

deemed to prohibit alterations within the limitations of article

304-307

1 Part II provided no unlawful change of occupancy is involved.

306.1.2. Minor Changes. — Changes, alterations or repairs to the
interior of a building and to the front facing a street or other
public space may be permitted provided such changes in the
opinion of the building official do not increase the size, or the
fire hazard of the building, or endanger the public safety and
are not specifically prohibited by this code.

306.1.3. Existing Projections. — No change or enlargement shall
be made to an existing part of a building now projecting
beyond the street lot line or building line where such is estab-
lished by law, except in conformity to the provisions of section
312 governing new construction.

306.2. Increase in Height and Area. — It shall be unlawful to
increase the height or area of an existing building or structure
unless it is of a type of construction permitted for new buildings
of the increased height and area and occupancy group within
the fire district in which it is located and as regulated by section

221.2, table 2-2.

306.3. Existing Excessive Area. — Any building heretofore law-
fully approved which exceeds the maximum allowable area
specified in section 221.2 table 2-2 may be extended if the
addition is separated from the existing building by a type A
fire division meeting the requirements of article 9 and section

221.1 table 2-1 and the additional area does not exceed the
limits of section 221.2 table 2-2 for the specific occupancy group
and type of construction.

SECTION 307.0. GENERAL AREA AND HEIGHT LIMITA-
TIONS

No building or building section shall be constructed or altered
so as to exceed the area limits and the height limits established
by section 221.2 table 2-2 based on the occupancy group classi-
fication of the building or building section, except as these may
be specifically modified by other provisions of this code, or as
further restricted by the City of Boston Zoning Code.

307.1. Area Limit. — The area limitations specified in section

221.2 table 2-2 shall apply to all buildings fronting on a street
or public space not less than thirty (30) feet in width accessible
to a public street.

307.2. Height Limit. — The height of all buildings and structures
shall be controlled as follows:

307.2.1. The height in feet and number of stories specified in
section 221.2 table 2-2 shall apply to all buildings and to all
separate parts of a building enclosed within lawful fire walls
complying with the provisions of article 9.

307.2.2. Buildings two (2) stories in height when permitted by
section 221.2 table 2-2 may be built to the same area limits
provided in section 221.2 table 2-2 for one (1) story buildings.
In buildings over two (2) stories in height when permitted by
section 221.2 table 2-2, the area limits of section 221.2 table 2-2
for one (1) story buildings shall be reduced for each story of
height over two (2) stories in all occupancy groups as herein
specified:

1-1/2 hour protected noncombustible construction

(Type 2-A) 1/20

All other types of- construction

(Types 2-B, 2-C, 3-A, 3-B, 3-C and 4-A)

3 Story 1/5

Over 3 Story 1/10

307.3. Measurement of Height. — In determining the height of
any part of a building for the purposes of this section, the grade
of the ground from which the height of the building is measured
is defined in section 201.

SECTION 308.0. AREA EXCEPTIONS

The provisions of this section shall modify the area of limits of
section 221.2 table 2-2 as herein specified.

308.1. Street Frontage Increase. — When a building or structure
has more than twenty-five (25) per cent of the building peri-
meter fronting on a street or other accessible unoccupied space
not less than thirty (30) feet in width leading to a street, the
tabular areas may be increased two (2) per cent for each one
(1) per cent of such excess frontage.

308.2. Sprinkler Increase. — When a building of low hazard or
moderate hazard storage, or mercantile, industrial, business,
school or assembly (occupancy group F-4) occupancy group is
equipped with an approved one-source automatic sprinkler sys-
tem, unless such sprinkler system is required by the provisions
herein or of article 4 or article 12 for structures of special use
and occupancy, the tabular areas may be increased by two
hundred (200) per cent for one (1) story buildings and one
hundred (100) per cent for buildings more than one (1) story
in height.

307-309
308.2.1. Area Sprinkler Requirements.

a. A one-source sprinkler system shall be provided on all
floors of mercantile and industrial buildings (occupancy
group C and D) which are more than twenty thousand
(20,000) square feet in area on any floor above or below
the grade floor when of types 1A, IB or 2A construction
or more than ten thousand (10,000) square feet when of
types 2B or 3A construction, or more than seven thou-
sand five hundred (7,500) square feet when of types 2C,
3B and 3C construction and more than six thousand
(6,000) square feet when of type 4A construction. This
provision shall not apply to buildings of one (1) story
without basement.

b. All buildings and structures used for the manufacture,
sale or storage of combustible materials and products
(occupancy groups A and Bl) shall be equipped with an
approved automatic sprinkler system when in excess of
the heights and areas for each construction type as
specified in section 310.2.1.

308.3. Maximum Total Area. — The maximum total area under
the combined provisions of section 308.1 and 308.2 shall not
exceed three and one-half (3-1/2) times the tabular area in
section 221.2 table 2-2.

SECTION 309.0. UNLIMITED AREAS

309.1. One-Story Buildings. — In other than frame construction,
the area of all buildings of assembly (occupancy group F-3),
business, industrial, mercantile and storage occupancy groups not
including high hazard uses, which do not exceed one (1) story
or eighty-five (85) feet in height shall not be limited outside
the fire limits; provided the exitway facilities comply with
the provisions of section 604, an automatic sprinkler system is
provided complying with the provisions of section 1213.1 and
the building is isolated as specified in section 309.2, except that
a sprinkler system shall not be required for buildings of type 2
or type 3A construction used exclusively for storage of non-
combustible materials not packed or crated in combustible
materials or as exempt by section 206.3 for special industrial
uses.

309.1.1. School Buildings. — Outside the fire zones one-story
school buildings of type 2, 3A and 3B construction may be

unlimited in area when a direct exitway to the outside of the
building is provided from each classroom and the building is
equipped with an approved automatic sprinkler system through-
out. A fire separation shall be provided on all sides of such
buildings as specified in section 309.2.

309.2. Fire Separation Distance. — The minimum fire separation
distance on all sides of one-story buildings of unlimited area
shall be determined by the type of construction as herein
specified:

Fireproof construction (types 1A and IB) 30 feet

Noncombustible, 1-1/2 hour protected (type 2A) . . .30 feet

Noncombustible, 3/4 hour protected (type 2B) 40 feet

Noncombustible, unprotected (type 2C) 50 feet

Exterior masonry, heavy timber (type 3A) 40 feet

Exterior masonry, protected ordinary (type 3B) ... .40 feet
Exterior masonry, unprotected ordinary (type 3C). . .50 feet

SECTION 310.0. HEIGHT EXCEPTIONS

310.1. Roof Structures. — In applying the provision of this code
governing height limits, the following appurtenant structures
shall not be included in the height of the building unless the
aggregate area of such structures including penthouses exceeds
thirty-three and one-third (33-1/3) per cent of the area of the
roof of the building upon which they are erected.

a. Roof tanks and their supports.

b. Ventilating, air conditioning, and similar building service
equipment.

c. Roof structures, bulkheads, and penthouses.

d. Chimneys.

e. Parapet walls four (4) feet or less in height.

f. Flag poles and weather vanes.

310.2. Automatic Sprinklers. — Except in buildings where auto-
matic sprinkler equipment is a requirement herein or of article
4 or article 12 for special uses or occupancies, all structures of
fireproof (type 1), noncombustible (type 2), and exterior masonry
wall (type 3) construction designed for business, industrial,
mercantile, low or moderate hazard storage uses may be erected
one (1) story or twenty (20) feet higher than specified in section
221.2 table 2-2 when equipped with an approved one-source
automatic sprinkler system.

310.2.1. Sprinkler Height and Area Requirements. — All buildings

309-311

and structures used for the manufacture, sale or storage of com-
bustible materials and products (occupancy groups A and B-l)
shall be equipped with an approved automatic sprinkler system
when more than three (3) stories or forty (40) feet in height and
more than ten thousand (10,000) square feet in area of fireproof
(type 1A or 1-B) construction; when more than three (3) stories
or forty (40) feet in height and seven thousand five hundred
(7,500) square feet in area of non-combustible (type 2-A) con-
struction; when more than two (2) stories or thirty (30) feet
in height and six thousand (6,000) square feet in area of pro-
tected noncombustible (type 2-B) or heavy mill (type 3-A)
construction; when more than one (1) story in height and three
thousand (3,000) square feet in area of ordinary (type 3-C) or
protected frame (type 4-A) construction; and in every usable or
occupiable cellar or story with ceiling located less than six (6)
feet above grade and more than three thousand (3000) square
feet in area.

SECTION 311.0. STREET ENCROACHMENTS

Except as herein provided, and subject to approval of the
Public Improvements Commission and Public Works Department
as required, no part of any building hereafter erected and no
additions to an existing building heretofore erected shall project
beyond the street lines or beyond the building line when such
line is established by the zoning law or any other statute con-
trolling building construction.

311.1. Projections Below Grade. — Subject to the provisions of
this section the following projections may be constructed below
grade to project beyond the street line:

311.1.1. Footings. — Exterior wall and column footings maybe
constructed to go beyond the street line not more than twelve
(12) inches provided that the top of the footing is not less than
eight (8) feet below the ground or sidewalk level.

311.1.2. Foundation Walls. — Foundation walls required to sup-
port permitted projections may be constructed to project not
more than the permitted projection beyond the street line.

311.1.3. Vaults. — Where permitted approved vaults may be
constructed to project beyond the street line but not beyond the
curb line. Vault covers shall be set flush with the sidewalk
and surfaced with non-skid material.

311.1.4. Tunnels Between Buildings. — Tunnels connecting build-
ings, and projecting beyond street lines, may be constructed
subject to the approval of the building official. Such tunnels shall |
comply with the provisions of this code and other applicable
laws and regulations.

311.1.5. Areaways. — Areaways shall not project beyond the I
street lot line more than four (4) feet; provided that every such .
areaway shall be covered over at the street grade by an ap- I
proved grating of metal or other noncombustible material.

311.2. Projections Above Grade. — All projections hereafter
permitted beyond the street lot line or the building line above
grade shall be so constructed as to conform to the provisions

of sections 311.4 and 312.

311.3. Projections Necessary for Safety. — In any specific ap-
plication, the building official may designate by approved rules
such architectural features and accessories which are deemed
desirable or necessary for the safety of the public and the
extent to which they may project beyond the street lot line or
the building line where such is established by statute, subject
to all provisions and restrictions that may be otherwise pre-
scribed by law, ordinance or rule of the authorities having
jurisdiction over streets or public spaces.

311.4. Permission Revocable. — Any permission, expressed or
implied, permitting the construction of projections within the
area of the street under the provisions of this article shall be
revocable by the City of Boston Council, except footings as
permitted under section 311.1.1.

311.4.1. All projections permitted beyond the street line by the
provisions of this article shall be constructed so that they may
be removed at any time without endangering the structural safety
or fire safety of the building except that footings as permitted
under section 311.1.1 need not be removable.

311.5. Existing Projections. — Any part of a building that pro-
jects beyond a street line on the date of the adoption of this
code may be maintained as constructed until its removal is
directed by the mayor and city council.

311.5.1. Alterations. — Approved alterations to existing projec-
tions beyond the street line may be permitted in whole or in
part, provided that such alterations conform with the require-
ments of this section.

311-312

SECTION 312.0. PERMISSIBLE PROJECTIONS BEYOND
STREET LINES

Subject to such provisions as may be otherwise prescribed by
law or ordinance, or by rule or regulation of a City of Boston
authority having jurisdiction over streets, highways, and pub-
lic spaces, and subject to approval of the Public Improvements
Commission and Public Works Department as required, the
following projections shall be permitted beyond the street lot line
;or the building line, as the case may be.

312.1. Fixed Projections. — Fixed projections are those elements
listed below, generally of an architectural character, that form
an integral part of the building facade. The aggregate area of
all fixed projections constructed to extend beyond the street line
shall not exceed ten (10) square feet within any one hundred
(100) square feet of wall area, except that a veneer may be ap-
plied to the entire facade of a building erected before the
effective date of this code, if such veneer does not project more
than four (4) inches beyond the street line. The area of any
fixed projection shall be measured at that vertical plane, para-
llel to the wall, in which the area of the projection is greatest.
This plane of measurement may be at the street line, the line of
maximum projection, or any point in between.

312.1.1. Entrance Details. — Entrance details, including steps,
and doors when fully open, may be constructed to project be-
yond the street line not more than twelve (12) inches. Entrance
steps that project beyond the street line shall be guarded at each
end by railings or cheek pieces at least three (3) ft. high or by
other members of the entrance detail providing equivalent pro-
tection.

312.1.2. Architectural Details. — Details such as cornices, eaves,
bases, sills, headers, belt course, opening frames, sun control
devices, rustications, applied ornament or sculpture, grilles,
windows when full open, air conditioning units, and other
similar elements may be constructed to project not more than
four (4) in. beyond the street line when less than ten (10) ft.
above the ground or sidewalk level, and not more than ten (10)
in. beyond the street line when more than ten (10) ft. above
the ground or sidewalk level.

312.1.3. Balconies. — Balconies, including railings and supporting
brackets, no parts of which are less than ten (10) ft. above the
ground or sidewalk level, may be constructed to project not more

than twenty-two (22) in. beyond the street line. When permitted
by article 6 and subject to approval of the building official,
fire escapes that are part of a required exitway may be con-
structed to project not more than four (4) ft. six (6) in. beyond
the street line provided no part, including any movable ladder oi
stair, is lower than ten (10) ft. above the ground or sidewalk
level when not in use.

312.1.4. Cornices or Roof Eaves. — Main cornices or roof eaves
located at least twelve (12) feet above the curb level shall pro-
ject not more than three (3) feet.

312.1.5. Oriel Windows. — Oriel windows with the lowest portion
at least ten (10) feet above the curb level shall project not more
than two and one-half (2-1/2) feet.

312.1.6. Marquees. — For the purpose of this section a marquee
shall include any object or decoration attached to or a part of
said marquee.

a. Marquees may be erected on public buildings, theaters,
hotels, terminals, large department stores, supermarkets,'
multi-family dwellings, and similar buildings of an es-
sentially public nature.

b. Projection and Clearance. — The horizontal clearance be-
tween a marquee and the curb line shall be not less than
two (2) feet. A marquee projecting more than two-thirds
(2/3) of the distance from the property line to the curb
line shall be not less than ten (10) feet above the ground
or pavement below.

c. Thickness. — The maximum height or thickness of a
marquee measured vertically from its lowest to its highest
point shall not exceed three (3) feet when the marquee
projects more than two-thirds (2/3) of the distance from
the property line to the curb line and shall not exceed
nine (9) feet when the marquee is less than two-thirds
(2/3) of the distance from the property line to the curb
line.

d. Roof Construction. — The roof or any part thereof may
be a skylight of approved plastics, or wired glass not
less than one-fourth (1/4) inch thick with no single
pane more than eighteen (18) inches wide. Every roof and
skylight of a marquee shall be sloped to downspouts
which shall conduct any drainage from the marquee in a
manner not to spill over the sidewalk.

e. Construction. — A marquee shall be supported entirely

312

from the building and constructed of noncombustible
material. Marquees shall be designed and constructed to
withstand wind or other lateral loads and live loads as
required in article 7 of this code. Structural members
shall be protected to prevent deterioration as required
by article 8.
f. Location Prohibited. — Every marquee shall be so located
as not to interfere with the operation of any exterior
standpipe or to obstruct the clear passage of stairways
or exitways from the building or the installation or
maintenance of street lighting.

312.1.7. Light Fixtures. — Light fixtures that are supported
entirely from the building may be constructed to project not
more than two (2) ft. beyond the street line, provided no part

i of the fixture is less than eight (8) ft. above the ground or
sidewalk level.

312.1.8. Flagpoles. — Flagpoles that are supported entirely from
the building may be constructed to project not more than
eighteen (18) ft. beyond the street line, but not closer than two
(2) ft. to the curb line, provided that no part of the flagpole
is less than fifteen (15) ft. above the ground or sidewalk level.

312.1.9. Signs.

a. Wall signs may be constructed to project not more than
twelve (12) in. beyond the street line when conforming
to the requirements of article 14.

b. Projecting signs may be constructed to project not more
than ten (10) ft. beyond the street line, but notcloser
than two (2) ft. to the curb line, when conforming to
the requirements of article 14, and provided that no part
of the sign is less than ten (10) ft. above the ground
or sidewalk level.

312.2. Awnings. — Awnings supported entirely from the building
may be constructed to project beyond the street line as follows:

312.2.1. Store Front Awnings. — Store front awnings may be
constructed to project beyond the street line not more than
eight (8) ft., provided no part of the awning is less than eight
(8) ft. above the ground or sidewalk level, except for a flexible
valance, which may be not less than seven (7) ft. above the
ground or sidewalk level, and provided that the awning box or
cover does not project more than twelve (12) in. They shall be
equipped with a mechanism or device for raising and holding

the awning in a retracted or closed position against the face of
the building.

312.2.2. Drop Awnings. — Awnings over windows or doors may
be constructed to project beyond the street line not more than
five (5) feet provided that no part of the awning is less than
eight (8) feet above the ground or sidewalk level.

312.2.3. Construction. — Subject to the provisions of section 315,
awnings shall be constructed of a noncombustible frame covered
with flameproofed canvas or cloth, slow-burning plastic, sheet
metal, or other equivalent material.

SECTION 313.0. PERMISSIBLE YARD AND COURT EN-
CROACHMENTS

No part of any building or structure shall extend into side
courts, inner courts or yards required for light and ventilation
of habitable and occupiable rooms by the provisions of article 5, |
or of the zoning law or other statutes controlling building
construction, except as hereinafter provided; but in no case shall
the encroachment exceed twenty (20) per cent of the legal area j
of yard or court required for light and ventilation purposes.

313.1. Roof eaves may project not more than three (3) feet
beyond the face of the walls or other vertical planes forming
the bounds of the minimum required legal yard or court area.

313.2. Steps and Architectural Features. — Steps, window sills,
belt courses and similar architectural features, rain leaders and
chimneys may project not more than two (2) feet beyond the
face of the walls or other vertical planes forming the bounds of
the minimum required legal yard or court area.

313.3. Exterior Stairways and Fire Escapes. — Outside stairways,
fire tower balconies, fire escapes or other required means of
egress may project not more than four (4) feet beyond the face
of the walls or other vertical planes forming the bounds of the
minimum required legal yard or court area.

SECTION 314.0. SPECIAL AND TEMPORARY PROJECTION

Special and temporary projections shall be subject to the ap-
proval of the Public Improvements Commission and Public
Works Department as required and the provisions of this
section.

312-315

314.1. Alley Projections. — The permissible projections beyond
street lot lines shall apply in general to building projections into
alleyways except as may be modified by the building official,
ordinance, or by special deed restriction.

314.2. Special Permits. — When authorized by special permit,
vestibules and storm doors may be erected for periods of time
not exceeding seven (7) months in any one year, and shall pro-
ject not more than three (3) feet nor more than one-fourth
(1/4) the width of the sidewalk beyond the street lot line.
Temporary entrance awnings may be erected with a minimum
clearance of seven (7) feet to the lowest portions of the hood or
awning when supported on removable steel or other approved
noncombustible supports.

SECTION 315.0. AWNINGS AND CANOPIES

Awnings and canopies shall be subject to the approval of the
Public Improvements Commission and Public Works Department
as required and the provisions of this section.

315.1. Permit. — A permit shall be obtained from the building
official for the erection, repair or replacement of any fixed
awning, canopy or hood except as provided in section 315.1.1,
and for any retractable awning located at the first story level
and extending over the public street or over any portion of a
court or yard beside a building serving as a passage from a
required exitway to a public street.

315.1.1. Exemption from Permit. — No permit shall be required
for the erection, repair or replacement of fixed or retractable
awnings installed on one- and two-family dwellings, unless they
project over public property, or for retractable awnings installed
above the first story or when the awning does not project over
the public street or over any court or yard serving as a passage
from a required exitway to a public street.

315.2. Special Applications of Awnings. — Except as may be
limited by section 312.2, fixed awnings supported in whole or
part by members resting on the ground and used for patio
covers, car ports, summer houses or other similar uses shall
comply with the requirements of section 315.4 for design and
structure. Such structures shall be braced as required to provide
rigidity.

315.3. Canopies. — Canopies shall be constructed of a metal
framework, with an approved covering, attached to the building

at the inner end and supported at the outer end by not more
than two (2) stanchions with braces anchored in an approved
manner and placed not less than two (2) feet in from the curb
line. The horizontal portion of the framework shall be not less
than eight (8) feet nor more than twelve (12) feet above the'
sidewalk and the clearance between the covering or valance anc
the sidewalk shall be not less than seven (7) feet. The width ol
canopies shall not exceed eight (8) feet.

315.4. Design and Construction. — Fixed awnings, canopies and*
similar structures shall be designed and constructed to withstand
wind or other lateral loads and live loads as required by article
7 of this code. With due allowance for shape, open construction
and similar features that relieve the pressures or loads. Structural
members shall be protected to prevent deterioration.

SECTION 316.0. ACCESSIBILITY TO FIRE FIGHTING

316.1. Frontage. — Every building, exclusive of accessory build-
ings, shall have at least eight (8) percent of the total perimeter
of the building fronting directly upon a street or frontage
space. For the purposes of this section, building perimeter shall
be measured at that story having the maximum enclosed floor
area.

316.2. Building Access. — Provisions shall be made for access
by the fire department to every building as follows:

316.2.1. Above Grade. — Access shall be provided directly from
the outdoors to each story below a height of 100 ft. except to
the first story or ground floor, by at least one (1) window or
readily identifiable access panel within each fifty (50) feet or
fraction thereof of horizontal length of every wall that fronts on
a street or frontage space. Windows shall be openable or break-
able from both the inside and the outside, and shall have a
height when open of at least forty-eight (48) inches and a width
of at least thirty-six (36) inches. Panels shall be openable from
both the inside and outside and shall have a height when open
of forty-eight (48) inches and a width of at least thirty-two (32)
inches. The sill of the window or panel shall not be higher than
thirty-six (36) inches above the inside floor.

316.2.2. Below Grade. — Access shall be provided directly from
the outdoors to the first basement or cellar story below grade,
except in one- and two-family dwellings, within each one
hundred (100) feet or fraction thereof of horizontal length of

315-316

every wall that fronts on a street or frontage space. Such access
shall be by stairs, doors, windows or other means that provide
an opening forty-eight (48) inches high and thirty-two (32) inches
wide, the sill of which shall not be higher than thirty-six (36)
inches above the inside floor. If an areaway is used to provide
below grade access, the minimum horizontal dimension shall be
at least one-third (1/3) the depth of the areaway or six (6)
feet whichever is less.

a. Access to additional stories below grade is not mandatory

since they are required to be sprinklered as provided in

section 1213.

316.2.3. Signs. — Where wall signs are erected to cover doors or
windows of existing buildings, access panels shall be provided
as necessary to comply with the requirements of sections 316.2.1.
and 316.2.2 above.

316.2.4. Location. — Wherever practicable, one access opening
in each story shall provide access to a stairway, or where there
is no stairway at the exterior wall, one access opening in each
story shall be located as close as practicable to a stairway.

316.2.5. Exemptions. — The provisions of 316.2.1 through 3 16.2.4
above shall not apply to any story that is completely protected
by an automatic sprinkler system conforming to the construction
requirements of article 12.

RS3

List of Reference Standards

First and Second Fire Zones

RS 3-1 FIRST FIRE ZONE

All that portion of the city which is included within a
line beginning at the intersection of the centre lines of
Dover and Albany streets, and thence running east
through the centre of said Dover street to the harbor
commissioners' line; thence by said harbor commis-
sioners' line around the northerly portion of the city
to a point on Charles River at the intersection of said
line with the easterly line of St. Mary's street extended;
thence along said easterly line of St. Mary's street
and the boundary line between Brookline and Boston
to the centre of Longwood avenue; thence through
the centre of said avenue to the centre of St. Alphonsus
street; thence through the centre of said street to the
centre of Ward street; thence through the centre of
said Ward street to the centre of Parker street; thence
through the centre of said Parker street to the centre
of Ruggles street; thence through the centre of said
Ruggles street to the centre of Washington street;
thence through the center of said Washington street
to a point opposite the centre of Palmer street; thence
through the centre of said Palmer street and through
the centre of Eustis street to the centre of Hampden
street; and thence through the centre of said Hampden
street and the centre of Albany street to the point
of beginning.

RS 3-2 SECOND FIRE ZONE

All that portion of the city which is included within a
line beginning at the intersection of the boundary
lines between the City of Boston and the cities of
Somerville and Everett; thence by the boundary lines
between the City of Boston and the cities of Everett
and Chelsea to the intersection with the centre line

of Trumbull street extended northerly; thence by said
centre line of Trumbull street extended, the centre line
of Trumbull street and said centre line extended south-
erly to the harbor line; thence by said harbor line
to its intersection with the easterly line of Pier No. 5,
belonging to the Boston and Albany Railroad Company;
thence by a straight line across Boston Harbor to its
intersection with the harbor line at the easterly corner
of Pier No. 1 in South Boston; thence by the harbor
line in the northerly, easterly and southerly portions
of South Boston to an angle in said harbor line nearly
opposite the intersection of the centre line of Columbia
road with the centre line of location of the Old Colony
Railroad; thence by a straight line to the said inter-
section; and by the centre lines of Columbia road,
Blue Hill avenue, Seaver street, Columbus avenue,
Atherton and Mozart streets, Chestnut avenue, Sheri-
dan, Centre and Perkins streets, South Huntington
avenue, Castleton street and the centre line of said
Castleton street extended to the boundary line between
the City of Boston and the town of Brookline; thence
by said boundary line to a point therein one hundred
feet southwest of Washington street in the Brighton
district; thence by a line parallel to and one hundred
feet southwesterly from the centre line of Washington
street to an angle formed by the intersection of said
line with the extension of a line parallel to and one
hundred feet northwesterly of the centre line of Market
street; thence by said extension and said line parallel
to and one hundred feet northwesterly of the centre
line of Market street to a point one hundred feet
south of the centre line of Western avenue; thence
by a line parallel to and one hundred feet south of
the centre line of Western avenue and said line ex-
tended to a point in the boundary line between the
City of Boston and the town of Watertown south of
Watertown Bridge, so called; thence by said boundary
line and the boundary lines between the Cities of
Cambridge and Somerville to the point of beginning,
but not including area within the boundaries of the
first fire zone.

Also those portions of Hyde Park upon or within

RS3

one hundred feet of the following named streets and
squares: Everett square, so called; Fairmount avenue
from River street to the Neponset river; River street
from the location of the Boston and Providence Rail-
road to Winthrop street; Hyde Park avenue on the
easterly side from the northerly side of Oak street to
Everett street; Hyde Park avenue on the westerly side
from the northerly side of Pine street extension, so
called, to a point on said Hyde Park avenue opposite
the southerly line of Everett street; Harvard avenue
from River street to Winthrop street; Maple street
from River street to a point one hundred and eighty
feet southerly therefrom; Central avenue from River
street to Winthrop street; Davison street from Fair-
mount avenue to a point three hundred feet north-
easterly therefrom; Grove street; Pierce street from
Fairmount avenue to a point three hundred feet north-
easterly therefrom; Knott street from Fairmount avenue
to a point three hundred feet easterly therefrom; Rail-
road avenue from Fairmount avenue to a point three
hundred feet northeasterly therefrom; Station street
from the Neponset river to a point three hundred
feet northeasterly from Fairmount avenue; Walnut
street from Fairmount avenue to a point three hundred
feet southwesterly therefrom; Maple street from Fair-
mount avenue to a point one hundred and twenty-five
feet westerly therefrom.

ARTICLE
SPECIAL USE AND OCCUPANCY REQUIREMENTS

400.0

401.0

402.0

403.0

404.0 —

405.0

406.0

407.0

408.0

409.0

410.0

411.0

412.0

413.0
414.0
415.0
416.0

417.0
418.0

TABLES

Scope
Definitions
Explosion Hazards
Volatile Flammables

Omitted

Existing Buildings

Liquified Petroleum Gases

Pyroxylin Plastics

Use and Storage of Motion
Picture Film

Use and Storage of Com-
bustible Fibers

Combustible Dusts, Grain
Processing and Storage

Paint Spraying and Spray
Booths

Dry Cleaning Establishments

Private Garages

Public Garages

Motor Fuel Service Stations

Motor Vehicle Repair Shops

Places of Public Assembly

419.0 Public Assembly Other than

Occupancy Group F-l

420.0 —

421.0

Omitted

422.0

Drive-In Motion Picture The-

atres

423.0

Omitted

424.0

Parking Lots

425.0 —

428.0

Omitted

429.0

Swimming Pools

430.0

Open Parking Structures

431.0

Deleted

432.0

Inter-Communicating Floor

Levels

433.0

Covered Malls, Covered

Walkways and Tunnels

434.0

Radioactive Materials and

Radiation-Producing

Equipment

RS 4

Reference Standards

403.2.1.1. 4-1 Capacity of Outside Underground Tanks for Volatile Flammable

Liquids
408.4.2. 4-2 Exposure Distance for Pyroxylin
418.3.4.1. 4-3 Wheelchair Viewing Positions
430.4.1. 4-4 Height and Area Limitation for Open Parking Structures

SECTION 400.0. SCOPE

In addition to the general requirements of this Code governing
the location, construction and equipment of all buildings and
structures and the fireresistive, height and area limitations of
section 221.1, table 2-1 and section 221.2, table 2-2, the pro-
visions of this article shall control all buildings and structures
designed for high hazard uses and occupancies which involve
extreme fire, smoke, explosion or toxic gas risks, and places of
assembly in which people congregate in large numbers and which
are susceptible to panic incidental to crowds. Except as herein
specifically provided, reference standard RS 4 shall be deemed
to comply with the requirements of this article.

Chemical plants, packing plants, grain elevators, refineries, flour
mills, and other special structures may be constructed in ac-
cordance with the recognized practices and requirements of the
specific industry. The building official may permit such varia-
tions from the requirements of this code which will secure
reasonable and economical construction with the necessary fire,
life and property safeguards. In granting such variations, due
regard shall be given to the isolation of the structure and fire
hazard from and to surrounding property.

400.1. Occupancies Involving Explosion Hazards. — The provi-
sions of this article shall apply to all occupancies involving the]
storage, manufacture, handling or filling of flammable and
volatile solids, liquids or gases which generate combustible and
explosive air-vapor mixtures and toxic gases including nitro-
cellulose film; pyroxylin plastics; grain and other combustible
dusts and pulverized fuels; combustible fibers; pyroxylin lacquer
spraying operations; liquified petroleum gases; alcohol, ether
and gasoline; flammable dusts and residues resulting from fab-
rication, grinding and buffing operations, and all other explosion
hazard risks.

400.2. Special High Hazards. — When necessary to resist a higher
degree of fire severity than specified herein, for high concen-
trations of combustible contents and for buildings of high
hazard occupancies which exceed five (5) stories or sixty-five (65)
feet in height, the building official may exceed the requirements
of section 221.1 table 2-1 governing the fireresistance ratings
of types of construction and protection of structural elements.

400.3. Exitway Facilities. — The exitway facilities of buildings
for hazardous uses and occupancies shall conform to the re-
quirements of article 6, except as may be modified by more
restrictive provisions of this article for specific uses.

400.4. Heating and Venting. — The requirements herein pre-
scribed for the installation of heating and venting appliances
and equipment for high hazard uses and occupancies shall be
construed as supplemental to the provisions of article 5, 10,
11 and 18.

400.5. Light and Electric Wiring. — Wherever flash fires and
explosion hazards are involved, all artificial lighting shall be
restricted to incandescent electric lights or other approved
lighting with keyless sockets and dust-tight, vapor-proof gloves
protected against mechanical injury. All wiring in vaults or com-
partments for the storage of highly flammable materials shall

400-402

be in metal or other approved conduit complying with the pro-
visions of article 15.

400.6. Boiler and Hazardous Equipment Room. — Boilers and
other equipment or devices, including breechings which involve
flame or spark producing apparatus shall not be exposed to fire
or explosive-hazard gases, vapors or volatile flammable liquids.
Such rooms and equipment shall be segregated by construction
of not less than two (2) hour fireresistance except as may be
required for specific occupancies without openings in the en-
closure walls and with means of direct entrance and egress from
the exterior, or such equipment shall be located in accessory
structures segregated from the main building.

400.7. Fire-Fighting and Extinguishing Equipment. — All build-
ings designed for specific hazardous occupancies shall be pro-
tected with approved automatic sprinkler systems or such other
fire-extinguishing and auxiliary equipment as herein provided
and in accordance with the requirements of article 12.

400.8. Segregation of Storage Spaces. — All rooms and spaces
used for the storage of volatile and flammable materials shall
be separately enclosed and segregated with fireresistive construc-
tion as herein required for specific occupancies.

400.9. Restricted Locations. — Except as otherwise specifically
provided in section 302.3, no high hazard occupancies shall be
located in the First Fire Zone, nor in a building of unprotected
frame (type 4-B) construction, nor in any case within two
hundred (200) feet of the nearest wall of a building classified
in a public assembly, school or institutional occupancy group.

SECTION 401.0. DEFINITIONS

For definitions to be used in the interpretation of this article,
see section 201.0.

SECTION 402.0. EXPLOSION HAZARDS

Every structure, room or space with occupancies involving ex-
plosion hazards shall be equipped and vented with explosion
relief systems and devices arranged for automatic release under
predetermined increase in pressure as herein provided for specific
occupancies or in accordance with reference standard RS4-1.
402.1. Venting Devices. — Venting devices to relieve the pressure
resulting from explosive air-vapor mixtures shall consist of
windows, skylights, vent flues or releasing roof or wall panels

which discharge directly to the open air or to a public place oil
other unoccupied space not less than twenty (20) feet in width
on the same lot. Such releasing devices shall be so located that
the discharge end shall be not less than ten (10) feet vertically
and twenty (20) feet horizontally from window openings or ex-
terior exitway stairs or balconies in the same or adjoining build-
ings or structures. The exhaust shall always be in the direction
of least exposure and never into the interior of the building.

402.2. Area of Vents. — The aggregate clear vent relief area shall
be regulated by the type of construction of the building andl
shall be not less than herein prescribed:

Heavy reinforced concrete frame 1 square foot for 80

cubic feet of volume

Light structural steel frame and ordinary

construction 1 square foot for 65

cubic feet of volume

Light wood frame construction 1 square foot for 50

cubic feet of volume

In no case shall the combined area of open windows, pivoted
sash or wall panels arranged to open under internal pressure be
less than ten (10) per cent of the area of the enclosure walls,
with not less than fifty (50) per cent of the opening arranged
for automatic release.

402.3. Construction of Vents. — All explosion relief devices shall
be of an approved type constructed of light weight, noncom-
bustible and corrosion-resistive materials, and the discharge end
shall be protected with approved screens of not more than three-
quarter (3/4) inch mesh, arranged to blow out under relatively
low pressures.

SECTION 403.0. VOLATILE FLAMMABLES

403.1. Process Storage.

403.1.1. Construction of Enclosures. — Process rooms shall be
separated from other uses and occupancies by walls, floors, and
ceilings of not less than two (2) hour fireresistance with one and
one-half (1-1/2) hour fire doors or the approved labeled equiv-
alent complying with article 9. The interior door openings shall
be provided with noncombustible sills not less than six (6) inches
high and the room shall be vented as required in section 402.

402-403

Floors shall be liquid tight and drained to comply with
section 874.

403.1.2. Fire Protection. — First aid fire appliances and auto-
matic sprinklers or other extinguishing equipment shall be
provided in accordance with article 12 and reference standard
RS4-24. Provisions shall be made to prevent leaking flammable
vapors from being exposed to open flames, fire or sparks.
403.2. Main Storage. — Main storage systems of volatile flam-
mable liquids shall be constructed and installed in accordance
with applicable portions of reference standards RS4-2 and
RS4-3. Such storage may be either outside underground, outside
aboveground, inside underground, or outside storage house. No
bulk storage tank shall be located less than three hundred (300)
feet from any building of assembly (occupancy group F), school
(occupancy group G) or institutional (occupancy group H)
occupancies.

403.2.1. Outside Underground System. — Outside tanks shall be
buried underground below the basement level of adjacent build-
ings, with the top of the tanks not less than two (2) feet below
grade or with a reinforced concrete or other approved struc-
tural cover not less than four (4) inches thick and a twelve (12)
inch earth cover. The maximum capacity of such tanks shall De-
limited by their location in respect to adjacent buildings which
are not an essential part of the installation and adjacent lot
lines as provided in section 403.2.1.1., table 4-1.
403.2.1.1. Table 4-1. Capacity of Outside Underground Tanks
for Volatile Flammable Liquids

Fire Separation Quantity of Storage

in Feet in Gallons

50 Unlimited

40 50,000

30 20,000

25 12,000

20 6,000

10 3,000

a. When within ten (10) feet of any building not an essen-
tial part of the installation, and the top of the tank is
above the lowest floor of the building, the capacity of
the tank shall be not more than five hundred and fifty
(550) gallons/

b. The capacity of storage of combustible liquids other than
volatile flammable as herein defined shall be restricted
to five (5) times the values specified in section 403.2.1.1.
table 4-1.

403.2.2. Outside Aboveground System. — Aboveground tanks
shall be located only outside the First Fire Zone; and the capa-
city, location, construction and exposures shall be subject to
special approvals of the building official and the fire official;
but in no case shall the fire separation be less than specified in
reference standard RS4-2.

403.2.3. Inside Underground System. — Inside underground tanks
shall be located not less than two (2) feet below the level of the
lowest floor of the building in which located or any other
building within a radius often (10) feet of the tank. In no case
shall such tanks be located under the sidewalk or beyond the
building line. It shall be unlawful to cover any tanks from sight
until after inspection and test and written approval of the build-
ing official and fire department. The maximum limit of indi-
vidual tank capacity shall be not more than five hundred and
fifty (550) gallons and the entire system shall be subject to
special approval of the building official and fire department.

403.2.4. Outside Storage House. — All outside storage houses
shall be constructed of noncombustible (types 1 or 2) construc-
tion. No opening shall be permitted in the enclosure walls with-
in eleven (11) feet of adjoining property lines or with a fire ex-
posure of less than eleven (11) feet from any building or struc-
ture not a part of the installation.

403.2.5. Special Restrictions. — The building official may re-
quire greater fire separations or he may limit storage capacities
under severe exposure hazard conditions when necessary for
public safety.

403.3. Accessory Occupancy. — A one-source sprinkler system
shall be provided in all portions of residential (occupancy groups
L-l and L-2) institutional (occupancy groups H-l and H-2) and
assembly and school buildings (occupancy groups F and G)
occupied for storage or workshop purposes which involve highly
combustible and flammable materials.

SECTION 404.0. OMITTED
SECTION 405.0. OMITTEE

403-406
SECTION 406.0. EXISTING BUILDINGS

406.1. Special Permit for Existing Occupancies. — Any existing
hazardous occupancy which was heretofore authorized by a per-
mit issued under the provisions of law or the regulations of
the fire and building officials may be continued by special per-
mit provided the continuance of such occupancy does not en-
danger the public safety.

406.2. Existing Occupancy Prohibited. — No existing building of
frame (type 4) construction which is more than two (2) stories
in height or more than five thousand (5,000) square feet in
area; or of nonfireproof (type 3) construction which is more
than four (4) stories in height shall be continued in use or here-
after occupied for the manufacture of pyroxylin plastics or
similar materials of high fire hazard and explosive characteristics.

406.3. Places of Assembly.

406.3.1. Change of Occupancy. — No existing building or struc-
ture or part thereof shall be altered or converted into a place
of assembly unless it complies with all provisions of this code
applicable to places of public assembly hereafter erected.

406.3.2. Existing Occupancy Altered. — When an existing build-
ing or structure heretofore used as a place of public assembly
is altered and the cost of such alteration is more than fifty
(50) per cent of the physical value of the building as defined
in article 1 Part II, all provisions of this code relating to new
places of public assembly shall be complied with. When the
cost of such alteration is less than fifty (50) per cent of the
physical value of the building, such alterations shall comply as
nearly as is practicable with the provisions of this code which
govern the arrangement and construction of seats, aisles, pas-
sageways, stage and appurtenant rooms, fire-fighting and ex-
tinguishing equipment and the adequacy of exitways.

406.3.3. Increase in Occupancy Load. — Whenever the occupancy
load of an existing place of public assembly is increased beyond
the approved capacity of its exitways, the building or part there-
of shall be made to comply with the requirements for a new
building hereafter erected for such public assembly occupancy.

406.4. Swimming Pools.

406.4.1. Change of Occupancy. — No existing pool used for
swimming or bathing or accessory equipment or part thereof
shall be altered or converted for any other occupancy unless it
complies with all provisions of this code applicable to the use
intended.

406.4.2. Continuation of Existing Occupancy. — Existing swim-
ming pools may be continued without change, provided the
safety requirements of section 429.8 are observed where required
by the building official.

SECTION 407.0. LIQUEFIED PETROLEUM GASES

The design, construction, location, installation and operation
of facilities for propane, butane and other petroleum gases,
normally stored in the liquid state under pressure for use in
all buildings and structures shall be in conformance with refer-
ence standard RS4-4. Refineries, tank farms and utility gas
plants shall be subject to special approval in accordance with
reference standard RS4-4.

SECTION 408.0. PYROXYLIN PLASTICS

The provisions of this section and reference standard RS4-5
shall regulate all buildings, structures and parts thereof for the
storage, handling or fabrication of pyroxylin plastics permitted
by Massachusetts Law whether in raw material, process, finished
product or scrap.

408.1. Exceptions. — The provisions of this section and of refer-
ence standard RS4-5 shall not apply to the incidental storage of
articles manufactured from pyroxylin plastics offered for sale
in mercantile buildings. (See section 205.)

408.2. Restrictions. — No permit for the storage or manufacture
of pyroxylin plastics, except as specified in section 408.1, shall
be issued for a building or structure hereafter erected, altered
or used which is occupied or located as follows:

408.2.1. Places of Assembly and Schools. — Within fifty (50)
feet of the nearest wall of a school, theatre or other place of
public assembly;

408.2.2. Residential Building. — As a residential building, occu-
pancy groups L-l, L-2 or L-3;

408.2.3. High Hazard Occupancies. — In quantities exceeding
one thousand (1,000) pounds in buildings where paints, var-
nishes, or lacquers are manufactured, stored or kept for sale; or
where matches, resin, oils, hemp, cotton, or any explosives are
stored or kept for sale;

408.2.4. Other Flammable Materials. — Where drygoods, gar-
ments or other materials of a highly flammable nature are

406-408

manufactured in any portion of the building above that used for
permitted nitro-cellulose products;

408.2.5. Tenant Factory Building. — In quantities exceeding one
hundred (100) pounds in any tenant factory building (occupancy
group D) in which more than five (5) people are employed or
likely to congregate on one (1) floor at any one time.
408.3. Inside Storage. — All pyroxylin raw material and pro-
ducts intended for use in further manufacture shall have storage
limited to one-half (1/2) day's supply but not to exceed the re-
quirements as herein provided:

408.3.1. Cabinets. — Quantities of more than twenty-five (25)
pounds and not more than five hundred (500) pounds shall be
stored in approved cabinets constructed of noncombustible
materials but in no case shall the total quantity of storage be
more than one thousand (1,000) pounds in any workroom or
space enclosed in floors, walls, and ceilings of not less than two
(2) hour fireresistance;

408.3.2. Vaults. — Quantities of more than one thousand (1,000)
pounds and not more than ten thousand (10,000) pounds shall
be stored in vaults enclosed in floors, walls and ceilings of not
less than four (4) hour fireresistance. The interior storage volume
of the vault shall be not more than fifteen hundred (1,500) cubic
feet and the vault shall be constructed vapor and gas-tight in
accordance with the approved rules, with one and one-half
(1-1/2) hour vapor-tight fire doors or the approved labeled fire
door assembly equivalent on each side of the door opening. The
vault shall be drained and provided with scuppers;

408.3.3. Tote Boxes and Scrap Containers.— During manufacture,
pyroxylin materials and products not stored in finished stock
rooms, cabinets or vaults shall be kept in approved covered
noncombustible tote boxes. Scrap and other refuse material
shall be collected in approved noncombustible containers in
quantities not greater than three hundred and fifty (350) pounds
and removed at frequent intervals as directed by the building
and /or fire official;

408.3.4. Ventilation. — Each separate compartment in storage
vaults shall be vented directly to the outer air through flues
complying with the requirements of article 10 for low tempera-
ture chimneys, or exterior metal smokestacks, or as otherwise
provided in the approved rules. The vent shall discharge not less
than four (4) feet above the roof of the building or on a street,
court or other open space not less than fifty (50) feet distant

from any other opening in adjoining walls which are not in
the same plane, nor nearer than twenty-five (25) feet vertically
or horizontally to an exterior exitway stairway or fire escape.
The area of the vent shall be not less than one (1) square
inch for each seven (7) pounds of pyroxylin stored;

408.3.5. Structural Strength. — The floors, walls, roof and doors
of all vaults, structures or buildings used for the storage or
manufacture of pyroxylin materials and products shall be de-
signed to resist an inside pressure load of not less than three
hundred (300) pounds per square foot;

408.3.6. Fire Protection. — Vaults located within buildings for
the storage of raw pyroxylin shall be protected with an ap-
proved automatic sprinkler system having not less than one
(1) head to each twelve (12) square feet of protected area. When
vaults are subdivided into two (2) or more sections, not less
than one (1) head shall be provided in each section.

408.4. Isolated Storage Buildings. — Pyroxylin products in quan-
tities greater than permitted for interior storage shall be housed
in isolated storage buildings. Such buildings shall be used for
no purpose other than packing, receiving, shipping and storage
of pyroxylin plastics unless otherwise approved by the building
official.

408.4.1. Capacity.— The maximum storage in any fire area en-
closed in construction of four (4) hour fireresistance shall be not
greater than one hundred thousand (100,000) pounds. The stor-
age capacity of the building and its separation from lot lines
and other buildings on the same lot shall be limited as provided
in section 408.4.2 table 4-2. When equipped with an approved
automatic sprinkler system complying with the provisions of
article 12 and as herein modified, the exposure distances may
be decreased fifty (50) per cent. Such systems shall be provided
with not less than one (1) automatic sprinkler head for each
thirty-two (32) square feet of protected area.

408.4.2. Table 4-2 Exposure Distance for Pyroxylin Storage
Buildings

Maximum Quantity Stored Fire Separation from Lot Line

in Pounds or Other Buildings in Feet

1,000 40

2,000 50

3,000 60

4,000 70

408-409
408.4.2. Table 4-2 Continued

5,000 80

10,000 100

20,000 125

30,000 150

40,000 160

50,000 180

75,000 200

100,000 225

150,000 250

300,000 300

408.5. Protection.

408.5.1. Heating Equipment. — All radiators, heating coils, piping
and heating apparatus shall be protected with approved noncom-
bustible mesh to maintain a clearance of six (6) inches of all
pyroxylin products from such equipment. All piping and risers
within six (6) feet of the floor shall be insulated with approved
noncombustible covering unless protected with wire guards.

408.5.2. Lighting Control. — All lighting shall comply with the
provisions of section 400.5 and shall be controlled from panel
boards located outside of storage compartments and vaults.

408.5.3. Standpipes. — First-aid standpipes shall be provided for
each five thousand (5,000) square feet of floor area equipped
with one and one-half (1-1/2) inch hose, complying with article 12.

408.5.4. Automatic Sprinklers. — All manufacturing and storage
spaces and vaults shall be protected with an approved automatic
sprinkler system as herein specified and with fire pails and por-
table fire extinguishers complying with article 12 and as approved
by the fire department.

408.5.5. Special Protection. — Special chemical extinguishers and
other first-aid fire appliances shall be provided around motors
and other electrical equipment in accordance with articles 12 and
15 and approved rules.

SECTION 409.0. USE AND STORAGE OF MOTION
PICTURE FILM

The use and storage of motion picture film and related opera-
tions shall comply with reference standard RS4-12 and the pro-
visions of this section.

409.1. Film. — The projection, use or storage of film having £
nitrocellulose base or an other flammable type base shall not be
permitted except under conditions specified in special permits 1
when issued by the fire department and when permitted by law.
Safety film meeting the specifications and test standards of ref-H
erence standard RS4-13 may be projected, used and stored.

409.2. Projection Machines. — Projection machines shall meet the
electrical requirements of article 15. The lamp housing of projec-
tion machines using carbon-arc or other light sources that emit |
gaseous discharge shall be equipped with, or connected to a
mechanical ventilation system of adequate capacity to exhaust
the products of combustion through ducts directly to the out-
doors. Such duct systems shall comply with the requirements of
article 18. When more than one projection machine or other
facility employing a carbon-arc or similar light source is used,
all may be vented by the same duct system if the capacity is
adequate for all facilities so connected.

409.3. Projection Rooms or Booths. — When enclosed, rooms or
booths, for the use and operation of motion picture projectors
hereafter installed as an integral part of a building, shall be
enclosed in walls, floor and ceiling of approved noncombustible
materials and construction, as herein provided.

409.3.1. Construction of Projection Rooms. — The size of the
room shall be adequate to accommodate the apparatus and
equipment, permit manual operation, and provide a clear work-
ing space of at least two (2) feet around the projection apparatus,
but in no case less than forty-eight (48) square feet in area and
seven (7) feet in height for one projector and twenty-four (24)
square feet for each additional machine. Observation and pro-
jector openings shall in no case exceed a maximum of seven
hundred twenty (720) square inches in area and port shutters
may be omitted.

409.3.2. Exitways from Projection Rooms. — At least two (2)
exitways shall be provided, equipped with incombustible or
metal clad self-closing doors, opening outwardly, not less than
two (2) feet by six (6) feet in size, unless otherwise approved
by the building official. No point within the room, booth, or
gallery shall be more than fifty (50) feet from an opening into
a corridor or space that provides access to an exitway at a
distance not greater than seventy-five (75) feet.

409.3.3. Ventilation of Projection Rooms or Booths. — Ventila-
tion shall be provided by an approved mechanical system of

409

ventilation, exhausting either directly to the outdoors or through
a noncombustible flue, which shall be used for no other purpose.
The exhaust capacity shall be not less than fifteen (15) cubic
feet nor more than fifty (50) cubic feet per minute for each arc
lamp, plus two hundred (200) cubic feet per minute for the
volume of the room. All ventilating flues shall be constructed
and installed to comply with article 18. All fresh air intakes
other than direct open air supply shall be protected with fire
shutters arranged to operate automatically.

409.3.4. Lighting Control. — Provisions shall be made for control
of the auditorium lighting and the emergency lighting systems of
theatres from inside of the booth and from at least one other
convenient point in the building as required in section 418.8.

409.3.5. Electrical Equipment. — Separate compartments of simi-
lar construction to the projection booth shall be provided for
storage batteries and motor generators, respectively. Ventilation
shall be provided for such compartments; ventilation for motor
compartment being independent of any other system. The duct
from such compartments leading to outdoors shall be constructed
of approved acid-resisting noncombustible material.

409.4. Motion Picture Studios.

409.4.1. Construction.— All buildings designed or used as motion
picture studios shall be protected with an approved two-source
automatic sprinkler system complying with the provisions of
article 12; except that the building official may exempt rooms
designed for housing electrical equipment from this requirement
when constructed of fireproof (type 1) construction.

409.4.2. Special Rooms. — Rooms and spaces used as carpenter
and repair shops, dressing rooms, costume and property stage
rooms shall be enclosed in floors, walls and ceilings of not less
than two (2) hour fireresistive construction.

409.4.3. Trim, Finish and Decorative Hangings. — All perma-
nently attached acoustic, insulating and light reflecting materials
and temporary hangings on walls and ceilings shall comply with
the requirements of article 9.

409.5. Film Laboratories. — No film laboratories shall be con-
ducted in other than buildings or structures built of noncom-
bustible materials equipped throughout with an approved auto-
matic sprinkler system.

409.6. Film Exchange. — All film exchanges and depots shall be
housed in buildings and structures of noncombustible con-
struction equipped throughout with an approved automatic
sprinkler system.

SECTION 410.0. USE AND STORAGE OF COMBUSTIBLE
FIBERS

The provisions of this section shall apply to all buildings and
structures involving the storage or use of finely divided com-
bustible vegetable or animal fibers and thin sheets or flakes of
such materials, involving a flash fire hazard, including among
others, cotton, excelsior, hemp, sisal, jute, kapok, and paper
and cloth in the form of scraps and clippings in excess of one
thousand (1,000) pounds. The provisions of reference standard
RS4-6 except as herein specifically provided shall be deemed to
conform to the provisions of this Code.

410.1. Construction Requirements. — All buildings designed for
the storage of combustible fibers as herein described shall be
constructed within the limits of height and area specified in
section 221.2 table 2-2 for high hazard occupancy (occupany
group A) except as follows:

410.1.1. Special Limits. — No single storage room or space shall
be more than twelve hundred fifty (1,250) square feet in area or
more than twelve thousand five hundred (12,500) cubic feet in
volume unless of protected noncombustible (type 2-B) or better
construction;

410.1.2. Floor Loads. — The floors of all buildings designed for
the storage of combustible fibers shall not be loaded in excess
of one-half (1/2) the safe load capacity of the floor, nor shall
such materials be piled to more than two-thirds (2/3) of the
clear story height;

410.1.3. Salvage Doors. — Every exterior wall shall be provided
with a door to each storage compartment arranged for quick
removal of the contents;

410.1.4. Wall Openings. — All openings in outside walls shall be
equipped with approved fire doors and fire windows complying
with article 9;

410.1.5. Roof Openings. — All skylights, monitors and other roof
openings shall be protected with galvanized wire or other ap-

409-411

proved corrosion-resistive screens with not less than thirty-six
(36) meshes to the square inch or with wired glass in stationary
frames;

410.1.6. Boiler Rooms. — All power and heating boilers and
furnaces shall be located in detached boiler houses or in a seg-
regated boiler room enclosed in three (3) hour fireresistive con-
struction with direct entrance from the outside, except that rooms
containing gas-fired heating equipment may have openings into
the warehouse protected with one and one-half (1-1/2) hour fire
doors or their approved equivalent;

410.1.7. Deleted.

410.2. Fire Protection. — Fire-extinguishing equipment shall be
provided complying with article 12 consisting of casks, pails and
portable chemical extinguishers and standpipes. Where deemed
necessary by the building official, a system of outside hydrants
and hose shall be provided. An approved automatic sprinkler
system complying with article 12 shall be required when the
area within type A fire divisions exceeds one thousand (1,000)
square feet.

410.3. Housekeeping. — No ashes, waste, rubbish or sweepings
shall be kept in wood or other combustible receptacles and shall
be removed from the premises daily. No grass or weed shall be
allowed to accumulate at any point on the premises.

410.4. Open Storage. — Only temporary open storage of com-
bustible fibers shall be permitted on the same premises with a
fiber warehouse and shall be kept covered on top and sides with
tarpaulins secured in place. Not more than seven thousand two
hundred (7,200) cubic feet of fiber shall be stored in the open;
and fire-extinguishing equipment shall be provided as directed
by the building official.

410.5. Special Treatments. — When combustible fibers are packed
in approved special noncombustible containers or when packed
in bales covered with approved wrappings to prevent ready igni-
tion, or when treated by approved chemical dipping or spraying
processes to eliminate the flash fire hazard, the restrictions
governing combustible fibers shall not apply.

SECTION 411.0. COMBUSTIBLE DUSTS, GRAIN
PROCESSING AND STORAGE

The provisions of this section and of reference standard RS4-7
except as herein specifically modified shall apply to all buildings

in which materials producing flammable dusts and particles which
are readily ignitable and subject to explosion hazards are stored
or handled, including among others, grain bleachers and eleva-
tors, malt houses, flour, feed or starch mills, wood flour manu-
facturing and manufacture and storage of pulverized fuel and
similar uses.

411.1. Construction Requirements.

411.1.1. Buildings. — All such buildings and structures, unless
herein otherwise specifically provided, shall be of fireproof (type
1), noncombustible (type 2), or of laminated planks or lumber
sizes qualified for heavy timber mill (type 3A) construction,
within the height and area limits of high hazard occupancy
(occupancy group A) of section 221.2 table 2-2; except that when
erected of fireproof (type 1A or IB) construction and the height
and area may be unlimited.

411.1.2. Grinding Rooms. — Every room or space for grinding
or other operations producing flammable dust shall be enclosed
with floors and walls of not less than two (2) hour fireresistance
when the area is not more than three thousand (3,000) square
feet and of not less than four (4) hour fireresistance when the
area is greater than three thousand (3,000) square feet.

411.1.3. Conveyors. — All conveyors, chutes, piping and similar
equipment passing through the enclosures of such rooms or
spaces shall be constructed dirt and vapor-tight, of approved
noncombustible materials complying with the applicable re-
quirements of article 16.

411.2. Explosion Relief. — Means for explosion relief shall be
provided as specified in section 402, or such spaces shall be
equipped with the equivalent mechanical ventilation complying
with article 18.

411.3. Grain Elevators. — Grain elevators, malt houses and
buildings for similar uses shall be located within thirty (30)
feet of interior lot lines or structures on the same lot, except
when erected along a railroad right of way.

411.4. Deleted.

SECTION 412.0. PAINT SPRAYING AND SPRAY BOOTHS

The provisions of this section shall apply to the construction,
installation and use of buildings and structures or parts thereof
for the spraying of flammable paints, varnishes, and lacquers or
other flammable materials, mixtures, or compounds used for

411-412

painting, varnishing, staining or similar purposes. All such con-
struction and equipment shall comply with reference standard
RS4-8.

412.1. Location of Spraying Processes. — Such processes shall
be conducted in a spraying space, spray booth, spray room or
shall be isolated in a detached building or as otherwise ap-
proved by the building official.

412.2. Construction.

412.2.1. Spray Spaces. — All spray spaces shall be ventilated
with an approved exhaust system to prevent the accumulation of
flammable mist or vapors. When such spaces are not separately
enclosed, noncombustible spray curtains shall be provided to
restrict the spread of fire.

412.2.2. Spray Booths. — All spray booths shall be constructed
of approved noncombustible materials equipped with mechanical
ventilating systems.

412.2.3. Spray Rooms. — All spray rooms shall be enclosed in
partitions of substantial construction of approved noncombus-
tible materials consistent with the requirements of reference
standard RS4-8. Floors shall be waterproofed and drained in
an approved manner. Floor drains to the building drainage
system and the public services shall be prohibited.

412.2.4. Storage Rooms. — Spraying materials in quantities of
not more than twenty (20) gallons may be stored in approved
cabinets ventilated at top- and bottom; when in quantities of
more than twenty (20) gallons and not more than one hundred
(100) gallons, they may be stored in approved double-walled
noncombustible cabinets vented directly to the outer air; and
all spraying materials in quantities of more than one hundred
(100) gallons shall be stored in an enclosure of not less than
two (2) hour fireresistance or in a separate exterior storage
building. In no case shall such storage be in quantities of more
than two hundred and fifty (250) gallons, except when stored
in isolated storage buildings; and except further that not more
than twenty-five (25) gallons of spraying materials shall be
stored in buildings in which pyroxylin products are manufac-
tured or stored.

412.3. Ventilation of Spraying Processes. — Spraying or dipping
spaces shall be mechanically ventilated during spraying or dip-
ping operations so that the velocity of air is at least one hun-
dred (100) linear feet per minute in the breathing zone of the
operator, conveying air toward the exhaust hood. The ventilat-

ing system shall be of sufficient capacity to prevent the accumu-
lation of mist or vapors. Air shall be admitted to the spraying
or dipping spaces in an amount equal to the capacity of the
fan or fans and in a manner that prevents short-circuiting the
path of air in the working zone of such spaces. The exhaust fan
control shall be interconnected with spray guns so that they can-
not be operated without the ventilation system being in opera-
tion. Exhaust fans shall in addition, be arranged to operate
independently of spray guns. Ventilation equipment shall be
kept in operation for a sufficient length of time after spraying
or dipping operations to exhaust all vapors, fumes, or residues
of spraying materials from the spray space, dip space, or drying
room.

412.3.1. Ventilating Ducts. — Ventilating ducts shall run di-
rectly to the outer air and be protected with a hood against the
weather. Ventilating ducts shall be constructed and installed to
comply with section 1019 and 1119 and article 18, but shall not
terminate within ten (10) feet horizontally of any chimney outlet,
or within twenty (20) feet of any exitway or any opening in an
adjoining wall.

412.3.2. Make-up Air. — Make-up air shall be supplied from a
point outside the spraying or dipping space.

412.3.3. Exhaust System. — The exhaust system from any spray-
ing, dipping, or drying space shall not be connected to any
other ventilating . system or be discharged into a chimney or
flue used for the purpose of conveying gases of combustion.

412.3.4. Equipment Location. — Unless equipped with approved
explosion-proof motors with nonferrous blade fans, the me-
chanical exhaust equipment shall be located outside the spray
spaces.

412.3.5. Access Doors. — Adequate access doors or panels,
tightly fitted, shall be provided to permit inspection and clean-
ing of ducts.

412.4. Electrical Equipment. — Artificial lighting and electric
equipment shall comply with section 400.5.

412.5. Fire Protection. — Sprinkler heads shall be provided in
all spray, dip and immersing spaces and storage rooms and
shall be installed in accordance with the requirements of article
12. When buildings containing spray areas are not equipped with
an approved automatic sprinkler system, the sprinkler heads in
booths and other spray areas and storage rooms may be sup-
plied from the building water supply when approved by the

412-413

building official, to comply with the provisions of section 1213
for partial sprinkler systems.

SECTION 413.0. DRY CLEANING ESTABLISHMENTS

Before any dry cleaning plant is constructed or an existing
plant is remodeled or altered, complete drawings shall be filed
showing to scale the relative location of the dry cleaning area,
the boiler room, finishing department, solvent storage tanks,
pumps, washers, drying tumblers, extractors, filter traps, stills,
piping and all other equipment involving the use of flammable
liquid solvents. All dry cleaning by immersion and agitation
shall be carried on in closed machines, installed and operated
in accordance with reference standard RS4-9.

413.1. Classification. — For the purpose of this code, all dry
cleaning and dry dyeing establishments shall be classified as
follows:

413.1.1. High Hazard. — All establishments employing gasoline
or other solvents having a flash point below one hundred (100)
degrees F. (Tag. closed-cup).

413.1.2. Moderate Hazard. — All establishments employing sol-
vents having a flash point between one hundred (100) degrees
F. and one hundred thirty-eight and two-tenths (138.2) degrees
F. (Tag. closed-cup).

413.1.3. Low Hazard. — All establishments employing solvents
with a flash point higher than one hundred thirty-eight and
two-tenths (138.2) degrees F. (Tag. closed-cup).

413.2. Construction of Dry Cleaning Plants.

413.2.1. High Hazard. — The construction or installation of high
hazard dry cleaning establishments shall be prohibited.

413.2.2. Moderate Hazard. — Moderate hazard dry cleaning es-
tablishments shall meet all of the requirements of this code ap-
plicable to industrial occupancy group D-l buildings. The room
or space in which such operations are conducted shall be en-
closed in not less than two (2) hour fireresistive construction
with not less than two (2) exitways from each dry cleaning or
dry dyeing room or space.

413.2.3. Low Hazard. — Low hazard dry cleaning establishments
shall meet all of the requirements of this code applicable to
industrial occupancy group D-2 buildings; except that such oc-
cupancies shall not be located in basements nor in a building
used for public assembly (occupancy group F) or for institu-
tional (occupancy group H) purposes.

413.2.4. Floor Construction of Dry Cleaning Plants. — The floor
finish in moderate hazard dry cleaning establishments shall be
noncombustible and impervious.

413.2.5. Basements of Dry Cleaning Plants. — The basements of |
all buildings in which moderate hazard dry cleaning establish-
ments are conducted shall be completely separated from the
superstructure with unpierced floor construction of not less
than two (2) hour fireresistance. The access to such basements
shall be from the exterior only.

413.3. Boiler Room Separation. — Boiler rooms and heating
equipment for moderate hazard dry cleaning plants shall be
separated from drying rooms, dry cleaning and dry dyeing
rooms with solid walls of not less than two (2) hour fireresis-
tance; or such boiler rooms shall be located in a separate
building.

413.4. Ventilation. — Mechanical ventilation systems in moderate
hazard plants shall be adequate to effect ten (10) complete air
changes per hour. Low hazard dry cleaning establishments shall
be provided with mechanical ventilation adequate to effect four
(4) complete air changes per hour. Ventilating systems shall be
arranged in such manner as to prevent solvent vapors from
being admitted to the combustion area of any device requiring
an open flame. Sufficient make-up air shall be introduced into
all parts of the establishment to equal the air exhausted by the
dry cleaning units, dryers, and exhaust ventilating system. Such
air shall not contain any flammable vapors. Openings or stacks
discharging solvent vapor-air mixtures to the outdoors shall be
located in accordance with the provisions of article 18.

413.5. Solvent Storage. — Interior above ground storage shall
be permitted for solvents with a flash point above one hundred
(100) degrees F. (tag. closed-cup) provided the aggregate quan-
tity of such solvent in use in the system and in storage is not
more than five hundred and fifty (550) gallons and the capacity
of any individual tank is not more than two hundred and
seventy-five (275) gallons.

413.6. Electric Wiring and Equipment. — All electrical equipment
and wiring shall conform to the requirements of article 15 for
hazardous locations; and the cylinders and shells of all washing
machines, drying tumblers, drying cabinets, extractors, and all
above ground storage containers shall be grounded as therein
required.

413

413.7. Fire Protection. — Every dry cleaning room, and dry dye-
ing room employing moderate hazard solvents shall be protected
with a fire-extinguishing system consisting of approved auto-
matic sprinklers, manually controlled steam blankets, carbon
dioxide flooding systems or other approved fire-extinguishing
equipment.

413.8. Coin-Operated Units. — In coin-operated establishments
all dry cleaning units shall be installed in such a manner that
the working or maintenance portion of the equipment shall be
separated from the front of the units by solid noncombustible
partitions. Coin-operated units shall be located within a diked
area, all parts of which are impervious to the solvent used in
such units. The diked section shall be a four (4) inch curb above
above the floor. Provisions shall be made for the collection of
solvent spillage into tanks of capacity sufficient to contain all of
the solvent in the dry cleaning units served, and for return of
the solvent to the cleaning units through a closed pipe system.
Access doors to the space in back of the units shall be kept
closed and locked. Solvent storage tanks and other sources of
danger shall be so situated as to be inaccessible to the general
public. In addition to the mechanical ventilation required for
low hazard dry cleaning establishments, the following mechanical
ventilation shall be provided:

413.8.1. Inward Flow. — All dry cleaning units shall have facili-
ties that create an inward flow of one hundred (100) cubic feet
of air per minute into the unit when the loading door is opened.

413.8.2. Emergency Ventilation. — Emergency ventilation of the
space in back of the dry cleaning units shall be provided so
that in emergencies a minimum of one (1) air change per minute
in the enclosed space will be provided. Emergency ventilation
equipment shall be on a circuit that is separate from the general
lighting and power circuits, and shall be taken off ahead of the
main switchboard, or shall be connected to the emergency light-
ing power source when such source is provided.

413.8.3. Scavenger Duct. — A scavenger duct system shall be
provided in the space in back of the units at each unit, and
shall be designed to pick up vapor surrounding the equipment
near the floor and exhaust it at the rate of one hundred (100)
cubic feet per minute. Scavenger ducts shall not be less than
five (5) square inches in area.

413.9. Separation of Direct-Fired Dryers. — In moderate hazard
dry cleaning establishments, direct-fired dryers shall not be used.
In low hazard dry cleaning establishments using nonflammable
solvents only, direct-fired dryers may be used, but such dryers
shall not be located within twenty-five (25) feet of a dry clean-
ing unit unless a noncombustible partition (which may be glazed),
equipped with self-closing doors, is provided between the dry
cleaning unit and the flame producing device. This partition may
provide either complete or partial separation, provided that any
partial separation shall be so arranged that the line of air travel
around the partition from the cleaning units to the dryer is a
minimum of twenty-five (25) feet. Where a solid noncombustible
partition is constructed extending to the ceiling and all portions
of the enclosure are solid, except for self-closing access doors,
and outdoor air for combustion and drying is supplied, the
separation may be reduced to fifteen (15) feet.

SECTION 414.0. PRIVATE GARAGES

Private garages shall comply with the requirements of reference
standard RS4-21 and the provisions of this section.
414.1. Attached Garages.

414.1.1. One- and Two-Family Dwellings. — Private garages,
attached to, or located above or below, a one- or two-family
dwelling shall have walls, partitions, floors and ceilings separating
the garage space from the dwelling constructed of not less than
one (1) hour fireresistance, with the sills of all door openings
between them raised not less than four (4) inches above the
garage floor. There shall be only one (1) opening between the
garage and each dwelling unit and there shall be no opening
from a garage directly into a living room, sleeping room or
kitchen. The door opening protectives shall be three-quarter
(3/4) hour fire doors complying with article 9 or one and three-
quarter (1-3/4) inch bonded solid core wood doors.

414.1.2. Multi-Family Dwellings. — Private garages located above
or below multi-family dwellings and in which no gasoline or oil
is stored or handled shall be of protected construction of not
less than two (2) hour fireresistance.

414.1.3. Deleted.

414.1.4. Other Conditions. — All private garages not falling
within the purview of sections 414.1.1 or 414.1.2, attached to
or located beneath a building shall comply with the require-
ments of section 415.1.3 for public garages.

413-415

414.2. Means of Egress. — Where living quarters are attached to,
or located above or below a private garage, required means of
egress facilities shall be protected from the garage area with one
(1) hour fireresistive construction.

414.3. Floors. — Garage floors shall be of concrete. The sills of
all door openings connecting a garage with a dwelling shall be
raised at least four (4) inches above the garage floor.

SECTION 415.0. PUBLIC GARAGES

Public garages shall comply with the applicable requirements of
the following sections and the requirements of reference standard
RS4-21. The portions of such buildings and structures in which
gasoline, oil and similar products are dispensed shall comply
with the requirements of section 416; the portions in which
motor vehicles are repaired shall comply with section 417; and
the portions in which paint spraying is done shall comply with
the requirements of section 412.

415.1. Construction. — All group 1 public garages hereafter
erected shall be classified as storage buildings, moderate hazard
(occupancy group B-l) and all group 2 public garages shall be
classified as storage buildings, low hazard (occupancy group B-2)
and shall conform to the height and area limitations of section
221.2 table 2-2 except as herein specifically provided. The areas
used for dispensing gasoline in such buildings shall be located
on the grade floor and shall comply with the requirements of
section 416.

415.1.1. Basements. — The first floor construction of public
garages of all classifications with basements shall be constructed
of not less than two (2) hour fireresistance and shall be water
and vapor proof. Where openings are provided in the floor they
shall be protected by a curb or ramp not less than six (6) inches
high above the floor to avoid the accumulation of explosive
liquids or vapors and prevent them from spilling to the lower
floor. There shall be not less than two (2) means of egress from
such areas, one (1) of which shall be directly to the outside
independent of the exitways serving other areas of the building.
A one-source sprinkler system shall be provided in basement and
sub-basement public garages.

415.1.2. Mixed Occupancy. — No group 1 public garage shall be
located within, or attached to, a building occupied for any other
use, unless separated from such other use by construction meet-

ing the requirements of section 902.4 table 9-2 for type A fire
divisions. Elevators, stairways, and exitway passageways con-
necting group 1 garages to other occupancies shall be accessible
only through vestibules constructed of materials having a two (2)
hour fireresistance rating. The floor area of such vestibules shall
be at least fifty (50) square feet but not more than seventy-five
(75) square feet. Ventilation shall be provided by a louver per-
manently open to the outdoor air having a net free area of one
hundred forty-four (144) square inches, located near the floor.
Vestibule doors shall be one and one-half (1-1/2) hour self-
closing fire doors, with a six (6) inch high sill provided at the
door between the vestibule and the garage. Both doors shall
swing in the direction of the elevators, stairways or exitway
passageways.

415.1.3. Roof Storage of Motor Vehicles. — The roof of a public
garage shall not be used for the parking or storage of motor
vehicles unless the building is of construction type 1A, IB or
2A, except as otherwise provided for on open parking structures.
When the roof of a building is used for parking or storage of
motor vehicles it shall be provided with a parapet wall or guard
rail not less than three (3) feet six (6) inches in height and a
wheel guard not less than eight (8) inches in height located and
sufficiently anchored so as to prevent any vehicle from striking
the parapet wall or guard rail. Guard rails shall comply with
the requirements for railings in article 7.

415.1.4. Floor Construction and Drainage. — Floors of public
garages shall be graded to drain through oil separators or traps
to avoid accumulation of explosive vapors in building drains or
sewers as provided in article 15. The floor finish shall be of con-
crete or other approved non-absorbent, noncombustible material.
415.2. Ventilation. — Public garages shall be ventilated in accor-
dance with the following provisions:

415.2.1. Mechanical Ventilation. — Garage spaces above or below
grade except as provided in section 415.2.3 below shall be pro-
vided with mechanical ventilation according to one (1) of or a
combination of the following methods:

a. Air exhaust at the rate of not less than one (1) cfm per
square foot of total floor area with properly designed
means for air inflow.

b. Air supply at the rate of not less than one (1) cfm per
square foot of total floor area with properly designed
means for air outflow.

415

c. Air exhaust or air supply at a rate sufficient to maintain
an average concentration of carbon monoxide not to
exceed one hundred (100) parts per one million (1,000,000)
parts of air for periods longer than one (1) hour and
with a maximum concentration at any time not to exceed
four hundred (400) parts of carbon monoxide per one
million (1,000,000) parts of air. The concentration of
carbon monoxide shall be determined by periodic tests
taken between three (3) and four (4) feet from the floor
by means of approved carbon monoxide detector tubes
or other equivalent means. This method of mechanical
ventilation may be used only if the overall design includes
automatic ventilating fan control by means of approved
carbon monoxide monitoring devices or by other ap-
proved means located so as to provide full protection for
the occupancy.

415.2.2. Air Supply and Exhaust. — Air supply shall be taken
from an uncontaminated source. Exhaust outlets shall be located
in accordance with the requirements of article 18 with one-half
(1/2) of them located six (6) inches above floor level. In public
garages where motor vehicles are parked by mechanical means,
the ventilation requirements shall be one-half (1/2) of those re-
quired above.

415.2.3. Natural Ventilation. — Garage spaces above grade pro-
vided with natural ventilation having a free openable area of at
least five (5) per cent of the total floor area of the space and
having adjustable openings measuring at least six (6) inches by
four (4) inches located within six (6) inches of the floor and at
most sixteen (16) feet apart on all outside and court walls need
not be provided with mechanical ventilation.

415.2.4. Repair Shops or Rooms. — When motor vehicles are
to be operated or engines are run for test purposes or minor
adjustments, provisions shall be made to collect the exhaust
fumes from each vehicle individually and to discharge such
fumes to the outer air by means of a positive induced draft.
The discharge from such systems shall be located so as not to
create a hazard to adjoining properties, but not less than eight
(8) feet above the adjacent ground level on the exterior of the
building and shall discharge into a yard or court. When neces-
sary to discharge across a walkway or private thoroughfare the
discharge opening shall be carried to a height of not less than
twenty-five (25) feet above the ground level or to a distance

four (4) inches above the highest point of the wall of the build-
ing or structure on which it is located.

415.2.5. Pits. — No pits shall be installed in floors below the!
first; and pits in first and upper stories shall be provided with
mechanical ventilation adequate to provide the ventilation re-
quired under section 415.2. The ventilation system shall be
operated at all times the pits are occupied by human beings.

415.3. Special Hazards. — No process shall be conducted in
conjunction with public garages involving volatile flammable
solvents, except as provided in section 403 for the storage and
handling of gasoline and other volatile flammables.

415.4. Heating and Protection of Equipment. — Radiation and
heating coils and pipes located within six (6) inches of the floor
shall be protected with wire mesh or other approved noncom-
bustible shields of adequate strength; and with asbestos or
other insulation on top of the equipment when located in par-
titions or near combustible racks or woodwork.

415.5. Boiler Rooms of Public Garages. — All heat generating
plants other than approved direct fired heaters shall be located
in separate buildings or shall be separately enclosed within the
structure with solid, water and vapor tight masonry. All rooms
housing boilers, stoves or other heating apparatus shall be cut
off from all other parts of the building with four (4) hour
fireresistive construction with entrance from outside only, and
no openings through the fire division other than those necessary
for heating pipes or ducts.

415.6. Sprinkler and Standpipe Requirements. — A one-source
sprinkler system shall be provided in garages more than ten
thousand (10,000) square feet in area or more than four (4)
stories high used for the storage of trucks loaded with combus-
tible materials, when of other than fireproof or protected
noncombustible construction (types 1A or IB) and (2A or 2B);
and in all group 1 public garages, as defined in article 2,
located in buildings of which the upper stories are designed for
other uses, when such garages have a storage capacity of
twenty (20) or more automobiles; except that when such build-
ings are more than seventy (70) feet in height, a two-source
sprinkler system shall be provided. In group 2 public garages,
as defined in article 2, located in buildings of which their
upper stories are designed for other uses, standpipe systems
complying with sections 1207 and 1208 or section 1209 shall be
provided.

415-416
415.6.1. Bus Garages. — A one-source sprinkler system shall be

provided in all bus garages which are more than thirty (30)
feet or two (2) stories in height, or which are designed as
passenger terminals for four (4) or more buses, or for the
storage or loading of four (4) or more buses.
415.7. Vehicle Exitways. — Vehicle exitways from garages shall
have a clear and unobstructed view, as they approach pedes-
strian sidewalks, of at least a ten (10) foot width from the
center line of the lane to the corner of the building at the
sidewalk. At a distance back five (5) feet from the sidewalk
line this width may be reduced to five (5) feet.

SECTION 416.0. MOTOR FUEL SERVICE STATIONS

416.1. Construction. — Buildings and structures used for the stor-
age and sale of motor fuel oils may be of all types of con-
struction within the height and area limitations of section 221.2
table 2-2 for business (occupancy group E) buildings and as
modified by sections 303 and 304.

416.1.1. Opening Protectives. — All permissible openings in walls
with a fire separation distance of less than twenty (20) feet
shall be protected with approved fire windows or fire doors
complying with article 9, except doors in such walls to rest
rooms.

416.1.2. Basements. — Motor fuel service stations shall have no
cellars or basements; and when pits are provided they shall
be vented as required in section 415.2.

416.2. Gasoline Storage. — All volatile flammable liquid storage
tanks shall be installed below ground and vented as specified
in section 403.

416.3. Location of Pumps. — No gasoline pumps or other mech-
anical equipment shall be installed so as to permit servicing of
motor vehicles standing on a public street or highway; except
when necessitated by the widening of streets or highways, the
use of the outer driveway of existing service stations may be
continued for servicing of vehicles when approved by the authority
having jurisdiction. The canopies and supports over pumps and
service equipment when located less than twenty (20) feet from
interior lot lines or from any building or structure shall be
constructed of approved noncombustible materials.

SECTION 417.0. MOTOR VEHICLE REPAIR SHOPS

All buildings and structures designed and used for repair and
servicing motor vehicles, motor boats, aircraft, or other motor
driven means of transportation shall be subject to the limita-
tions of section 221.1 table 2-1 and section 221.2 table 2-2 for
moderate hazard industrial buildings (occupancy group D-l).
Such buildings shall be used solely for that purpose.

417.1. Enclosure Walls. — Exterior walls, when located within
six (6) feet of interior lot lines or other buildings shall have
no openings therein.

417.2. Handling of Volatile Flammables. — All volatile flam-
mables shall be stored and handled as provided in section 416.2.

417.3. Ventilation. — All rooms and spaces used for motor
vehicle repair shop purposes shall be provided with an approved
system of mechanical ventilation providing at least four (4)
air changes per hour and meeting the requirements of section
415.2 and article 18.

417.4. Fire Prevention. — No open gas flames except heating
devices complying with section 415.5, torches, welding apparatus,
or other equipment likely to create an open flame or spark
shall be located in a room or space in which flammable liquids
or highly combustible materials are used or stored.

SECTION 418.0. PLACES OF PUBLIC ASSEMBLY

The provisions of this section shall apply to all buildings and
structures, or parts thereof, which are classified in the occu-
pancy group F-l, and in all other places of public assembly,
(occupancy groups F-2, F-3 and F-4), except as specifically
exempted in section 419.
418.1. Restrictions.

418.1.1. High Hazard Occupancies. — No place of public assem-
bly shall be permitted in a building classified in the high
hazard group (occupancy group A).

418.1.2. Deleted.

418.1.3. Frame Construction. — No theatre with stage, fly gallery
and rigging loft shall be permitted in a building of frame
type 4-B construction.

418.1.4. Location. — All buildings used for assembly purposes
shall front on at least one (1) street in which the main entrance

417-418

and exitway discharge shall be located. The main exitway dis-
charge shall be of sufficient width to accommodate one-half (Vi)
of the total occupant load, but shall be not less than the total
required width of all aisles, exitway passageways and stairways
leading thereto, and shall connect to a stairway or ramp leading
to a street. A bowling alley shall have a main exitway of
sufficient capacity to accommodate fifty (50) per cent of the
total occupant load, without regard to the number of aisles
which it serves.

418.1.5. Trim, Finish and Decorative Hangings. — All perma-
nent acoustic, insulating and similar materials and accessories
shall comply with the flame resistance requirements of article 9.
Moldings and decorations around the proscenium openings shall
be constructed entirely of noncombustible material.

418.1.6. Existing Buildings. — Nothing herein contained shall
prohibit the alteration of a building heretofore occupied as a
place of public assembly for such continued use provided the
occupancy load is not increased and seats, aisles, passageways,
balconies, stages, appurtenant rooms and all special permanent
equipment comply with the requirements of this article.

418.1.7. New Buildings. — No building not heretofore occupied
as a place of public assembly shall hereafter be altered to be
so occupied unless it is made to comply with all the pro-
visions of this article.

418.2. Means of Egress Requirements. — Every place of assem-
bly and parts thereof including tiers, balconies and individual
rooms so used shall have means of egress sufficient to provide
for the total capacity thereof as determined in accordance with
article 6, except as herein provided for or as specifically ex-
empted in section 419.

418.2.1. Types of Exitways. — Each level of an assembly occu-
pancy shall have access to the main exitway and in addition
shall be provided with exitways of sufficient width to accom-
modate two-thirds (2/3) of the total occupant load served by
that level. Such exitways shall open directly to a street or
into an exitway court, enclosed stairway, outside stairway, or
exitway passageway leading to a street. Such exitways shall
be located as far apart as practicable and as far from the
main exitway as practicable. Such exitways shall be accessible
from a cross aisle or a side aisle. The number, location and
construction of all exitways shall comply with all the pro-
visions of section 418.2.

418.2.2. Minimum Number of Exitways. — Every place of public
assembly with an occupant load of one thousand (1000) persons
shall have at east four (4) separate exitways as remote from
each other as practicable. Every place of public assembly with
an occupant load of six hundred (600) to one thousand (1000)
persons shall have at least three (3) separate exitways as re-
mote from each other as practicable. Every place of public
assembly with an occupant load of three hundred (300) to six
hundred (600) shall have at least two (2) separate exitways as
remote from each other as practicable. Every place of public
assembly with an occupant load of less than three hundred
(300) shall have at least two (2) means of egress as remote
from each other as practicable; consisting of separate exitway
discharges or doors leading to a corridor or other spaces
giving access to two (2) separate and independent exitways in
different directions.

418.2.3. Number of Stairways in Auditorium. — Each tier above
the main floor of a theatre or other auditoruim shall be pro-
vided with at least two (2) interior enclosed or protected stair-
ways which shall be located on opposite sides of the struc-
ture; except that enclosures shall not be required for stairs
serving the first balcony only, or mezzanine thereunder. Such
stairways shall discharge to a lobby on the main floor. Exit-
way stairways serving galleries above the balcony shall lead
directly to the street or open public space as provided in
section 418.2.1.

418.2.4. Emergency Means of Egress from Main Floor of
Auditorium. — In addition to the main floor entrance and exit-
way, emergency means of egress shall be provided in con-
formance with section 418.2.1. on both sides of the auditorium
which lead directly to an exitway and/or exitway discharge
to the street independent of other exitways, or to an exitway
court as defined in this code.

418.2.5. Emergency Egress from Balconies and Galleries.—

Emergency means of egress shall be provided in conformance
with section 418.2.1. from both sides of each balcony and
gallery with direct exitways and/or exitway discharges to the
street or to an exitway court. There shall be no communication
from any portion of the building to the emergency exitway
stairways except from the tier for which such exitway is ex-
clusively intended.

418
18 2 6. Exitway Courts. — All exitway courts shall be not less
urn six (6) feet wide for the first six hundred (600) persons
) be accommodated or fraction thereof, and shall be increased
ne (1) foot in width for each additional two hundred fifty
>50) persons. Such courts shall extend sufficiently in length
b indicate the side and rear emergency exitways from the

uditorium.

18.2.7. Hardware. — All required exitways shall be equipped
'ith self-releasing panicproof latches or bolts of an approved
/pe complying with section 614.4.2.

18.2.8. Width of Exitway Doors. — Exitway openings shall be
t least thirty-six (36) inches wide for single doors and at

feast sixty-six (66) inches but not more than eighty-eight (88)
iches wide for the doors swinging in pairs, except that in
ssembly spaces having an occupant load of over three hundred
300) persons, single door openings shall be at least forty-four
44) inches wide.

U8.2.9. Exitway Lights. — All exitway doors shall be marked
: vith illuminated signs complying with section 626 which shall
; >e kept lighted at all times during occupancy of the building.
U8.3. Theatre Type Seating.

1118.3.1. Fixed Seats. — In all theatres and similar places of
issembly except churches, stadiums and reviewing stands, in-
dividual fixed seats shall be provided with an average width
taf not less than twenty (20) inches and no seat less than nine-
teen (19) inches wide. All seats shall be provided with separating
arms and arranged in rows not less than thirty-three (33)
[inches apart, back to back, measured horizontally. The spacing
between the back of one (1) chair in any row and any part
of the chair in the row behind it, including arm blocks, when
[the seat is in the lift-up position for automatic operation and
in the horizontal position for non-lift-up or nonautomatic opera-
tion, when measured horizontally between plumb lines, shall
be at least twelve (12) inches, and this spacing shall be increased
for the following reason:

Where a difference in floor level occurs between any two (2)
rows, the spacing shall be increased by one (1) inch where the
difference in level is at least six (6) inches but less than eleven
(11) inches; by two (2) inches where the difference in level
is at least eleven (11) inches but less than seventeen (17) inches;
by three (3) inches where the difference in level is at least
seventeen (17) inches but less than twenty-three (23) inches;

and by four (4) inches where the difference in level is twentj
three (23) inches and over.

418.3.2. Continental Seating. — With Continental seating, th
spacing of rows of unoccupied seats shall provide a clear widt
between rows measured horizontally as follows (automati
or self-rising seats shall be measured in the seat-up position
other seats shall be measured in the seat-down position):
Eighteen (18) inches clear width, between rows of eighteen (1£
seats or less; twenty (20) inches clear width between rows o
thirty-five (35) seats or less; twenty-one (21) inches clear widtl
between rows of forty-five (45) seats or less; twenty-two (22
inches clear width between rows of forty-six (46) seats or more

418.3.3. Number of Seats. — Aisles shall be provided so tha 1
no more than seven (7) seats intervene between any seat an<
the aisle or aisles, except as indicated for continental seatinj
in section 418.3.2 and as follows :

With Continental seating, the number of intervening seat
between any seat and an aisle may be increased to forty-nin<
(49) where exitway doors are provided along each side aisl<
of the row of seats at the rate of one (1) pair of exitway door:
for each five (5) rows of seats. Such exitway doors shall provid(
a minimum clear width of sixty-six (66) inches.

418.3.4. Wheel Chair Viewing. — Performance viewing position'
shall be provided for wheel chair persons in accordance with
section 418.3.4.1. table 4-3. These positions shall be located
so as not to interfere with egress from any row of seats and
shall be reachable by means of ramps and/or elevators. Steps
shall not be allowed in the line of travel from the main ap-
proach entry to the designated locations.

418.3.4.1. Table 4-3 Wheel Chair Viewing Positions

Capacity of Number of

Assembly Space Viewing Positions

75 to 500 Minimum 2

501 to 1000 Minimum 3

1001 to 1500 Minimum 4

Over 1500 — Minimum 4 plus 1 for each 400 over 1500

418.3.5. Box Seats. — In boxes or loges with level floors, the
seats need not be fastened when not more than fourteen (14)
in number.

418
418.4. Aisles. — Every portion of any assembly building which
contains seats, tables, displays, equipment or other materials
shall be provided with aisle leading to exitways as follows:

418.4.1. Longitudinal Aisles. — The width of longitudinal aisles
at right angles to rows of theatre type seats and with seats
on both sides of the aisle shall be not less than three (3) feet
six (6) inches, increasing one and one-half (IV2) inches for each
ifive (5) feet in length toward the exitway, cross aisle, or foyer.
The width of the longitudinal aisle with banks of seats on one
side only shall be not less than thirty-six (36) inches, increasing
one and one-half (l'/2) inches for each five (5) feet in length
toward the exit, cross aisle, or foyer. Minimum widths shall be
measured at the point farthest from an exitway, cross aisle,
or foyer.

418.4.2. Cross Aisles. — When there are twenty-seven (27) or
more rows of seats on the main floor of theatres, cross aisles
shall be provided so that no block of seats shall have more
than twenty-two (22) rows. The width of such cross aisles shall
not be less than the sum of the required width of the widest
aisle plus fifty (50) per cent of the total required width of the
remaining aisles which it serves; but no cross aisle shall be
less than forty-two (42) inches wide, or when bordering on
means of entrance not less than forty-eight (48) inches wide.
In balconies and galleries of theatres, one or more cross aisles
shall be provided when there are more than ten (10) rows of
seats.

418.4.3. Gradient. — Aisles shall not exceed a gradient of one
(1) foot of rise in eight (8) feet of run.

418.4.4. Balcony Steps. — Steps may be provided in balconies
and galleries only, and such steps shall extend the full width
of the aisle with treads and risers complying with article 6,
which shall be illuminated by lights on both sides or by a
step light or otherwise to insure an intensity of not less than
one (1) foot candle.

418.4.5. Railings and Protective Guards. — Metal or other ap-
proved noncombustible railings or protective guards shall be
provided on balconies and galleries as herein provided:

a. A railing or protective guard at least thirty (30) inches
high above the floor shall be provided along the fascia
of all balconies, loges, and boxes, except that the guard
shall be at least thirty-six (36) inches high at the bottom
of stepped aisles. When rails or other parts of such

guards are designed with ledges more than two and one
half (2'/2) inches wide, the top surface of the ledge:
shall slope down toward the seating area at an angh
of at least thirty (30) degrees from the horizontal. Th<
guards shall provide an unperforated curb or toeguarc
at least twelve (12) inches high above the level of th<
floor of the balcony, loge, or box.

b. Railings and protective guards at least thirty (30) inches
high above the floor shall be provided at cross aisles
where fixed seat backs of any adjacent lower level dc,
not project at least twenty-four (24) inches above the]
cross aisle level.

c. Where seatings are arranged in successive tiers, and the
height of rise between platforms exceeds eighteen (18)
inches, a railing or protective guard, not less than twenty-
six (26) inches in height along the entire row of seats
at the edge of the platform, shall be used.

d. Guards shall be designed to meet the load requirements
for railings in article 7.

418.5. Theatre Foyers.

418.5.1. Capacity. — Adjacent to the main floor and to each
balcony, if any, of every theatre or similar place of public
assembly for theatrical use with stage and scenery loft, not
including churches, and except in the first story, there shall
be a foyer, consisting of a lobby, corridor, or passageway,
one or more, with an aggregate net floor area exclusive of
stairs and landings of not less than one (1) square foot for each
occupant of the main floor or balcony thus served (non-comu-
lative). One such area may serve two or more main floors or
balconies on the same level if large enough for the largest
two occupancy loads served. A main floor with a balcony
seating of not more than one hundred and fifty (150) persons
may have a common foyer. The use of foyers and lobbies and
other available spaces for harboring occupants until seats become
available shall not encroach upon the clear floor area herein
prescribed or upon the required clear width of front exitways.
418.5.2. Egress. — When the foyer is not directly connected to
the public street through the main lobby, an unobstructed
corridor or passageway shall be provided, which leads to and
equals in minimum width the required width of main entrances
and exitways.

418

418.5.3. Gradient. — The rear foyer shall be at the same level
as the back of the auditorium and the exitways leading there-
from shall not have a steeper gradient than one (1) foot in
eight (8) feet.

418.5.4. Construction. — The partitions separating the foyer
from the auditorium and other adjoining rooms and spaces of
theatres shall be constructed of not less than two (2) hour
fire re si stance; except that opening protectives may be con-
structed of noncombustible materials without fireresistance
rating.

418.5.5. Waiting Spaces. — Waiting spaces for harboring occu-
pants shall be located only on the first or auditorium floor.
Separate means of egress in addition to the required theatre
means of egress shall be provided from the waiting space based
on an occupancy of one (1) person for each three (3) square
feet of waiting space area.

418.6. Theatre Stage Construction.

418.6.1. Stage Enclosure Walls. — Except as provided for in
section 418.9.6, every stage hereafter erected or altered for
theatrical performances which is equipped with portable or fixed
scenery, lights and mechanical appliances, shall be enclosed on
all sides with solid walls of not less than four (4) hour fire-
resistance, extending continuously from foundation to at least
[four (4) feet above the roof. There shall be no window opening

in such walls within six (6) feet of an interior lot line; and
all permissible window openings shall be protected with three-
quarter (3/4) hour fire windows complying with article 9.

418.6.2. Floor Construction.

a. In Class F-la structures the entire stage shall be of not
less than three (3) hours fireresistive construction com-
plying with the requirements of section 213.0 except as
follows:

1. Any portion of the stage floor used for passing
scenery and scenic elements to a lower level may
consist of heavy timber construction supporting tight
fitting traps of at least three (3) inches nominal
solid wood or of equivalent materials in terms of
fireresistance, strength, and stiffness properties. Stage
lifts shall comply with the provisions of article 13.
Any portion of the stage floor that is equipped
with stage lifts shall be of noncombustible con-

struction. Joints between lift platforms and adjacen

floors will be tightly fitted.
2. Finish flooring shall comply with the provisions o;

section 922.1.2 table 9-4, article 9.

b. In Class F-lb structures, raised platforms may be buill

as stages when they are supported on floors having the

fireresistance ratings required by section 221.1 table 2-1

and section 213.0, in accordance with the following:

1. The area below the platform shall be enclosed or
all sides with solid construction.

2. The horizontal area of stage construction shall nol
exceed the following: $

Maximum area
Wood frame 400 square feel!

Fire retardant treated wood 1,200 square feel]

Noncombustible frame unlimited,

3. The floor of the stage, when wood is used, shall
be at least one (1) inch nominal thickness, and shall/
be laid on a solid, noncombustible backing, or all'
spaces between supporting members shall be fire- j
stopped with noncombustible material.

418.6.3. Roofs and Rigging Lofts. — The roof over the stage in
Class F-la structures shall be of not less than three (3) hourj
fireresistive construction. The rigging loft, fly galleries and pin!
rails need not be fire protected, but shall be constructed of
approved noncombustible materials.

418.6.4. Footlights and Stage Electrical Equipment. — Footlights
and border lights shall be installed in troughs constructed of
noncombustible materials. All electrical equipment shall con-
form to the requirements of article 15. The switchboard shall
be so located as to be accessible at all times and shall be
fully protected from falling objects and the storage or placing
of stage equipment against it shall be prohibited.

418.6.5. Stage Means of Egress. — At least one (1) approved
means of egress shall be provided from each side of the stage
and from each side of the space under the stage, and from each
fly gallery and from the gridiron to a street, exitway court or
passageway to a street. An iron ladder shall be provided from
the gridiron to a scuttle in the stage roof. All required exit-
way openings to the outer air shall be protected with approved
self-closing fire doors, complying with article 9. All exterior
openings which are located on the stage for egress or loading

418

ind unloading purposes which are likely to be open during
occupancy of the theatre, shall be constructed with vestibules
to prevent air draughts into the auditorium. In Class F-la
structures, at least two (2) means of egress, remote from each
Dther, shall be available from every point on a stage, each
•vithin a travel distance limitation of one hundred and twenty-
'ive (125) feet. The occupant load of the stage shall be based
upon one (1) person per fifteen (15) square feet for the per-
forming area and on one (1) person per fifty (50) square feet
for the remaining area. When any portion of a stage is used
for audience seating at any time, means of egress of adequate
capacity shall be provided for that portion, within the travel
distance limitations for assembly space seating. Exitway openings
serving a stage directly shall have a capacity of seventy-five
(75) persons per unit of exit width. In Class F-lb structures,
at least two exitways, remote from each other shall be available
from every point on a stage, each within a travel distance
limitation of one hundred and fifty (150) feet. The occupant
load of the stage shall be based upon one (1) person per
twenty-five (25) square feet of area. When any portion of a
stage is used for audience seating at any time, means of egress
•of adequate capacity shall be provided for that portion within
the travel distance limitations for assembly space seating. Exit-
iway openings serving a stage directly shall have a capacity
of one hundred (100) persons per unit of egress width.

418.6.6. Proscenium Wall. — There shall be no other openings
jin the wall separating the stage from the auditorium except
the main proscenium opening; two (2) doorways at the stage
level, one (1) on each side thereof; and, where necessary, not
more than two (2) doorways to the musicians pit from the space
below the stage floor. Each such doorway shall not exceed
twenty-one (21) square feet in area and shall be protected with
approved automatic and self-closing fire door assemblies com-
plying with article 9 with a combined fireresistance rating of
three (3) hours or the approved labeled equipment.

418.6.7. Proscenium Curtain. — When stage ventilation is pro-
vided for by means other than emergency exhaust fans, the pro-
scenium opening shall be protected with an automatic firere-
sistive and smoke-tight curtain designed to resist an air pressure
of not less than ten (10) pounds per square foot normal to
its surface, both inward and outward. The curtain shall with-
stand a one-half (1/2) hour fire test at a temperature of not

less than seventeen hundred (1700) degrees F. without the
passage of flame. The curtain shall be operated by an auto-
matic heat activated device to descend instantly and safely
and to completely close the proscenium opening at a rate of :
temperature rise of fifteen (15) to twenty (20) degrees F. per
minute; and by an auxiliary closing of the proscenium open- I
ing. When stage ventilation is provided for by emergency ex-
haust fans, the proscenium curtain shall have fireresistive prop-
erties conforming with the requirements of article 9. No curtain
shall be located between the audience area and the stage unless
it is designed to permit the air movement that is required for
the operation of the emergency exhaust fan stage ventilation
system to bypass or pass through the curtain without excessive
billowing. Motion picture screens shall be noncombustible, or
have a flame spread rating not over twenty-five (25), or be of
materials that have been rendered flameproof in accordance with
the provisions of article 9. The construction supporting screens
shall be noncombustible, and shall comply with the require-
ments of article 7. When the provisions of section 418.9.6 are
followed, there are no requirements for a proscenium curtain.

418.6.8. Deleted.

418.6.9. Stage Ventilation. — Stage ventilation shall be provided
by either of the following systems:

a. Metal or other approved noncombustible ventilators,
equipped with movable shutters or sash shall be pro-
vided over the stage, constructed to open automatically
and instantly by approved heat activated devices, with
an aggregate clear area of opening not less than one-
eighth (1/8) the area of the stage, except as otherwise
provided in section 418.1.2. Supplemental means shall
be provided for manual operation of the ventilator.

b. Emergency ventilation shall be provided for all stages
in F-la places of assembly to provide a means of re-
moving smoke and combustion gases to the outdoors in
the event of a fire, as follows:

1. A mechanical exhaust system shall be provided of
sufficient capacity to exhaust an amount of air at
least equai to the sum of the following:
2 cfm per square foot of the performing area.
4 cfm per square foot of that portion of stage area
that is not designated as performing area.
4 cfm per square foot of rigging loft area.

418

2. The exhaust system shall be activated both manually
and automatically, manual operation shall be by
means of a manually operated switch located at
the fire control station as required by section 418.9.6
and adjacent to at least one means of egress from
the stage. Such means of egress shall be remote
from the fire control station. Automatic activation
shall be by means of the sensing devices that start
the operation of the sprinklers. Exhaust air openings
of ducts shall be located so as to provide the most
effective removal of smoke and combustion gases.

3. The exhaust system shall be provided with an auto-
matic emergency by-pass damper in the exhaust
duct on the suction side of the fan. Such damper
shall close to the fan in the event of a power
failure to the fan motor and shall open directly to
the outdoors if the fan is located outside the build-
ing, or shall open to a duct leading directly to the
outdoors if the fan is located inside in the building.
When located inside the building, the fan shall be
insulated with a minimum of one (1) inch mag-
nesia block or the equivalent in insulating and
fireresistive qualities. Exhaust fans shall have drive
and bearings located outside of the fan impeller
housing. The exhaust system shall not be connected
to exhaust openings in any space other than the
stage or rigging loft, and shall be constructed to
comply with the provisions of article 18. All
switches shall be clearly labelled "emergency stage
ventilation" and shall be painted red.

4. The emergency ventilation system shall be connected
to both the normal and emergency light and power
circuits.
418.7. Auxiliary Stage Spaces. — Auxiliary stage spaces such as
understage areas, dressing rooms, green rooms, storage room,
work shops, and similar spaces associated with the use of the
stage shall be of fireproof (type 1) construction and shall be
separated from the stage and all other parts of the building
by walls of not less than three (3) hour fireresistance and the
requirements herein prescribed.

418.7.1. Understage Areas. — When the stage floor is equipped
with traps or stage lifts, the room or space below the stage

into which the traps or lifts open shall be completely enclosed!
by construction having at least the fireresistance rating re-fi
quired for the stage floor, and such room or space shall not |t
be used as a workshop or storage area. Storage shall not be il
deemed to include the location in this area of scenery or t
scenic elements used during a performance. However, no com- 1
bustible material that has a flame-spread rating greater than I
twenty-five (25) or that has not been rendered flame-proof in
accordance with article 9 of this code may be stored in this
location at any time.

418.7.2. Exitway Access. — No point within any auxiliary stage
space shall be more than fifty (50) feet from a door providing
access to an exitway.

418.7.3. Number of Means of Egress. — There shall be at least
two (2) independent means of egress available from every
auxiliary space, one (1) of which shall be available within a
travel distance of seventy-five (75) feet. A common path of
travel of twenty (20) feet to the two (2) exitways shall be
permitted.

418.7.4. Occupant Load. — The occupant load of dressing rooms]
shall be based on one (1) person per fifty (50) square feet of
area.

418.7.5. Sprinklers. — Auxiliary stage spaces shall be equipped I
with automatic sprinklers installed in conformance with the I
provisions of article 12.

418.7.6. Combustibles. — No workshop involving the use of com- 1
bustible or inflammable paint, liquids, or gases or their storage
shall open directly upon a stage.

418.7.7. Interior Finish. — The interior finish of auxiliary stage
spaces shall comply with the requirements of article 9.

418.7.8. Opening Protectees. — Openings and necessary doorways
at stage level connecting such rooms with the stage shall be
protected with one and one-half (1-1/2) hour self-closing fire
doors or the approved labeled equivalent complving with arti-
cle 9.

418.8. Lighting. — During occupancy, all places of assembly
shall be lighted to comply with the requirements of section
627, or as herein prescribed.

418.8.1. Aisles. — Aisles or cross aisles shall be provided at
all times with at least one-half (1/2) foot candle of artificial
illumination by electrical means.

418

418.8.2. Other Places of Public Assembly. — All areas and por-
tions of buildings used as places of public assembly other than
theatres shall be lighted by electric light to provide a general
illumination of not less than five (5) foot candles.

418.8.3. Exitway Lighting. — In addition to the requirements of
article 6, lighting shall be provided in the following areas:

a. Foyers and Waiting Spaces. — Foyers and waiting spaces
shall be artificially lighted by electrical means at all
times during occupancy of a place of assembly so as
to provide all illumination of at least five (5) foot candles
at the level of the floor and on the surface of all stairs,
steps, ramps, and escalators within the foyers and waiting
spaces.

b. Open Exterior Spaces. — Yards or courts which serve as
open exterior spaces shall be artificially lighted by elec-
trical means at all times between sunset and sunrise
during occupancy of a place of assembly so as to pro-
vide illumination of at least five (5) foot candles at the
level of the floor over at least the required area.

418.8.4. Control. — The lighting of exitways, aisles and audi-
toriums shall be controlled from a location inaccessible to un-
authorized persons. Supplementary control shall be provided
as specified in section 409.3.4. in the motion picture projec-
tion room.

418.8.5. Emergency Lighting. — All assembly spaces shall be pro-
vided with emergency lighting facilities sufficient to provide
at least five (5) foot candles of illumination at the floor level.
Such lighting shall be on circuits that are separate from the
general lighting and power circuits, either taken, off ahead of
the main switch or connected to a separate emergency lighting
power source, and be arranged to operate automatically in the
event of failure of the normal lighting system.

418.9. Fire Protection and Fire Fighting Equipment. — Every
theatre-type structure classified in the F-l occupancy group
shall be equipped with fire-extinguishing equipment complying
with the requirements of article 12 and as herein specified.
418.9.1. Sprinkler System. — Approved automatic sprinkler sys-
tems complying with the provisions of section 1213, 1214, and
as herein noted for Class F-l a structures shall be provided
to protect all parts of the building except the auditorium,
foyers and lobbies or in the immediate vicinity of automatic
equipment or over dynamos and electric equipment. Such pro-

tection shall be provided above all rigging lofts over the stage,
under the gridiron, under all fly galleries, in dressing rooms,
over the proscenium opening on the stage side, under the stage,
in all basements, cellars, work rooms, store rooms, property
rooms and in toilet, lounge and smoking rooms. Sprinkler:
above rigging lofts shall be located so that no gridiron 01
other obstruction intervenes between the sprinkler heads anc
the scenery or scenic elements.

418.9.2. Standpipes. — Standpipe fire lines complying with the
provisions of sections 1207 and 1208 shall be provided with
outlets and hose attachments one on each side of the audito
rium in each tier; one on each side of stage; and protecting each
property, store, and work room.

418.9.3. Hose Outlets. — A sufficient quantity of hose shall
be provided, equipped with regulation fire department coup-
lings, nozzle and hose spanner, to reach all areas as specified
in article 12.

418.9.4. First-Aid Hand Equipment. — Approved portable two
and one-half (2-1/2) gallon fire extinguishers shall be provided
and located as follows: two (2) on each tier or floor of the
stage; one (1) immediately outside of the motion picture pro-
jection room; one (1) in each dressing room; and one (1) in
each work, utility and storage room. Fire axes and firehooks
shall also be provided as directed by the fire official; and all
fire extinguishers and fire tools shall be securely mounted on
walls in plain view and readily accessible.

418.9.5. Vertical Water Curtains. — A deluge sprinkler system
designed to form a vertical water curtain that completely sepa-
rates the audience areas from stage areas and rigging lofts
may be substituted for the enclosure requirements of section
418.6.1. and the curtain requirements of section 418.6.7 when
constructed as follows:

a. Stage areas and rigging lofts totally sprinklered in ac-
cordance with section 418.9.1. shall be completely sepa-
rated from audience area by a vertical water curtain
with sprinkler heads spaced to provide a water density
of at least three (3) gpm per linear foot. The water
curtain system shall be controlled by a deluge valve
actuated by a "rate of rise system" and "fixed tempera-
ture system." The heat actuating devices shall be located
on not more than ten (10) foot centers around the
perimeter of the sprinklered area or as otherwise required

418

Ifor the type of device used to assure operation of the
system. In addition to the automatic controls, manual
operating devices shall be located at the first control
station as required by section 418.9.7. below and adjacent
to at least one (1) exitway from the stage. Such exitway
shall be remote from the fire control station.

b. When openings are provided in the stage floor for stage
lifts, trap doors or stairs, sprinklers spaced five (5) feet
on centers shall be provided around the opening at the
ceiling below the stage, and baffles at least twelve (12)
inches in depth shall be installed around the perimeter
of the opening.

c. All valves controlling sprinkler supplies shall be pro-
vided with tamper switches wired to an annunciator panel
located at the fire control station.

d. The operation of any section of the sprinkler system and
the deluge system shall activate the emergency ventilating
equipment required in section 418.6.9.

e. The water flow alarm, tamper switches and deluge system
equipment shall be provided with central station super-
vision in addition to the required local alarm.

418.9.6. Emergency Control Panel. — In Class F-la structures, an
emergency control panel shall be provided, as follows:

a. It shall be located on or adjoining the stage, except
that where the stage is surrounded by seating, it shall
be located so as to permit a view of the audience and
stage areas. It shall be manned in accordance with the
requirements of the fire department at all times during
the presentation of a performance to an audience.

b. It shall be equipped with tell-tale lights to indicate when
feeders and sub-feeders of emergency light and power
circuits are in operation in assembly spaces, and all
exitways, including foyers and waiting spaces.

c. It shall, when a deluge type sprinkler system is pro-
vided, be equipped with manual operating devices to
activate the sprinkler system. It shall also be provided
with a signal system to show when any portion of the
sprinkler system has been deactivated.

d. It shall be provided with switches to provide for op-
eration of the emergency ventilating system. Controls
for the ventilating system shall be electrically supervised.
The supervisory circuit shall be provided with a trouble

bell and light, both of which shall be activated in tfrJ
event of a failure in the ventilation system. A silencing
switch may be provided, and where provided, shall hav<
either an automatic reset or shall ring again when the
trouble is corrected.

e. It shall be equipped with a public address system serving j
loudspeakers in the assembly space. The public address i
system shall be connected to both the normal and emer- \
gency light and power circuits.

f. It shall be equipped with an alarm system and intercom
connected to the manager's office, the dressing rooms,
and to a supervisory central fire station.

In Class F-lb structures having an occupant load over six
hundred (600) persons, an emergency control panel shall be pro-
vided, as follows:

a. It shall be located so as to have a view of the audi- !
ence and stage areas, and shall be manned during the)
presentation of a performance to an audience, by a com-
petent person instructed in its use.

b. It shall be equipped with tell-tale lights to indicate when
feeders and sub-feeders of emergency light and power;
circuits are in operation in assembly spaces and all exit- 1
ways, including foyers and waiting spaces.

c. It shall be equipped with a public address system serving
loudspeakers in the assembly space. The public address
system shall be connected to both the normal and emer- 1
gency light and power circuits.

SECTION 419.0. PUBLIC ASSEMBLY OTHER THAN OC-
CUPANCY GROUP F-l

Other places of public assembly including exhibition halls,
armories, bowling alleys, broadcasting studios, chapels, churches,
community houses, dance halls, gymnasiums, lecture halls, mu-
seums, night clubs, rinks, roof gardens and similar occupancies
shall comply with the general means of egress requirements of
article 6 and the applicable requirements of section 418, ex-
cept as otherwise provided for in sections 418.4.5 and 418.5.4 or
as herein specifically exempted. Places of public assembly which
are equipped with a stage, movable scenery, scenery loft and
dressing rooms shall comply with all the requirements of section
418 for occupancy group F-l.

419.1. Number of Exitways. — Every tier, floor level and story
of places of public assembly shall be provided with the mini-

418-419

mum number of required, approved exitways, as provided for
in sections 418.1.4, 418.2 and the applicable subsections of
section 418.2.

419.2. Aisles With Fixed Seats. — All rows of seats shall be
individually fixed or fixed in rigid units between longitudinal
aisles complying with sections 418.3 and 418.4 except as pro-
vided for chapels and churches in which the minimum side
aisle width shall be thirty-six (36) inches. Where permitted,
continuous fixed benches shall comply with the provisions of
section 421.7.

419.3. Aisles Without Fixed Seats. — Tables and chairs in all
rooms and spaces for public assembly shall provide convenient
access by unobstructed aisles not less than thirty-six (36) inches
wide which lead to required exitways complying with article 6.
Tables and chairs shall be so arranged that the distance from
any chair at any table by way of a path between tables and
chairs is not greater than eighteen (18) feet to an aisle leading
to an exitway. The width of the path shall be at least eighteen
(18) inches; except that it may be reduced by one (1) inch for
each one (1) foot that the distance to the aisle is less than
eighteen (18) feet, but may not be reduced to less than twelve
(12) inches. Chairs, when placed with the front edge of the seat
on a line with the edge of the table, shall not protrude into
this path. Booths containing up to eight (8) seats may be used,
provided they open directly on an aisle.

419.6. Kitchen and Service Pantries. — Where kitchen and service
pantries are provided, they shall be separately enclosed in
partitions, floors and ceilings of not less than one (1) hour
fireresistance, except for opening protectives; and no required
exitway shall pass through such areas.

419.7. Bowling Alleys. — The storage and use of all volatile
flammable liquids shall comply with section 403 and the finish-
ing rooms shall be separately enclosed in two (2) hour fire-
resistive construction with floor finish of concrete or other
noncombustible, nonabsorbent material. Finishing rooms shall
not be permitted in areas below grade.

419.8. Skating Rinks. — No skating rinks shall be located be-
low the floor nearest grade.

419.9. Exhibition Type Areas. — When a building or a portion
of a structure exceeding fifteen thousand (15,000) square feet
in area is used as an exhibition hall, museum or other occu-
pancy group F-3 occupancy for the display or sale of com-

bustible products, goods or materials, or having combustible
display equipment either on a temporary or permanent basis
the following requirements shall apply.

419.9.1. Sprinklers. — An approved automatic sprinkler system
complying with the provisions of sections 1213 and 1214 shall
be installed throughout the exhibit space and accessory areas.

419.9.2. Draft Curtains. — Draft curtains and emergency smoke
and heat venting equipment shall be installed in accordance
with the provisions of reference standard RS4-22.

419.9.3. Fan Requirements. — Fans in air-handling systems serving
these areas shall be arranged to shut down automatically when
the temperature of the air in the system becomes abnormally
high in accordance with the provisions of reference standard
RS4-23.

419.9.4. Means of Egress. — The arrangement of temporary
partitions or booths shall not obstruct any exitway and shall
not increase the access to exitway travel distance from any
part of the exhibition floor. Means of egress routes shall be
clearly marked and not obscured.

SECTION 420.0. OMITTED
SECTION 421.0. OMITTED

SECTION 422.0. DRIVE-IN MOTION PICTURE THEATRES

The location of drive-in motion picture theatres shall be ap-
proved by the City of Boston authority having jurisdiction thereof.

422.1. Arrangement of Lanes. — Separate entrance and exitway
lanes shall be provided not less than twelve (12) feet in width,
with not less than forty (40) foot intervals between access lanes.
The parking space for each car shall not be less than nine (9)
feet by twenty (20) feet in area, and so arranged to provide
continuous lanes of travel.

422.2. Projection Booth.— The projection booth shall comply
with sections 409.3 and 409.4 and shall be supported on a struc-
ture of type 2-C or other approved noncombustible construction.
No motor vehicle shall be permitted to park within twenty (20)
feet of the projection booth or room.

422.3. Projection Screens. — Projection screens and supporting
structures shall comply with the requirements of section 418.6.7.
and shall be designed in accordance with the requirements of

419-424

article 7 as applied to signs. Motor vehicle parking spaces shall
not be closer than twenty (20) feet to any projection screen.

422.4. Toilet Facilities. — Separate toilet facilities shall be pro-
vided for each sex as required in article 17 for places of public
assembly.

422.5. Fire Protection. — Sufficient approved portable fire ex-
tinguishers shall be provided in readily accessible locations,
plainly and visibly identified by signs, at distances of not
more than one hundred and fifty (150) feet so as to be available
to every motor vehicle as directed by the fire official. The
fire extinguishers shall be mounted on posts or platforms pro-
tected from mechanical injury with substantial guards as approved
by the building official.

SECTION 423.0. OMITTED

SECTION 424.0. PARKING LOTS

This section shall apply to the construction, alteration, and use
of open parking lots. Open parking lots shall be unobstructed
and free of other uses.

424.1. Curb Cuts. — Parking lots shall be arranged to afford
ready means of entrance and exit at sidewalk level; and special
permits shall be secured for curb cuts from the administrative
authorities. For the purposes of this section, a curb cut shall
be defined as the total length of cut curb, including splays.

424.1.1. Street Frontage. — For street frontages of one hundred
(100) feet or less, the amount of cut curb shall not exceed
sixty (60) per cent of the frontage of the lot. No single curb
cut shall exceed thirty (30) feet in length, and there shall not
be more than two curb cuts on any street frontage of one
hundred (100) feet or less. The minimum distance between two
curb cuts shall be five (5) feet. For additional street frontage
over one hundred (100) feet there may be an additional curb
cut for each fifty (50) feet of frontage.

424.1.2. Distance From Lot Lines. — No curb cut shall com-
mence within eight (8) feet of a side lot line, except that on
lots with street frontages of fifty (50) feet or less, or on corner
lots, the curb cut may commence two (2) feet, six (6) inches
from the side lot line.

424.1.3. Distance From Intersections. — The distance of curb
cuts from the intersection of street lines shall comply with the
zoning resolution.

424.1.4. Limit. — Notwithstanding any of the above computations,
no curb cut shall be less than ten (10) feet.

424.2. Lanes and Parking Spaces. — Access lanes shall be pro-
vided for each row of cars not less than twelve (12) feet in
width; and the parking space shall be not less than eight (8)
feet by eighteen (18) feet in area for each motor vehicle.

424.3. Parking Lot Offices. — Parking lot offices, attendant shel-
ters, storage facilities, and similar structures used in conjunction
with open parking lots may be provided for accessory use,
but shall comply with the fire district limitations of section 303.

424.4. Protection of Adjoining Property. — Open parking lots
shall be completely separated from adjoining land by curbs or
bumpers of concrete, masonry, steel, heavy timber, or other
similar and equally substantial materials, securely anchored so
as to stop motor vehicles. Curbs and bumpers shall be at
least eight (8) inches high and eight (8) inches wide. The only
openings permitted in required curbs and bumpers shall be
for drainage and for motor vehicle entrances and exits, and
at pedestrial entrances.

424.5. Surface and Drainage. — All driveways and open spaces
used for the parking or storage of motor vehicles shall be
surfaced with concrete asphalt, or equivalent durable, dust-
less materials. Where the surface paving of an open parking
lot is nonporous, such lot shall be drained to dry wells or a
storm water system. An asphaltic concrete surface, not to ex-
ceed one and one-half (1-1/2) inches in thickness after com-
paction, shall be considered a porous surface provided such
surface will pass an amount of water equivalent to one-half
(1/2) inch of rainfall per hour. Parking lots graded with rolled
or compacted cinders, gravel or other approved nonabsorbent
materials to prevent raising of dust shall be maintained to
prevent drainage onto adjoining property or the sidewalk.

424.6. Electric Illumination. — Electric light wiring shall be pro-
vided on approved standards to furnish adequate automatic
illumination of driveways and lanes as required by the munici-
pal authorities for street lighting, but in no case shall such
illumination be less than one-tenth (1/10) of one (1) watt per
square foot of parking area.

424-429

424.7. Fire Protection. — Fire protection shall be provided in
accordance with pertinent regulations of the Fire Department
of the City of Boston.

424.8. Sidewalk Protection. — Suitable barriers subject to the
approval of the building official shall be erected where re-
quired to prevent enroachment of vehicles upon abutting side-
walks or other public ways.

SECTION 425.0. OMITTED

SECTION 426.0. OMITTED

SECTION 427.0. OMITTED

SECTION 428.0. OMITTED

SECTION 429.0. SWIMMING POOLS

429.1. General. — Pools used for swimming or bathing shall
be in conformity with the requirements of this section, pro-
vided, however, these regulations shall not be applicable to
any such pool less than twenty-four (24) inches deep or having
a surface area less than two-hundred and fifty (250) square
feet, except when such pools are permanently equipped with
a water recirculating system or involves structural materials.
For purposes of this code, pools are classified as private
swimming pools or public and semi-public swimming pools, as
defined in section 429.2.

Materials and constructions used in swimming pools shall
comply with the applicable requirements of this Code.
Pools used for swimming or bathing and their equipment or
accessories which are constructed, installed and maintained in
accordance with reference standard RS4-19 shall be deemed
to conform to the requirements of this Code, provided the
requirements of section 429.8 and Article VI of the Sanitary
Code of the Commonwealth of Massachusetts, Department of
Public Health are included in the installation.

429.2. Classification of Pools. — Any constructed pool which
is used, or intended to be used, as a swimming pool in con-
nection with a single family residence and available only to
the family of the householder and his private guests shall be
classified as a private swimming pool.

Any swimming pool other than a private swimming pool shall
be classified as a public or semi-public swimming pool.

429.3. Plans and Permit.

429.3.1. Permits. — No swimming pool or appurtenances thereto
shall be constructed, installed, enlarged or altered until a
permit has been obtained from the building official. The ap-
proval of all city, and state authorities having jurisdiction over
swimming pools shall be obtained before applying to the build-
ing official for a permit. Certified copies of these approvals
shall be filed as part of the supporting data for the application
for the permit.

429.3.2. Plans. — Plans shall accurately show dimensions and
construction of pool and appurtenances and properly estab-
lished distances to lot lines, buildings, walks and fences; de-
tails of water supply system, drainage and water disposal
systems, and all appurtenances pertaining to the swimming
pool. Detail plans of structures; vertical elevations; and sections
through the pool showing depth shall be included.

429.4. Locations. — Private swimming pools shall not encroach
on any front or side yard required by this code or the zoning
code. No wall of a swimming pool shall be located less than
six (6) feet from any rear or side property line or ten (10)
feet from any street property line.

429.5. Design and Construction. — Pools shall be constructed
so as to be water tight and easily cleaned. They shall be
built of approved non-absorbent materials with smooth white
or light colored surfaces and shall be free of open cracks and
open joints. All corners at the juncture of pool walls and pool
floor shall be coved with a maximum radius of six (6) inches
at depths less than five (5) feet and with a maximum radius
of three (3) feet less than the depth of the pool at the point
in question, for depths greater than five (5) feet.

429.5.1. Structural Design. — The pool structure shall be engi-
neered and designed to withstand the expected forces to which
it will be subjected, in conformance with the requirements
of article 7.

429.5.2. Wall Slopes. — The side and end walls of all artificial
and semi-artificial pools shall be vertical and shall have a
safety ledge at the deep end of the pool, located at a level
four (4) feet six (6) inches below the surface of the water.
Safety ledges shall be four (4) inches wide, sloping one quarter
(1/4) inch toward the pool.

429

429.5.3. Floor Slopes. — The slope of the floor on the shallow
side of transition point shall not exceed one (1) foot vertical
to twelve (12) feet horizontal. The transition point between
shallow and deep water shall not be more than five (5) feet
deep. There shall be no break in slope on the shallow side
of the transition point.

429.5.4. Surface Cleaning. — All swimming pools shall be pro-
vided with a recirculating skimming device or overflow gutters
to remove scum and foreign matter from the surface of the
water, in conformance with Article VI of the Commonwealth
of Massachusetts, Department of Public Health Sanitary Code.

429.5.5. Walkways. — Walkways shall be continuous around the
pool with a minimum width of four (4) feet of unobstructed
clear distance including a curb at the pool edge, if such curb
is used. Walkways of a width of eight (8) feet are desirable.
A minimum of three (3) feet walk width shall be provided
around any piece of diving equipment. All walks, decks, and
terraces shall have a minimum slope of one-quarter (1/4) inch
per foot toward adequate drains or points at which the water
will have a free unobstructed flow to approved points of dis-
posal at all times.

429.5.6. Steps and Ladders. — Steps or ladders for entering
and leaving the pool shall be of such construction as to mini-
mize danger of accidents. Except in a flush deck pool, a
minimum of one (1) ladder shall be provided for each seventy-
five (75) feet of swimming pool perimeter, and not less than
two such devices shall be provided at any pool. At least one
shall be provided at the shallow end of the pool. Step holes
inserted into the pool wall shall not be permitted. Stairways
shall not project into the pool, but shall be recessed into the
wall and walkway of the pool, except when not exceeding four
(4) in number and extending the full length of any side of the
pool. Ladders shall have an approved handrail on each side
leading out over the walkway. Stairways shall have an approved
handrail at one side or in the center of the stairstep except
that handrails may be omitted when there are not more than
four (4) steps in number or extending the full length of any
side. Handrails and treads of ladders or stairs shall be of an
approved non-slip material.

429.5.7. Markings. — In addition to the requirements of Article
VI of the Commonwealth of Massachusetts Department of
Public Health Sanitary Code, pool markings shall be as herein

prescribed. Swimming lanes shall be marked on the bottom
with dark colored material of the same kind as the pool lining.
The outlet of the pool shall be plainly marked by a black or j
dark colored circle or by the use of a conspicuously colored
outlet grating. The depth of water at the deepest point and at
the five (5) foot point shall be conspicuously marked on both
sides of a pool with deep water at one end. In large pools
with deep water only in the middle, the three (3) and five (5)
foot depth lines shall be conspicuously marked on the bottom,
and portions of the area may also be designated by surface
floats.

429.6. Water Supply, Treatment and Drainage Systems. — All
water supply, treatment and drainage systems shall conform
to the requirements of Article VI of the Sanitary Code, De-
partment of Public Health, Commonwealth of Massachusetts.

429.7. Appurtenant Structures and Accessories. — All appurtenant
structures and accessories shall comply with the requirements
of Article VI of the Commonwealth of Massachusetts, Depart-
ment of Public Health, Sanitary Code as well as herein pre-
scribed.

429.7.1. Appurtenant Structures. — All appurtenant structures,
installation, and equipment, such as showers, dressing rooms,
equipment houses or other buildings and structures, including
plumbing, heating and air conditioning, amongst other ap-
purtenant to a swimming pool, shall comply with all applicable
requirements of this code and the zoning laws of the City of
Boston.

429.7.2. Accessories. — All swimming pool accessories shall be
designed, constructed, and installed so as not to be a safety
hazard. Installations or structures for diving purposes shall
be properly anchored to insure stability, and properly designed
and located for maximum safety.

429.8. Safety Precautions.

429.8.1. Electrical Safety. — The construction and installation
of electric wiring for equipment in or adjacent to swimming
pools, to metallic appurtenances in or within five (5) feet of
the pool, and to auxiliary equipment such as pumps, filters, and
similar equipment shall conform to article 680 of the Massachu-
setts Electric Code, Form FPR-11.

429.8.2. Equipment Installations. — Pumps, filters, and other
mechanical and electrical equipment for public and semi-public
swimming pools shall be enclosed in such a manner as to be

429-430

accessible only to authorized persons and not to bathers. Con-
struction and drainage shall be such as to avoid the entrance
and accumulation of water in the vicinity of electrical equipment.
429.8.3. Swimming Pool Safety Enclosures. — Every person own-
ing land on which there is situated a swimming pool, shall
erect and maintain thereon an adequate enclosure either surround-
ing the property or pool area, sufficient to make such body of
water inaccessible to small children. Such enclosure, including
gates therein, must be not less than four (4) feet above the under-
lying ground; all gates must be self-latching with latches placed
four (4) feet above the underlying ground or otherwise made
inaccessible from the outside to small children.

SECTION 430.0. OPEN PARKING STRUCTURES

Open parking structures shall comply with the most restric-
tive applicable requirements of reference standard RS4-21 and
of this section. In addition, the portions of such buildings
and structures in which gasoline, oil and similar products are
dispensed shall comply with the requirements of section 416;
the portions in which motor vehicles are repaired shall comply
with section 417; and the portions in which paint spraying is
done shall comply with the requirements of section 412.
430.1. General Requirements. — Passenger vehicle structures shall
be constructed of noncombustible materials throughout, in-
cluding structural framing floors, roofs and walls. Any en-
closed rooms or spaces on the premises shall comply with the
applicable requirements of this code. Open passenger vehicle
parking structures are those structures used for the parking
or storage of passenger motor vehicles designed to carry not
more than nine (9) persons.

430.1.1. Ramp type parking structures are those employing
a series of continuously rising floors or a series of intercon-
necting ramps between floors permitting the movement of pas-
senger automobiles under their own power to and from the
street level.

430.1.2. Deleted.

430.1.3. For special fireresistive requirements, see section 905.0.

430.1.4. For exitway requirements, see section 611.5.

430.1.5. The minimum clear height of any parking tier shall
be at least seven (7) feet.

430.2. Separations. — Parking structures may be erected with-j
out enclosure walls except that an enclosure wall with not less!
than two (2) hour fireresistance, without openings therein, shall
be provided when located within fifteen (15) feet of interior lot;
lines. Open parking structures in buildings of other occupancy
group classification shall not be permitted unless separated from
other occupancies by construction having at least a two (2)
hour fireresistance rating.

430.3. Basements. — Basements and other below grade areas of
open parking structures shall comply with the requirements as
set forth in section 415.1.2, basements of public garages, and
section 905.0.

430.4. Heights and Areas. — Heights and areas of open parking
structures shall not exceed the limits in the following table, 4-4,
except as noted in section 905.2.2.

430.4.1. Table 4-4 Height and Area Limitation for Open Parking
Structures

Construction Maximum Allowable Allowable Area per

Classification Height (Feet) Parking Tier (sq. ft.)

1-A Unlimited Unlimited

1-B Unlimited Unlimited

2- A 100 50,000

2-B 100 50,000

430.4.2. The area of an open parking structure having not
more than two (2) tiers above grade shall not be limited.

430.4.3. The areas of structures wherein more than twenty-five
(25) per cent of the perimeter has frontage on street or other
open space leading to a street, each of which is not less than
thirty (30) feet wide may be increased as provided in section
308.1. The above limits of height permit parking on the roof.
430.5. Ramps.— Ramps used for the movement of motor vehicles
and as required exits need not be enclosed when serving tiers
above grade. Such ramps shall have a gradient not exceeding 1
in 7, with nonslip surfaces. A landing having a minimum dimen-
sion of twenty (20) feet shall be provided at the discharge point
of all ramps at the street level, within the street line. Where a
ramp is also used for the parking of motor vehicles, it shall
be considered as a parking tier and may not serve as an exit-
way for the occupants of the structure.

430-432

430.6. Elevators. — Passenger elevators in open parking struc-
tures shall comply with the requirements of article 16 except
that hoistways may be enclosed with non-combustible con-
struction.

430.7. Curbs and Bumpers. — Curbs or bumpers of noncom-
bustible materials shall be provided at the perimeter of each
parking tier. Such curbs or bumpers shall be at least twelve
(12) inches high, substantially anchored, and so located that no
part of any motor vehicle will contact a wall, partition or
railing.

430.8. Railings. — Substantial railings or protective guards of
noncombustible materials shall be provided at the perimeter of
all parking tiers, except where exterior walls are provided, and
around all interior floor openings. Such railings or guards shall
be at least three feet six inches (3'-6") high, and shall be de-
signed in accordance with the requirements of article 7.

430.9. Floor Openings. — A curb or ramp at least six (6) inches
high shall also be provided at all interior floor openings. All
floors shall be pitched to provide adequate drainage.

SECTION 431.0. OMITTED

SECTION 432.0. INTER-COMMUNICATING FLOOR
LEVELS

Where necessary for the functional design of the building, any
structure other than one classified in occupancy group H-2,
Institutional, may be permitted to have a maximum of three
(3) communicating floor levels without enclosure or protection
between such areas, provided that there is compliance with all
of the conditions prescribed within this section and subject to
the approval of the building official.

432.1. Arrangement. — The arrangement of such levels must be
permitted by section 221.2 table 2-2 of this code.

432.2. Grade. — The lowest or next to the lowest level is a level
accessible from the street, or from outside the building at grade,
with floor level at main entrance not more than twenty-one (21)
inches above nor more than twelve (12) inches below grade at
said main entrance.

432.3. Unobstructed View. — The entire area including all com-
municating floor levels shall be sufficiently open and unobstruc-
ted so that it may be reasonably assumed that a fire or other

dangerous condition in any part will be immediately obvious to
the occupants of ail communicating levels and areas.

432.4. Exitways. — Exitway capacity shall be sufficient to pro
vide simultaneously for all the occupants of all communicating
levels and areas. All communicating levels in the same fire area
shall be considered as a single floor area for purposes of deter-
mination of required exitway capacity. Each floor level, con-
sidered separately, shall have at least one-half (1/2) of its
required exitway capacity provided by exitways leading directly
out of that area without traversing another communicating floor
level or being exposed to the spread of fire or smoke therefrom.

432.5. Enclosing Walls. — The enclosing walls of the space created
by the communicating floor levels shall have a fireresistive rating
not less than that required for interior exitway stairways, section
618, with approved fire doors or windows provided in openings
therein, all so designed and installed as to provide a complete
barrier to the spread of fire or smoke through such openings. |

SECTION 433.0. COVERED MALLS, COVERED WALK-
WAYS AND TUNNELS

This section shall apply to connections between buildings such

as covered malls, covered walkways and tunnels, located above

or below grade level, that are used as a means of travel by

persons.

433.1. Definitions.

433.1.1. Covered Mall. — A covered or roofed interior area hav-
ing a minimum horizontal dimension of thirty (30) feet used as
a pedestrian public-way and connecting buildings and/or a
group of buildings housing individual or multiple tenants.

433.1.2. Covered Walkway. — A roofed, unobstructed walkway
the least horizontal dimension is less than thirty (30) feet, con-
necting buildings and used as a means of travel by persons and
where less than fifty (50) per cent of the perimeter is enclosed.

433.1.3. Enclosed Walkway. — A roofed, unobstructed walkway
where the least horizontal dimension is less than thirty (30) feet,
connecting buildings and used as a means of travel by persons
and where fifty (50) per cent or more of the perimeter is en-
closed.

433.1.4. Tunneled Walkway. — An unobstructed underground
walkway connecting buildings and used as a means of travel by
persons.

432-433
433.2. Construction.

433.2.1. Covered Mall.—

a. The roof construction and supporting members of a
covered mall shall be required to be of a type of con-
struction in accordance with section 221.1 table 2-1 and
section 221.2 table 2-2 as permitted for the buildings
connected, but not less than one (1) hour or heavy tim-
ber construction throughout. All unprotected walls and
openings separating a tenant area from the mall area
shall be provided with an automatically actuated water
curtain unless the tenant area is provided with a com-
plete automatic sprinkler system.

b. Concealed spaces, when permitted in a mall roof as-
sembly, shall be separated from adjoining buildings by
not less than one (1) hour fireresistive construction.

c. Except where an approved automatic sprinkler system is
installed, combination or dry standpipe hose cabinets
shall be provided for each two hundred (200) feet of
mall length.

d. Access openings not less than four (4) feet in size in the
roof for fire department use shall be provided for each
one hundred (100) feet of mall length on each side of
the mall.

433.2.2. Covered Walkway. — A covered walkway shall be of
any type of construction permitted by this Code, provided the
walls and openings at the point of connection to the building
shall be protected so as to reasonably prevent the spread of
fire from one building into the other.

433.2.3. Enclosed Walkway. — An enclosed walkway shall be re-
quired to be of a type of construction permitted for the build-
ings connected. Separation between the enclosed walkway and
the building to which it is connected, except when used as an
exitway outlet, shall be of not less than one (1) hour fireresistive
construction, and openings therein shall be protected by a fixed
or automatic self-closing fire assembly having a three-fourths
(3/4) hour fireresistive rating.

433.2.4. Tunneled Walkway. — A tunneled walkway shall be of
a type of construction suitable for underground location. Separa-
tion between the tunneled walkway and the building to which
it is connected shall be not less than two (2) hour fireresistive
construction, and openings therein shall be protected by a fire

assembly having a one and one-half (1-1/2) hour fireresistivej
rating.

433.3. Transparent or Translucent Roofs. — In lieu of the roof
construction outlined in section 433.2, roofs of covered malls,
covered walkways and enclosed walkways may be constructed
of noncombustible supporting elements and approved translucent
or transparent panels, subject to the limitations herein established
and any further requirements of the building official. Wall and
opening protection shall be in conformance with section 433.2.

433.3.1. Structural Requirements. — All supporting members and
paneling shall conform to the requirements of article 7.

433.3.2. Slope. — Flat roofs shall not be allowed. Roofs shall be
pitched at a minimum of four (4) feet vertical in twelve (12) feet
horizontal. Curved roof surfaces shall have a rise equal to
fifteen (15) per cent of the span.

433.3.3. Condensate. — Provisions shall be made in the design of
the roof structure for the removal of condensate from the inner
surface of the roof structure. Such provisions may be either in-
corporated into the design of the supporting element or may be
attached thereto, but in no case shall they be detrimental to
the use of the enclosed area below.

433.3.4. Plastic Panels. — Plastic panels to be incorporated as a
part of the construction of covered malls, walkways, and tunnels
shall comply with the applicable requirements of article 20.

433.3.5. Glass Panels. — Size, shape and type of material used
shall be subject to approval of the building official.

433.3.6. Allowable Areas. — When complying with the provisions
of this code, covered malls constructed of transparent or trans-
lucent materials whose supporting elements are of type 1 con-
struction may not be more than fifty thousand (50,000) square
feet in area. For all other types of allowable construction, the
basic allowable area for covered malls constructed of transpar-
ent or translucent materials shall be twice the value indicated
in section 221.2 table 2-2 for occupancy group F-3. All areas
regardless of construction shall be sprinkered in conformance
with section 1213.1.5.

433.4. Multiple Levels. — Balconies and mezzanines in covered
malls shall conform to the requirements of section 432.0.

433.5. Allowable Areas. — (For other than transparent or trans-
lucent roofs). When complying with the provisions of this code,
covered malls of type 1 construction may not be more than one
hundred and fifty thousand (150,000) square feet unless sprin-

433

klers are provided. For all other types of construction, the basic
allowable area for covered malls shall be as indicated in sec-
tion 221.2 table 2-2 for group F-3 occupancy. The area of
covered malls may be tripled when the covered mall is provided
with a complete automatic sprinkler system. Unlimited areas
as provided in section 221.2 table 2-2 shall not apply. Refer
to section 433.3.6 for allowable areas explicitly for transparent
or translucent roofs.

433.6. Exitways.

433.6.1. Covered Mall. — One-half (1/2) of the required egress
width for buildings connected by a covered mall shall lead to
the outside by means other than through the mall. The covered
mall connecting buildings shall have not less than two (2) inde-
pendent exitways located as remotely as practicable from each
other. These exitways shall have a total exit width equal to that
required for the exitways from all buildings which are within
one hundred (100) feet travel distance to the mall exitways. The
maximum distance of travel to an exitway measured within the
mall shall not exceed two hundred (200) feet. In order to pro-
vide free and unencumbered travel in the mall to the outside,
each side of the mall floor area shall be provided with an un-
obstructed space, not less than twelve (12) feet in width; parallel
to the building lines and extending to the exitway from the
mall. This width shall be designed to carry the weight of fire
trucks.

433.6.2. Enclosed and Tunneled Walkways. — Enclosed and
tunneled walkways shall not be accepted as a required means of
egress unless they comply with the provisions of this article.
When the length of enclosed or tunneled walkways not meeting
the provisions of this article for required exitways is more than
one and one-half (1-1/2) times the maximum allowable distance
of travel of the most restrictive occupancy being connected, one
(1) or more exitways from the enclosed or tunneled walkway
shall be provided. Such exitways shall be located as remotely
from points of connection between the enclosed or tunneled
walkway and the buildings as is practicable.

433.7. Ventilation. — Smoke and heat venting shall be provided
for covered malls and enclosed walkways and tunneled walk-
ways. Such venting systems shall be in accordance with refer-
ence standard RS4-22.

SECTION 434.0. RADIOACTIVE MATERIALS AND
RADIATION-PRODUCING EQUIPMENT

This section shall apply to the construction, alteration, and use
of buildings or spaces for radioactive materials and radiation-
producing equipment. In addition to the requirements of this
section, occupancies involving radioactive materials and radiation-
producing equipment shall also comply with applicable require-
ments of the Health Code of the City of Boston, and of title
10 of the code of federal regulations relating to atomic energy,
and of reference standard RS4-20.

434.1. Laboratories. — All laboratories required to register under
the requirements of the above codes shall comply with the
following:

434.1.1. Construction. — All buildings in which such laboratories
occur shall be of noncombustible group I construction.

434.1.2. Floors. — All floors shall comply with the fireresistance
requirements for the class of construction, and provide the
degree of radioactive resistance required by applicable city, state,
and federal regulations. A finished material shall by applied to
provide a continuous nonporous surface which may be readily
removed.

434.1.3. Interior Finish. — All insulation of acoustical treatments
and interior partitions shall be of noncombustible material. Walls
and ceilings shall have nonporous finishes of class A rating.

434.1.4. Sprinkler Protection. — Automatic sprinkler protection
complying with the construction provisions of article 12 shall
be provided, and such protection shall be designed for the type
of combustible materials wherever such material is used, and for
the radioactive material that may be expected to melt, vaporize,
or oxidize under fire conditions. Laboratory equipment sus-
ceptible to damage from water or other materials used in the
sprinkler system may be shielded by hoods except when the
equipment provided a source of combustion. Where sprinkler
protection uses water, or small water-spray installations are used
to fight small isolated fires, floors shall be provided with
drainage so that water may be carried to retention tanks for
later disposal as required when contamination of water is to
be anticipated.

434.1.5. Electrical Equipment. — Artificial lighting and electric
equipment shall comply with section 400.5.

434

434.1.6. Ventilation. — Exhaust air from areas in which radio-
active materials are used or stored shall be exhausted to the
outdoors in such manner as not to create a health hazard, and
shall not be recirculated to other areas of the building. Air
pressure in rooms in which radioactive materials are used or
stored shall be maintained below the air pressure of adjoining
rooms, so that there is no flow of radioactive gases or dusts
into adjoining rooms.

a. Ducts shall be of sheet steel not less than No. 16
manufacturers' standard gage or of other equivalent non-
combustible material having a melting point above
1800°F. Exhaust ducts within the building, on the dis-
charge side of the fan, shall be welded airtight. Exhaust
ducts within the building, on the suction side of the fan
shall have laps in the direction of air flow with smoke-
tight joints, and shall be subjected to a smoke test in ac-
cordance with the requirements for chimneys in article
10. Access hatches with tight-closing covers shall be pro-
vided for cleaning and for fire-fighting in the exhaust
system ducts.

b. Fume hoods shall be exhausted to the outdoors. Con-
trols for hood fans shall be interlocked so that contam-
inated air cannot be drawn into any space from a hood
where the exhaust fan is not in operation.

c. Fan equipment other than the impeller and impeller
housing shall be located outside the exhaust stream.

d. When the degree of contamination of the exhaust stream
exceeds the concentration limits permitted by the health
code, the duct system shall be equipped with devices to
decontaminate the air to a safe level before discharging
to the outdoor air.

434.1.7. Plumbing. — Drainage lines from sinks used for radio-
active wastes shall be without traps, and shall lead to retention
tanks as required in section 434.1.4.

434.2. Radiation Machines. — Radiation machines or particle
accelerators, linear accelerators, cyclotrons, syncrotons, betatrons
shall be located only in buildings of noncombustible group I
construction; however, this requirement shall not apply to con-
ventional medical, dental, research, or industrial x-ray machines
of less than 1,000,000 volt capacity.

434.3. Storage. — Radioactive materials shall be stored in sealed
containers. When required by the building official to avoid too

concentrated an exposure within any one space, radioactive
materials shall be stored in vaults designed in accordance with
the radiation shielding or other requirements for the materials
to be stored. When any materials are subject to melting, vapor-
ization, or oxidation under fire conditions, the storage vaults
shall be constructed of walls having a fireresistance rating of at
least four (4) hours, and the vaults shall be equipped with auto-
matic sprinklers complying with the construction requirements
of article 12 and shall be vented through devices to decontam-
inate the air to a safe level. Doors opening into storage vaults
shall meet shielding requirements and have a fire-protection
rating of not less than three (3) hours. All bins, shelving, parti-
tions, and pallets in storage vaults shall be of noncombustible
materials. Other methods of storage permitted by the health
department or the atomic energy commission, such as storage
under water, may be used.

RS4

List of Reference Standards

ANSI PH22.31 1967
Motion Picture Safety Film

APHA 1957

Swimming Pools and other Public Bathing Places,

Recommended Practice for Design, Equipment and

Operation

Mass-DPS Form B-3 1947

Tents Used as Public Halls, Miscellaneous Halls,
and Mercantile or Other Establishments, Regulations
Applicable to

Mass-DPS Form B-5 1967

Construction, Alteration, Remodeling, and Recon-
struction of Grandstands, Bleachers, Stadia or Arenas,
and Race Track Crash Barriers, Regulations Governing

Mass-DPS Form C 1955

Use of the Cinematograph and Similar Apparatus for
the Exhibition of Motion Pictures-Laws, Rules and
Regulations Governing the

Mass-DPS FPR 2 1963

Dry-Cleaning and Dry-Dyeing, and the Keeping,
Storage and Use of Cleaning and Dyeing Fluid in
Connection Therewith.

Mass-DPS FPR 4 1968

Construction and Maintenance of Buildings or Other
Structures Used as Garages and the Related Storage,
Keeping and Use of Gasoline.

Mass-DPS FPR 5 1962

Construction, Location, Installation and Operation of
Liquefied Petroleum Gas Systems, Gas Piping and
Appliance Installations in Buildings.

Mass-DPS FPR 6 1948
Manufacturing and Handling of Plastics.

Mass-DPS FPR 13 1965

Keeping, Storage, Manufacture or Sale in Limited

Quantities of Flammable Fluids, Solids, or Gases.

NFPA Vol. 1 1969-70
Flammable Liquids

NFPA 24 1969

Outside Protection (Yard Piping)

NFPA 30 1969

Flammable and Combustible Liquids Code

NFPA 32 1964

Dry Cleaning Plants

NFPA 33 1969

Spray Finishing Using Flammable and Combustible

Materials

NFPA 34 1966

Dip Tanks Containing Flammable or Combustible Li-
quids

NFPA 40 1967

Cellulose Nitrate Motion Picture Film

NFPA 42 1967

Pyroxylin Plastic in Factories, Storage, Handling and

Use

NFPA 43 1967

Pyroxylin Plastic in Warehouses, Wholesale and Retail

Stores

NFPA 58 1969

Liquefied Petroleum Gases, Storage and Handling

NFPA 59 1968

Liquefied Petroleum Gases at Utility Gas Plants

RS4

NFPA 60 1961

Pulverized Fuel Systems, Installation and Operation of

NFPA 61 A 1962

Starch Factories, Prevention of Dust Explosions in

NFPA 61B 1959

Terminal Elevators, Prevention of Dust Explosions

NFPA 61C 1962

Flour and Feed Mills, Allied Grain Storage Elevators,

Prevention of Dust Explosions

NFPA 63 1964

Industrial Plants, Fundamental Principles for Preven-
tion of Dust Explosions in

NFPA 64 1959

Country Grain Elevators, Prevention of Dust Ignitions

NFPA 68 1954

Explosion Venting Guide

NFPA 88 1968

Garages

NFPA 90A 1969

Air Conditioning and Ventilating Systems

NFPA 102 1967

Tents and Grandstands and Air-Supported Structures

Used for Places of Assembly

NFPA 204 1968

Smoke and Heat Venting Guide

NFPA 329 1965

Underground Flammable and Combustible Liquid

Tanks, Leakage From

NFPA 501B 1968
Mobile Homes

NFPA 654 1963

Dust Explosion Prevention in Plastic Industry

NFPA 656 1959

Spice Grinding Plants, Prevention of Dust Ignitions in

NFPA 657 1967

Confectionery Manufacturing Plants, Prevention of

Dust Explosions in

NFPA 701 1969

Flame-Resistant Textiles and Films, Standard Method

of Tests for

NFPA 801 1955

Radioactive Materials, Safe Practice for Laboratories

Handling of

NFPA 802 1960

Nuclear Reactors, Fire Protection Practice for

US Federal Test Method Standard No. 191 1968
Method 5190 Textile Test, Burning Rate of Cloth,
30° Angle

RS 4-1 NFPA 68 1954

Explosion Venting Guide

RS 4-2 NFPA 30 1969

Flammable and Combustible Liquids Code

RS 4-3 Mass. FPR 13 1965

Keeping, Storage, Manufacture or Sale in Limited
Quantities of Flammable Fluids, Solids, or Gases.

NFPA 329 1965

Underground Flammable and Combustible Liquid

Tanks, Leakage From

RS 4-4 Mass. FPR 5 1962

Construction, Location, Installation and Operation of
Liquefied Petroleum Gas Systems, Gas Piping and
Appliance Installations in Buildings, Rules and Regu-
lations Governing the

NFPA 58 1969

Liquified Petroleum Gases, Storage and Handling

RS 4-1 RS 4-7

NFPA 59 1968

Liquified Petroleum Gases at Utility Gas Plants

Mass. FPR 6 1948

Manufacturing and Handling of Plastics

NFPA 42 1967

Pyroxylin Plastic in Factories, Storage, Handling and

Use

NFPA 43 1967

Pyroxylin Plastic in Warehouses, Wholesale and Retail

Stores

NFPA 654 1963

Plastics Industry, Dust Explosion Prevention

Mass. FPR 13 1965

Keeping, Storage, Manufacture or Sale in Limited

Quantities of Flammable Fluids, Solids or Gases.

NFPA 60 1961

Pulverized Fuel Systems, Installation and Operation of

NFPA 61A 1962

Starch Factories, Prevention of Dust Explosions in

NFPA 61B 1959

Terminal Elevators, Prevention of Dust Explosions

NFPA 61C 1962

Flour and Feed Mills, Allied Grain Storage Elevators,

Prevention of Dust Explosions

NFPA 63 1964

Industrial Plants, Fundamental Principles for Pre-
vention of Dust Explosions in

NFPA 64 1959

Country Grain Elevators, Prevention of Dust Ignitions

NFPA 654 196J

Plastics Industry, Dust Explosion Prevention

NFPA 656 1959

Spice Grinding Plants, Prevention of Dust Ignitions in

NFPA 657 1967

Confectionery Manufacturing Plants, Prevention of

Dust Explosions in

RS 4-8 NFPA 33 1969

Spray Finishing Using Flammable and Combustible
Materials

NFPA 34 1966

Dip Tanks Containing Flammable or Combustible

Liquids

RS 4-9 Mass-DPS FPR 2 1963

Dry-Cleaning and Dry-Dyeing, and the Keeping,
Storage and Use of Cleaning and Dyeing Fluid in
Connection Therewith.

NFPA 32 1964

Dry Cleaning Plants

RS 4-10 NFPA 24 1969

Outside Protection (Yard Piping)

RS 4-11 NFPA 102 1967

Tents and Grandstands and Air-Supported Structures
Used for Places of Assembly

Mass-DPS Form B-3 1947

Tents Used as Public Halls, Miscellaneous Halls, and
Mercantile or Other Establishments, Regulations Ap-
plicable to

Mass-DPS Form B-5 1967

Construction, Alteration, Remodeling, and Recon-
struction of Grandstands, Bleachers, Stadia or Arenas,
and Race Track Crash Barriers, Regulations Governing

RS 4-8 RS 4-21
RS 4-12 Mass-DPS Form C 1955

Use of the Cinematograph and Similar Apparatus for

the Exhibition of Motion Pictures, Laws, Rules and

Regulations Governing the

RS 4-13 ANSI PH22.31 1967
Motion Picture Safety Film

NFPA 40 1967

Cellulose Nitrate Motion Picture Film

RS 4-14 NFPA 701 1969

Flame-Resistant Textiles and Films, Methods of Tests
for

RS 4-15 US Federal Test Method Standard No. 191

Method 5190 Textile Test, Burning Rate of Cloth,
30° Angle

RS 4-16 deleted

RS 4-17 deleted

RS 4-18 deleted

RS 4-19 APHA 1957

Swimming Pools and Other Public Bathing Places,
Recommended Practice for Design, Equipment and
Operation

RS 4-20 NFPA 801 1955

Radioactive Materials, Safe Practice for Laboratories
Handling

NFPA 802 1960

Nuclear Reactors, Fire Protection Practice for

RS 4-21 Mass FPR 4 1968

Construction and Maintenance of Buildings or Other
Structures Used as Garages and the Related Storage,
Keeping and Use of Gasoline.

NFPA 88 1968

Garages

RS 4-22 NFPA 204 1968

Smoke and Heat Venting Guide

RS 4-23 NFPA 90A 1969

Air Conditioning and Ventilating Systems

RS 4-24 NFPA Vol. 1 1969-70
Flammable Liquids

ARTICLE
LIGHT, HEAT, VENTILATION AND NOISE CONTROL

500.0

Scope

515.0

Omitted

501.0

Definitions

516.0

Ventilation of Shafts other

502.0

Plans and Specifications

than Elevator and Dumb-

503.0

Standards of Natural Light

waiter Hoistways and

504.0

Standards of Natural Ventila-

Stairways

tion

517.0

Omitted

505.0

Standards of Heating

518.0

Courts

506.0

Existing Buildings

519.0

Omitted

507.0

Standards of Artificial Light

520.0

Obstruction of Courts

508.0

Standards of Mechanical

521.0

Fire Emergency Exhaust Sys-

Ventilation

tem

509.0

Ventilation of Special Spaces

522.0

Omitted

510.0

Omitted

523.0

Window Cleaning Safeguards

511.0

Omitted

524.0

Noise Control in Multiple

512.0

Institutional Buildings

Dwellings

513.0

Omitted

RS5

Reference Standards

514.0

Omitted

TABLES

5-1 505.1.1. Minimum Space Temperature Requirements

FIGURE

5-1 508.2.1. Minimum Outside Air Requirements for Ventilation and Air
Conditioning

SECTION 500.0. SCOPE

The provisions of this article shall establish and control the
minimum requirements for light, heat, ventilation, and noise
control except as otherwise provided in articles 4 and 6.

500.1. Standards. — The provisions of reference standard RS 5
are a part of this article.

500.2. Tests and Inspections. — All equipment and systems shall
be tested and /or inspected to disclose defects or operating con-
ditions dangerous to life or health. Such equipment or systems
shall not be operated until defects or dangerous conditions are
corrected.

SECTION 501.0. DEFINITIONS

For definitions to be used in the interpretation of this article 2.

SECTION 502.0. PLANS AND SPECIFICATIONS

Plans for all buildings and structures other than one- and two-
family and multi-family dwellings, which are designed for hu-
man occupancy, shall designate the number of occupants to be
accommodated in the various rooms and spaces. When means of
artificial lighting and ventilation are required, the application
shall include details and description of the mechanical system
to be installed as herein required or as specified in article 18.

SECTION 503.0. STANDARDS OF NATURAL LIGHT

503.1. Natural Light Requirements. — Provide every habitable
room with natural light complying with the provisions of this
article.

503.2. Natural Light Sources and Locations. — Natural light,
when required, shall be admitted by windows, skylights, moni-
tors, glazed doors, transoms, fixed lights, jalousies, or other
natural-light transmitting media. Such sources shall face or open
upon the sky, or upon a public street, space, alley, park, high-
way, or right of way, or upon a yard, court, plaza, or space
above a setback, when such yard, court, plaza, or space above
a setback is located upon the same lot and is of the dimensions
required by the applicable provisions of the zoning resolution.

503.3. Area of Natural Light Sources. — The transmitting area
of all sources of natural light not closer than thirty (30) inches
to the finished floor shall aggregate at least ten (10) percent of
the floor area of the space served.

SECTION 504.0. STANDARDS OF NATURAL VENTILA-
TION

504.1. Occupiable Rooms. — Ventilation of occupiable rooms
shall be by natural or mechanical means, or both, except where
mechanical ventilation is required by Sections 508.0. or 509.0.

504.2. Habitable Rooms. — All habitable rooms shall have
natural ventilation.

502-505

504.3. Alcoves. — An alcove or room opening off another room
or space shall be ventilated as a separate room, unless the
opening between the alcove and the room or space is at least
eighty (80) percent of the area of the common wall, and the
floor area of the alcove does not exceed twice the area of the
opening.

504.4. Balconies. — The area of an interior balcony or mezza-
nine which opens to form part of another room or space shall
be added to the area of the room or space in which it is
located to compute the ventilation required for both spaces.

504.5. Natural Ventilation Openings. — Natural ventilation shall
be from unobstructed windows, skylights, monitors, doors,
louvers, jalousies, or other similar openings. Such openings
shall be direct to the sky, public street, space, alley, park, high-
way, or right of way; or upon a yard, court, plaza, or space
above a setback, where such yard, court, plaza, or space above
a setback is located on the same lot and is of the character-
istics required by the applicable provisions of the zoning code
and section 518.

504.6. Area of Natural Ventilating Openings. — Natural venti-
lating openings from habitable spaces shall have a free area
when open of at least five (5) percent of the floor area of the
space ventilated. In occupiable spaces, the free openable area
shall be the basis to determine the minimum requirements for
supplementary mechanical ventilation. Free openable area is
the cross sectional area at plane of greatest restriction to air
flow, exclusive of insect screening.

SECTION 505.0. STANDARDS OF HEATING

505.1. Heating Requirements. — All habitable or occupiable
spaces, and spaces listed in table 5-1 shall be heated in ac-
cordance with the requirements of this article and reference
standard RS 5-1. Heating systems shall be capable of producing
the temperature listed in table 5-1 when outdoor temperature
is plus five (5) degrees F., and wind velocity is fifteen (15)
miles per hour, plus due allowance for stack effect in tall
buildings. Heating equipment shall not be required when either
of the following conditions exist:

a. Where occupancy is seasonal, the space contains no
undrained water pipes, and the rooms or buildings will
not be occupied between November 1 and May 1 of the
following year.

b. Where the processes or activities normally conducted
within the space will generate sufficient heat to produce
the prescribed indoor temperature during the time of
occupancy.

505.1.1. Table 5-1 Minimum Space Temperature Requirements*

Minimum
Temperature
Rooms or Spaces (degree F.)

Habitable rooms in all buildings G\70

Building equipment and machinery rooms 50

Patients' rooms, bathrooms and toilet rooms, stairs
and corridors in hospitals and nursing homes. 75

Bathrooms and toilet rooms, except patients' bath-
rooms and toilet rooms in hospitals and nursing
homes. 70

Offices, waiting rooms, art galleries, museums, li-
braries, meeting rooms, churches, classrooms, audi-
toriums, lecture halls, night clubs, restaurants,
theatres, nursery rooms, and spaces where persons
are engaged in sedentary activities 70

Laboratories, light machine work, product inspections,
loft buildings, shops, stores, display rooms, show
rooms, sales rooms, and spaces where persons are
engaged in moderate physical activities. 65

Gymnasia, dance halls, skating rinks, bowling alleys,
heavy assembly workrooms or shops, and spaces
where persons are engaged in vigorous physical
activities. 60

Automotive repair shops 50

Storage areas, garages, space where work or pro-
cess requires a low temperature None

Hospital operating rooms, and recovery, labor, and
delivery rooms 80

Swimming pools, bath houses, and shower rooms 75

505-506
NOTE: *Where the listed temperatures differ from those that
are required to be maintained under the provisions of rules,
regulations, or laws of the state or city, the higher temperature
shall apply.

505.2. Minimum Temperature Requirements. — Where the occu-
pancy of any space does not conform exactly with one of the
listed spaces, the temperature shall be determined by the re-
quirements of the listed space to which it most nearly conforms.

505.3. Devices Producing Incidental Heat. — Devices within a
space such as motors, generators, resistors, lights, compressors,
steam-heated vessels, etc. which are in constant use during the
period of occupancy and which produce heat may be considered
as a supplementary heating device. Their heating capacity may
be deducted from the required capacity of the heating devices
in the room in the following percentage:

a. If the equipment heat is liberated within

seventy two (72) inches of the floor 100 percent

b. If the equipment heat is liberated above

seventy two (72) inches from the floor 60 percent

c. If the equipment heat is liberated within

an exhaust hood 30 percent

505.4. Capacity of Heat Sources. — Heat sources shall have a
gross output capacity sufficient to provide for the required heat-
ing load, including, if applicable, appropriate allowance for
process loads, uncontrolled distribution losses, the heating of
domestic hot water and temperature recovery (so-called pick-up)
after night set-back.

SECTION 506.0 EXISTING BUILDINGS

506.1. Unsafe Conditions. — If any existing space does not meet
the requirements of this article for light and ventilation and, in
the opinion of the building official, is dangerous to the health
and safety of the occupants, upon his written order the repairs
or installations required to conform to this article shall be made.

506.2. Alterations. — No building, or part thereof, shall here-
after be altered or rearranged so as to reduce any of the space
conditions to less than the required standards prescribed in this
article. No additional room shall be created unless made to
conform to the requirements of this article.

506.3. Noise Control. — In multi-family dwellings, the installa-
tion of new mechanical equipment shall conform to the require-
ments of Section 524.0. Repairs to existing equipment is not
considered as new equipment.

SECTION 507.0. STANDARDS OF ARTIFICIAL LIGHT

507.1. Artificial Light Requirements. — Adequate means for pro-
ducing artificial light shall be provided in every occupiable
space in every building hereafter erected and in the portions of
existing buildings where alterations are performed, except as
follows:

a. Artificial light is not required in rooms or spaces nor-
mally occupied exclusively during the daylight hours
between one hour after sunrise and one hour before sun-
set and which- have natural light sources as required by
Sections 503.2. and 503.3.

b. Artificial light is not required in rooms or spaces with
less than forty (40) sq. ft. floor area if they are not
regularly occupied and if they contain no heat produc-
ing equipment, no hazardous equipment or automatic
safety devices.

507.2. Means of Egress. — Provide artificial illumination of
means of egress as required in article 6.

507.3. Places of Assembly. — Provide artificial illumination of
places of assembly as required in articles 4 and 6.

507.4. Bathrooms and Toilet Rooms. — Provide artificial illum-
ination of bathrooms and toilet rooms averaging not less than
ten (10) foot candles, thirty (30) inches above the floor.

SECTION 508.0. STANDARDS OF MECHANICAL VENTI-
LATION

508.1. Areas Requiring Mechanical Ventilation. — Mechanical

ventilation shall be provided in all occupiable rooms or spaces
where the requirements for natural ventilation are not met; in
all rooms or spaces, which because of the nature of their use or
occupancy, involve the presence of dust, fumes, gases, vapors,
or other noxious or injurious impurities, or substances which
create a fire hazard; or where required by the provisions of
Section 509.0. or articles 4 and 6.

506-508
508.2. Outside Air. — Where mechanical ventilation is required
the minimum amount of outside air introduced into any room
or enclosed space shall be at least equal to the amount required
by Figure 5-1.

508.2.1. Figure 5-1 Minimum Outside Air Requirements for
Ventilation and Air Conditioning

700

600

500

400

300

o 200
<

en
9=
< 100

\ 1
\ A

^ I

—

4 8 12 16 20 24 28
MINIMUM OUTDOOR AIR, CU. FT. PER PERSON PER MIN.

508.2.2. Curve A- Ventilation Only. — The values obtained from
Curve A represent the minimum volume of outdoor air required
for adults quietly occupied. Where the space has mechanical
cooling, the values of Curve A represent the minimum amount
of air to be circulated.

a. Values of Curve A shall be increased by twenty-five (25)
percent for areas in which the occupancies contain or
involve:

L. Grade school children

2. Light smoking

3. Food Service

4. Other occupancies involving light air contam-
ination

b. Values of Curve A shall be increased fifty (50) percent
for areas in which the occupancies contain or involve:

L. Manual labor

2. Sports

3. Dancing

4. Heavy smoking

5. Other occupancies involving heavy air contam-
ination

c. Values of Curve A shall be increased by an appropriate
amount to remove excess heat or moisture generated by
equipment in the occupied area.

508.2.3. Curve B- Mechanical Cooling. — The values obtained
from Curve B represent the minimum volume of outdoor air
required for adults quietly occupied where adequate control is
maintained over temperature and humidity and where odor re-
moval apparatus is used if smoking is permitted in the occupied
area.

a. Where only part of the above-mentioned controls are
maintained, the values of Curve B must be increased in
accordance with good engineering design and subject to
the approval of the building official.

508.3. Means of exhaust. — Exhaust may be accomplished by:

a. Forcing leakage through openings communicating directly
to the outdoor air.

b. By drawing the vitiated air from spaces into the return
air duct of the system apparatus. When exhaust is to
a return air duct the system apparatus shall be equipped
to mix outdoor and return air under conditions which
assures that the minimum amount of outdoor air will

508

never be less than the sum of the minimum outdoor
air ventilation requirements of all the spaces served by
that system,
c. By drawing air into a fan powered exhaust system dis-
charging directly to the outdoor air.

508.4. Make-up Air. — Sufficient air to replace the exhaust
quantity shall be admitted to spaces which are under forcible
exhaust by one or by any combination of the following methods:

a. If permitted by this Code, by infiltration through louvres,
registers, or other permanent openings in walls, doors,
or partitions of adjoining spaces where air is supplied
in sufficient excess to meet the requirements of both
spaces.

b. By infiltration through natural ventilation openings when
the heating system is properly designed to permit such
infiltration without causing drafts objectionable to the
occupants.

c. By other methods acceptable to the building official,
and in conformance with good engineering practice.

d. If permitted by this Code, exhaust may be accomplished
by forcing leakage through permanent openings to ad-
joining spaces from which air is removed by method
508. 3. c. provided the total amount of ventilation of
both spaces is not reduced to less than the amounts
required by Figure 5-1 and provided the space is not of
the type from which recirculation of air is prohibited.

508.5. Prohibited Use of Recirculated Air. — Air drawn from the
following spaces may not be recirculated: mortuary rooms,
hospital operating rooms, bathrooms, water closet compartments,
locker rooms, toilet rooms, rooms that must be isolated to
prevent the spread of infection, or any space where flammable
vapors, dust, odors, or noxious gases are present in amounts
exceeding the Threshold- Limit Values established for same by
reference standard RS 5-2.

508.6. Use of Adsorption Devices. — If recirculation of air is
permitted, the required outdoor air supply may be reduced up
to fifty (50) percent, provided that an equivalent quantity of
the recirculated air is passed through approved adsorption de-
vices. The adsorption material, the material quantity and the
means provided for maintaining the effectiveness of the adsorp-
tion devices shall be acceptable to the building official and in
conformance with good engineering practice.

508.6.1. Improper Maintenance. — Should adsorption devices be
improperly maintained in the opinion of the building official,
he may order their removal. If the adsorption devices are
removed the ventilating system shall not be operated unless
it will supply one hundred (100) percent of the outdoor air
required by this section or section 509.0.

508.6.2. Test Records. — The building owner shall continuously
maintain a record showing the manufacturer's recommendation
for frequency of tests, the method of making tests, and the
results of periodic tests of the adsorption devices. Such tests
shall be made and certified by the manufacturer or by a labora-
tory acceptable to the building official at least twice every six
(6) months. The records of- such tests shall be maintained for
a period of at least two (2) years, and shall be available for
inspection by the building official.

508.7. Installation of Ventilating Systems. — Where mechanical
ventilation is installed as an alternate or supplement to natural
ventilation, or is required under the conditions herein prescribed,
the system, equipment, and distributing ducts shall be installed
in accordance with the applicable provisions of articles 10, 11
and 18.

SECTION 509.0 VENTILATION OF SPECIAL SPACES

509.1. Kitchens. — Kitchens shall be ventilated as follows:

509.1.1. Dwelling Units. — Kitchens located within dwelling units
and having a floor area of greater than seventy (70) square feet
shall have natural ventilation as prescribed in section 504.0.
When the floor area is seventy (70) square feet or less, the
kitchen shall be ventilated by either of the following:

a. Natural means complying with section 504.0.

b. Mechanical means exhausting at least two (2) cfm of
air per square foot of floor area.

509.1.2. Other than Dwelling Units. — Kitchens, except those
located within dwelling units, and any spaces where cooking
of any kind is done, shall be ventilated by either of the following:

a. Natural means complying with section 504.0. or mechan-
ically- air cooled means complying with Figure 5-1 section
508.2 and supplemented with auxiliary mechanical supply
and exhaust ventilation adequate to remove the fumes
and smoke from the cooking equipment when operating,
in accordance with the provisions of article 18.

508-509

b. Non-air cooled mechanical means exhausting at least
three (3) cfm of air per square foot of floor area, but
in no case less than one hundred fifty (150) cfm.

509.1.3. Warming Area. — Kitchens, snack bars, or pantries,
where the operation consists of heating or warming previously
prepared food that was cooked elsewhere, or where food is
prepared in vending machines, may be ventilated by either or
a combination of the following:

a. Natural ventilation complying with section 504.0.

b. Mechanical ventilation complying with section 508.0.

509.1.4. Means of Exhaust. — Air shall be exhausted through
ducts or chimneys constructed in accordance with the provisions
of articles 10, 11 and 18.

509.1.5. Make-up Air. — Make-up air shall be provided by one
of the methods described in section 508.4.

509.2. Bathrooms and Toilet Rooms. — Bathrooms and toilet
rooms shall be ventilated as follows:

509.2.1. Natural Ventilation. — When ventilated by natural means,
the natural ventilation openings shall comply with sections
504.5. and 504.6. except:

a. In no case shall the net free area of the ventilation
openings be less than one and one-half (1-1/2) square
feet.

b. In occupancy groups H-l and H-2, the ventilation open-
ing may be to a vent shaft provided that the net free
area of the opening is not less than three (3) square
feet. The vent shaft cross-sectional area shall be equal
to the sum of the required minimum ventilation openings
plus one-fifth (1/5) square foot for every foot of height
but not less than nine (9) square feet and open to the
outer air at the top; or, the vent shaft may be open
at the sides above the roof with louvres providing net
free area equal to the area of the shaft.

509.2.2. Natural Ventilation by Shaft or Duct. — Ventilation
may be by individual vent shafts or ducts constructed of non-
combustible materials with a minimum cross-sectional area of
one (1) square foot plus one-third (1/3) square loot for each
additional water closet or urinal above two (2) in number.
The upper termination of such ducts shall be equipped with
a wind actuated ventilator cap with throat area equal to the
duct area.

509.2.3. Mechanical Ventilation. — When a bathroom or toilet
room is not ventilated by natural ventilation as required by
this section, it shall be mechanically ventilated as follows:

a. Rooms containing only one water closet or urinal shall
be mechanically ventilated by an exhaust system capable
of exhausting at least fifty (50) cfm.

b. Rooms containing more than one water closet or urinal,
and any auxiliary spaces such as those used in hand
basins, slop sinks, and locker rooms, shall be mechanically
ventilated by an independent exhaust system capable of
exhausting at least forty (40) cubic feet of air per minute
per water closet or urinal. The outdoor air supply shall
conform to the requirements of section 508.0.

c. Toilet exhaust systems shall be arranged to expel air
directly to the outdoors.

509.2.4. Make-up Air. — Make-up air shall be provided by one
of the methods described in section 508.4.

509.3. Inside Locker Rooms. — Inside locker rooms and dressing
rooms for more than one (1) person shall be ventilated at a
rate of four (4) changes of air per hour or as required by
section 508.3., whichever is greater.

509.4. Corridors. — Corridors shall have ventilation provisions
to supply outdoor air in conformance to whichever of the
following is greater:

a. For make-up of air exhausted to adjoining spaces.
Provisions for make-up air supply shall conform to section
508.4.

b. Natural sources complying with section 504.5. to provide
ventilating- openings equivalent to at least two and one-
half (2-1/2) percent of the floor area.

c. In occupancy groups H-l, I-U2 and L-2 mechanical
supply of at least one-half (1/2) cubic foot of outdoor
air per minute per square foot of floor area.

509.5. Crawl Spaces.

509.5.1. Buildings and Structures Without Basements. — In
buildings and structures constructed without basements, and
in which the first floor construction does not bear directly on
the ground, a space at least eighteen (18) inches high shall be
provided directly under the floor beams, girders or still of the
first floor construction. Where the floor above such a space is
constructed of wood or metal, the space shall be ventilated by
one of the following means:

509

a. At least four widely separated ventilating openings,
providing a total net free area of at least one-eight
hundreth (1/800) of the area of the crawl space, shall
be provided in the foundation walls, and the ground
within the crawl space shall be covered with a vapor
barrier in durability equivalent to at least fifty-five (55)
pound roofing felt with unsealed laps and with a
transmission rate of one (1) perm or less.

b. At least two (2) ventilating openings, providing a total
net free area of at least one-fifteen hundreth (1/1500)
the area of the crawl space shall be provided in founda-
tion walls, provided that a vapor barrier with a trans-
mission rate of one (1) perm or less is installed over
the entire underside of the first floor construction and
overlaps the walls.

509.5.2. Buildings and Structures With Basements. — No founda-
tion wall vents shall be required where one side of a crawl
space is completely open, except for structural members, to a
basement that has an area at least equivalent to that of the
crawl space, provided that the basement is naturally ventilated
by openings complying with Sections 504.5. and 504.6.

509.6. Ventilation of Boiler Rooms. — Boiler rooms shall be
ventilated in a manner that will provide air for combustion in
accordance with the provisions of articles 10 and 11.

509.7. Ventilation of Spaces With Excessive Temperatures,
Strong Odors, Hazardous Concentrations of Toxic Substances,
or Airborne Irritants. — Each such space shall be ventilated by
a system designed and installed to prevent any of the following
conditions:

a. Excessive temperatures that may be detrimental to the
occupants.

b. Concentrations of substances in the air in amounts
exceeding the Threshold Limit Values established for
same by reference standard RS 5-2.

c. The danger of concentrations of any other airborne
irritants and impurities, such as steam, gases, vapor,
and dust, that may be injurious to health.

Where the exhausted air may contain toxic substances or strong
objectionable odors, the exhaust system shall be independent
of exhaust systems serving other parts of the building.

509.8. Ventilation for Special Uses and Occupancies. — Special
uses and occupancies shall be ventilated in accordance with

the requirements of articles 4 and 6. Ventilation of stage areas
shall be in accordance with the requirements of article 4.

SECTION 510.0 OMITTED

SECTION 511.0 OMITTED

SECTION 512.0 INSTITUTIONAL BUILDINGS

Spaces in buildings of the institutional occupancy group shall be
lighted and ventilated as herein required except that in buildings
used for enforced detention of people (occupancy group H-l)
openings to the street or court may be indirectly through
intermediate corridors or other approved means.

SECTIONS 513.0.-515.0. OMITTED.

SECTION 516.0. VENTILATION OF SHAFTS OTHER
THAN ELEVATOR AND DUMBWAITER HOISTWAYS
AND STAIRWAYS.

All enclosed vertical shafts extending through more than two
(2) stories of every building or structure, except elevator or
dumbwaiter hoistways, and stairways, shall be automatically
vented to the outer air as herein required or as specified in
section 911.

516.1. Extending to Roof. — Shaft enclosures extending to the
roof shall be provided with a metal skylight constructed to
comply with section 928.2. or with windows of equivalent area
or with approved automatic means of removing hot air and
gases.

516.2. Thermostatic Control. — The operation of fire shutters,
skylights and other vent relief devices may be controlled by
fusible links designed to operate at a fixed temperature of not
more than one hundred and sixty (160) degrees F., or by
electric or pneumatic operation under a rapid rise in temperature
at a rate of fifteen (15) to twenty (20) degrees F. per minute
or by other approved methods.

509-518
516.3. Not Extending to Roof. — Shaft enclosures not extending
to the roof shall have means of gas and smoke relief or
adequate mechanical ventilation conforming to section 911.1.
and article 18.

SECTION 517.0. OMITTED

SECTION 518.0. COURTS

All courts required to serve for light and ventilation purposes
shall comply with requirements of this section.

518.1. Width of Court.

518.1.1. Minimum Width. — Every such court shall have a mini-
mum width of three (3) inches for each foot of height or frac-
tion thereof but not less than five (5) feet for outer courts
and twice these values for inner courts as defined in 518.4.1.

518.1.2. Irregular Court Width. — In the case of irregular or
gore-shaped courts, the required minimum width of court may
be deemed to be the average width, provided that no such
court shall be less than five (5) feet at any point.

518.2. Area of Court. — The cross-sectional area of- a required
court shall be not less than one and one-half (1-1/2) times the
square of its required minimum width; nor shall the length of
any court be more than twice its required minimum width.

518.3. Access to Court. — A door or other means of access shall
be provided at the bottom of every court for purposes of clean-
ing.

518.4. Air Passages to Court.

518.4.1. Inner Court. — Every court serving one or more habitable
rooms that does not open for its full height on one or more
sides to a street or legal yard shall be connected at or near the
bottom with a street or yard by a horizontal passage of fire-
resistive construction. Such passage shall have a cross-sectional
area of not less than twenty-one (21) square feet, and shall
remain fully open at both ends and unobstructed for its full
size and length, except that grilles of noncombustible construction
complying with the approved rules may be permitted at the ends
of the passage.

518.4.2. Fire-resistance. — The walls, floors and ceilings of such
passages shall have a fire-resistance rating conforming to sec-
tion 220.1., Table 2-1, but not less than two (2) hours in
buildings of types 1, 2 or 3 construction and not less than
three-quarter (3/4) hour in type 4 construction.

518.5. Court Walls. — When in the opinion of the building
official, windows facing on courts do not receive adequate direct
light by reason of peculiar arrangement or orientation, he may
require the walls to be constructed of light colored masonry,
or to be painted and maintained a light color to furnish addi-
tional reflected light.

518.6. Court Drainage. — The bottom of every court shall be
graded and drained to a public sewer or other approved dis-
posal system complying with the Massachusetts Plumbing Code;
and shall be paved with concrete or other non-absorbent material
when required by the building official.

SECTION 519.0. OMITTED

SECTION 520.0. OBSTRUCTION OF COURTS

520.1. Permissible Projections. — Every required court shall re-
main unobstructed for its required area and full height, except
for the projections permitted in section 313. In residential
and institutional buildings, clothes poles, arbors, garden trellises
and other such accessories shall not be prohibited in the open
spaces at ground level.

520.2. Motor Vehicle Parking. — When approved by the building
official, required court areas may be used for automobile
parking spaces or private garages not exceeding one (1) story
in height when accessory to and only for the use of the occu-
pants of a residential building, provided required windows for
light and ventilation are not obstructed thereby.

SECTION 521.0. FIRE EMERGENCY EXHAUST SYSTEM.

In all buildings and structures herein required to have fire
emergency exhaust systems, the exitways shall be constructed
with:

a. Vertical fire vent stacks and lateral fire vent ducts as
herein provided, or

b. Windows to the outer air, or

c. Mechanical exhaust systems, or

d. Other equivalent approved means for dissipating smoke,
heated air and toxic gases directly to the outer air in
the event of fire.

518-521

521.1. Where Required. — Fire emergency exhaust systems shall
be provided:

a. In buildings used for H-l and H-2 (institutional)
occupancy and for L-l and L-2 (hotel and apartment
house) occupancy groups which:

1. Exceed three (3) stories or forty (40) feet in height,
and

2. Exceed ten thousand (10,000) square feet in floor
area, and

3. Are occupied by more than fifty (50) persons above
the first floor, or have more than twenty-five (25)
sleeping rooms above the first floor.

b. In all fully enclosed industrial buildings without exterior
window openings for ventilation purposes.

521.2. Fire Vent Ducts. — Exitways which are not ventilated
by windows opening directly to the outer air shall have a
system of collecting fire ducts in each story to remove the
smoke and gases in event of fire. Fire vent ducts shall connect
to screened openings of not less than one (1) square foot in
area located in each exitway and complying with sections 1009
and 1119. Ducts shall have cross-sectional area equal to the
sum of the screened openings upstream of the section.

521.3. Thermostatic Operation. — When not connected to a vent
stack, the inlet openings on each story shall be controlled by
automatic opening heat-operated devices as required in section
516.2.

521.4. Fire Vent Stacks. — When the fire ducts do not discharge
directly to the outer air in each story, one or more fire vent
stacks of adequate capacity shall be installed to accommodate
the discharge from the fire duct system in any enclosed fire
area on one floor, but in no case shall any individual stack be
less than four (4) square feet in area, and all stacks shall
terminate in an approved wind-actuated ventilator outlet above
the roof.

521.5. Location of Stacks. — The vent stack shall be located
in as central a position as practicable with respect to the floor
area vented thereby, preferably in the vicinity of vertical shafts,
and shall extend continuously to the roof.

521.6. Vent Control of Stacks. — The vent control of the
vertical stacks shall consist of approved noncombustible dampers,
shutters, or glazed metal sash designed to open outwardly,
located not less than twenty (20) feet distant from window

openings or exit doors in adjoining walls, and shall be equipped
with a thermostatic unit arranged to open at a predetermined
rate of temperature rise in accordance with the approved rules.
Auxiliary mechanical means for manual operation of all vent
controls shall be provided in an accessible location designated
by the building official.

521.7. Stack Construction. — The stack enclosure shall be con-
structed to be vapor and smoke tight with walls of not less
than two (2) hours fire-resistance, with no openings other than
the fire duct inlets and the top outlet.

521.8. Mechanical Exhaust Systems. — When mechanical exhaust
is required to operate the emergency system either in horizontal
ducts or vertical vent stacks, the installation shall be thermo-
statically controlled and installed in accordance with the pro-
visions of article 18 and the approved rules.

SECTION 522.0. OMITTED.

SECTION 523.0. WINDOW CLEANING SAFEGUARDS.

All buildings and structures over fifty (50) feet or four (4)
stories in height, other than one- and two-family and multi-
family dwellings (occupancy groups L-2 and L-3), in which the
windows are cleaned from the outside shall be provided with
anchors or other approved safety devices for all window open-
ings. Such anchors, belt terminals or other devices shall be of
approved design, constructed of corrosion-resistive materials
securely attached to the window frames or anchored in the
enclosure walls of the building. Cast iron or cast bronze anchors
shall be prohibited.

Industrial Bulletin No. 21-Revised Rules and Regulations for
the Prevention of Accidents in Window Cleaning, Massachusetts
Department of Labor and Industry contains further mandatory
requirements for window cleaning safeguards.

523.1. Exterior Scaffolds. — Window cleaning anchors may be
eliminated on buildings which provide mechanically operated
exterior scaffolds, or other approved methods for washing
windows.

523.2. Pivoted Windows. — Buildings of occupancy group E
(Business Buildings) over forty (40) feet or three (3) stories in
height, in which the windows are designed to pivot for cleaning
from the inside, shall be provided with a roof mounted, record-

521-524

ing type anemometer to determine the wind velocity; and no
window shall be pivoted when the wind velocity exceeds fifteen
(15) miles per hour.

SECTION 524.0. NOISE CONTROL IN MULTIPLE DWEL-
LINGS

524.1. Requirements. — Interior walls, partitions and floor-ceiling
constructions in spaces or buildings of occupancy groups L-l
and L-2 shall be designed and constructed in accordance with
the requirements of this section, to provide minimum protection
for each dwelling unit from extraneous noises emanating from
other dwelling units. In addition, airborne sound from exterior
mechanical equipment of buildings in any occupancy group shall
conform to the requirements of this section.

524.2. Field Testing. — Where conditions indicate that the in-
stalled construction or equipment does not meet the noise control
prescribed in this section, measurements shall be taken to
determine conformance or nonconformance. For conformance
with this section, the results of such measurements shall not
fail by more than two (2) decibels to meet the requirements
in any octave band, or by more than two (2) points to meet
any sound transmission class or impact noise rating requirements.

524.3. Acoustical Isolation of Dwelling Units.
524.3.1. Airborne Noise.

a. Walls, partitions, and floor-ceiling constructions separa-
ting dwelling units from each other or from public halls,
corridors, or stairs shall have a minimum sound trans-
mission class rating of forty-five (45) for airborne noise.
The requirement shall not apply to dwelling unit entrance
doors.

b. Sound transmission class ratings shall be obtained by
tests conducted in accordance with the procedures of
reference standard RS 5-3, except as provided in (c.)
below.

c. The sound transmission class ratings of construction
assemblies as listed in the applicable standards specified
in reference standards RS 5-3, RS 5-4, and RS 5-5 may
be used to determine conformance with the requirements
of (a.) above and with any other section that requires
a specific sound transmission class rating.

d. Penetrations or openings in walls, partitions, or floors
for pipe sleeves, medicine cabinets, hampers, electric
devices, or similar items shall be packed, sealed, lined,
backplastered, or otherwise isolated by sufficient mass
to maintain the required sound transmission class ratings.

e. Where grilles, registers, or diff users in one (1) dwelling
unit are connected by ductwork with grilles, registers, or
diffusers in another dwelling unit, the duct shall be
designed by means of length, offsets, sound absorbent
lining, sound traps, or any combination thereof, to pro-
vide a minimum noise reduction of thirty (30) decibels
in the third octave band relative to transmitted sound.
Such ductwork systems shall not transmit self-generated
noises, due to any attached part or component, which
results in radiation of noise into any habitable space.

524.3.2. Structure-Bourne Noise.

a. Floor-ceiling constructions separating dwelling units from
each other or from public halls or corridors shall have
a minimum impact noise rating of fifty (50).

b. Such impact noise rating shall be obtained by tests
conducted in accordance with the procedure of reference
standard RS 5-4, except as provided in (c.) below.

c. The impact noise rating of a floor-ceiling construction
listed in the applicable standards specified in reference
standards RS 5-3, RS 5-4, and RS 5-5 shall be used to
determine conformance with the requirements of (a.)
above and with any other paragraph that requires a
specific impact noise rating. Constructions shall be de-
signed and installed to avoid short circuiting the isola-
tion devices that are incorporated into the constructions.

RS5

REFERENCE STANDARD RS 5

LIGHT, HEAT, VENTILATION AND NOISE CONTROL

List of Reference Standards

ACGIH 1968

Industrial Ventilation, A Manual of Recommended

practice. Appendix — Threshold Limit Values.

ASHRAE 1967

Guide and Data Book, Handbook of Fundamentals

ASHRAE 1968

Guide and Data Book, Applications

ASHRAE 1969

Guide and Data Book, Equipment

ASTM E90 1966

Recommended Practice for Laboratory Measurement
of Airborne Sound Transmission Loss of Building
Floors and Walls

IBI 1967

Noise Control with Insulation Board for Homes,

Apartment, Motels, Offices. 4th edition.

NCMA 1955

Sound Reduction Properties of Concrete Masonry

Walls

NCMA 1959

Sound Transmission Loss and Air Flow Resistance

Measurements on Concrete Block Walls.

US FHA 1967

Guide to Airborne, Impact, and Structure Bourne

Noise Control in Multifamily Dwellings

RS 5-1 ASHRAE 1967

Guide and Data Book — Handbook of Fundamentals '

ASHRAE 1968

Guide and Data Book — Applications

ASHRAE 1969

Guide and Data Book — Equipment

RS 5-2 ACGIH 1968

Industrial Ventilation, A Manual of Recommended
Practice. Appendix — Threshold Limit Values.

RS 5-3 ASTM E90 1966

Recommended Practice for Laboratory Measurement
of Airborne Sound Transmission Loss of Building
Floors and Walls

RS 5-4 US FHA 1967

Guide to Airborne, Impact, and Structure Borne
Noise Control in Multifamily Dwellings

RS 5-5 IBI 1967

Noise Control with Insulation Board for Homes,
Apartments, Motels, Offices. 4th Edition.

NCMA 1955

Sound Reduction Properties of Concrete Masonry

Walls

NCMA 1959

Sound Transmission Loss and Air Flow Resistance

Measurements on Concrete Block Walls.

MEANS OF EGRESS

ARTICLE

600.0 Scope

601.0 Definitions

602.0 Plans and Specifications

603.0 Occupancy Requirements

604.0 Unlimited One Story

Buildings
605.0 Air-Conditioned Buildings

606.0 Existing Buildings

607.0 Maintenance of Exitways

608.0 Occupancy Load
609.0 Types and Location of

Exitways
610.0 Capacity of Means of

Egress Parts
611.0 Number of Exitways

612.0 Exitway Access — Passage-

ways, Corridors, and
Balconies

613.0

614.0
615.0
616.0
617.0
618.0
619.0
620.0
621.0
622.0
623.0
624.0
625.0
626.0
627.0
RS6

Grade Passageways and
Lobbies as Exitway
Elements

Means of Egress Doorways

Revolving Doors

Horizontal Exitways

Exitway Ramps

Interior Exitway Stairways

Access to Roof

Smokeproof Towers

Exterior Exitway Stairways

Moving Exitway Stairways

Elevators in Exitways

Fire Escapes

Omitted

Exitway Signs and Lights

Means of Egress Lighting

Reference Standards

TABLES

6-1
6-2
6-3
6-4

608.1.4
609.3.2
610.2.1
614.1.1

Occupancy Allowances

Maximum Allowable Exitway Access Travel Distance
Determination of Exitway and Access Requirements
Maximum Occupant Load — For Spaces With One Door

SECTION 600.0. SCOPE

The provisions of this article shall control the design, construc-
tion and arrangement of building elements required to insure
safe means of egress from all buildings hereafter erected, and
from all buildings hereafter altered to a new occupancy load, or
occupancy group, or required for inherent fire safety of the
occupants. Existing buildings and occupancies shall be controlled
by the provisions of section 606.

600.1. Modification of Means of Egress Requirements. — When
strict compliance with the provisions of this Code is not prac-
tical, the building official may accept alternate means of egress
which will accomplish the same purpose, by the procedure
established in article 1 for modification of this Code or by
adoption of approved rules.

600.2. Minimum Requirements. — It shall be unlawful to alter
any building or structure in any manner that will reduce the
means of egress below the requirements of this Code for new
buildings of the proposed use and occupancy.

600.3. Other Standards. — Compliance with the applicable provi-
sions of reference standard RS 6 shall be deemed to meet the
requirements of this article, unless otherwise specifically provided
herein.

SECTION 601.0. DEFINITIONS

For definitions to be used in the interpretation of this article,
see section 201.

SECTION 602.0. PLANS AND SPECIFICATIONS

602.1. Arrangement of Exitways. — The plans shall show in
sufficient detail the location, construction, size and character of
all exitways together with the arrangement of aisles, corridors,
passageways and hallways leading thereto and the exitway dis-
charges therefrom all in compliance with the provisions of
this Code.

602.2. Number of Occupants. — In other than one- and two-
family dwellings, the plans and the application for permit shall
designate the number of occupants to be accommodated on every
floor, and in all rooms and spaces when required by the build-
ing official. When not otherwise specified, the minimum number
of occupants to be accommodated by the means of egress facil-
ities shall be determined by the occupancy load prescribed in
section 608. The posted occupancy load of the building shall be
limited to that number.

SECTION 603.0. OCCUPANCY REQUIREMENTS

Every building and structure and part thereof hereafter erected
shall have the prescribed number of exitways of one or more of
the approved types defined in this article. Every exitway in com-
bination with the exitway access thereto and exitway discharge
therefrom shall provide a safe and continuous means of egress to
a street or to an open space with direct access to a street.
603.1. General Requirements. — The occupancy group classifica-
tion of the building, the number of occupants, the floor area,

600-603

r the travel distance to an exitway and the capacity of the exitway

shall be considered in determining the exitway requirements.

603.2. Mixed Occupancy Groups. — When a building is classified
in more than one occupancy group in accordance with the pro-
visions of article 2, the exitway requirements for the entire
building shall be determined on the basis of the occupancy group
having the strictest exitway requirements, or the exitway require-
ments for each building section shall be determined separately or
when places of assembly, night clubs and rooms and spaces for
similar occupancies are provided in a building section, the exit-
ways shall be adequate for the combined occupancy tributary
thereto.

603.3. Incidental Occupancies. — When a building contains inci-
dental occupancies classified in occupancy groups other than
that under which the building is classified, the exitway require-
ments for the floor on which such occupancies occur shall be
based upon those of the occupancy group under which the
building is classified; but the exitway access and exitway require-
ments for the incidental occupancy shall be based upon the
occupancy group classification of the incidental occupancy.

603.4. Multiple Occupancy. — Where a building, floor, or space
is used for multiple purposes involving different activities at
different times, that occupancy involving the greatest number of
occupants shall be used in determining the exitway requirements

603.5. Multiple Tenants. — When more than one (1) tenant
occupies any one (1) floor of a building or structure, each tenant
shall be provided with separate direct access to the required
number of approved exitways without passing through premises
occupied by other tenants, except as permitted for balconies in
section 612.7.

603.6. Building Access. — All buildings classified in occupancy
groups other than A, B-l or B-2, open structures of D-2 or
L-3, shall have at least one (1) primary entrance accessable to
and usable by individuals in wheelchairs. Such entrance shall
provide access to a level that makes elevators available in build-
ings where elevators are provided. Where ramps are used to
comply with this requirement, they shall have a slope not
greater than 1 in 10, and shall otherwise conform to the pro-
visions of section 617.

SECTION 604.0. UNLIMITED ONE STORY BUILDINGS

In one (1) story business, industrial and storage buildings of
unlimited area when permitted under the provisions of section
309, sufficient exitways shall be provided to accommodate the
entire occupancy load on each front of the building; and the
unobstructed length of travel to a street exitway or to the en-
trance of an enclosed tunnel or other enclosed exitway leading
to a street shall not exceed the maximum travel distances pro-
vided in section 609.3.2 table 6-2 except as may be specifically
provided for in reference standard RS 6-1.

SECTION 605.0. AIR-CONDITIONED BUILDINGS

605.1. Location of Stairways. — In all buildings, without exterior
window openings in all stories, that are artificially ventilated
and/or air conditioned as provided in section 517, the stairway
element of required exitways shall be located as to be accessible
to the fire department either through the access openings speci-
fied in section 861 or as otherwise approved in at least alternate
stories of the building.

605.2. Exhaust Ducts.

605.2.1. Exitways. — No exhaust ducts or vents of air-condi-
tioning systems shall discharge into stairway enclosures.

605.2.2. Exitway Access. — Corridors serving as exitway access
shall not be used as the return exhaust from air-conditioned
spaces through louvres or other devices in the doors or parti-
tions enclosing such air-conditioned spaces, unless such pas-
sageways are equipped with approved products of combustion
detectors to automatically stop the supply and exhaust fans and
close the louvres and unless such use is approved by the build-
ing official.

SECTION 606.0. EXISTING BUILDINGS

606.1. Owner Responsibility. — The owner or lessee of every
existing building and structure shall be responsible for the safety
of all persons in or occupying such premises with respect to
the adequacy of means of egress therefrom as required by this
Code.

606.2. Unsafe Means of Egress.

604-606
606.2.1. Inadequate Exitways.— In any existing building or
structure, not now provided with exitway facilities as herein
prescribed for new buildings and in which the exitways are
deemed inadequate for safety by the building official, such addi-
tional provision shall be made for safe means of egress as he
shall order.

606.3. No Change in Use. — When there is no change in occu-
pancy group or occupancy load, the minimum exitway require-
ments shall be as follows:

606.3.1. New Exitways. — If new or altered exitway facilities
are installed or constructed they shall comply with all the re-
quirements for new buildings.

606.3.2. Existing Exitways. — In all buildings (other than one-
and two-family dwellings), exceeding three (3) stories or forty
(40) feet in height, or having more than seventy (70) occupants
above or more than forty (40) occupants below the grade floor,
all existing unenclosed stairways shall be enclosed with partitions
and opening protectives of three-quarter (3/4) hour fireresistance
rating complying with article 9; or such exitways may be pro-
tected with a partial sprinkler system operated on the house
water supply when complying with article 12. Existing enclosures
of substandard fireresistive construction shall be covered on the
stair side only with the component materials required for a
three-quarter (3/4) hour fireresistive assembly.

606.3.3. Fire Excapes. — In buildings not over five (5) stories
or seventy (70) feet in height, fire escapes complying with the
requirements of section 624 may be accepted as a secondary
means of egress when deemed adequate by the building official
and when approved access to the street is provided from the
termination of the fire escape.

606.4. Existing Occupancy Changed. — In every building or
structure in which there is a change from one occupancy group
to another or when there is an increase in occupancy load,
the exitway facilities serving the new use and occupancy shall
be made to comply with all the provisions of this article for
buildings hereafter erected.

SECTION 607.0. MAINTENANCE OF EXITWAYS

607.1. Obstructions. — It shall be unlawful to obstruct, or re-
duce in any manner the clear width of any doorway, hallway,
passageway, exitway access or any other portion of a means
of egress required by the provisions of this Code.

607.2. Exterior Exitways. — Exterior stairways and fire escapes
shall be kept clear of all flower boxes, pots and other obstruc-
tions; and no display sign or other obstruction shall be attached
to the building as to interfere with free operation and use of
such elements of a means of egress.

607.3. Maintenance. — All exterior stairways and fire escapes
shall be kept free of snow and ice. They shall be properly
painted before and after erection; and shall be scraped and
painted as often as necessary to maintain them in safe condi-
tion and good repair.

SECTION 608.0. OCCUPANCY LOAD

608.1. Design Occupancy Load. — In determining required exit-
way facilities, the number of occupants for whom exitway
facilities shall be provided shall be established by the largest
number computed as follows:

608.1.1. The actual number of occupants for whom each occupied
space, floor, or building, as the case may be, is designed for, or,

608.1.2. The number of occupants computed at the rate of one
occupant per unit of area as prescribed in section 608.1.4 table
6-1, or,

608.1.3. The number of occupants of any space as computed in
608.1.1 or 608.1.2 above plus the number of occupants similarly
computed for all spaces that discharge through the space in
order to gain access to an exitway.

608.1.4. Table 6-1. Occupancy Allowances

Net Floor
Occupancy Group Area per Occupant

(square feet)

Billiard Rooms 50

Bowling Alleys 50 See section 608. 1.4. a.

Classrooms 20

Courtrooms 40

Dance Floors 10

Dining Spaces (non-residential) 12

Exhibition Spaces 10

Garages and Open Parking Structures 250

Gymnasiums 15

Habitable rooms 140

Industrial Shops 200

In schools : 50

Institutional Sleeping Rooms

Adults 75

Children 50

Infants 25

K indergarten 35

Kitchen (non-residential ) 200

Laboratories 50

Preparation rooms 100

Locker rooms 12

Lodge rooms 15

Offices 100

Passenger Terminals or Platforms See section 608.1 .4.b.

Sales area (retail)

First floor and basement 25

All other floors 50

Seating Areas (audience in all assembly occupancies)

Fixed Seats See section 608. 1. 4. c.

M oveable Seats 10

Skating Rinks 15

Stages 15 performing area

50 other areas

Standing room (audience in all assembly occupancies) 4

Storage rooms 200

a. or if greater, the following: allow five (5) persons per
alley, which shall include fifteen (15) feet of runway,
plus one (1) person for each ten (10) square feet of
space remaining,

b. 1.5 times the capacity of all passenger vehicles that can
be unloaded simultaneously,

c. designed number of seats or occupants.

608.2. Mezzanine Floors. — The occupancy load of a mezzanine I
floor discharging through a floor below shall be added to thejl
main floor occupancy and the capacity of the exitways shall be I
designed for the total occupancy load thus established.

608.3. Roofs. — Roof areas occupied as roof gardens or for
assembly, storage or other purposes shall be provided with exit- I
way facilities to accommodate the required occupancy load, but
in no case shall there be less than two (2) approved means ofH
egress for assembly uses from such roof areas.

608.4. Special or Unlisted Occupancies. — Where data regarding
the square feet per person for an occupancy is not listed in
section 608.1.4. table 6-1, the occupant load shall be established'
by the architect or engineer, subject to the approval of the I
building official.

608.5. Conflict. — When there are special requirements for speci-
fic occupancies and uses in article 4 which differ from general I
requirements herein prescribed, such special provisions shall il
take precedence.

608.6. Non-Simultaneous Occupancy. — The occupant load of,
toilets, locker rooms, meeting rooms, storage rooms, employee I
cafeterias, and similar rooms or spaces that are not occupied
at the same time as other rooms or spaces on the same floor
of a building, may be omitted from the occupant load calcula-
tion of the floor on which they are located, to the extent that
such spaces only serve occupied rooms on the same floor.

608.7. Modifications.

608.7.1. When the actual occupant load of any space will be
significantly lower than that listed in section 608.1.4 table 6-1,
the building official may establish a lower basis for the deter-
mination of the occupant load.

608.7.2. When a building existing on the effective date of this
Code is altered or changed in occupancy or use so as to re-
quire enlarged exitway facilities, the building official may author-
ize the alteration or change in occupancy or use without an
enlargement of exitway facilities, provided the occupant load
is limited to that accommodated by the existing exitway facilities
as determined by the provisions of this Code, and the building
or space is posted accordingly with a sign. Such signs shall be
at least twelve (12) inches in width and sixteen (16) inches in
height. The lettering shall be red on a white backg, ound. The
letters shall be not less than one and one-quarter (1-1/4) inches
high.

608-609
SECTION 609.0. TYPES AND LOCATION OF EXITWAYS

All approved means of egress and parts thereof, including door-
ways, passageways, corridors, hallways, interior stairways, ex-
terior stairways, moving stairways, smoke-proof towers, ramps,
horizontal exitways, bridges, balconies, fire escapes and com-
binations thereof shall be arranged and constructed as provided
herein and in compliance with article 16 for moving stairways
and article 9 for fire enclosure requirements.

609.1. Arrangement. — All exitways and access thereto and
discharge therefrom shall be so located that they are clearly
visible or their locations clearly indicated. They shall be kept
readily accessible and unobstructed at all times. They shall be
so arranged as to lead directly to the street or to an area of
refuge with supplemental means of egress that will not be ob-
structed or impaired by fire, smoke or other cause.

609.2. Remote Locations. — Whenever more than one (1) means
of egress is required from any room, space or floor of a build-
ing, they shall be placed as remote from each other as practi-
cable, and shall be arranged to provide direct access in separate
directions from any point in the area served. Door openings
to scissor stairs shall be at least fifteen (15) feet distant from
each other.

609.3. Length of Travel.

609.3.1. General Requirement. — Where not otherwise specifically
required by other sections of this Code, the maximum travel
distance of exitway access from the most remote point in any
room or space to the center of a door opening directly on an
open exterior space or to an exitway shall not be greater than
the limit specified in section 609.3.2 table 6-2 for the occupancy
group classification of the room or space, nor greater than the
specific minimum travel distance requirements of article 4.

609.3.2. Table 6-2. Maximum Allowable Exitway Access Travel
Distance.

Occupancy Group

of Building or

Space

Group
Desig-
nation

Maximum
Distance

Unsprin-
klered

Travel
(ft.)

Sprin-
klered

High Hazard

150

Storage

B-l

100

150

B-2*

125

175

Mercantile

150

200

Industrial

D-l

125

175

D-2

150

200

Business

200

300

Assembly

150

200

School

100

150

Institutional

H-l

125

175

H-2

125

175

Residential**

L-l

150

200

L-2

150

200

L-3

N.R.

N.R. — No Requirements

♦Except that all Public Garages shall be one hundred (100)
feet if unsprinklered and one hundred and fifty (150) feet
if sprinklered. See 611.5.2 for open parking structures.
**Unless otherwise specified in sections 611.3.1, 613.3.2, or
621.1.1.

609.3.3. Travel Distance Within Dwelling Units. — In buildings
classified in occupancy groups L-l and L-2, the maximum travel
distance from the centerline of a door from any habitable room
within a dwelling unit either to the centerline of a door opening
on a corridor providing access to the exitway or to a door

609-610

| within the unit opening on an exitway shall not be greater than
forty (40) feet. Such travel distance shall be included in the
maximum travel distance established in section 609.3.2 table 6-2.

609.3.4. Measurement. — Travel distance shall be measured along
a natural and unobstructed path of travel. Where the path of
travel is over an access stair, it shall be measured along an
inclined straight line through the center of the outer edge of
each tread.

SECTION 610.0. CAPACITY OF MEANS OF EGRESS PARTS

610.1. Unit of Egress Width. — Except as provided in sections
614 and 622, the unit of egress width for all approved types of
means of egress parts and facilities specified in section 609 shall
be twenty-two (22) inches with a credit of one-half (1/2) unit
for each twelve (12) inches clear width in addition to one (1)
or more twenty-two inch units. Fractions of a unit of width
less than twelve (12) inches shall not be credited.

610.2. Design Capacity Allowance. — Except as may be specifi-
cally modified in article 4, the design capacity of the means of
egress shall be measured in units of egress width and the number
of persons per unit of width shall be determined by the occupancy
group classification and the means of egress part as listed in
section 610.2.1 table 6-3. Where computations of total required
width give fractional results, the next larger whole number of
egress units or whole number plus one-half (1/2) may be
neglected in cases where such fractions constitute less than ten
(10) percent of the total required number of units. Notwith-
standing any of the above computations, no means of egress
part or facility shall be narrower than the minimum width require-
ments specified in section 610.2.1 table 6-3 or elsewhere in
this Code.

610.2.1 Table 6-3.

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NOTES on Table 6-3

a. Where a door opening is divided by mullions into two or more door open-
ings, each such opening shall be measured separately in computing the number
of units of egress width.

b. Reduce listed capacity of ramps by 25 percent when slope exceeds 1 in 10.

c. See section 612.2.

d. Except as otherwise required for schoolhouses by the Board of Schoolhouse
Structural Standards of the Commonwealth of Massachusetts.

e. Except as otherwise required for tents in Form B-3 Regulations — Massachusetts
Department of Public Safety.

f. Applies to corridors serving patients. Other corridors shall have a minimum
width of 44 inches.

g. There shall be no patient bedrooms between an exitway and the end of the
corridor (dead end).

h. See section 611.1 and 611.2.

610.3. Sprinkler Allowance. — When the building is protected
with an approved automatic sprinkler system complying with the
requirements of article 12, and such sprinkler protection is not
specifically required by this Code, the capacity per story per
unit egress width may be increased fifty (50) percent above the
values specified in section 610.2.1 table 6-3.

610.4. Horizontal Exitway Allowance. — When an approved
horizontal exitway complying with the provisions of section 616
is provided in buildings of storage, mercantile, industrial, busi-
ness, school and assembly occupancies, the capacity per story
per unit egress width of stairways may be increased fifty (50)
percent above the value specified in section 610.2.1 table 6-3;
and in buildings of institutional occupancy groups, the capacity
per unit egress width may be increased one hundred (100)
percent.

610.5. Combined Total Allowance. — When both approved auto-
matic sprinklers and horizontal exitways are provided as specified
in this Code, the capacity per unit egress width of stairways
may be increased seventy-five (75) percent above the values
specified in section 610.2.1 table 6-3.

610.6. Area of Refuge Allowance. — The capacity of required
area of refuge enclosed within Type A fire divisions or fire walls
shall be computed on a net floor area allowance of three (3)
square feet for each occupant to be accommodated therein, not
including areas of stair, elevator and other shafts or courts.

SECTION 611.0. NUMBER OF EXITWAYS

The following general requirements apply to buildings of all
occupancy groups. More restrictive requirements that may be

provided in article 4 for special uses and occupancies shall take
precedence over the general provisions of this section.

611.1. Exitways from Floors Above and Below Grade. — There
shall be not less than two (2) approved independent exitways
serving every floor area above and below the first or grade
floor, at least one (1) of which shall be an interior enclosed
stairway, except in one- and two-family dwellings and as modi-
fied in section 611.3 and section 621.1. Exitways in dwellings
shall be so arranged that they may be reached without passing
through another living unit, except as permitted for balconies
in section 612.7.

611.2. Grade Floor Exitways. — From the first or grade floor
direct exitways shall be provided to the street consisting of one
(1) unit of egress width for each fifty (50) occupants on the
grade floor in buildings of the high hazard occupancy group and
for each one hundred (100) occupants in all other occupancy
groups, in addition to the exitways from upper and lower floors.

611.3. Buildings with One Exitway. — Only one (1) exitway con-
sisting of an interior enclosed stairway shall be required in
buildings of the occupancy group and characteristics specified:
611.3.1. Residential Buildings. —

a. In multi-family dwellings, occupancy group L-2, not
more than, three (3) stories and attic in height for not
more than six (6) families, nor more than three thousand
(3,000) square feet in area for types 1A, IB, 2A or 2B
construction nor more than two thousand four hundred
(2,400) square feet in area for types 3A or 3B construc-
tion. The distance of travel to the one required exitway
shall not exceed fifty (50) feet and the stairway shall
be enclosed in partitions of two (2) hour fireresistance
with three-quarter (3/4) hour fire doors complying with
provisions of article 9 at the openings.

b. In multi-family dwellings, occupancy group L-2, not
over two (2) stories and nonhabitable attic in height, for
not more than eight (8) families, nor more than four
(4) families to a floor nor more than three thousand
(3,000) square feet in area for all types of construction
except types 2C, 3C and 4B. The distance of travel to
the one (1) required exitway shall not exceed fifty (50)
feet and the stairway shall be enclosed with partitions of
not less than one and one-half (1-1/2) hour fireresistance

611-612

with three-quarter (3/4) hour fire doors complying with
article 9 at the openings,
c. Every sleeping room in buildings allowed by sections
611. 3.1. a. and 611.3. l.b. to have only one (l)exitway,
unless it has two (2) doors providing separate ways of
exitway access, or has a door leading directly to the out-
side of the building, shall have at least one (1) outside
window which can be opened from the inside without
the use of tools and of such design that it may serve
as an emergency exit if the normal avenues of escape
are blocked, providing a clear opening of at least four
hundred (400) square inches, with no dimension less
than sixteen (16) inches and with the bottom of the
opening not more than four (4) feet above the floor.

611.4. Basement Recreation Rooms. — In residential buildings
(occupancy group L-l and L-2), the basements of which are
used as playrooms or for similar recreation purposes, with an
occupancy load of twelve (12) or more, such areas and the
exitway shall be enclosed with partitions and ceilings of not less
than three-quarter (3/4) hour fireresistive construction. A direct
secondary exitway from the basement to the street, shall be
acceptable in lieu of the requirements for an enclosed stairway.

611.5. Open Parking Structures.

611.5.1. Number of Exitways. — Open parking structures shall
have not less than two (2) exitways from each parking tier.

611.5.2. Distance to Exitway. — The maximum distance from
any point on a parking tier to an exitway at that tier shall not
exceed one hundred (100) feet if driver parked.

611.5.3. Ramps as Exitways. — Ramps used for the movement
of vehicles need not be enclosed and may be considered as re-
quired exitways

a. in structures not exceeding eighty-five (85) feet in height
where vehicles are attendant parked, or

b. in other structures having not less than two (2) en-
closed stairways.

SECTION 612.0. EXITWAY ACCESS-PASSAGEWAYS,
CORRIDORS, AND BALCONIES

612.1. Exitway Access. — Direct exitway access shall be pro-
vided to required exitways through a continuous path consisting
of aisles, corridors, balconies, or passageways kept readily
accessible and unobstructed at all times and kept free of com-
bustible contents except that in buildings classified in occupancy

groups H-l and H-2, and schoolhouses in occupancy group G,
combustible contents may be stored in noncombustible lockers
and combustible bulletin boards meeting the requirements of
section 922.1.2., table 9-4, shall be permitted.

612.1.1. Turnstiles and Gates. — Access from public areas through
turnstiles, gates, rails or similar devices shall not be permitted
unless they conform to the requirements of section 615.0.

612.2. Dead Ends. — Exitway access passageways and corridors
in all stories above the first which serve more than one (1)
exitway shall provide direct connection to such exitways in
opposite directions from any point in the corridor so that dead
ends are avoided. In no case shall the length of travel in a
dead end corridor be more than the length listed in section
610.2.1 table 6-3 except that when a corridor is completely
enclosed in construction having a two (2) hour fireresistance
rating, with all corridor doors being self-closing and having a
fire protection rating of one and one-half (1-1/2) hour, the per-
missible length of dead ends may be increased one hundred
(100) percent above the length listed in section 610.2.1 table
6-3. Dead end distance shall be measured from the centerline
of the door opening nearest to the closed end of the corridor
to the center of an exitway door opening, or to the center of
that point in the corridor where travel to two (2) or more
exitways becomes available in two (2) directions.

612.3. Minimum Dimensions.

612.3.1. Width — Capacity. — The minimum width and capacity
of corridors shall be as listed in section 610.2.1 table 6-3. The
required minimum width shall be measured in the clear between
the narrowest points produced by any projections such as radi-
ators, lockers, drinking fountains, or room or locker door
swings, except that such width may be reduced by projections
up to eighteen (18) inches wide to the extent of two (2) inches
per unit of egress width if the total area of such projections
does not exceed five (5) percent of the area of the wall on
which they occur.

612.3.2. Height. — A clear height of seven feet six inches (7'6")
shall be provided for at least seventy-five (75) percent of the
floor area, with no point less than seven (7) feet in height.
No projection below the ceiling shall be located so as to ob-
struct full view of exitway signs.

612
612.3.3. Length Between Smoke Barriers. — The maximum dis-
tance between smoke barriers that subdivide corridors shall be
two hundred (200) feet for educational buildings of occupancy
group G and one hundred fifty (150) feet for institutional occu-
pancy groups H-l and H-2. Smoke barriers shall consist of
partitions constructed of noncombustible materials or fire re-
tardant treated wood and containing smoke stop doors conform-
• ing to the following:

Smoke stop doors. — Smoke stop doors shall be self-closing,
swinging doors of metal, metal covered, or one and three-
quarter (1-3/4) inch bonded solid core wood with clear wire
glass panels having an area of at least six hundred (600) square
inches per door, except that in buildings not over two (2)
stories high, smoke stop doors may be of one and three-eighths
I (1-3/8) inch bonded solid core wood with clear wire glass
panels, unless the doors are also used as horizontal exitways in
which case they shall comply with the provisions of section 616.
Smoke stop doors shall close the opening completely with only
such clearance as is reasonably necessary for proper operation.
Smoke stop doors shall normally be in the closed position, ex-
cept that they may be left open if they are arranged to close
automatically by an approved device which is actuated by an
interior fire alarm system meeting the requirements of article 12.

612.4. Opening Protectives.

612.4.1. Doors. — In buildings of H-l, H-2 or L-l occupancy
groups (institutional or hotel) more than two (2) stories in
height, or with more than twenty-five (25) occupants above the
first floor, all doors from rooms opening on a corridor or pas-
sageway serving as an exitway access shall be three-quarter
(3/4) hour fire doors or one and three-quarter (1-3/4) inch
thick bonded solid core wood doors or their approved equivalent
complying with article 9.

a. Transoms in the walls of corridors shall have the equiv-
alent fireresistance of the door, but operable transoms
shall not be permitted.

b. Louvres shall be prohibited except in the lower third of
toilet room doors when used as a source of make-up air
for the toilet room ventilation required in article 5.

612.4.2. Borrowed Lights. — In corridors required to have a one
(1) hour fireresistance rating, fixed one-quarter (1/4) inch wire
glass panels may be installed in not more than twenty (20)

percent of the common wall between the corridor and any room
or space, provided that no panel exceeds seven hundred and
twenty (720) square inches in area.

612.5. Changes in Level. — Changes in level requiring less than
two (2) risers in a corridor shall be by a ramp complying with
section 617. Risers and treads shall comply with the require-
ments of section 618.

612.6. Exterior Corridors. — Exterior corridors shall be roofed,
and shall have solid floors drained to prevent accumulations of
standing water. Such floors may serve as fire canopies when so
constructed. Exterior corridors shall be protected along their
outer side by guards or parapets at least three (3) feet six (6)
inches high. Openings in guards or parapets shall be of such
dimensions as to prevent the passage of a five (5) inch diameter
ball. Where the outer side of an exterior corridor is more than
fifty (50) percent enclosed with solid material, it shall be treated
as an interior corridor.

612.7. Balconies. — Balconies may serve as a means of egress
from dwelling units in buildings classified in occupancy group
L-2 under the following conditions:

612.7.1. They shall serve at least two (2) dwelling units.

612.7.2. They shall be constructed as required for exterior
corridors, except that parapets or guards shall not be higher
than four (4) feet on the outer side of the balcony.

612.7.3. The dwelling units served by balconies shall be sepa-
rated from each other by construction having at least a two (2)
hour fireresistance rating. Such separation shall extend at least
three (3) feet beyond the outside face of the exterior wall of
the building. An opening at least twenty (20) inches wide shall
be provided between the end of this separation and the balcony
parapet or guard, and the opening shall be maintained free and
unobstructed for the full height of the balcony, except that
privacy screens openable from either side may be permitted in
the opening.

612.7.4. Access from dwelling units to the balconies shall be
through doors having glass panels at least two (2) feet wide and
four (4) feet high, without muntins, screens, or other obstruc-
tions to hinder entry by breaking the glass panels. The doors
shall be lockable only from the inside by devices that can be
easily released from the outside after breaking the glass. A
combination lock or lock required to be opened by a key or
removable device or tool shall not be used.

612-613
SECTION 613.0. GRADE PASSAGEWAYS AND LOBBIES
AS EXITWAY ELEMENTS

Every required interior and exterior vertical exitway which does
not adjoin a street shall be directly connected to the street or
to an open court leading to the street by an enclosed passage-
way, hallway, lobby or other unobstructed exitway element,
constructed as provided in this section and in section 909.0,
and maintained free of all obstructions at all times. Not more
than fifty (50) percent of the total number of exitways provided
for a building, area or part thereof may be served by a single
grade passageway, hallway, lobby or other unobstructed exit-
way, except as provided in section 613.8 below.

613.1. Capacity. — The capacity of exitway passageways, hall-
ways, lobbies, or other unobstructed exitway elements, shall be
as listed for the exitway element in section 610.2.1 table 6-3.

613.2. Minimum Width. — The minimum width of an exitway
passageway, hallway, lobby or other unobstructed exitway ele-
ment, serving one (1) vertical exitway shall be equal to the
width of the vertical exitway. The minimum width of an exit-
way passageway serving two (2) or more vertical exitways shall
be equal to seventy-five (75) percent of the width of all of the
vertical exitways that it serves. Width shall be measured in the
clear between the narrowest points at any projections such as
radiators, door swings or pilasters.

613.3. Height. — Exitway passageways shall have a clear height
of seven feet six inches (7'6") for at least seventy-five (75)
percent of the floor area, with no point less than seven (7)
feet in height. No projection below the ceiling shall be located
so as to obstruct full view of exitway signs.

613.4. Changes in Level. — Changes in level requiring less than
two (2) risers in an exitway passageway shall be by a ramp
complying with section 617.0. Risers and treads shall comply
with the requirements of section 618.0.

613.5. Construction. — The construction of exitway passageways

shall be as required by section 221.1, table 2-1, for the appli-
cable construction type of the building.

613.6. Openings. — No openings other than exitway doors shall
be permitted in exitway passageways, except as provided in
section 613.8 below.

613.7. Interior Finish. — The interior finish of passageways,
hallways, lobbies, and other unobstructed exitway elements,

shall be in accordance with the requirements of section 922.1.2,

table 9-4.

613.8. Street Floor Lobbies. — Street floor lobbies may be used

as exitway passageways when they comply with the requirements

of section 613.1 through 613.7 above subject to the following

modifications:

613.8.1. Vertical Exitways Served. — One hundred (100) percent
of the total number of vertical exitways provided for a building
may be served by a street floor lobby, if egress is provided in
two (2) different directions from the discharge points of all
vertical exitways to open exterior spaces that are remote from
each other.

613.8.2. Width. — Street floor lobbies serving as exitway pas-
sageways shall be increased in width to accommodate the occu-
pant load of all communicating spaces on the lobby floor that
have egress through them.

613.8.3. Openings. — Openings between street floor lobbies ser-
ving as exitway passageways and elevators or communicating
spaces shall comply with the following:

a. Doors. — All doors shall be one and one-half (1-1/2)
hour self-closing fire doors, except that when the com-
municating space is unsprinklered and is classified in
occupancy groups F, G, H or L or is completely sprink-
lered in accordance with the construction provisions of
article 12 and is classified in occupancy groups B-2, C,
D-2 or E, then three-quarter (3/4) hour self-closing fire
doors may be provided. In lieu of three-quarter (3/4)
hour doors, glass or other noncombustible doors may be
used if installed in combination with one and one-half
(1-1/2) hour automatic fire doors located on the lobby
side and protected by automatic sprinklers over the doors
on the room side. The maximum amount of door opening
in any wall shall not exceed twenty (20) percent of the
area of such wall.

b. Show Windows. — Show windows facing on street floor
lobbies serving as exitway passageways shall have a
maximum floor area of twenty-four (24) square feet, shall
be protected by automatic sprinklers complying with the
construction requirements of article 12, shall be glazed
by one-quarter (1/4) inch polished plate glass or equiva-
lent, and shall be backed by construction having a two
(2) hour fireresistance rating. All openings in such back

613-614

construction shall comply with the provisions of a. above.

Adjoining show windows shall be separated from each
other by construction having a two (2) hour fireresistance
rating.
613.8.4. Occupancy. — Street floor lobbies serving as exitway
passageways may be occupied by newsstands, candy and tobacco
stands, information booths or similar occupancies, if such stands
or booths are constructed of noncombustible materials, occupy
not more than a total of five (5) percent of the net floor area
of the lobby, and do not infringe upon the required clear width
of the lobby at any point.

SECTION 614.0. MEANS OF EGRESS DOORWAYS

The requirements of this section shall apply to all doorways
serving as a component or element of a required means of egress;
except this section shall not apply to doorways leading to or
from required stairways (see section 618.6, 620.5 and 621.3).

614.1. Number of Doorways. — When the occupancy load exceeds
the number of persons listed in section 614.1.1 table 6-4 there
shall be at least two (2) means of egress door openings as remote
from each other as practicable. Such doorways shall provide
independent access to separate exitways except that these doors
may open upon a common access way leading to separate exit-
ways either in opposite directions.

614.1.1. Table 6-4. Maximum Occupant Load — For Spaces With
One Door

Occupancy Group Max. Occupant Load

Classification with One (1) Door

A 10

B 50

C 75

D 50

E 75

F 75

G 75

H 15

L 20

614.2. Size of Means of Egress Doors. — The required width of
means of egress doors shall be determined from the capacity as
listed in section 610.2.1 table 6-3. A door forty (40) inches wide

shall be deemed the equivalent of two (2) full units of egress
width. The height of doors shall in no case be less than six and
two-thirds (6-2/3) feet. In applying the provision of this Code the
nominal door dimensions shall be used for computing required
size of doors. The maximum width of a single door shall be
forty-eight (48) inches. The minimum width shall be thirty (30)
inches except as provided in article 4 or as tabulated below:

a. Single doors opening from classrooms to corridors,
thirty-six (36) inches.

b. All door openings used by patients in buildings classified
occupancy group H-2, forty-four (44) inches.

c. Doors swinging in pairs (no mullion), forty-eight (48)
inch opening.

614.3. Location of Exitway Doors. — The doorways opening from
a building to a street or grade passageway to a street shall be
located as remote as practicable from each other. The required
doorways opening from a room or space within a building lead-
ing to an exitway hallway shall be located as remote as practicable
from each other. The distance of exitway access travel from any
point in a room or space to a required exitway door shall not
exceed the limitations of section 609.3.2, table 6-2, unless other-
wise specifically provided for in this Code.

614.4. Swing of Doors. — Except as provided in reference stan-
dard RS6-4, all means of egress doors shall be hung to swing
in the direction of egress travel without obstructing the required
width of egress component. Grade exitway doors shall not project
more than twelve (12) inches beyond the street lot line comply-
ing with section 312.1.1. Where separate doors are provided for
entrance and exitway use, and the entrance door is designed to
swing only inwards under normal use, it shall be equipped with
an emergency release bracket that will disengage the door
operator and permit the door to swing outward under total
pressure of not more than fifteen (15) pounds.

614.5. Door Hardware.

614.5.1. Operation. — Required means of egress doors shall be
readily openable at all times from the side from which egress is
to be made and shall not require a key to operate from that
side, except that locks may be used in penal and mental insti-
tutions and areas, where required for security, and in banks,
museums, jewelry stores and other places where extra safeguards
are required, subject to the approval of the building official,
and provided the locks are equipped with electrical release de-

614

vices for remote control in case of emergency. Except as other-
wise approved by the building official for security requirements
doors opening into interior enclosed stairs shall not be locked
from either side except that doors may be locked to prevent
access to the stair from the outdoors at the street floor. Hard-
ware shall be provided on all exitway doors to hold them in a
closed position against the pressure of expanding gases.

614.5.2. Panic Proof. — Exitway doors shall be equipped with
panic proof hardware in rooms of occupancy group F-l, F-2 if
the occupancy load exceeds one hundred (100) persons, F-3 and
F-5 if the occupancy load exceeds three hundred (300) persons,
and F-4 and G except when opening directly outdoors at grade
from rooms having an occupant load of less than seventy-five
(75) persons. The panic proof hardware shall be of an approved
type and shall release when a pressure exceeding fifteen (15)
pounds is applied to the releasing device in the direction of
egress. The releasing device shall be placed at least three (3)
feet but not more than four (4) feet above the floor. Required
panic hardware shall not be equipped with any locking or
dogging device, set screw, or other arrangement which can be
used to prevent the release of the latch when pressure is ap-
plied to the releasing device.

614.5.3. Remote Control. — In rooms of occupancy group H-l
(institutional) occupied as places of detention, approved releas-
ing devices with remote control shall be provided for emergency
use.

614.5.4. Fireresistance of Hardware. — Exitway doorways of
specified fireresistance rating shall include approved hardware
in the assembly to comply with sections 904 and 917.

614.5.5. Mechanical Operations. — Where required exitway doors
are arranged to be opened by mechanical devices of any kind,
they shall be so constructed that the door may be opened
manually and will release under a total pressure of not more
than fifteen (15) pounds applied in the direction of exitway
travel.

614.6. Door Construction. — All required exitway doors shall
be self-closing fire doors complying with article 9, except for
grade floor exitway doors and as herein provided for approved
collapsible revolving doors and where one and three-quarter
(1-3/4) inch bonded solid core wood doors are permitted.
614.6.1. Grade Exitway Doors. — Exitway doors at grade maybe
glazed with plate glass not less than seven thirty-seconds (7/32)

inches thick, or with any other approved glazing materials.
Approved plate glass doors having one (1) or more unframed
edges may be used provided they are constructed of tempered
glass not less than one-half (1/2) inches thick.

SECTION 615.0. REVOLVING DOORS

615.1. Limitations of Use.

615.1.1. Where Permitted. — Except in places of occupancy
group F (assembly) which either have an occupancy load of
more than two hundred (200) or are excluded by reference
standard RS6-2, and except in buildings of occupancy group
H (institutional), approved automatic collapsible revolving doors
when constructed and installed as herein provided shall be ac-
cepted in required exitway doorways from the first floor to the
street. These automatic collapsible revolving doors shall not
exceed fifty (50) percent of the required exitway capacity at any
location. Approved swinging doors may be provided to furnish
one-half (1/2) the required egress width in accordance with
provisions of this article, and these shall be located within
twenty (20) feet of the revolving door with one (1) swinging
door adjacent to each side of the revolving door.

615.1.2. Prohibited Construction. — Braces or other devices that
prevent normal operation of the automatic releasing mechanism
shall be prohibited.

615.2. Width of Passage.

615.2.1. Unit Egress Width. — Automatic collapsible revolving
doors approved as an element of a required exitway shall pro-
vide a minimum of one (1) clear unit egress width of passage-
way through the vestibule when the leaves are in a collapsed
position.

615.2.2. Minimum Diameter — The minimum diameter of ap-
proved revolving doors shall be adequate to provide the required
clear egress width when collapsed, but in no case less than six
and one-half (6-1/2) feet in diameter.

615.3. Speed Control. — All approved automatic collapsible re-
volving doors shall be equipped with an approved speed con-
trol governor adjustable to safe traffic speed as required by the
approved rules, but in no case more than fifteen (15) revolutions
per minute.

615.4. Construction. — All approved automatic collapsible re-
volving doors shall be constructed as follows:

614-616

615.4.1. Operating Mechanism. — Each wing is independently
supported by a hanger with a corrosion resistant safety release
which, when pressure of between sixty (60) to eighty (80) pounds
is exerted simultaneously on the wings on opposite sides of the
door pivot, the door wings will fold back on themselves in
the direction of egress.

615.4.2. Use of Wood. — Where not otherwise required by the
provisions of article 9, the doors may be constructed of wood
or other approved materials of similar combustible characteristics
with a minimum thickness of one and one-quarter (1-1/4) inches.

615.4.3. Floor Covering. — Approved mats or other floor cover-
ings complying with the provisions of article 9, not more than
one-half (1/2) inch thick, may be installed within the enclosure
when permanently secured to the structural flooring and finishing
flush with the adjacent floor area.

615.4.4. Glazing. — The doors shall be glazed with not less than
one-quarter (1/4) inch plate glass and provided with at least
one (1) push bar.

615.5. Maintenance. — The owner shall be responsible at all
times for the operation and maintenance of revolving doors,
and shall have the doors inspected at intervals not to exceed
six (6) months. All parts of the doors, including the safety
release and speed control mechanism, shall be maintained in good
working order. Inspection reports shall be made in writing and
kept on file at the premises for at least two (2) years.

SECTION 616.0. HORIZONTAL EXITWAYS

A horizontal exitway is a way of passage from one building
to an area of refuge in another building on approximately the
same level, or a way of passage through or around a fire wall
or fire partition to an area of refuge on approximately the same
level in the same building, which affords safety from fire or
smoke from the area of escape and areas communicating there-
with.

616.1. Horizontal Exitway Types. — A horizontal exitway may
consist of any one of the following types:

616.1.1. Doors through walls or partitions having at least a
two (2) hour fireresistance.

616.1.2. Balconies (open air) or exterior vestibules leading
around the end of a fire division to another fire area or building.

616.1.3. Bridges or tunnels between two (2) buildings.

616.2. Door Requirements. — When serving as horizontal exit-
ways doors shall comply with the following:

616.2.1. Size of openings in fire walls or fire divisions shall
comply with the provisions of section 908, but in no case shall
the width of one (1) opening used as a required exitway be
greater than eighty-eight (88) inches nor shall the area exceed
eighty (80) square feet.

616.2.2. Opening Protectives. — The opening in fire walls or fire
divisions which are required to have a fireresistance rating of
two (2) hours shall be protected with a one and one-half (1-1/2)
hour door assembly. Doors in fire divisions or fire walls having
a three (3) hour or four (4) hour fireresistance rating shall be
as required by section 917.

616.2.3. Door Swing. — Doors shall be self-closing and swinging
in the direction of exitway travel and when travel is in both
directions as when two (2) areas of refuge serve as areas of
refuge for each other, at least two (2) door openings shall be
provided, the doors of which swing in opposite directions.
Double-acting doors shall not be permitted.

616.2.4. Unlocked Doors. — Horizontal exitway doors shall be
kept unlocked and unobstructed whenever the area on either
side of the horizontal exitway is occupied.

616.3. Balcony, Bridge and Tunnel Requirements. — When ser-
ving as horizontal exitways, balconies, bridges and tunnels
shall comply with the following:

616.3.1. Their width shall be equal to at least the width of
the doors opening on them, but in no case less than forty-four
(44) inches.

616.3.2. They shall be enclosed at each end by doors complying
with 616.2 above.

616.3.3. The floor level at doors shall be the same as that of
the building except that the floor level of open balconies or
open bridges shall be not less than five (5) inches lower.

616.3.4. Where there is a difference in level between the areas
connected, the floors of the horizontal exitways shall be ramped
not more than one (1) inch in ten (10) inches.

616.3.5. Exterior wall openings within thirty (30) feet horizon-
tally of any open bridge or balcony or below any open bridge
or balcony shall be provided with opening protectives having a
three-quarter (3/4) hour fire protection rating.

616-617

616.3.6. Balconies shall not face or open on yards or courts
less than twelve (12) feet wide, and shall be constructed as
required for exterior corridors.

616.3.7. Exterior bridges shall be constructed of noncombus-
tible materials. Interior bridges or tunnels shall be constructed
of materials providing a two (2) hour fireresistance rating.

616.4. Area of Refuge. — The areas connected by the horizontal
exitway shall be either public areas or spaces occupied by the
same tenant and the area of refuge shall be adequate to house
the total occupancy load of both connected areas as provided in
section 610.6.

616.5. Egress from Area of Refuge.

616.5.1. Stairway Exitway. — When the horizontal exitway is
not at ground level, there shall be at least one (1) interior en-
closed stairway or smokeproof tower on each side of the hori-
zontal exitway and any fire area nqt having a stairway accessible
thereto shall be considered as part of an adjoining section with
such stairway; but in no case shall the length of travel between
the horizontal exitway and the required stairway exceed the re-
quirements of section 609.3.

616.6. Capacity. — The capacity of horizontal exitways shall be
determined by the requirements listed in section 610.2.1 table
6-3. Only the widths of doors swinging in the direction of exit-
way travel to the area of refuge shall be counted.

SECTION 617.0. EXITWAY RAMPS

Ramps may be used as exitways components. When used in
lieu of interior stairways, they shall comply with all the applic-
able requirements of required interior stairways as to enclosure,
capacity, and limiting dimensions.

617.1. Capacity. — The capacity of ramps shall be as listed in
section 610.2.1 table 6-3.

617.2. Maximum Grade. — Unless otherwise limited by regula-
tions of the Commonwealth of Massachusetts, ramps shall not
have a slope steeper than as follows: 1 in 8 except that in
buildings classified in occupancy group H the slope shall not
exceed 1 in 10, and except as provided in article 4 for places
of assembly, in section 603.6 for building access, and in section
616.3.4 for horizontal exitways.

617.3. Design.

617.3.1. Changes in Direction. — Ramps shall be straight with
changes in direction being made at level platforms or landings,
except that ramps having a slope not greater than one (1) in
twelve (12) at any place, may be curved.

617.3.2. Length. — The sloping portion of ramps shall be at
least three (3) feet but not more than thirty (30) feet long be-
tween level platforms or landings.

617.3.3. Platforms. — Level platforms or landings, at least as
wide as the ramp, shall be provided at the bottom, at inter-
mediate levels where required, and at the top of all ramps.
Level platforms shall be provided on each side of door open-
ings into or from ramps, having a minimum length in the
direction of exitway travel of three (3) feet, and when a door
swings on the platform or landing a minimum length of five (5)
feet.

617.3.4. Doors. — Door openings into or from ramps shall com-
ply with the requirements for stair exitway doors in section
618.6. No door shall swing over the sloping portion of a ramp.

617.3.5. Guards and Railings. — Guards and railings of ramps
shall comply with the applicable requirements of section 618.5
except that only ramps having a slope steeper than one (1) in
twelve (12) need comply with the requirements for handrails,
and intermediate handrails shall not be required.

617.3.6. Surface. — Approved non-slip surfaces shall be provided
for all exterior ramps, interior ramps exceeding a slope of one
(1) in ten (10) and where the use is such as to involve or con-
tribute to the danger of slipping.

SECTION 618.0. INTERIOR EXITWAY STAIRWAYS

618.1. Capacity of Exitway Stairs. — The capacity of stairways
and doors per unit of egress width shall be computed in accor-
dance with section 610.2.1, table 6-3.

618.2. Minimum Dimensions.

618.2.1. Width. — All interior required stairways shall be not
less than forty-four (44) inches in width except as follows:

a. Such width may be reduced to thirty-six (36) inches in
buildings of occupancy groups L-l, L-2 and L-3 serving
not more than thirty (30) occupants per stair on any
floor and in buildings classified in occupancy groups B,
D and E serving not more than sixty (60) persons per

617-618

stair and in exitways from boiler rooms and similar
service spaces not open to the public or in general use
by employees.

b. Such width may be reduced to thirty (30) inches for
unenclosed stairways located within a single dwelling
unit, or when serving mezzanines or balconies having
an occupant load not exceeding twenty-five (25) persons.

c. When the boiler room is less than three hundred (300)
square feet in area, housing a low pressure boiler, and is
completely enclosed in two (2) hour fireresistive construc-
tion with approved opening protectives and an iron ladder
or other approved direct exitway is furnished to the
street, the primary exitway stairway may be omitted.

618.2.2. Headroom. — Headroom in a flight of stairs shall be
measured vertically from an inclined plane, which contains the
line of the nosing or upper front edge of each tread and extends
to its intersection with a landing, to any point directly above
the plane that limits the headroom of the stair or vertically
from the same inclined plane up to a parallel inclined plane
through a point limiting the headroom. The minimum headroom
thus measured shall be seven feet zero inches (7'0") except that
six feet eight inches (6'8") shall be permitted over a landing or
when the parallel inclined planes are each at an angle of twenty-
two and one-half (22-1/2) degrees or less with the horizontal.

618.2.3. Restrictions. — No stairways shall reduce in width in
the direction of exitway travel.

618.3. Landings and Platforms. — Landings and platforms shall
be provided at the head and foot of each flight of stairs, except
at the head of basement stairs in one- and two-family dwellings,
and shall comply with the following:

618.3.1. Width. — The least dimension of landings and platforms
perpendicular to direction of travel shall be not less than the
required width of stairway. On a straight run stair, the distance
between risers of upper and lower flights at intermediate landings
or platforms need not be more than forty-four (44) inches.

618.3.2. Vertical Rise. — In buildings of occupancy group F
(assembly) and occupancy group H (institutional), the height of
vertical rise shall not exceed eight and one-third (8-1/3) feet
between landings and intermediate platforms. In all other build-
ings, no stairway shall have more than fifteen (15) nor less than
three (3) risers between landings.

618.3.3. Landings and platforms shall be enclosed on sides by
walls, grilles or guards at least three (3) feet high.
618.4. Treads and Risers.

618.4.1. Dimensions. — Treads and risers of required stairs shall
be so proportioned that the sum of two (2) risers and a tread,
exclusive of projection of nosing, is not less than twenty-four
(24) inches nor more than twenty-five and one-half (25-1/2)
inches. The maximum riser height and minimum tread width
shall comply with the following:

Maximum

Minimum

Occupancy Group

Riser Height

Tread Width

(inches)

One- and Two-Family Dwellings

(Occupancy Group L-3)

Closed Risers

8-1 '4

plus 1-1 4 nosing

Open Risers

8-1/4

plus 1 2 nosing

All Other Residential (Occupancy

Groups L-l and L-2)

plus 1-1/4 nosing

Institutional (Occupancy Group

H-2)

plus nosing

Assembly and Other Institutional

7-1 2

1 2 plus nosing

All Others

7-3 4

1 2 plus nosing

NOTE: Treads may be undercut a distance equal to the nosing. A nosing shall
not be required when tread width is eleven (11) inches or wider.

618.4.2. Winders. — No winders shall be permitted in required
exitway stairways except that in one- and two-family dwellings
and in ornamental stairways not required as an element of an
exitway, treads with a minimum width of four (4) inches and an
average width of nine (9) inches may be permitted. The width
of winder treads when measured eighteen (18) inches from the
narrower end shall be at least equal to the width of tread
above or below the winding section.

618.4.3. Curving or Skewed Stairs. — Curving or skewed stairs
may be used as elements of required means of egress when the
tread and riser relationship is in accordance with 618.4.1 . when
measured at a point eighteen (18) inches in from the narrow
end of the tread; and no tread shall be more than three (3)
inches narrower or three (3) inches wider at any point than the
width established eighteen (18) inches in from the narrow end;
and when the stairs have a radius of twenty-five (25) feet or
more at the inner edges.

618.5. Stairway Guards and Handrails. — Unless otherwise speci-
fically provided for in this code all stairways shall have con-
tinuous guards and handrails on both sides, and in addition

618

thereto, stairways required to be more than eighty-eight (88)
inches in width shall have intermediate handrails dividing the
stairway into portions not more than eighty-eight (88) inches
wide except that on monumental outside stairs intermediate
handrails may be omitted. No guard shall be required for inside
edge of stairs which reverse direction at intermediate landings,
where the horizontal distance between successive flights is not
more than one (1) foot. Similarly no guard shall be required
for intermediate landings which are no more than one (1) foot
clear of walls.

618.5.1. Handrail Details.

Handrails may project not more than three and one-half (3-1/2)
inches into the required stair width and shall provide one and
one half (1-1/2) inch finger clearance.

Handrails shall be about three (3) feet, measured vertically,
above the center of the treads.

Handrails shall be returned to walls or posts at each end of
the stairway, except in one- and two-family dwellings.

618.5.2. Guard Details.

Guards shall be not less than forty-two (42) inches in height
measured vertically above the nosing of the tread except guards
protecting changes in level one (1) story or less on interior bal-
conies and mezzanines shall be not less than thirty-six (36)
inches high.

Guards shall be constructed so that the area in the plane of
the guard from the top of the tread to the top of the guard
is subdivided or filled in one (1) of the following methods:

a. Two (2) horizontal rails for thirty-six (36) inches high
guards with a curb at least one (1) inch high above the
nosing at the edge of the stairs and at least three (3)
inches high at the edge of the landings.

b. A sufficient number of intermediate longitudinal rails
constructed so that the clear distance between rails
(measured at right angles to the rail) does not exceed
ten (10) inches. The bottom rail shall be not more than
(10) inches (measured vertically) from the tread nosing.
In lieu of the proceeding, the building official may ac-
cept a two (2) rail guard when the hazard involved is
otherwise minimized by the railing construction and/or
limited vertical separation of the stair from a horizontal
surface below.

c. Balusters spaced not more than six (6) inches apart.

d. Panels of wire mesh, or expanded metal, or ornamental
grills which provide protection equivalent to that pro-
vided by the intermediate rails or balusters specified in
the two preceding paragraphs.

e. Walls.

f. Any combination of the foregoing.

618.6. Stair Exitway Doors.

618.6.1. Width. — The total width of all exitway doors (or door)
to a stairway at any one landing shall be not less than the
number of units of egress width required for the capacity of the
stairway which services the floor or area from which the exitway
doors (or door) lead; but in no case shall such a door be less
than thirty (30) inches nominal width- in occupancy group L-3
buildings (one- and two-family dwellings) and thirty-two (32) |
inches nominal width in occupancy group E (business) buildings.

618.6.2. Direction of Swing. — All doors shall swing on a landing
in the direction of exitway travel. When open, stair exitway doors
shall not reduce the width of landings to less than the minimum
required for its capacity and in no case to less than thirty-six
(36) inches.

618.6.3. Door Construction. — All doorway opening protectives,
including the frames and hardware, shall be approved self-
closing swinging doors complying with article 9 except in one-
and two-family dwellings where one and three-quarter (1-3/4)
inch bonded solid wood doors are permitted.

618.7. Spiral Stairways — Permitted Uses.

618.7.1. Unenclosed spiral stairways of noncombustible con-
struction, and having a tread length of at least thirty (30)
inches, may be used as an element of a required means of egress
from mezzanine or balcony areas not more than two hundred
and fifty (250) square feet in area nor more than one-third (1/3)
the area of the floor below, nor having an occupancy load ex-
ceeding twenty-five (25) persons. The maximum number of
persons per unit of egress width shall be ten (10). Spiral stairways
may also be used as an element of a required means of egress
in a single family dwelling.

618.7.2. Unenclosed spiral stairways may serve as access stairs
between two (2) floor levels in buildings other than occupancy
group H provided that the total unenclosed area of the two (2)
levels thus integrated does not exceed the allowable area for
one (1) floor in section 221.2, table 2-2. Except as permitted

618

in 618.7.1, such stairs shall be additional to and shall not ob-
struct or interfere with the required means of egress. The max-
imum number of persons per unit of egress width shall be ten
(10).

618.8. Monumental and Service Stairways. — Except as otherwise
provided for in section 418.2.2, monumental, ornamental, service,
convenience, or other supplementary stairways in buildings of
other than occupancy groups D, F, and H (industrial, assembly,
and institutional) providing access between not more than two
adjoining stories and when not a part of a required exitway may
be erected without stairway enclosures when the total unenclosed
area between the fire divisions of the two levels thus integrated
does not exceed the allowable area for one floor in section
221.2, table 2-2. Such stairways shall be additional to and shall
not obstruct or interfere with required exitways.

618.9. Stairway Construction. — Unless otherwise provided here-
in, all required interior stairways shall be built entirely of non-
combustible materials with solid risers, treads, and landing
platforms and all finish floor surfaces of non-slip noncombustible
materials; except that wood handrails shall be permitted, com-
plying with the requirements of section 618.5.

618.9.1. Strength. — All stairways, platforms, landings and floors
in areas used as a means of egress, in other than one- and two-
family dwellings, shall be adequate to support a live load of
one hundred (100) pounds per square foot.

618.9.2. Enclosures. — See section 221.1, table 2-1.

618.9.3. Combustible Construction. — In all buildings of type
3 or 4 construction of all occupancy groups other than assembly
and institutional buildings, not over three (3) stories or forty
(40) feet in height with not more than seventy-five (75) occu-
pants above nor more than forty (40) occupants below the
grade floor, the stairways and their enclosures may be con-
structed of wood or other approved materials of similar com-
bustible characteristics and of adequate strength.

618.9.4. Enclosures for Combustible Construction. — The enclo-
sure and underside of stairways of combustible construction,
except in one- and two-family dwellings, shall be protected with
fireresistive partitions and ceilings as herein required, firestopped
as specified in section 877, 909 and 921; and the space below
the stairs shall be kept open or shall be solidly enclosed with
fireresistive partitions.

SECTION 619.0. ACCESS TO ROOF

619.1. Access. — In buildings or in building sections more than
three (3) stories or forty (40) feet in height with roofs having a
slope of less than twenty (20) degrees, access to the roof shall be
provided by means of a stairway or a ladder and trap door,
except that access to setback roof areas may be through a door
or window opening to the roof. Where the roof is used as a
roof garden or for other habitable purposes, sufficient stairways
shall extend to it to provide the necessary exitway facilities
from the roof as required for such occupancy. Roof trap doors
shall be constructed to comply with section 927.

619.2. Roof Enclosures. — Stairways extending through roofs
shall be enclosed in roof structures of fireresistive construction
meeting the requirements of section 927.

SECTION 620.0. SMOKEPROOF TOWERS

620.1. Where used as a required exitway, smokeproof towers
shall conform to the requirements of this section.

620.2. Access. — Exitway access to the stairway at each story
shall be through a vestibule or balcony with an unobstructed
width not less than the required stairway width, but not less
than forty-four (44) inches in any case, open on at least one (1)
side to a street, alley, yard or court with four (4) feet high guard
railings across the open side. Outside vestibules or balcony
floors shall be level with or installed below the building floor
where climatic conditions involve possibility of door obstruction
by snow or ice. No step shall be permitted into the stair en-
closure.

620.3. Court Size. — The yard or court shall have a minimum
area of two hundred (200) square feet and a minimum dimen-
sion of ten (10) feet and the exterior open side of the vestibule,
balcony or landing shall have a minimum area of eighteen (18)
square feet and a minimum width of thirty (30) inches.

620.4. Interior Open Courts. — When interior open courts are
used to vent the access balcony or vestibule, special provision
shall be made in the design to avoid the creation of vertical
drafts resulting in negative pressures which would retard the
opening of the exitway door to the stairway from the balcony
or vestibule.

620.5. Opening Protectives.

619-621

620.5.1. Windows. — All window openings in the exterior wall
of the building, facing on the yard or court within thirty (30)
feet below or to the side of any access balcony or vestibule
shall be protected with three-quarter (3/4) hour opening pro-
tectees complying with article 9.

620.5.2. Doors. — Door openings from building to vestibules
or balconies and to the stairways shall be not less than forty-
four (44) inches wide. The doors shall be capable of being
opened from both sides without a key, complying with all the
requirements of section 618.6 for exitway doors for stairways,
except that the fireresistance rating shall be not less than one
and one-half (1-1/2) hours or the approved labeled equivalent
complying with article 9.

620.6. Terminal Passageway. — The smokeproof tower shall ter-
minate at grade level and shall provide egress to the street
independently of all other stairways. When grade passageways
are used, they shall comply with the requirements of section
613; except that there shall be no openings therein other than
the smokeproof tower and street exitway doorways and the enclo-
sure walls shall be of four (4) hour fireresistive construction
and the floor and roof of three (3) hour fireresistive construc-
tion.

620.7. Construction. — The construction of smokeproof towers
shall be of walls with a four (4) hour fireresistive rating without
openings other than the required doorways; with platforms,
landings and balconies of not less than three (3) hour fireresis-
tive construction and with stairways complying with all the
applicable construction details specified for interior stairways
in section 618.

SECTION 621.0. EXTERIOR EXITWAY STAIRWAYS

621.1. As Required Exitway. — Exterior stairways conforming to
the requirements for interior stairways in all respects, except as
to enclosures and except as herein specifically modified, may
be accepted as an element of a required means of egress in
buildings not exceeding six (6) stories or seventy-five (75) feet in
height for other than occupancy group H (institutional) provided
there is at least one (1) additional approved interior stairway,
except as provided in section 621.1.1 for residential buildings
and section 621.3 for single exitway buildings.

Exterior stairways which are accepted as exitway elements in
residential buildings of occupancy groups L-2 and L-3 shall be
relieved from requirements for fire doors, but shall be provided
with handrails and guards as required for interior stairs and as
required by section 612.2 and shall be covered by a roof pro-
viding protection from the weather.

621.1.1. Motel Buildings. — In the residential portion of motels
(occupancy group L-l) not more than three (3) stories and non-
habitable attic or forty-five (45) feet in height, interior enclosed
stairways may be omitted where at least one (1) door from
each motel unit opens onto an open porch or balcony served
by at least two (2) stairways so located as to provide a choice
of independent, unobstructed means of egress directly to the
grade. Such porches and stairways shall comply with the require-
ments for interior stairways as specified in section 618.0. Porches
and balconies shall be not less than four and one-half (4-1/2)
feet in width. The stairways shall be not less than three feet
eight inches (3'8") in width and shall be located remotely from
each other. The maximum travel distance from any motel unit
to the nearest stairway shall be seventy-five (75) feet. Porches
and stairways shall be located at least ten (10) feet from adjacent
property lot lines and from other buildings on the same lot
unless openings in such buildings are protected by three-quarter
(3/4) hour fireresistive doors or windows.

621.2. Guards and Canopies. — Guards shall be provided on all
exposed sides of required exterior stariways to a height of at
least three feet six inches (3'6") constructed of wire or other
noncombustible weather resisting mesh of such dimensions as
to prevent the passage of a five (5) inch diameter ball. The top
of the stairway shall be protected with a hood or canopy of
metal or other approved noncombustible material.

621.3. Opening Protectees.

621.3.1. Doors. — Except as specified in section 621.1 for resi-
dential buildings, access shall be provided at each story through
a three-quarter (3/4) hour self-closing fire door of the required
number of unit egress widths. Doors shall open upon a landing
either level with or not more than one (1) five (5) inch step
below the floor.

621.3.2. Windows. — In buildings more than three (3) stories in
height, or with an occupancy load of more than seventy-five (75)
above or more than forty (40) below grade, the openings below

621-622

and within ten (10) feet horizontally of the stairway shall be
protected with approved three-quarter (3/4) hour automatic
fire windows.

621.4. Location.

621.4.1. Access to Street. — All required exterior stairways shall
be located so as to lead directly to a street or open space with
direct access to a street; or when located on the rear of the
building may lead through a passageway at grade complying
with section 613.

621.4.2. Projection. — In no case shall exterior stairways project
beyond the street lot line.

621.5. Construction. — Exterior stairs shall be constructed entirely
of noncombustible materials, except that handrails may be of
wood and except that on buildings of type 3 or 4 construction
classified in occupancy groups other than F or H, exterior stairs
may be built of combustible materials when the buildings are
two (2) stories or thirty (30) feet in height or less and have an
occupant load not exceeding forty (40) persons per floor above
the street below. Treads, landings, and platforms shall be solid
and unperforated but risers may be open.

621.6. Capacity. — The capacity of exterior stairs shall be deter-
mined in accordance with the requirements of section 610.2.1
table 6-3.

SECTION 622.0. MOVING EXITWAY STAIRWAYS

622.1. When Acceptable. — Moving stairways of the horizontal
non-slip tread type moving in the direction of egress may be
used subject to the approval of the building official as an ap-
proved exitway element in buildings of all occupancy groups
except groups F and H, when constructed and approved in
accordance with the requirements of this article and the provi-
sions of article 16. When accepted as an element of a required
means of egress, they shall be enclosed with fireresistive parti-
tions as specified in section 618.

622.1.1. Additional Requirements. — Only escalators moving in
the direction of egress may be credited as exitways, except that
any escalator may be credited when it is connected to an auto-
matic fire detection system that will cause it to stop simultan-
eously with the detection of fire. The detection system shall com-
ply with the construction provisions of article 16. Where an
escalator provides exitway facilities from only one floor of a

building, the automatic detection system shall be located on that
floor. Where escalators provide exitway facilities from more than
one floor, the detection system shall be located on all floors so
served, and shall cause escalators on all floors of the section
of the building that they serve to stop operating. The stopping
mechanism shall operate to bring the escalator to a gradual,
rather than an abrupt stop. In factories and office buildings re-
versible escalators may be accepted as a required element of a
means of egress, provided that a readily accessible main operating
panel, from which all escalator units in the exitway group may
be stopped or reversed, is located on the street or ground floor
adjacent to and in the same enclosure with the escalators.

622.2. Limiting Dimensions.

622.2.1. Width. — The width between moving stairway balustrades
shall be not less than twenty-two (22) inches nor more than
forty-eight (48) inches, measured at the narrowest point at a
height of twenty-seven (27) inches vertically above the nose line
of the steps. In no case shall such width exceed the width of
the steps by more than thirteen (13) inches.

622.2.2. Treads and Risers. — The depth of the moving tread
shall be not less than fifteen and three-quarters (15-3/4) inches;
and the rise between treads shall not exceed eight and one-half
(8-1/2) inches.

622.3. Capacity. — The occupancy capacity shall be computed
in accordance with section 610.2.1, table 6-3 based on the fol-
lowing:

Units of Minimum Width (in.) at

Egress Width Step Balustrade(a) Enclosure (b)

1-1/2 24 32 52

2 40 48 68

a. Measured 27 inches above front edge of tread.

b. Clear width above handrails.

622.4. Landings and Platforms. — Landings and platforms shall
be provided at the top and bottom of each unit as required
for interior exitway stairways.

622.5. Railings. — Guards shall be surmounted with moving
handrails traveling at the same speed as the stairway.

622.6. Egress. — Means of egress to the street shall be provided
as specified herein for interior stairways except that in mer-
cantile buildings completely equipped with a two-source auto-

622-624

matic sprinkler system, moving stairways may be accepted for
one-third (1/3) the total required exitway capacity when dis-
charging through the main grade floor area.
622.7. Construction.

622.7.1. Noncombustible Materials. — Only noncombustible ma-
terials shall be used in the construction of moving stairways in
accordance with article 16.

622.7.2. Fireresistance. — The enclosure shall afford the fire-
resistance required for approved interior exitway stairways.

622.7.3. Extension to Roof. — The construction shall comply
with all the applicable requirements of this Code for interior
exitway stairways except that a fixed stairway or ladder and trap
door may be substituted for the extension to the roof when
required.

622.7.4. Height of Travel Per Unit. — No single moving stair-
way unit shall have a vertical travel of more than two (2)
stories nor more than thirty-five (35) feet. Escalators shall have
an inclination of not over thirty (30) degrees from the horizontal.

622.7.5. Rate of Travel. — The maximum speed of an escalator
shall not exceed one hundred twenty-five (125) feet per minute,
measured along the angle of inclination.

SECTION 623.0. ELEVATORS IN EXITWAYS

Elevators shall not be allowed as exitways, nor installed in a
common enclosure with exitway stairways. The path of travel
of any exitway stairway shall not pass directly in front of any
elevator hoistway door except as noted in section 623.1.
623.1. Grade Corridor. — The width of a grade corridor into
which exitway stairways and elevators discharge shall not be
less than three-quarters (3/4) of the combined width for stair-
ways and elevators; but in no case shall the width of corridor
be less than five (5) feet when accommodating the discharge
from five (5) or less elevators; and not less than one-half (Vi)
foot additional for each additional elevator.

SECTION 624.0. FIRE ESCAPES

624.1. Where Permitted. — Fire escapes shall be permitted only
by special order of the building official in existing buildings
or structures not exceeding seventy (70) feet in height, when
constructed in accordance with the approved rules and when

more adequate exitway facilities cannot be provided. The capac- |
ity of fire escapes shall be as provided in section 610.2.1, tablei
6-3 for stairs.

624.2. Location. — When located on the front of the building I
and projecting beyond the building line, the lowest landing;
shall be not less than ten (10) or more than fourteen (14)1
feet above grade, equipped with a counterbalanced stairway
to the street and with fixed ladder to the roof. In alleyways I
and thoroughfares less than thirty (30) feet wide, the clearance I
under the lowest landing shall be not less than fourteen (14) I
feet.

624.3. Construction. — All fire escapes shall be constructed in I
accordance with reference standard RS6-3.

SECTION 625.0. DELETED

SECTION 626.0. EXITWAY SIGNS AND LIGHTS

626.1. Size and Location. — The location of all required exit-
ways on every floor except in occupancy group L-3 shall be
clearly indicated by approved signs reading "EXIT" with letters
to be not less than five (5) inches in height with one-half (Vi)
inch strokes. Exitway signs shall be installed immediately above
the head and on the center line of each exitway door or pair
of exitway doors and visible from the immediate exitway access.
Such signs shall be placed at an angle with the exitway opening
if such placement is required for the signs to serve their pur-
poses. In long corridors, in open floor areas, and in all other
situations where the location of the exitway may not be readily
visible or understood, directional signs shall be provided to
serve as guides from all portions of the corridor or floor.

626.2. Power Source. — Except in buildings not provided with
artificial lighting all "EXIT" signs shall be illuminated at all
times when the building is occupied from independently con-
trolled electric circuit or other source of power.

626.3. Exitway Sign Design. — Exitway signs shall read only
"EXIT" and shall be of the externally lighted or internally
lighted type, except that they may be nonilluminated in build-
ings not provided with artificial lighting.

626.3.1. Externally Lighted-. — The artificial light source on
externally lighted signs shall provide at least twenty-five (25)
foot candles on the exposed face of the sign. Visibility of the
sign shall not be obscured by the location of the light source.

624-626

626.3.2. Internally Lighted. — For internally lighted signs, the
average initial brightness of the letters shall be at least twenty-
five (25) foot lamberts, and where an illuminated background
is used, its average - initial brightness shall be at least two
hundred and fifty (250) foot lamberts. The light source shall
not be modified or changed nor shall lamp life multipliers be
used so as to reduce these brightness levels.

626.3.3. Sign Color. — Externally lighted signs shall have either
red letters on a white background or white letters on a red
background (or other approved color combinations) impressed,
mounted, or painted such that both letters and background
shall be in a vertically flat plane. The background of internally
lighted signs shall be either stenciled metal with a light gray
or white color, or translucent frosted, opal glass, slow-burning
plastic, or the plastic edge-glow type with white plastic sep-
arators. The letters for internally lighted signs shall be trans-
lucent red or other approved color.

626.3.4. Durability. — In locations where breakage may occur,
exitway signs shall be of shock resistant materials, or shall
otherwise be protected against breakage. The signs shall be
washable, non-toxic, non-radioactive and if subjected to fire
must be self-extinguishing when the flame is removed.

626.4. Directional Sign Design. — Directional exitway signs shall
comply with all of the requirements for exitway signs in section
626.3 and shall also include a red arrow on white background
or white arrow on red background (or other approved color
combinations), not less than eight and one-half (8V2) inches
long from tail to head, with a body not less than one-half
O/2) inch wide. The words "THIS WAY OUT" or words of
similar meaning may be added to the directional signs. Direc-
tional signs shall be suitably lighted as heretobefore described
in these regulations for "Exit Signs."

626.5. False Exits. — Any door, passageway, stair or other
means of communication that is not an exitway or that is not
a way to an exitway, but is so located as to be mistaken for
an exitway, shall be identified with a sign reading "NOT AN
EXIT", or shall be identified by a sign indicating its use or
purpose, or shall be provided with a directional exitway sign.

626.5.1. Mirrors. — No full length mirror which reflects an
egress shall be placed or remain unless provided with an ap-
proved guard rail at least thirty-two (32) inches from the floor.

SECTION 627.0. MEANS OF EGRESS LIGHTING

Means of egress lighting shall be in conformance with the
requirements of this section and the provisions of reference
standard RS 6-3 when more restrictive.

627.1. Artificial Lighting. — All required means of egress, except
one and two family dwellings in occupancy group L-3, shall
be equipped with artificial lighting facilities to provide the
intensity of illumination herein prescribed continuously during
the time that conditions of occupancy of the building require
that the exitways be available.

627.2. Intensity of Illumination. — Except as provided for in
section 627.3 illumination of at least three (3) foot candles
measured at the floor level shall be maintained continuously,
during occupancy, in exitways and their access facilities for
their full length at changes in direction in and intersections of
corridors, balconies, exitway passageways, stairs, ramps, escala-
tors, bridges, tunnels, landings and platforms. Illumination shall
be so arranged that the failure of any one (1) light shall not
leave any area in darkness.

627.3. Places of Assembly. — In places of assembly for the
exhibition of motion pictures or other projections by means
of directed light, the illumination of floors of exitway access
areas may be reduced during such period of projection to not
less than one (1) foot candle.

627.4. Independent Power Source. — Emergency lights shall be
provided with a second or emergency source of current and a
transfer switch which will automatically disconnect the normal
service and instantly connect the emergency service when the
voltage of the normal service falls below fifty (50) percent of
the nominal lamp voltage and which will also automatically
disconnect the emergency service and instantly connect the
normal service when the voltage of the latter is restored to
eighty (80) percent of the nominal lamp voltage. The emer-
gency source of current shall be either a separate feeder from
a reliable generating plant independent of that from which the
normal service is taken, or an approved trickle charge wet
ceil battery or battery system.

627.4.1. Duration of Illumination. — Emergency lighting shall
produce and maintain, for a period of not less than one and
one-half (l'/2) hours, the minimum intensity of illumination.

627

627.4.2. Inspection. — Complete emergency lighting systems of
batteries and generators, transfer switches and related lights
shall be inspected and tested at intervals of once a week and a
record kept thereof by the building owner.

627.4.3. Location. — All emergency lighting fixture heads shall
be located, directed and locked into position so that they pro-
vide a continuous path of light to a required egress.

627.5. Restrictions. — Phosphorescent materials shall not be
used as a method of providing illumination nor shall battery
operated electric lights or portable lamps or lanterns be used
as primary sources of lighting.

RS6

REFERENCE STANDARD RS 6
MEANS OF EGRESS

List of Reference Standards

RS 6 Mass. DPS Form B-l 1969

Regulations Applicable to Buildings

Mass. DPS Form B-2 1968

Building Regulations for Schoolhouses, Board of

Schoolhouse Structural Standards

Mass. DPS Form B-4 1950

Installation, Use and Maintenance of Revolving

Doors, Rules and Regulations

NFPA 101 1967

Life Safety Code

RS6-1 NFPA 101 1967

Life Safety Code

RS 6-2 Mass. DPS Form B-4 1950

Installation, Use and Maintenance of Revolving
Doors, Rules and Regulations

RS 6-3 Mass. DPS Form B-l 1969

Regulations Applicable to Buildings

RS 6-4 Mass. DPS Form B-2 1968

Building Reg"lations for Schoolhouses, Board of
Schoolhouse Structural Standards

ARTICLE

STRUCTURAL AND FOUNDATION LOADS
AND STRESSES

700.0

Scope

727.0

701.0

Definitions

702.0

Design Safe Load

728.0

703.0

Test Safe Load

704.0

Design Live Load

729.0

705.0

Design Dead Load

730.0

706.0

Existing Buildings

731.0

707.0

Unit Live Loads

732.0

708.0

Concentrated Loads

733.0

709.0

Impact Loads

710.0

Special Loads

734.0

711.0

Roof Loads

735.0

712.0

Snow Load

713.0

Wind Load

736.0

714.0

Wind on Vertical Surfaces

737.0

715.0

Wind Load on Roof

738.0

716.0

Wind Loads on Signs, Tank

739.0

and Radio Towers, Chim-

740.0

neys and Other Building

741.0

Elements

742.0

717.0

Unusual Wind Exposures

743.0

718.0

Overturning and Sliding

744.0

719.0

Earthquake Load

720.0

Combined Loading

721.0

Live Load Reduction

745.0

722.0

Allowable Working Stresses

746.0

723.0

Alloy and Special Steels

747.0

724.0

Light Weight Metals

748.0

725.0

Bearing Pressures of Soils

749.0

and Rocks

RS 7

726.0

Subsurface Explorations

Bearing Test and Settlement
Analysis

Allowable Foundation Pres-
sure

Spread Foundations

Footing Design

Timber Footings

Steel Grillages

Unreinforced Concrete
Foundations

Masonry Unit Footings

Reinforced Concrete
Foundations

Floating Foundations

Pile Foundations

Corrosion Protection

Allowable Pile Loads

Timber Piles

Precast Concrete Piles

Cast-In-Place Concrete Piles

Concrete-Filled Pipe Piles

Concrete Filled Pipe with
Steel Core (Drilled-In-
Caissons)

Structural Steel Piles

Composite Piles

Special Piles and Caissons

Lateral Support

Foundation Piers

Reference Standards

TABLES

7-1 725.2.3 Allowable Bearing Pressures of Foundation Materials

SECTION 700.0. SCOPE

The provisions of this article shall control the structural design
of all buildings and structures and their foundations hereafter
erected to insure adequate strength of all parts thereof for the
safe support of all super-imposed live and special loads including
wind to which they may be subjected in addition to their own
dead load, without exceeding the allowable stresses prescribed in

this code. In no case shall the assumed loads be less than the
minimum values established herein. The provisions of reference
standard RS-7 shall become part of this article.

SECTION 701.0. DEFINITIONS

For definitions to be used in the interpretation of this article,
see section 201.

SECTION 702.0. DESIGN SAFE LOAD

702.1. Structural Analysis. — The safe load for any structural
member or system of construction shall be determined by
accepted engineering analysis except as provided in sections
703 and 803 for tests of assemblies not capable of analysis.

702.2, Check Tests. — When there is reasonable doubt as to the
design capacity of any structural unit or assembly, or as to the
adequacy of a structure to serve the purpose for which it was
intended, the building official may require that check tests be
made of the assembled unit and its connections or he may
accept certified reports of such tests from accredited testing
authorities conducted in accordance with the approved rules.

SECTION 703.0. TEST SAFE LOAD

703.1. When Required. — When not capable of design by accepted
engineering analysis, any system of construction or structural
unit and its connections shall be subjected to the tests prescribed
in article 8 or to such other tests acceptable to the building
official that simulate the actual loads and conditions of applica-
tion that occur in normal use; or he may accept certified reports
of such tests conducted by an accredited testing laboratory pro-
viding such tests meet the requirements of this code and the
approved rules. Such tests shall not be required to be made on
any concrete or masonry construction until it is at least sixty
(60) days old.

703.2. Test Load. — When approved by test, every structural
assembly shall sustain without failure a minimum superimposed
load equal to its own dead load plus one-half (0.5) times the
dead load plus one and eight-tenths (1.8) times the live load
(the applied test load equals 0.5D + 1.8L), or to a load
causing a stress equal to eighty (80) per cent of the yield point

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of the constituent materials whichever is less. Under tne ap-
proved working load, the deflection shall not exceed the limits
prescribed in section 803 or 804.

SECTION 704.0. DESIGN LIVE LOAD

704.1. Required Live Load. — The live loads to be assumed in
the design of buildings and structures shall be the greatest load
produced by the intended use and occupancy, but in no case
less than the minimum uniformly distributed unit loads required
in section 707 for specific uses.

704.2. Loads Not Specified. — Where the occupancy or use of a
space does not conform to any of those specifically provided for
in reference standard RS 7-2, the design load shall be deter-
mined by the architect or engineer and submitted to the building
official for approval.

SECTION 705.0. DESIGN DEAD LOAD

705.1. Construction Materials. — In estimating dead load for the
purposes of structural design, the actual weight of the building
materials or construction assemblies to be supported except as
provided for in section 705.1, shall be used, but in no case less
than the unit dead loads prescribed in reference standard RS 7-1.

705.2. Service Equipment. — The weight of all building service
equipment including plumbing stacks, heating and air conditioning
equipment, electrical equipment, elevators, elevator machinery,
flues, and similar fixtures shall be included in the dead load
supported by the structural frame. The weight of equipment that
is part of the occupancy of a given area shall be considered as
live load.

705.3. Partition Load.

705.3.1. In structures in which permanent partitions occur, their
weight shall be counted as affecting the design of all supporting
structural members, including columns and foundations, as part
of the dead load; and in those portions of office buildings in
which the prescribed live load does not exceed fifty (50) pounds
per square foot, allowance for partition weight shall always be
made whether or not partitions are shown on plans.

705.3.2. If a layout of partitions is included in the building
plans, the weights of the partitions and their locations shall be
determined in accordance therewith; or such layout shall be

used to determine an equivalent load per square foot of floor
to be applied uniformly as a superimposed dead load for pur-
poses of design. But the allowance for partition weight in por-
tions of buildings given to office occupancy, when expressed
in pounds per square foot of floor, shall in no case be less
than a minimum of two (2) pounds for each foot of story height
for each square foot of floor.

705.3.3. — In estimating loading from actual weights of partitions
it may be assumed that the partition occupies a space one (1)
foot wide, and a deduction may be made of the live load
displaced on this width.

705.3.4. — The equivalent uniform partition loads in reference
standard RS 7-1 may be used in lieu of actual partition weights
except for bearing partitions or partitions in toilet room areas,
at stairs and elevators and similar areas where partitions are
concentrated. In such cases, actual partition weights shall be
used in design.

705.3.5. — Arch action of partitions shall not be assumed to
relieve the supporting members.

SECTION 706.0. EXISTING BUILDINGS

In the reconstruction, repair, extension or alteration of existing
buildings, the allowable working stresses used in design shall be
as follows:

706.1. Building Extended. — When an existing building is altered
by an extension in height or area, all existing structural parts
affected by the addition shall be strengthened where necessary
and all new structural parts shall be designed to meet the
requirements for buildings hereafter erected;

706.2. Building Repaired. — When repairs are made to the
structural portion of an existing building, and the uncovered
structural portions are found unsound, such parts shall be made
to conform to the requirements for buildings hereafter erected;

706.3. Existing Live Load. — When an existing building hereto-
fore approved is altered or repaired within the limitations pre-
scribed in article 1 - Part II, the structure may be designed for
the loads and stresses applicable at the time of erection, subject
to the approval of the building official.

706.4. Posted Live Load. — Any existing building heretofore
approved, in which there is no change in use to a new occu-
pancy group requiring greater floor loads, may be posted for

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the originally approved live loads, provided the building is
structurally safe in all its parts and adequate for its existing use,
subject to the approval of the building official.

SECTION 707.0. UNIT LIVE LOADS

The plans for all buildings and structures intended for other
than residential uses shall specify the live loads for which each
floor or part thereof has been designed.

707.1. Uniform Live Load. — The minimum design values estab-
lished in reference standards RS 7-2 for various occupancies or
uses shall be used.

707.2. Heavy Truck Loads. — The floor loads for garages designed
to house trucks or buses exceeding twenty thousand (20,000)
pounds gross weight shall be determined by the actual load con-
ditions; but in no case shall the assumed load be less than one
hundred and fifty (150) per cent of the maximum wheel load on
any point of the floor construction.

SECTION 708.0. CONCENTRATED LOADS

In the design of floors and structural systems, consideration
shall be given to the effects of known or probable concentrations
of load to which they may be subjected.

708.1. — The concentrated live loads established in reference
standard RS 7-2 for various occupancies or uses shall be used
placed so as to produce maximum stress.

708.2. — Floors that support any items of machinery, electrical
or mechanical equipment, or other concentrated live load in
excess of one thousand (1,000) pounds (including the weights of
pads or bases) shall be designed to support such weight as a
concentrated load or group of concentrated loads.

708.3. Nonconcurrence.

708.3.1. — When a concentrated live load is present, the uniformly
distributed load may be considered to be omitted in the area
occupied by the concentrated load.

708.3.2. — Where reference standard RS 7-2 indicates that the
concentrated live load is nonconcurrent with the uniform live
load, it may be assumed that the total concentrated load is to
be omitted when the uniform load is present and that the total
uniform load is to be omitted when the concentrated load is
present.

SECTION 709.0. IMPACT LOADS

The unit live loads specified in section 707 shall be assumed
to include adequate allowance for ordinary impact conditions.
Provision shall be made in the structural design for special uses
which involve moving loads, vibration and impact forces. The
minimum added allowance for impact for all hangers supporting
floors and balconies shall be thirty-three (33) per cent of the live
loads contributing to the stress in the hanger.

709.1. Elevators. — All moving elevator, dumbwaiter, and escala-
tor loads shall be increased one hundred (100) per cent for im-
pact and the structural supports shall be designed within the
limits of deflection specified by the state safety code for elevators.

709.2. Machinery. — Unless machinery is isolated from the
support framing, the loads for supports of reciprocating or
heavy power driven units shall be increased at least fifty (50)
per cent and the loads for supports of light shaft or motor
driven units shall be increased at least twenty-five (25) per cent
to provide for impact.

709.2.1. — Care shall be taken to avoid near resonant conditions
for machinery and other vibratory loads.

709.3. Crane Runways.

709.3.1. Vertical Loads. — Actual maximum wheel loads occur-
ring when the crane is lifting its capacity load shall be used. To
allow for impact, the lifted load shall be increased twenty-five
(25) per cent or the wheel loads increased fifteen (15) per cent
whichever produces greater stress condition.

709.3.2. Horizontal Loads. — The lateral load (due to crane
trolley travel) shall be twenty (20) per cent of the sum of the
capacity load and trolley weight, applied one-half (1/2) at the
top of each rail and acting in either direction normal to the
runway rail. The longitudinal load (due to crane travel) shall be
twenty (20) per cent of the maximum total reaction (not including
impact) on the rail being considered, applied at the top of the
rail and acting parallel to the runway.

709.4. Assembly Structures. — Seating areas in grandstands,
stadiums, and similar assembly structures shall be designed
to resist the simultaneous application of a horizontal swaying
load of at least twenty-four (24) pounds per linear foot of seats
applied in a direction parallel to the row of the seats, and of at
least ten (10) pounds per linear foot of seats in a direction
perpendicular to the row of the seats. When this load is used

709

in combination with wind for outdoor structures, the wind load
shall be one-half (1/2) of the design wind load, and the pro-
visions of article 7 relating to infrequent stress conditions shall
apply to this loading condition.

709.5. Monorail Beams and Supports.

709.5.1. — Vertical loads shall be the sum of the capacity load
and trolley weight. To allow for impact, the lifted load shall be
increased ten (10) per cent for hand-operated and twenty-five
(25) per cent electrically-operated trolleys.

709.5.2. — Longitudinal loads shall be twenty (20) per cent of the
sum of the capacity load and the weight of the trolley.

709.5.3. — Lateral load shall be twenty (20) per cent of the sum
of the capacity load and the weight of the trolley.

709.5.4. — Centrifugal forces shall be considered for curved tracks.

709.6. Passenger Vehicles. — Areas used for, and restricted by
physical limitations of clearance to, the transit or parking of
passenger vehicles shall be designed for the uniformly distributed
and concentrated loads for parking areas for such vehicles as
provided in reference standard RS 7-2, applied without impact.
An exception with regard to concentrated loads is made for
members or constructions which, because of physical limitations,
cannot be subjected to direct load from the vehicle or from a
jack or hoist used to raise or suspend the vehicle. Such members
or constructions shall be designed for the loads corresponding to
the actual usage.

709.7. Truck Loads. — Minimum loads (including vertical, lateral,
and longitudinal) and the distribution thereof shall meet the
applicable requirements of reference standard RS 7-3, except
that impact shall be taken as ten (10) per cent of the vertical
reaction.

709.8. Railroad Equipment. — Minimum loads (including vertical,
lateral, longitudinal, and impact) and the distribution thereof
shall meet the applicable requirements of reference standard
RS 7-4.

709.9. Heliports and Helistops.
709.9.1. Concentrated Loads.

a. Landing Area — Helicopter landing areas shall be designed
for the most severe of the following vertical loads acting
at any location:
1. A single concentrated load equal to three-quarters

(3/4) of the gross weight of the helicopter and acting

on an area of one (1) square foot.

2. Concentrated loads representing the gross wheel

reactions of the helicopter acting simultaneously

and increased one-third (1/3) for impact.

b. Taxiing Area — Helicopter taxiing areas shall be designed

for concentrated loads in accordance with (a. 2) above.

709.9.2. Uniform Live Load. — The landing and taxiing areas

shall be capable of supporting a uniformly distributed live load

of forty (40) psf acting nonconcurrently with the concentrated

loads.

SECTION 710.0. SPECIAL LOADS

Provisions shall be made for all special loads herein prescribed
and all other special loads to which the building or structure
may be subjected.

710.1. Below Grade. — All retaining walls and other walls below
grade shall be designed to resist lateral soil pressures with due
allowance for hydrostatic pressure and for all superimposed
vertical loads. When a portion or the whole of the adjacent
soil is below a free water surface, calculations shall be based
on the weight of the soil as diminished by buoyancy, plus full
hydrostatic pressure.

710.2. Hydrostatic Uplift. — All foundation slabs and other
footings subjected to water pressure shall be designed to resist
a uniformly distributed uplift equal to the full hydrostatic
pressure.

710.3. Railings and Parapets.

710.3.1. — Railings and parapets around stairwells, balconies,
areaways, and roofs, and other railings in similar locations
other than those for places of assembly, shall be designed to
resist the simultaneous application of a lateral force of forty (40)
plf and a vertical load of fifty (50) plf, both applied to the top
of the railing. For railings and parapets at the front of theater
balconies and in similar locations in places of assembly, the
lateral force shall be increased to fifty (50) plf and the vertical
load to one hundred (100) plf. An exception is made for railings
in one- and two- family dwellings, which shall be designed for
a lateral force of twenty (20) plf plus a vertical load of twenty
(20) plf, both applied at the top of the railing. The total lateral
force and total vertical load shall be at least two hundred (200)
pounds each.

710.3.2. — Intermediate and bottom rails, if provided, shall be

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designed for the simultaneous application of forty (40) plf
applied horizontally and fifty (50) plf applied vertically; however,
lateral and vertical design loads on intermediate and bottom rails
need not be considered in the design of posts and anchorages.
For railings having solid panels, the panels shall be designed
for a uniform lateral load of twenty (20) psf.

710.3.3. — Where railings or parapets support lighting fixtures,
allowance shall be made for the additional loads imposed thereby.

710.3.4. — Railings, bumpers, or similar devices used in parking
areas to resist the impact of moving vehicles shall be designed
to resist a lateral load of three hundred (300) plf applied at
least twenty-one (21) inches above the roadway; but in no case
shall the load be less than twenty-five hundred (2,500) pounds
per vehicle.

710.4. Construction Loads and Erection Stresses. — Construction
loads and erections stresses shall be limited by appropriate con-
struction and erection procedures to the basic design loads and
corresponding working stresses required by this code for the
particular occupancies and materials of construction.

710.5. Sidewalks and Driveways.

710.5.1. — All sidewalks and driveways or portions thereof that
are structurally supported shall be designed for a live load of
one hundred (100) psf uniformly distributed and in accordance
with the provisions of article 8. Where subject to intentionally
or accidentally imposed wheel loads of vehicles, such portions
of sidewalks and driveways shall be designed for a uniformly
distributed load of six hundred (600) psf or for the maximum
vehicular wheel load that could be imposed thereon, whichever
develops the greater stresses. Where the imposed load is limited
by physical restrictions to the weight of passenger cars the
provisions of section 709.6 shall apply.

710.5.2. — Appurtenant components of sidewalks and driveways,
including manholes, manhole covers, vault covers, gratings, etc.,
shall be designed for the loads prescribed in section 710.5.1
above, and shall conform to the standards of the city agency
having jurisdiction.

710.6. Columns in Parking Areas. — Unless specially protected,
columns in parking areas subject to impact of moving vehicles
shall be designed to resist the lateral load due to impact and
this load shall be considered a load of infrequent occurence.
For passenger vehicles, this lateral load shall be taken as a
minimum of twenty-five hundred (2,500) pounds applied at least

twenty-one (21) inches above the roadway and acting simul-
taneously with other design loads.

710.7. Bins and Bunkers. — Loads on component parts of bins
and bunkers may be reduced for friction on sidewalls, but in
all cases the sidewalls and their supports shall be proportioned
for the probable increase of vertical loads. Where stresses would
be increased in any component by arching of the fill, the effect
of such arching shall be considered.

710.8. Temperature Loads. — The design of enclosed buildings
more than two hundred and fifty (250) feet in plan dimension
shall provide for the forces and/or movements resulting from an
assumed expansion corresponding to a change in temperature
of 40° F. For exterior exposed frames, arches or shells regard-
less of plan dimensions, the design shall provide for the forces
and/or movements resulting from an assumed expansion and
contraction corresponding to an increase or decrease in tempera-
ture of 50° F. For determining required anchorage for piping,
the forces shall be determined on the basis of temperature
variations for the specific service conditions. Friction forces in
expansion bearings shall be considered.

710.9. Shrinkage and Creep. — The design of reinforced concrete
components shall provide for the forces and/or movements
resulting from shrinkage and creep of the concrete between
contraction joints. The design of arches and similar structures
shall provide for effects of shrinkage, plus rib-shortening, plus
plastic flow.

SECTION 711.0. ROOF LOADS

The structural components and supports of roofs and marquees
shall be designed to resist wind, live, dead and other loads as
prescribed below.

711.1. Minimum Roof Load.

711.1.1. — Snow load as provided in section 712.0.

711.1.2. — Wind load as provided in section 715.0.

711.1.3. — Earthquake load as provided in section 719.0.

711.2. Concentrated Loads. — The provisions of section 708
shall apply.

711.3. Overhanging Eaves. — In other than one (l)and two (2)
family dwellings overhanging eaves, cornices and other roof
projections shall be designed for a uniformly distributed live

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load of at least sixty (60) pounds per square foot, or more
if required by the provisions of section 712.2.3.
711.4. Special Loads.

711.4.1. — When used for purposes such as promenades, assembly
areas, or roof gardens, design shall be made for live loads cor-
responding to the particular usage, as indicated in reference
standard RS 7-2. Such loads shall be considered as noncon-
current with the wind load or with the live load specified in
section 711.1. The design live and wind loads for roofs, as
specified elsewhere in this article, shall be deemed to provide for
incidental use of the roof of a building by the occupants thereof.

711.4.2. — Roofs shall be designed for the maximum possible
depth of water that may be ponded thereon as determined by
the relative levels of roof deck and overflow weirs, scuppers,
edges or serviceable drains in combination with the deflected
structural elements.

711.4.3. — Girders and roof trusses (other than joists) over garage
areas regularly utilized for the repair of vehicles and over man-
ufacturing floors or storage floors used for commercial purposes
shall be capable of supporting, in addition to the specified live
and wind loads, a concentrated live load of two thousand (2,000)
pounds applied at any lower chord panel point for trusses, and
at any point of the lower flange for girders.

711.4.4. — Where roofs are landscaped, the uniform design live
load on the landscaped portions shall be thirty (30) psf. The
weight of the landscaping materials shall be considered as dead
load and shall be computed on the basis of saturation of the
earth. The areas adjacent to the landscaped portions shall be
considered as assembly areas, unless specific provision is made
to prevent such use.

711.4.5. — Where equipment is placed on roofs, the design shall
provide for the support of such equipment.

SECTION 712.0. SNOW LOAD

712.1. Shape of Roof. — When the effect of the shape of roof
structure as determined by actual test indicates lesser or greater
snow retention value than specified in this article, the roof load
shall be modified accordingly. The effect of adjacent vertical
surfaces shall be in accordance with section 712.2.3.
712.1.1. — Flat roofs and roofs having a rise of two (2) inches

or less per foot of run shall be designed to support a vertical
snow load of thirty (30) pounds per square foot of horizontal
projection

712.1.2. — Roofs having a rise of more than two (2) and less
than twelve (12) inches per foot of run shall be designed for a
vertical snow load of (34r2r) pounds per square foot of horizon-
tal projection in which r is the rise in inches per foot of run.

712.1.3. — Roofs having a rise of twelve (12) inches or more per
foot of run shall be designed for a vertical snow load of ten
(10) pounds per square foot of horizontal projection.

712.1.4. — If the roof under consideration is above an area which
is normally unheated or extensively insulated so that normal
melting is prevented, then the snow load applied under sections
712.1.1, 712.1.2, 712.1.3 and 712.2.1 shall be increased by one-
third (1/3).

712.2. Special Snow Load Conditions.

712.2.1. Valleys. — For horizontal valleys, loadings shall be
increased to provide for accumulations of snow. The loading
intensity shall be assumed to vary from forty-five (45) psf at
the low point to fifteen (15) psf at the ridge.

712.2.2. — For a roof having curved or pyramidal shapes, the
proposed live load shall be established by the architect or
engineer subject to approval by the building official.

712.2.3. — For a roof having a rise of six (6) inches per foot or
less, and which abuts or is not more than fifteen (15) feet away
from a vertical surface that extends to a height of H feet above
the roof deck, the design snow load intensity shall be modified
as follows:

a. H less than three (3) feet: No change.

b. H at least three (3) feet but less than ten (10) feet:
Design load shall vary linearly from a maximum of
12H pounds per square foot at the vertical surface to a
minimum at a distance of 2H from the vertical surface.
The minimum shall be the design load as otherwise
specified in this section.

c. H equal to ten (10) feet or more: Design load shall vary
linearly from a maximum of one hundred twenty (120)
pounds per square foot at the vertical surface to a
minimum at a distance of twenty (20) feet from the
vertical surface. The minimum shall be the design load
as otherwise specified in this section.

712.2.4. — For roofs subject to additional snow load due to

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sliding snow from adjacent inclined surfaces, the design snow
load shall be established by the architect or engineer, subject
to the approval of the building official.

712.2.5. — Whenever any building is to be constructed above the
roof of an adjoining building, it shall be the duty of the person
causing such building to be constructed to protect the roof, sky-
lights and other roof outlets of the adjoining building from
possible injury resulting from drift and/or sliding snow loads to
the extent prescribed in sections 712.2.3 and 712.2.4. Such
person shall be afforded a license to enter and inspect the
adjoining building and perform such work thereon as may be
necessary for such purposes; otherwise the duty of protecting the
roof, skylights and other roof outlets of the adjoining building
shall devolve upon the owner thereof.

SECTION 713.0. WIND LOAD

The structural frame of all buildings, signs, tanks and other
exposed structures or parts of structures shall be designed to
resist the horizontal pressures due to wind in any direction,
both inwardly and outwardly, allowing for suction on the lee-
ward side, as provided in sections 714 to 718 inclusive.
713.1. Torsional Resistance. — The structural frame of all buildings
and structures subjected to wind or other lateral loads shall be
designed to resist the torsional moment due to eccentricity of
the resultant load with respect to the center of resistance of the
structure, to the wind or other lateral load.

SECTION 714.0. WIND ON VERTICAL SURFACES

The wind pressures on vertical surfaces shall be those pre-
scribed in section 714.1, distributed in accordance with section
714.2 and if required, modified by sections 714.3 and 714.4.
714.1. Design Pressures. — Design pressures due to wind acting
on vertical surfaces shall be not less than the pressure (P) as
prescribed in reference standard RS 7-5 as modified by the
proper coefficients specified in this code.

714.1.1. — Total horizontal pressure on the walls of rectangular
buildings (combining the effect of pressure on the windward
walls and suction on the leeward walls) ... 1.0 P.

714.1.2. — Total horizontal pressure acting simultaneously on
each of any two (2) perpendicular walls of a rectangular building

(combining the effect of pressure on the windward walls and

suction on the leeward walls) . . . 0.7 P.

714.1.3. — Pressure in or out on an exterior wall . . . 0.7 P.

714.2. Distribution of Wind Force. — The wind pressure shall
be distributed between opposite walls, two-thirds (2/3) as a
normal pressure on the windward side and one-third (1/3) as a
normal outward suction on the leeward side.

714.3. Wail Framing and Wall Panels. — In buildings provided
with one-third (1/3) or more wall openings or subject to being
open or broken, an internal pressure of 2/3 P or internal suction
of 1/3 P whichever is critical shall be assumed to occur simul-
taneously with the above external pressures and suctions. For
lesser amounts of wall openings the internal pressure or suction
assumed shall be one-half (1/2) of the foregoing values.

714.4. Secondary Members. — Secondary wall framing, wall
panels, sheathing and girts and their connections shall be
designed for external and internal pressures or suctions which
are one and one-half (1-1/2) times those values determined in
accordance with sections 714.1, 714.2, and 714.3.

714.5. Design Wind Load for Glass. — Firmly supported lights of
glass of four (4) square feet or more in area installed in a
vertical position, or at an angle of not more than twenty (20)
degrees from the vertical, shall be designed to withstand wind
pressure in accordance with design criteria stated in reference
standard RS 7-6.

SECTION 715.0. WIND LOAD ON ROOFS

The external wind pressures and suctions specified in sections
715.1 and 715.2 shall be considered in the design of primary
roof framing and trusses.

External wind pressures and suctions to be considered in the
design of secondary roof framing, purlins, roof panels and
sheathing and their connections shall be one and one-half (1-1/2)
times those determined in accordance with those sections. Internal
pressures to be considered in the design of secondary roof
framing and roof panels and sheathing and their connections
shall be those specified in section 714.3 for wall elements.
715.1. Horizontal and Pitched Roofs. — Design wind forces on
roofs, assumed to be acting on primary roof framing members,
shall be not less than the pressure (P) specified in section 714.1
modified by the following coefficients.

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715.1.1. — For roof slopes thirty (30) degrees or less, either a
pressure of 0.4P or a suction of 1.2P over the entire roof area.
715.1.2.— For roof slopes of more than thirty (30) degrees either:

a. a pressure of 0.6P on the windward slope with a suction
of 0.4P on the leeward slope; or

b. a pressure of 0.9P on the windward slope with a zero
suction on the leeward slope.

715.2. Curved Roofs. — The external wind forces assumed to be
acting upon the primary framing members in the windward
quarter of curved roofs shall be not less than the wind pressure
specified in section 714.1 multiplied by the rise-to-span ratio of
the entire roof arch and shall be considered as acting as an
inward acting pressure. An external suction of not less than
seven-tenths (7/10) of the pressure specified in section 714.1
shall be assumed to be acting upon the center half of all arch
roofs and an external suction of not less than six-tenths (6/10)
of such pressures shall be assumed to be acting upon the lee-
ward quarter of all such roofs. All wind pressures acting upon
curved roofs shall be considered as acting normal to the chord
of the curved section under consideration.

715.3. Test Determination. — With the approval of the building
official, wind force on a building may be based on shape
coefficients obtained from wind tunnel tests of models or by
other approved methods. Such shape coefficients shall include
the full effect of openings in wall or roof surfaces. In such
cases the velocity pressure "q" to be used at any height shall
be taken as .77 p.

715.4. Anchorage. — Roof framing shall be anchored to wall
framing and walls to foundations so as to resist wind uplift and
sliding in excess of seventy-five (75) per cent of the dead load
resistance.

715.5. Uplift on Eaves. — Overhanging eaves, cornices and other
local projections shall be designed and constructed to withstand
an upward pressure of 1.5 P.

SECTION 716.0. WIND LOADS ON SIGNS, TANK AND
RADIO TOWERS, CHIMNEYS AND OTHER BUILDING
APPURTENANCES

Minimum wind pressures to be used in the design of these
and other building appurtenances shall be determined using the

value of P as specified in section 714.1 applied either in con-
formance with this section or in conformance with reference
standard RS 7-11.

716.1. Signs and Towers. — The wind pressure on ground signs
and towers other than radio and television towers, and their
supports or portions thereof having seventy-five (75) per cent or
more of solid surface shall be assumed at 1.2 P and having less
than seventy-five (75) per cent of solid surface shall be 1.6 P of
net exposed area of the structure normal to the direction of the
wind.

716.2. Roof Structures. — The wind pressure on roof signs, tank
towers, stacks, chimney and other exposed roof structures with
plane surfaces shall be assumed at 1.6 P applied to the net
projected area of the structure normal to the direction of the
wind except as provided in sections 716.3 and 716.4.

716.3. Shielding Effect. — No shielding effect of one element by
another shall be considered when the distance between them
exceeds four (4) times the projected smallest dimension of the
windward element.

716.4. Effect of Shape. — The wind pressure on circular tanks,
stacks or other circular structures shall be assumed 0.7P applied
to the projected area; and for hexagonal or octagonal structures
1.0P.

716.4.1. — For special shaped structures such as spheres, guys,
cables, solid girders, the design wind pressure shall be deter-
mined as provided for in section 715.3.

SECTION 717.0. UNUSUAL WIND EXPOSURES

For buildings and structures located in unusually exposed
positions subjected to higher wind loads than herein specified,
the design wind load shall be determined by the highest values
in reference standard RS 7-5.

SECTION 718.0. OVERTURNING AND SLIDING

The overturning moment due to the wind load on all structures
shall not exceed seventy-five (75) per cent of the moment of
stability resulting from the dead load of the building, unless the
building or structure is anchored to resist the excess overturning
moment and the excess horizontal shear over sliding friction.

716-721
SECTION 719.0. EARTHQUAKE LOAD

All structures except one (1) or two (2) family dwellings and
minor accessory buildings shall be capable of safely withstanding
the lateral forces prescribed for Zone 2 in reference standard
RS 7-12.

SECTION 720.0. COMBINED LOADING

The structural frame of all buildings shall be investigated for
the combined effect of lateral and vertical loading and the
individual members of the frame shall be proportioned as follows:

720.1. With Earthquake. — For combined stresses due to earth-
quake load together with dead, live and snow loads, the allow-
able working stress for the structural material may be increased
thirty-three and one-third (33-1/3) per cent.

720.2. Wind. — For combined stresses due to wind load together
with dead, live and snow loads, the allowable working stress
for the structural material may be increased thirty-three and
one-third (33-1/3) per cent.

720.3. Minimum Section. — The section determined for the
combined loadings herein specified shall be compared with that
required for dead, live and snow loads only, and the section of
greatest strength shall determine that to be used in the structure.

SECTION 721.0. LIVE LOAD REDUCTION

In all buildings and structures except places of assembly, the
design live loads may be reduced on columns, piers, walls,
trusses, girders and foundations as herein specified; but in no
case shall a reduction be applied to the roof live load.
721.1. Live Loads 100 Pounds or Less. — For live loads of one
hundred (100) pounds or less per square foot, the design live
load on any member supporting one hundred fifty (150) square
feet or more may be reduced at the rate of eight-hundredths
(0.08) per cent per square foot of area supported by the mem-
bers, except for reductions controlled by section 721.2. The

reduction shall exceed neither R as determined by the following
formula, nor sixty (60) per cent:
R = 100 x ( D + L \

U.33L I
in which

R = reduction in per cent

D = dead load per square feet of an area supported by the

member
L design live load per square feet of area supported by
the member

721.2. Special Limitations.

721.2.1. — For live loads exceeding one hundred (100) pounds
per square foot, no reduction shall be made, except that the
design live loads on columns may be reduced twenty (20) per
cent.

721.2.2. — No live load reduction shall be permitted for the fol-
lowing: members and connections (other than columns, piers,
and walls) supporting floor areas used for storage (including
warehouses, library stacks, and record storage); and areas used
as place of assembly, for manufacturing, and for retail or whole-
sale sales. For columns, piers, and walls supporting such floor
areas the maximum live load reduction shall be twenty (20) per
cent.

721.2.3. — No live load reduction shall be permitted for calculating
shear stresses at the heads of columns in flat slab or flat plate
construction.

721.3. Foundations and Column Supports. — The full dead load
plus the reduced live load as herein prescribed shall be used in
the design of foundations and of trusses or girders which sup-
port columns.

SECTION 722.0. ALLOWABLE WORKING STRESSES

722.1. Controlled Materials. — The design and working stresses
of all controlled materials as defined in section 201, or of any
structural material that is identified as to manufacture and grade
by mill tests or the strength and stress grade is otherwise con-
firmed to the satisfaction of the building official, shall conform
to the specifications and methods of design of accepted engi-
neering practice or to the approved rules in the absence of
applicable standards. A building or structure may be erected in
whole or in part of controlled design and materials.

721-725

722.2. Ordinary Materials. — The use of ordinary materials without
selection and without controlled design and supervision, or when
the material is not identified as to strength and stress grade,
shall be limited to the average unit working stresses prescribed
in reference standard RS 7-7.

722.3. New Materials. — For materials and assemblies which are
not specifically provided for in this code the working stresses
shall be specifically established by individual tests as provided in
sections 703 and 803 on the actual materials to be used until
adequate statistical evidence permits the establishing of generally
applicable working stresses by the building official with sub-
sequent testing limited to representative samples for quality
control as he may require.

SECTION 723.0. ALLOY AND SPECIAL STEELS

The use of alloy, high carbon or other special high-strength
steels shall be permitted in the design and construction of
buildings and structures as controlled materials and as prescribed
in section 833 in accordance with provisions of referenced
standards.

SECTION 724.0. LIGHT WEIGHT METALS

When not specifically provided for in article 8 light weight
metals and their alloys may be used in the design and con-
struction of buildings or structures only after special approval
of the building official, subject to the determination of the physi-
cal properties by tests as prescribed in article 8 and in accor-
dance with the provisions of section 834.

SECTION 725.0. BEARING PRESSURES OF SOILS AND
ROCKS

All applications for permits for the construction of new
buildings or structures, and for the alteration of permanent
structures which require changes that may affect their foundation,
shall be accompanied by a statement describing the soils in the
bearing strata, including sufficient records and data to establish
their character and load-bearing capacity. Such records shall be
certified by a licensed professional engineer.

725.1. Satisfactory Foundation Materials. — The foundations of
every permanent structure shall be supported by satisfactory
bearing strata which shall mean:

a. Natural strata of rock, gravel, sand, inorganic silt, in-
organic clay, or any combination of these materials with
the limitations stated in section 725.2.3.

b. Compacted fills which satisfy the provisions of section
752.2. l.d.

c. Natural strata or artificial fills which can be changed into
satisfactory bearing materials by pre-consolidation with a
temporary surcharge in accordance with the provisions of
section 725. 2. I.e.

725.1.1. — Where footings are supported at different levels, or at
different levels from footings of adjacent structures, foundation
plans shall include vertical sections showing to true scale all such
variations in grade. The effect of such differences in footing
levels on the bearing materials shall be considered in the design.

725.1.2. — Foundations shall be constructed so that freezing
temperatures will not penetrate into underlying soils that contain
more than five (5) per cent (by weight), passing a No. 200
mesh sieve. The foundations and grade beams of permanent
structures, except when founded on sound rock, and except
as otherwise provided in section 725.1.3 shall be carried down
at least four (4) feet below an adjoining surface exposed to
natural freezing. No foundation shall be placed on frozen soil.
Foundations shall not be placed in freezing weather unless
adequately protected.

725.1.3. — Foundations of detached garages or similar accessory
structures not exceeding eight hundred (800) square feet in area
and not over one (1) story high, and grade beams of all struc-
tures, need not be carried more than one (1) foot below an
adjoining surface exposed to natural freezing if the underlying
soil to a depth of at least four (4) feet beneath the surface, and
extending at least four (4) feet outside the building, is sand,
gravel, cinders, or other granular materials containing not more
than five (5) per cent (by weight) passing a No. 200 mesh sieve.

725.1.4. — Foundations subject to hydrostatic uplift shall have
adequate provisions to prevent heaving.

725.1.5. — Basements and cellars shall be waterproofed in a
manner consistent with their proposed use up to the maximum
probable ground-water level. Under boilers, furnaces, and other
heat-producing apparatus, suitable insulation shall be installed

725
to protect the waterproofing against damage from heat as
specified in articles 10 and 11. Foundations under heat-producing
units shall be so insulated as to prevent evaporation of moisture
from any underlying soil that is subject to shrinkage, and to
protect the heads of wood piles against damage from heat.
725.2. Classification of Bearing Materials and Allowable Bearing
Pressures.

725.2.1. Classification of Bearing Materials. — The terms used
in this section shall be interpreted in accordance with generally
accepted engineering nomenclature. In addition, the following
more specific definitions are used for bearing materials in the
Greater Boston area:

a. Rocks

Shale — A soft, fine-grained sedimentary rock.
Slate — A hard, fine-grained metamorphic rock of sedi-
mentary origin.

Conglomerate — A hard, well cemented metamorphic rock
consisting of fragments ranging from sand to gravel and
cobbles set in a fine-grained matrix (locally known as
Roxbury Puddingstone.)

b. Granular Materials

Gravel — A mixture of mineral grains at least seventy (70)

per cent (by weight) of which is retained on a No. 4

mesh sieve and possessing no dry strength.

Sand — A mixture of mineral grains at least seventy (70)

per cent (by weight) of which passes a No. 4 mesh sieve

and which contains not more than fifteen (15) per cent

(by weight) passing a No. 200 mesh sieve.

Coarse Sand — A sand at least fifty (50) per cent (by

weight) of which is retained on a No. 20 mesh sieve.

Medium Sand — A sand at least fifty (50) per cent (by

weight) of which passes a No. 20 mesh sieve and at

least fifty (50) per cent (by weight) is retained on a No.

60 mesh sieve.

Fine Sand — A sand at least fifty (50) per cent (by weight)

of which passes a No. 60 mesh sieve.

Well-graded Sand and Gravel — A mixture of mineral

grains which contains between twenty-five (25) per cent

and seventy (70) per cent (by weight) passing a No. 4

mesh sieve, between ten (10) and forty (40) per cent (by

weight) passing a No. 20 mesh sieve, and containing not

more than eight (8) per cent (by weight) passing a No.

200 mesh sieve.

c. Cohesive Materials

Glacial Till — A very dense, heterogeneous mixture ranging
from very fine material to coarse gravel and boulders and
generally lying over bedrock. It can be identified from
geological evidence and from the very high penetration
resistance encountered in earth boring and sampling
operations.

Clay — A fine-grained, inorganic soil possessing sufficient
dry strength to form hard lumps which cannot readily be
pulverized by the fingers.

Hard Clay — An inorganic clay requiring picking for
removal, a fresh sample of which cannot be molded by
pressure of the fingers.

Medium Clay — An inorganic clay which can be removed
by spading, a fresh sample of which can be molded by a
substantial pressure of the fingers.

Soft Clay — An inorganic clay, a fresh sample of which
can be molded with slight pressure of the fingers.
Inorganic Silt — A fine-grained, inorganic soil consisting
chiefly of grains which will pass a No. 200 mesh sieve,
and possessing sufficient dry strength to form lumps
which can easily be pulverized with the fingers.
Note: Dry strength is determined by drying a wet pat of
soil and breaking it with the fingers.

d. Compacted Granular Fill

A fill consisting of gravel, sand-gravel mixtures, coarse
or medium sand, crushed stone, or slag, containing not
more than eight (8) per cent (by weight) passing a No.
200 mesh sieve and having no plasticity, shall be con-
sidered satisfactory bearing material when compacted in
nine (9) inch thick layers, measured before compaction,
with adjustment of water content as necessary to achieve
required compaction by applying to each layer a minimum
of four (4) coverages of one of the following:

1 . A vibratory roller with a steel drum with minimum
weight of two (2) tons with a speed not exceeding
one and one-half (1-1/2) miles per hour;

2. A rubber-tired roller having four (4) wheels abreast
and weighted to a total load of not less than thirty-
five (35) tons;

725

3. With the treads of a crawler type tractor with total
load of not less than thirty-five (35) tons;

4. Other types of materials, compaction equipment, and
procedures as may be approved by the building
official on the basis of sufficient evidence that they
will achieve compacted fills having satisfactory prop-
erties.

The building official will require a competent inspector,
qualified by experience and training and satisfactory to
him. to be on the project at all times while fill is being
placed and compacted. The inspector shall make an
accurate record of the type of material used, including
grain-size curves, thickness of lifts, type of compaction
equipment and number of coverages, the use of water
and other pertinent data. Whenever the building official
or the inspector questions the suitability of a material,
or the degree of compaction achieved, bearing tests shall
be performed on the compacted material in accordance
with the requirements of section 727.0. A copy of all
these records and test data shall be filed with the building
official.

c. Preloaded Materials

1 . The building official may allow the use of certain
otherwise unsatisfactory natural soils and uncom-
pacted fills for the support of one (1) story struc-
tures, after these materials have been preloaded to
effective stresses not less than one hundred and fifty
(150) per cent of the effective stresses which will be
induced by the structure.

2. The building official may require the loading and
unloading of a sufficientlylarge area, conducted under
the direction of a competent engineer, approved by
the building official, who shall submit a report con-
taining a program which will allow sufficient time
for adequate consolidation of the material, and an
analysis of the preloaded material and of the prob-
able settlements of the structure.

725.2.2. Bearing Values. — The maximum pressure on soils
under foundations shall not exceed values specified in section

725.2.3, table 7-1, except when determined in accordance with
provisions of section 727.0 and in any case subject to the
modifications of subsequent sections of this article.

725.2.3. Table 7-1

Allowable Bearing Pressures of Foundation Materials

Class of Material Allowable Bearing I

Pressure in Tons
Per Square Foot(*}|

Massive igneous rocks and conglomerate,
all in sound condition (sound condition

allows minor cracks)

100

Slate in sound condition (minor cracks

allowed)

Shale in sound condition (minor cracks

allowed)

10(0

Residual deposits of shattered or broken

bedrock of any kind except shale

Glacial Till

Gravel, well-graded sand and gravel

Coarse sand

Medium sand

Fine sand

1 to2(t)

Hard clay

Medium clay

2(t)

Soft clay

l(t)

Inorganic silt, shattered shale, or any
natural deposit of unusual character not

provided for herein

Compacted granular fill

2to5($)

Preloaded materials

(*■)

The allowable bearing pressure given in this section, or when
determined in accordance with the provisions of section 727
will assure that the soils will be stressed within limits that
lie safely below their strength. However, such allowable
bearing pressure for Classes 9 to 12, inclusive, do not assure
that the settlements will be within the tolerable limits for a
given structure.

Alternatively, the allowable bearing pressure shall be computed
from the unconfined compressive strength of undisturbed
samples, and shall be taken as 1.50 times that strength for
round and square footings, and 1.25 times that strength for
footings with length-width ratios of greater than four (4);
for intermediate ratios interpolation may be used.
Value to be fixed by the building official in accordance with
sections 726.0. and 727.0.

725-727
SECTION 726.0. SUBSURFACE EXPLORATIONS

726.1. Where Required. — Where borings or tests are required,
they shall be made at a sufficient number of locations and to
such depths, and they shall be supplemented by such field or
laboratory tests and engineering analyses, as are necessary in
the opinion of the building official. When it is proposed to
support the structure directly on bedrock, the building official
may require drill holes or core borings to be made into the
rock to a sufficient depth to prove that bedrock has been
reached.

726.2. Soil Samples and Borings Reports. — Samples of the
strata penetrated in test borings or test pits, representing the
natural disposition and conditions at the site, shall be available
for examination of the building official. Wash or bucket samples
shall not be accepted. Duplicate copies of the results obtained
from all completed and uncompleted borings, plotted to a true
relative elevation and to scale and of all test results or other
pertinent soil data shall be filed with the building official.

SECTION 727.0. BEARING TEST AND SETTLEMENT
ANALYSES

Whenever the allowable bearing pressure on bearing materials,
or the load bearing capacity of single piles or groups of piles
is in doubt, the building official may require load tests and/or
settlement analyses to be made at the expense of the applicant
and the results anaylzed under the direction of a foundation
engineer approved by the building official.

727.1. Approval of Test Method. — The apparatus and procedure
used shall be approved by the building official before they are
used. A complete record of the test results together with a soil
profile shall be filed by the licensed engineer who shall have a
fully qualified representative on the site during all boring and test
operations.

727.2. Loading Equipment. — The load shall be applied by direct
weight or by means of a recently calibrated jack. Each load shall
be maintained constant for the required period with an accuracy
of plus or minus three (3.0) per cent.

727.2.1. Area. — For bearing materials of Classes 1 to 5, inclusive,
the loaded area shall be not less than one (1) square foot and
for other classes not less than four (4) square feet.

727.3. Loading Procedure. — The application of the test load
shall be in steps equal to not more than one-half (1/2) the
contemplated design load, to at least twice the contemplated
design load, except as provided in section 727.7. The unloading
shall be in at least two (2) steps, to the design load and then
to zero (0) load. During the loading cycle the contemplated design
load and twice the contemplated design load shall be maintained
constant for at least twenty-four (24) hours and until the rate
of settlement or rebound does not exceed two hundredths (.02)
of an inch per twenty-four (24) hours. The load for all other
load steps including the zero (0) load at the end of the test shall
be maintained constant for a period of not less than four (4)
hours. Sufficient readings for each load step shall be made to
define properly the time-deflection curve.

727.4. Measurements. — Observation of vertical movement shall
be made with dial extensometers graduated to at least one
thousandth (.001) of an inch. The readings shall be sufficient in |
number to define the progress of the settlement or rebound i]
and shall be referred to a beam, the ends of which rest on or^
are fixed to reliable supports located at least eight (8) feet from"
the center of the test. In addition, the elevation of the supports I
shall be checked frequently with reference to a fixed benchmark. I
The entire measuring setup shall be protected against direct sun- 1
light, frost action, and other disturbances that might affect its I
reliability. Temperature readings, both inside and outside the
test enclosure, shall be made when the vertical movements are
recorded.

727.5. Additional Requirements for Soil Bearing Tests. — Bearing
tests shall be applied at the elevations of the proposed bearing
surfaces of the structure, except that the load may be applied |
directly on the surface of compacted granular material, Class 14.
The excavation immediately surrounding an area to be tested
shall be made no deeper than one (1) foot above the plane of
application of the test. The test plate shall be placed with
uniform bearing. For the duration of the test, the material
surrounding the test area shall be protected effectively against
evaporation and frost action.

727.6. Determination of Design Load. — The proposed design
load shall be allowed provided that the requirements of section
725 are fulfilled and the settlements under the design load and
twice the design load do not exceed three-eights (3/8) of an inch
and one (1) inch, respectively.

727

727.7. Additional Requirements for Pile Load Tests. — A single
pile shall be load tested to not less than twice the design load.
When two (2) or more piles are to be tested as a group, the
total load shall be not less than one and one-half (1-1/2) times
the design load for the group.

Provided that the load-settlement curve shows no sign of
failure and provided that the permanent settlement of the top
of the pile, after removal of all load at the completion of the
test, does not exceed one-half (1/2) inch, the maximum design
load shall be the load allowed in this part for the type of pile
or one-half (1/2) of the maximum applied load, whichever is
less.

Whenever the soil conditions are such that substantial driving
resistance and/or significant support of the pile test load is
derived from soil strata overlying the intended bearing stratum
this support shall be removed or the results of the pile test shall
be analyzed so as to evaluate the actual support furnished by
the bearing stratum.

727.8. Application of Pile Load Test Results. — The results of
the load test can be applied to other piles within the area of
substantially similar sub-soil conditions as that for the test pile,
providing the performance of the test pile has been satisfactory
and the remaining piles are of the same type, shape and size
as the test pile; are installed using the same methods and equip-
ment and are driven into the same bearing strata as the load
tested pile to an equal or greater penetration resistance.

727.9. Settlement Analysis. — Whenever a structure is to be
supported by medium or soft clay (materials of classes 1 1 and
12), the settlements of the structure and of neighboring structures
due to consolidation of the clay shall be given careful con-
sideration, particularly if there are large variations in thickness
of the clay or the structure has substantial variation in net load
at foundation grade. The building official may require a settle-
ment analysis to be made by a competent engineer with special-
ized training and experience in soil mechanics in case the live
and dead loads of the structure, as specified in article 7, minus
the weight of the excavated material, induce a maximum stress
greater than three hundred (300) pounds per square foot at
midheight of the underlying soft clay.

727.9.1. — The settlement analysis will be based on a computation
of the net increase in stress that will be induced by the structure
and realistically appraised live loads, after deducting the weight

of excavated material under which the clay was fully consoli-
dated. The effects of fill loads within the building area or fill
and other loads adjacent to the building shall be included in the
settlement analysis. The appraisal of the live loads may be based
on surveys of actual live loads of existing buildings with similar
occupancy. The soil compressibility may be derived using one or
more of the following methods:

a. A review of settlement records and behavior of other
buildings in Greater Boston having similar subsoil pro-
files.

b. Consolidation tests on undisturbed specimens with a
diameter of at least two and one-half (2-1/2) inches. The
report shall include a description of the method of
sampling and of the quality of the samples.

c. Consolidation test data from other projects in Greater
Boston where the clay is found to be similar when
compared on the basis of detailed description of undis-
turbed soil samples, the natural water content and the
liquid and plastic limits.

727.9.2. — Should the analysis indicate that the settlements would
cause excessive stresses in the structure or would impair its
usefulness, the design of the foundation and/or the superstruc-
ture shall be modified so that the anticipated settlements will be
reduced to tolerable values.

SECTION 728.0. ALLOWABLE FOUNDATION PRESSURE

The maximum allowable pressures on foundation materials shall
be in accordance with section 725.0 and as modified herein.

728.1. Rock Foundations. — Where subsurface explorations at
the project site indicate variations or doubtful characteristics in
the structure of the rock upon which it is proposed to construct
foundations, a sufficient number of borings shall be made to a
depth of not less than ten (10) feet below the level of the
footings to provide assurance of the soundness of the foundation
bed and its bearing capacity.

728.2. Bearing Pressure on Rock. — The tabulated bearing pres-
sures for rocks of Classes 1 and 3, inclusive, shall apply where
the loaded area is on the surface of sound rock. Where the
loaded area is below such surface these values may be increased
ten (10) per cent for each foot of additional depth, but shall not
exceed three (3) times the tabulated values.

727-729

728.3. Bearing Pressures for Classes 4 to 9, Inclusive. — The

allowable bearing pressures for materials of Classes 4 to 9,
inclusive, may exceed the tabulated values by five (5) per cent
for each foot of depth of the loaded area below the minimum
required in section 729.0 but shall not exceed twice the tabulated
values. For areas of foundations smaller than three (3) feet in
least lateral dimension, the allowable design bearing pressures
shall be one-third (1/3) of the allowable bearing pressures
multiplied by the least lateral dimension in feet.

728.4. Bearing Pressures on Clay. — The tabulated bearing pres-
sures for Classes 10 to 12, inclusive, shall apply only to pressures
directly under individual footings, walls, and piers; and in case
structures are founded on or are underlain by deposits of these
classes, the total load over the area of any one bay or other
major portion of the structure, minus the weight of all materials
removed, divided by the area, shall not exceed one-half (1/2)
the tabulated bearing pressures.

728.5. Vertical Pressures. — The computed vertical pressure at
any level beneath a foundation shall not exceed the allowable
bearing pressures for the material at that level. Computation of
the vertical pressure in the bearing materials at any depth below
a foundation shall be made on the assumption that the load is
spread uniformly at an angle of sixty (60) degrees with the hori-
zontal; but the area considered as supporting the load shall not
extend beyond the intersection of sixty (60) degree planes of
adjacent foundations.

728.6. Investigation of Settlement. — Whenever there is any
doubt about the settlements of a proposed structure or the
effect on neighboring structures, the building official shall
require that the magnitude and distribution of the probable
settlements be investigated. This requirement shall also apply
to slabs on grade.

728.7. Disturbance of Bearing Materials. — Whenever the bearing
materials are disturbed from any cause, for example by the in-
ward or upward flow of water and/or by construction activities,
the extent of the disturbance shall be evaluated and appropriate
remedial measures taken, satisfactory to the building official.

SECTION 729.0. SPREAD FOUNDATIONS

Except when erected upon sound bedrock or when protected
from frost, foundation walls, piers and other permanent sup-

ports of all buildings and structures shall extend a minimum of
four (4) feet below finished grade except as provided in section
725.1.3. Spread footings of adequate size shall be provided when
necessary to properly distribute the load within the allowable
bearing pressure of the soil.

729.1. Depth of Spread Foundations. — The bottom surface of
any footing resting on material of classes 4 to 15, inclusive,
shall be at least eighteen (18) inches below the lowest ground
surface or the surface of a floor slab bearing directly on the
soil immediately adjaceent to the footing.

729.2. Light Structures. — One-story structures without masonry
walls and not exceeding eight hundred (800) square feet in area
may be founded on a layer of satisfactory bearing material not
less than three (3) feet thick, which is underlain by highly
compressible material, provided that the stresses induced in the
unsatisfactory material by the live and dead loads of the struc-
ture and the weight of any new fill, within or adjacent to the
building area, will not exceed two hundred and fifty (250)
pounds per square foot.

SECTION 730.0. FOOTING DESIGN

730.1. Design Loads. — The loads to be used in computing the
pressure upon bearing materials directly underlying foundations
shall be the live and dead loads of the structure, as specified
in section 721 including the weight of the foundations and of any
immediately overlying material, but deducting from the resulting
pressure per square foot the total weight of a one (1) square foot
column of soil, including the water in its voids, which extends
from the lowest immediately adjacent surface of the soil to the
bottom of the footing, pier or mat. Foundations shall be con-
structed so as to resist the maximum probable hydrostatic
pressures.

730.2. Pressure Due to Lateral Loads. — Where the pressure on
the bearing material due to wind or other lateral loads is less
than one-third (1/3) of that due to dead and live loads, it may
be neglected in the foundation design. Where this ratio exceeds
one-third (1/3) foundations shall be so proportioned that the
pressure due to combined dead, live, wind loads, and other
lateral loads shall not exceed the allowable bearing pressures
by more than one-third (1/3).

729-733

730.3. Earthquake Loads. — Special provision shall be made in

the foundation design to comply with the provisions of section
719.

730.4. Vibratory Loads. — Where machinery or other vibrations
may be transmitted through the foundations, consideration shall
be given in the design of the footings to prevent detrimental
disturbance of the soil.

730.5. Eccentric Loads. — Eccentricity of loadings in foundations
shall be fully investigated and the maximum pressure on the
basis of straight-line distribution shall not exceed the allowable
bearing pressures.

SECTION 731.0. TIMBER FOOTINGS

731.1. Where Permitted. — Timber footings may be used only for
wood frame structures. Such footings shall be placed entirely
below the permanent water level unless the timber is treated in
accordance with the provisions of section 740.5.

731 .2. Untreated Timber. — The compressive stresses perpendicular
to the grain in untreated timber footings, supported upon piles,
with the pile cut-off and the top of the footing and capping
entirely below permanent ground water or mean low water level,
shall not exceed seventy (70) per cent of the allowable stresses
for the species and grade of lumber in accordance with the
provisions of section 853.

SECTION 732.0. STEEL GRILLAGES

Structural steel grillage foundations shall have at least six (6)
inches of concrete cover below the bottom of the steel and shall
have at least four (4) inches of concrete cover above the steel
and between the sides of the steel and the adjacent soil.

SECTION 733.0. UNREINFORCED CONCRETE FOUNDA-
TIONS.

733.1. Concrete Strength. — Concrete in unreinforced foundation
footings shall be so proportioned as to develop an ultimate
compressive strength of not less than two thousand (2000)
pounds per square inch at twenty-eight (28) days.

733.2. Placement. — No concrete for foundations shall be poured
through water. When placed under or in the presence of water,

the concrete shall be deposited by approved and properly operated
equipment which insures minimum segregation of the mix and
negligible turbulence of the water.

733.3. Dimensions. — In unreinforced concrete footings, the edge
thickness shall be not less than twelve (12) inches for footings
on soil or rock; except for wood frame buildings up to two (2) |
stories in height, these thicknesses may be reduced to eight (8)
inches.

733.4. Protection. — Concrete footings shall be protected from
freezing during construction and for a period of not less than
five (5) days thereafter and in no case shall water be allowed
to flow through the deposited concrete.

SECTION 734.0. MASONRY UNIT FOOTINGS

734.1. Dimensions. — Masonry unit footings shall be laid in
cement mortar or cement-lime mortar complying with section
816 and the depth shall be not less than twice the total pro-
jection beyond the wall, pier or column; and the width shall be
not less than twelve (12) inches wider than the wall supported
thereon.

734.2. Offsets. — The maximum offset of each course in brick
foundation walls stepped up from the footings shall be one and
one-half (1-1/2) inches if laid in single courses, and three (3)
inches if laid in double courses.

SECTION 735.0. REINFORCED CONCRETE
FOUNDATIONS

735.1. Design. — Reinforced concrete foundations shall comply
with sections 841, 842, 843 and 844 and the applicable reference
standards therein listed for the design of reinforced concrete.

735.2. Pile Caps. — The minimum distance from the edge of the
cap to the nearest pile surface shall be six (6) inches and there
shall be at least two (2) inches of concrete between the top of
the pile and the steel reinforcement of the cap. The pile caps
shall extend not less than three (3) inches below the pile cut-off.

735.3. Protection. — When the concrete is deposited directly
against the ground, the reinforcement shall have a minimum
cover of three (3) inches, at all other surfaces of foundation
concrete, the reinforcement shall have a minimum cover of two
(2) inches.

733-737
SECTION 736.0. FLOATING FOUNDATIONS

The design of floating foundations shall include a settlement
analysis in accordance with the provisions of section 727.9.

SECTION 737.0. PILE FOUNDATIONS

737.1. Site Investigation. — In addition to the provisions of
section 726.0, the building site shall be investigated for all
conditions which might promote deterioration of pile foundations,
and approved protective measures meeting the requirements of
section 738.0 shall be taken to prevent corrosion or other
destructive action from deleterious conditions.

737.2. Spacing. — The minimum center-to-center spacing of piles
shall be not less than twice the diameter at cut-off of a round
pile, nor less than one and three-quarter (1-3/4) times the diag-
onal dimension of a rectangular pile. When driven to or pene-
trating into rock, the spacing shall be not less than twenty-four
(24) inches. When receiving principal support from end-bearing
on materials other than rock or through frictional resistance,
the spacing shall be not less than thirty (30) inches.

737.3. Walls. — All piles in wall foundations shall be staggered
about the center line of the wall at a minimum distance of one-
half (1/2) the top diameter therefrom. A foundation wall re-
strained laterally so as to ensure stability both during and after
construction may be supported by a single row of piles.

737.4. Isolated Columns. — An isolated column when supported
by piles shall rest upon not less than three (3) piles, at least
one (1) of which is offset; except that for one (1) story buildings
an isolated column may rest upon two (2) piles when its axis is
not more than one and one-half (1-1/2) inches off the line
connecting the centers of the two (2) piles, or upon a single
pile when other than wood or wood-composite piles are used
and its axis is not more than one and one-half (1-1/2) inches off
the center of the pile, provided the top of the pile is laterally
supported.

737.5. Minimum Dimensions. — Piles of uniform cross section
shall have a minimum outside nominal dimension of ten (10)
inches except as provided in section 741.2.1. Tapered concrete
piles shall have a minimum butt diameter at cut-off of twelve
(12) inches and a diameter of not less than eight (8) inches
measured one (1) foot above the tip.

737.6. Splices. — Splices shall be avoided insofar as practicable.
Where used, splices shall be such that the resultant vertical and
lateral loads at the splices are adequately transmitted. Splices
shall be so constructed as to provide and maintain true align-
ment and position of the component parts of the pile during
installation and subsequent thereto. The ends of each section of
steel pipe or other steel elements shall be cut perpendicular to
the axis and bearing surfaces shall be true-fitted with milled or
ground faces or by flame cutting or other approved method.
Splices shall develop one hundred (100) per cent of the strength
of pile section in whatever state of stress.

737.7. Jetting. — Jetted piles shall be driven to the required load
resistance as determined by the application of the approved pile
driving formula in section 739.2.1, after the flow of jet water
has stopped.

737.8. Precautions. — When piles have been damaged in driving,
or driven in locations and alignment other than those indicated
on the plans, or that have capacities less than required by the
design, the affected pile groups and pile caps shall be investigated
and if necessary, the pile groups or pile caps shall be redesigned
or additional piles shall be driven to replace the defective piles.
Piles shall be driven to embedment in the supporting stratum,
as determined by borings.

737.8.1. Method of Driving. — The method of driving shall be
such as not to impair the strength of the pile and shall meet
with the approval of the building official. Measurements to
determine the value of "s", as defined in section 739. 2.1. a,
shall not be made immediately after the introduction of fresh
cushion block material, or an interruption in the driving opera-
tion or when the pile head is shattered, broomed, crumpled, or
otherwise damaged.

The cushion block, where used, shall be of hardwood with its
grains parallel with the axis of the pile and be enclosed in a
tight-fitting steel housing, or a demonstrated equal. Wood chips,
pieces of rope, old hose, or automobile tires and similar materials
shall not be used as a cushion block.

Shattered, broomed, crumpled, or otherwise damaged pile heads
shall be cut back to sound material before continuing the
driving.

In case a follower is used, it shall be of steel, seasoned white
oak or hickory, equipped on its lower end with a metal socket

737-738
or hood suitable for encasing the pile head and to protect it
from being damaged during driving.

737.8.2. Pile Heave. — Where piles are driven through soft soil
to hard bearing material providing high point resistance, the
grades of all piles or pile casings previously driven or redriven
shall be measured to detect heave; and if heave of one-half
(1/2) inch or more occurs in any pile or pile casing, such pile
or pile casing shall be redriven to its original point elevation and
thereafter to the required final driving resistance. A preaugered
hole for each pile may be used, as required, to reduce detrimental
heave and negative friction.

737.8.3. Records. — The owner shall engage a competent in-
spector, qualified by experience and training and satisfactory to
the building official to be present at all times while piles are
being driven and to inspect all work in connection with the
piles. The inspector shall make an accurate record of the
material and the principal dimensions of each pile, of the weight
and fall of the ram, the type, size, and make of hammer, the
number of blows per minute, the energy per blow, the number
of blows per inch for the last six (6) inches of driving, together
with the grades at point and cut-off. A copy of these records
shall be filed in the office of the building official.

SECTION 738.0. CORROSION PROTECTION

Where boring records, previous experience, or site investiga-
tions indicate any condition which might promote deterioration
or possible deleterious action on pile materials due to soil con-
stituents, changing water levels or other causes such pile materials
shall be adequately protected as stated herein.

738.1. Wood Preservative Treatments. — The preservative treat-
ment of timber piles shall comply with the provisions of section
740.5 and the applicable standards in reference standard RS 7-9.

738.2. Steel and Steel-Concrete Piles. — At locations where steel
and steel-concrete piles will be in contact with sea water or any
other material that is known to be corrosive to steel, one of the
following procedures shall be used:

a. Remove all such objectionable material.

b. Effectively protect the steel surface from pile cut-off
grade to a grade fifteen (15) feet below the bottom of
the objectionable materials by means of:

1. Cathodic protection as approved by the building
official; or

2. An approved encasement of not less than three (3)
inches of dense concrete; or

3. An effective protective coating subject to the approval
of the building official; or

4. Deducting one-eighth (1/8) inch in thickness of
material from exposed surfaces when computing
the area of steel for support of load.

SECTION 739.0. ALLOWABLE PILE LOADS

The allowable load on piles shall be determined by the appli-
cable formulas complying with accepted engineering practice
and as stated herein. The maximum load capacity shall be
limited by the supporting capacity as obtained from bearing
upon or embedment in bearing materials as defined in sections
725 and 728 but in no case shall the load exceed the capacity
of the pile designed in accordance with the provisions of section
739.1 and the requirements of article 8 for the construction
materials involved.

739.1. Lateral Support of Axially Loaded Piles. — The length
of a pile below the ground surface shall be considered as a
plain column with continuous lateral support. The length above
the ground surface shall be designed as an unsupported column
in accordance with the provisions of section 748.

739.2. Determination of Allowable Load. — In the absence of
capacities based on load tests, except for the type of piles
covered in sections 742.2 and 7.44.0 the load on a single pile
shall not exceed the higher of the two (2) values determined
in accordance with sections 739.2.1 and 739.2.2, nor the max-
imum loads on piles as provided in sections 739.2.3 and 740.0
thru 746.0.

739.2.1. Driving Formula

a. Where the design load capacity of the pile does not ex-
ceed fifty (50) tons, the allowable load may be computed
by means of the following driving formula:

R= L^E

/Wp

s+o.iyWr

where

R= allowable pile load in pounds

739
E= energy per blow in foot-pounds which for drop
hammers is the product of the weight in pounds
of the hammer and the height of fall in feet,
and which for other types of hammers may be
taken as that established by the hammer manu-
facturer. For batter piles, proper allowance shall
be made for the resultant loss of energy.

Wp = the ratio of the weight W p of the pile and other
Wr driven parts to the weight W r of the striking
part of the hammer, except that this ratio shall
not be entered into the formula as less than unity.
s = the average penetration in inches per blow for
the final six (6) inches of driving, except that if
an abrupt high increase in resistance is en-
countered, "s" shall be taken as the average
penetration per blow for the last five (5) blows.
The minimum value of "s" which may be used
in the formula is five hundredths (5/100) of an
inch.
When the design load capacity of a pile exceeds fifty (50)
tons the required driving resistance shall be increased,
above that required by the driving formula, in section
739. 2.1. a, based on load tests or past experience under
similar conditions.

The energy E per blow in foot-pounds delivered by the
hammer shall be numerically not less than fourteen (14)
per cent of R in pounds and/ W r \ shall not be greater
than 3.5. \W /

The value of "s" must be determined with the hammer
operating at one hundred (100) per cent of the rated
number of blows per minute for which the hammer is
designed.

Any driving resistance developed in strata overlying the
bearing material shall be discounted.
If the driving of the pile has been interrupted for more
than one (1) hour, the value of "s" shall not be deter-
mined until the pile is driven at least an additional
twelve (12) inches, except when it encounters refusal on
or in a material of Classes 1 to 5, inclusive.
When the constant tapered portion of a pile, including a
timber pile, is driven through a layer of gravel, sand, or

hard clay (Classes 6 to 10, inclusive, and Class 14)
exceeding five (5) feet in thickness, and through an
underlying soft stratum, the bearing capacity shall not be
determined in accordance with the driving formula, unless
jetting is used during the entire driving of the tapered
portion of the pile through the layer of gravel, sand,
hard clay, or Class 14 material, or unless a hole is pre-
excavated through said layer for each pile.

739.2.2. Friction Formula in Clay. — The allowable load on a
pile stopped in inorganic clay may be based on a friction value
of five hundred (500) pounds per square foot of embedded pile
surface for a design load not to exceed twenty-two (22) tons,
or on a friction value determined from pile load tests. The
embedded length shall be the length of the pile below the
surface of the inorganic clay, or below the surface of imme-
diately overlying satisfactory bearing material. The area of em-
bedded pile surface shall be computed by multiplying the
embedded length by the perimeter of the smallest circle or poly-
gon that can be circumscribed around the average section of the
embedded length of the pile. The method of determining the
allowable load described in this paragraph shall not be used for
a pile in which the drive-pipe is withdrawn or for piles which
are driven through the clay to or into firmer bearing materials.

In case these piles are in clusters the allowable load shall be
computed for the smaller of the following two (2) areas: (1) the
sum of the embedded pile surfaces of individual piles; (2) the
area obtained by multiplying the perimeter of the polygon
circumscribing the cluster at the surface of the satisfactory
bearing material by the average embedded length of pile.

739.2.3. Jacked Piles. — The allowable load on a single pile
installed by jacking shall not exceed one-half (1/2) the load
applied to the pile at the completion of jacking, provided that
the final load is kept constant for a period of four (4) hours
and that the settlement during that period does not exceed one-
twentieth (1/20) of an inch.

739.3. Negative Friction. — Where a pile or a group of piles is
placed in subsiding fill or soil, the effect of the downward
frictional forces shall be given consideration in the design.

739.4. Limiting Load. — Where weaker materials underlie the
bearing material into which the piles are driven, the allowable
pile load shall be limited by the provision that the vertical
pressures in such underlying materials produced by the loads on

739-740

all piles in a foundation shall not exceed the allowable bearing
pressures of such materials as established by analysis applying
accepted principals of soil mechanics. Piles or pile groups shall
be assumed to transfer their loads to the underlying materials
by spreading the load uniformly at an angle of sixty (60) degrees
with the horizontal, starting at a polygon circumscribing the
piles at the top of the satisfactory bearing material in which
they are embedded; but the area considered as supporting the
load shall not extend beyond the intersection of the sixty (60)
degree planes of adjacent piles or pile groups.
739.4.1. — The allowable load on a pile shall not be limited to
the load obtained by multiplying its point area by the allowable
bearing pressure given in section 725.0.

SECTION 740.0. TIMBER PILES

740.1. Species. — Piles shall be of type I species, type II species
or other species approved for such use by the building official.

a. Type I species shall include southern yellow pine, oak,
Douglas fir and other woods of similar strength and
physical characteristics.

b. Type II species shall include Norway pine, spruce and
other woods of similar strength and physical characteristics.

740.2. Quality Requirements. — The quality of all round timber
piles shall at least conform to class A and B, round timber piles
listed in reference standard RS 7-10.

Round timber piles shall be cut above the ground swell, have
a continuous taper from the point of butt measurement to the
tip and be free from decay, red heart, or insect attack. All
knots and limbs shall be trimmed or smoothly cut flush with the
surface of the pile or swell surrounding the knot. A straight line
from the center of the butt to the center of the tip shall lie
entirely within the body of the pile. The axis of a wood pile
shall not deviate from a straight line more than one (1) inch
for each ten (10) feet of length. Short crooks shall not deviate
more than two and one-half (2-1/2) inches in five (5) feet.
Spiral grain shall not exceed one-half (1/2) of a complete twist
in any twenty (20) feet of length, unsound or cluster knots are
prohibited and splits and shakes are limited.

740.3. Minimum Dimensions.

a. Piles shall be of adequate size to resist the applied loads

without having to endure compressive stress parallel with
the grain in excess of the following:

1. Six hundred (600) pounds per square inch for type I
species of wood or four hundred twenty-five (425)
pounds per square inch for type II species of wood
on the pile cross section located at the surface of
the bearing stratum for piles driven into materials
of classes 6 thru 10.

2. Three hundred sixty (360) pounds per square inch for
type I species of wood or two hundred fifty-five
(255) pounds per square inch for type II species of
wood on the pile cross section at the tips of piles
driven to bearing on materials of classes 1 thru 5.

b. The piles shall measure at least six (6) inches in diameter
at the tip and at least ten (10) inches in diameter at the
cut-off, with these measurements being taken under the
bark.

c. All piles shall be driven in one (1) piece except as
provided in section 746 for composite piles.

740.4. Cut-Off. — The tops of all timber piles shall be cut off
in a horizontal plane; and if not treated by an approved pre-
servative process, the cut-off shall be below mean low water
level or lowest ground water level, and shall be subject to the
building official's approval. He may require the owner to
install and maintain in good condition at least one (1) ground
water observation well within the building, which shall be
accessible to the building official.

740.5. Treated Piles. — Timber piles pressure treated with creosote
or creosote-coal-tar solution, and conforming to the requirements
of this section, may be cut off above permanent ground water
level when used for the support of buildings not exceeding two
(2) stories in height.

740.5.1. Treatment. — Creosoted wood piles of southern yellow
pine, Douglas fir, red oak or Norway pine shall be creosoted
under pressure in accordance with reference standard RS 7-9 to
a final net retention of not less than twenty (20) pounds per
cubic foot of creosote for piles exposed to sea water and not
less than twelve (12) pounds of creosote per cubic foot for
piles for other normal exposure. The tops of such piles at cut-
off shall be given three (3) coats of hot creosote, followed by a
coat of coal-tar pitch; and the cut-off shall be made in sound
wood and be encased not less than three (3) inches in the
concrete pile cap.

740-741
740.5.2. Certification. — Before any treated piles are driven, the
building official shall be furnished three (3) copies of a certificate
of inspection, issued by an approved independent testing labora-
tory, certifying that the piles were free of decay, were properly
peeled and otherwise prepared before treatment; and that the
method of treatment, the chemical composition and the amount
of retention of the preservative conform to the requirements of
this section.

740.6. Maximum Load on Wood Piles. — The load on a wood
pile shall not exceed the allowable load specified in section 739.
For timber piles driven into material of classes 6 through 10
the area at the surface of the bearing stratum shall be used to
compute the allowable load.

740.6.1. The maximum load on a timber pile shall not exceed
thirty-five (35) tons.

740.7. Precautions in Driving. — To avoid damage to the pile,
the size of the hammer shall be such that the driving energy in
foot-pounds per blow shall not exceed numerically the point
diameter of the pile in inches multiplied by fifteen hundred
(1500). The total driving energy in foot-pounds for six (6)
inches of penetration shall for all types of hammers be numeri-
cally no greater than the point diameter in inches times thirty-
two thousand (32,000) for type I species of wood or times
twenty-two thousand (22,000) for type II species of wood. For
the last inch of penetration the energy in foot-pounds shall not
exceed numerically the point diameter in inches multiplied by
six thousand (6,000). In any case driving shall be stopped
immediately when abrupt high resistance to penetration is
encountered. Any sudden decrease in driving resistance shall be
investigated with regard to the possibility of breakage of the
pile; and if such sudden decrease in driving resistance cannot
be correlated to boring data, and if the pile cannot be removed
for inspection, it shall be considered adequate reason for rejection
of the pile.

SECTION 741.0. PRECAST CONCRETE PILES

741.1. Concrete Strength. — No precast concrete pile shall be
driven before the concrete has attained a compressive strength
of not less than four thousand (4000) pounds per square inch
based on tests of cylinders cast from the same batches and
cured under the same conditions as the pile concrete. These

piles shall be so proportioned, cast, cured, handled and driven
as to resist without significant cracking the stresses induced by
handling and driving as well as by loads.

741.2. Design. — The piles shall be designed and reinforced in
accordance with the applicable reinforced concrete regulations
cited in section 842.0. If for any reason the pile is injured,
or the reinforcement is exposed, its use shall be condemned.
The lateral reinforcement at both ends of the pile shall be
spaced sufficiently close to resist impact stresses due to driving
and in no case more than three (3) inches on center. When
driven to or into bearing materials of Classes 1 to 5, inclusive,
or through materials containing boulders, they shall have metal
tips of approved design.

741.2.1. Dimensions. — The minimum lateral dimension of a
precast concrete pile shall be ten (10) inches.

741.2.2. Limitation of Load. — The load on a precast concrete
pile shall not exceed the allowable load specified in section 739
nor twenty-five (25) per cent of the twenty-eight (28) day strength
of the concrete, but not exceeding twelve hundred (1200) pounds
per square inch. For prestressed concrete piles twenty-five (25)
per cent of the effective prestress in the concrete after losses
shall be deducted from twenty-five (25) per cent of the twenty-
eight (28) day strength or twelve hundred (1200) pounds per
square inch, whichever is less, in computing the maximum pile
load.

741.3. Protection. — A minimum covering of two (2) inches of
concrete shall be provided over all reinforcements, except that
for piles to be exposed to sea water and other severe environ-
ments, a three (3) inch protective covering shall be furnished in
the zone of such exposure.

741 .4. Minimum Spacing. — The minimum spacing center-to-center
of precast concrete piles shall be two and one-half (2-1/2) times
the square root of the cross-sectional area at the butt.

741.5. Splices. — Splices shall not be permitted in precast con-
crete piles.

741.6. Driving Precautions. — When driving through extremely
soft soil or in pre-drilled or jetted holes, the hammer ram veloc-
ity and stroke shall be reduced to avoid critical tensile stresses.
If a pile-driving cap is used, it shall fit loosely around the pile
top so as not to restrain the pile from rotating.

The top of the pile must be perpendicular to the longitudinal
axis of the pile, and the ends of any prestressing or reinforcing

741-742
steel shall be cut flush with the top of the pile to prevent
direct impact on the steel during driving.

SECTION 742.0. CAST-IN-PLACE CONCRETE PILES

In this section a distinction is made between poured-concrete
piles and compacted-concrete piles. A poured-concrete pile is
formed by pouring concrete into a driven casing that is perma-
nently installed in the ground. A compacted-concrete pile is
formed by placing concrete having zero (0) slump, in small
batches, and compacting each batch. All cast-in-place concrete
piles shall be so made and placed as to ensure the exclusion of
all foreign matter and to secure a well-formed unit of full
cross-section. The minimum strength of concrete for cast-in-
place piles shall be three thousand (3000) pounds per square
inch. While placing the concrete the casing or drive-pipe shall
contain not more than three (3) inches of water.
742.1. Poured Concrete Piles.

742.1.1. Design. — The shape of the pile may be cylindrical, or
conical, or a combination thereof, or it may be a succession of
cylinders of equal length, with the change in diameter of ad-
joining cylinders not exceeding one (1) inch.

742.1.2. Loading. — The load on poured-concrete piles shall not
exceed the allowable load specified in section 739 nor twenty-
five (25) per cent of the twenty-eight (28) day strength of the
concrete, but not exceeding eleven hundred (1,100) pounds per
square inch, when applied to the cross-sectional area computed
on the following bases:

a. For metal-cased piles driven to and into materials of
Classes 1 to 4, inclusive, using the diameter measured
one (1) foot above the point, except that when the rock
is immediately overlain by a bearing stratum consisting of
one (1) or a combination of bearing materials of Classes
5, 6 and 7, using the diameter at the surface of the
bearing stratum.

b. For metal-cased piles, driven through compressible mater-
ials, including Classes 11, 12, 13 and 15 and into a
bearing stratum consisting of one (1) or a combination
of bearing materials of Classes 5 to 10, inclusive, using
the diameter at the surface of the bearing stratum.

742.1.3. Installation. — Immediately before filling with concrete,
the inside of the casing shall be thoroughly cleaned to the

bottom and inspected by lowering a light bulb, or by means of
a light beam. To be accepted: (a) the diameter shall not vary
more than twenty (20) per cent from the original value, (b) the
point of the casing shall not deviate more than ten (10) per cent
of the length of the pile from the design alignment, and (c) the
casing shall not deviate by more than four (4) per cent of the
length of the casing from a straight line connecting the mid-
points of the ends of the casing. If the bottom of the casing is
out of sight, the shape and alignment of the casing shall be
surveyed with a suitable instrument. No load shall be allowed
on a pile, the casing of which shows signs of buckling. No
casing or drive-pipe shall be filled with concrete until all casings
or drive-pipes within a radius of seven (7) feet, or within the
heave range, whichever is greater, have been driven to the re-
quired resistance.
742.2. Compacted Concrete Piles.

742.2.1. Loading. — The load on compacted concrete piles shall
be limited by the provisions of section 739.4.1 except that the
circumscribing polygon shall start at the junction of the shaft
and the enlarged base, and the bearing area shall be taken at
planes six (6) feet or more below said junction; and the allow-
able load on a compacted concrete pile shall not exceed one
hundred forty (140) tons.

742.2.2. Installation. — The installation of such piles shall fulfill
the following listed requirements:

a. The drive-pipe used for installing the piles shall be not
less than twenty (20) inches outside diameter for piles
which have an allowable load of eighty-five (85) tons
or greater, and not less than sixteen (16) inches outside
diameter for piles which have an allowable load of less
than eighty-five (85) tons. For loads less than fifty (50)
tons, smaller drive casings may be used subject to the
approval of the building official.

b. The enlarged base of the pile shall be formed on or in
bearing materials of Classes 1 to 9, inclusive. The Class
9 material (fine sand) shall have a maximum of six (6)
per cent by weight finer than the No. 200 mesh sieve
and shall be non-plastic.

c. The concrete in the base shall have a minimum com-
pressive strength at twenty-eight (28) days of four thou-
sand (4000) pounds per square inch, shall be of zero (0)

742
slump, and shall be placed in batches not to exceed five

(5) cubic feet in volume.

The last batch of concrete shall be driven into the en-
larged base with not less than twenty-five (25) blows,
each of not less than one hundred and forty thousand
(140,000) foot-pounds. For lower allowable loads, the
required number of blows on the last batch shall vary
in proportion to the allowable load. On the basis of
test data, and subject to approval by the building official,
the hammer blow energy may be reduced, in which case
the number of blows on the last batch shall vary in-
versely with the energy delivered per blow.
During injection of the last five (5) cubic feet the level
of concrete in the drive casing shall be not more than

(6) inches above the bottom of the casing.

As the drive-pipe is being withdrawn, not less than two
(2) blows of at least forty thousand (40,000) foot-pounds
each shall be applied to compact each batch of concrete
in an uncased shaft.

An uncased shaft shall not be formed through inorganic
clay or inorganic silt unless a hole is made through such
soil by a non-displacement method, at least equal to the
inside diameter of the drive-pipe unless the individual
piles are located more than nine (9) feet apart and
outside the heave range. Compacted concrete piles shall
have cased shafts when spaced closer than nine (9) feet
apart and when installed through inorganic clay or
inorganic silt.

An uncased shaft shall not be formed through peat or
other organic soils.

The permanent metal casing shall be fastened to the
enlarged base in such a manner that the two (2) will
not separate. The concrete may be placed in the metal
casing in the same manner as for poured-concrete piles.
No metal casing shall be filled with concrete until after
all piles within a radius of at least nine (9) feet have
been driven. The stresses in metal-cased shafts shall not
exceed eleven hundred (1,100) pounds per square inch on
the concrete and, in addition, nine-thousand five hundred
(9,500) pounds per square inch on the steel casing, por-
vided that its wall thickness is at least two-tenths (2/10)

of an inch. When required by soil conditions allowance

shall be made for corrosion as specified in section 738.

742.2.3. Spacing. — The center-to-center spacing of piles shall

be not less than three (3) times the shaft diameter and not less

than three and one-half (3.5) feet.

SECTION 743.0. CONCRETE FILLED PIPE PILES

743.1. Concrete Strength and Placement. — Concrete-filled pipe
piles may be driven open-end or closed-end. Concrete shall have
a minimum compressive strength of three thousand (3000) pounds
per square inch at twenty-eight (28) days' age. After driving all
pipes within a seven (7) foot radius, or within heave range
whichever is greater, and immediately before filling with concrete,
the inside of the pipe shall be thoroughly cleaned to the bottom
and inspected by lowering a light bulb, or by means of a light
beam. To be acceptable: (a) the diameter shall not vary more
than twenty (20) per cent from the original value, (b) the point
of the pile shall not deviate more than ten (10) per cent of the
length of the pile from the design alignment and (c) the pile
shall not deviate by more than six (6) per cent of the length of
the pile from a straight line connecting the midpoints of the
ends of the pile. If the bottom on the pile is out of sight, or
cannot be seen because the pile cannot be dewatered, the shape
and alignment of the pile shall be surveyed with a suitable
instrument. No load shall be allowed on a pile which shows
signs of buckling. Concrete shall not be placed through water,
except that the building official may approve the use of a
properly operated tremie or pumped concrete in still water,
providing the pipe is proven to be free of other material.

743.2. Steel Pipe. — All steel pipe shall conform to the applicable
standards listed in reference standard RS 7-8 for welded and
seamless steel pipe and tubes and for hot rolled carbon steel
sheets. The yield point used in the design of steel casings shall
be that of the fabricated element as determined by test.

743.3. Design. — The load on concrete-filled pipe piles shall not
exceed the allowable load determined in accordance with section
739.0, nor a load computed on the basis of stress in the con-
crete at twenty-five (25) per cent of the twenty-eight (28) day
strength, but not exceeding eleven hundred (1100) pounds per
square inch, and stress in the steel at nine thousand (9000)

742-744
pounds per square inch, nor shall the load carried by the steel
on this basis exceed one-half (1/2) the total load on the pile.

743.4. Minimum Thickness. — The minimum wall thickness of all
load-bearing pipe shall be two-tenths (2/10) inches. When re-
quired by soil conditions, allowance shall be made for corrosion
as specified in section 738.

743.5. Splices. — All splices of the steel section shall be welded
to one hundred (100) per cent of the strength of the pipe and
otherwise shall comply with section 737.7 and shall be designed
to insure true alignment of the pipe and uniform transmission
of load from one (1) pipe length to another.

SECTION 744.0. CONCRETE FILLED PIPE WITH STEEL
CORE (DRILLED-IN-CAISSONS)

744.1. Construction. — These units shall consist of a shaft section
of concrete-filled pipe extended to and firmly seated in bedrock
of classes 1 or 2 with an uncased socket drilled into the bed-
rock which is filled with cement grout. The steel core shall be
centered in the shaft and shall extend through the cement grout
to the bottom of the socket.

744.2. Steel Shell. — The steel shell shall be seamless or welded
steel pipe with a minimum yield point of thirty-three thousand
(33,000) pounds per square inch fitted with an approved cutting
shoe and structural cap, or with other approved means of
transmitting the superstructure load. The minimum diameter
for drilled caissons shall be twenty-four (24) inches and minimum
shell thickness five-sixteenths (5/16) inches. Steel shall be pro-
tected under the conditions specified in section 738. Splices
shall be welded to develop one hundred (100) per cent of the
strength of the pipe.

744.3. Concrete Fill. — The concrete fill of caissons shall be con-
trolled concrete with a minimum compressive strength of four
thousand (4000) pounds per square inch at twenty-eight (28)
days. It shall be so placed that it shall fill completely the space
between the steel core and the pipe. In case the socket cannot
be kept free from inflow of water, the pipe shall be filled to
its top with clean water before placing the cement grout.
The details of the design and the installation, including the
cleaning and inspection of the socket, the placement of concrete
under water or in the dry, the method of centering the steel

core and all other phases of the work shall be submitted to the
building official for approval.

744.4. Rock Socket. — A socket, approximately of the inside
diameter of the pipe, shall be made in bedrock of Classes 1 or
2 to a depth that will assure load transfer when computed for
a bearing on the bottom surface of the socket in accordance
with sections 725 and 728 acting together with a bond stress on
the perimeter surface of the socket of one hundred (100) pounds
per square inch. Before placement of concrete, the socket and
pipe shall be thoroughly cleaned and the rock inspected by a
competent engineer or geologist satisfactory to the building
official. This inspection may be performed by means of an
underwater television camera, the position of which is readily
controllable to permit thorough inspection of the exposed rock
surface in the socket.

744.5. Steel Core. — The steel core shall consist of a structural
steel member. The mating ends of the sections shall be spliced
so to safely withstand the stresses to which they may be sub-
jected. The minimum clearance between structural core and
shell shall be two (2) inches. When such cores are installed in
more than one (1) length, they shall be assembled to develop
the full compressive strength of the section.

744.6. Driving Precautions. — The steel shell shall be driven not
more than two (2) per cent of the length out of plumb.

744.7. Spacing. — The minimum center-to-center spacing shall
be not less than two and one-half (2-1/2) times the outside
diameter of the steel shell.

744.8. Allowable Load. — The load on concrete-filled pipe piles
with steel cores shall not exceed the allowable load determined
in accordance with the provisions of section 744.4 nor that
computed on the basis of eleven hundred (1100) pounds per
square inch on the area of the concrete plus nine thousand
(9,000) pounds per square inch on the net area of the steel
pipe plus sixteen thousand (16,000) pounds per square inch on
the area of the steel core.

SECTION 745.0. STRUCTURAL STEEL PILES

745.1. Steel. — Steel sections may be of any type of steel per-
mitted by the provisions of reference standard RS 8-42.

a. Rolled structural steel piles shall be of H form, with
flange projection not exceeding fourteen (14) times the

744-746

minimum thickness of metal in either flange or web and
with total flange width at least eighty-five (85) per cent
of the depth of the section. No section shall have a
nominal thickness of metal less than four-tenths ( .4 )
inch nor a nominal depth in the direction of the web of
less than eight (8) inches.

b. The use of built-up sections or sections of other than
"H" form will be permitted if the several components of
the section are adequately connected to develop the
strength of the adjacent components and if the ratio
of width to thickness of the component parts does not
exceed the values for conventional "H" sections.

c. The tips of all steel H piles having a thickness of metal
less than five-tenths (0.5) inches which are driven to end
bearing on rock of class 1 through 3 by an impact ham-
mer, shall be reinforced. The installation of all steel H
piles by impact hammer to end bearing on rock of classes
1 through 3 shall be conducted so as to terminate driving
directly when the pile reaches refusal on the rock surface.

d. Structural caps shall be rigidly attached to the pile
section and shall be designed to transfer the full load
into the piles; except that when the pile extends into
the footing sufficiently to develop the full load by bond,
or to permit the use of mechanical devices to develop the
full load by shear, structural caps shall not be required.

745.2. Splices. — If piles are spliced, the splice shall develop one
hundred (100) per cent of the strength of the section.

745.3. Protection. — Structural steel piles shall be protected
under the conditions specified in section 738 or due allowance
shall be made for corrosion as therein specified.

745.4. Allowable Load. — The load on such piles shall not
exceed the allowable load determined in accordance with section
739, nor a load based on stress of eight thousand five hundred
(8,500) pounds per square inch on the cross-section.

SECTION 746.0. COMPOSITE PILES

746.1. Design. — A composite pile shall consist of a combination
of not more than two (2) of any of the different types of piles
provided for in this part. The pile shall fulfill the requirements
for each type and in addition the provisions of this section.

The requirements of section 742.1.3 shall apply to the entire
length of a pipe-shell composite pile.

746.2. Limitation of Load. — The allowable load on composite
piles shall be that allowed for the weaker of the two (2) sections.
For wood-composite piles the allowable load shall not exceed
eighty (80) per cent of that allowed for the wood section alone.
Wood-shell composite piles shall not be used for support of
buildings exceeding two (2) stories in height.

746.3. Splices. — The connection between the two (2) types of
piles shall be constructed so as to prevent their separation, to
maintain their alignment, to support the load, and to be water-
tight where concrete must be placed subsequent to the driving.

746.4. Spacing. — The center-to-center spacing shall be governed
by the larger of the spacings, required in this part, for the types
composing the pile.

SECTION 747.0. SPECIAL PILES AND CAISSONS

Types of piles or caissons not specifically covered by the
provisions of this code may be permitted provided sufficient
test data, design and construction information are filed for the
approval of the building official.

SECTION 748.0. LATERAL SUPPORT

748.1. Surrounding Materials. — Any soil other than water or
fluid soil shall be deemed to afford continuous lateral support
to any type of pile or pier. When piles are driven through soil
which will be removed subsequent to the completion of the [
foundation, the resistance offered by such material shall not be
considered to contribute to the lateral supporting capacity.

748.2. Lack of Support. — The portion of a pile or pier that
is not laterally supported shall be designed as a column in
accordance with section 842 taking into consideration the end
fixity conditions.

746-749

SECTION 749.0. FOUNDATION PIERS

A foundation pier is here, defined as a structural member
which extends to a satisfactory bearing material, and which may
be constructed in an excavation that afterwards is backfilled by
an approved method, or by filling the excavation with concrete,
or which may be built by sinking an open or pneumatic caisson.

749.1. Manner of Construction. — The manner of construction
shall be by non-displacement methods and shall permit in-
spection of the bearing material in place.

749.2. Base Enlargement. — The bases of foundation piers may
be enlarged by spread footings, pedestals or belled bottoms.
749.2.1. Belled Bases. — Bell-shaped bases shall have a minimum
edge thickness of four (4) inches. The bell roof shall slope not
less than sixty (60) degrees with the horizontal unless the base
is designed in accordance with sections 841 or 842.

749.3. Design of Piers. — Foundation piers may be designed as
concrete columns with continuous lateral support. The unit
compressive stress in the concrete at the least cross section
shall not exceed twenty-five (25) per cent of the twenty-eight
(28) day strength of the concrete nor eleven hundred (1100)
pounds per square inch.

749.3.1. — When the center of cross section of a foundation pier
at any level deviates from the resultant of all forces more than
one sixtieth (1/60) of its height or more than one tenth (1/10)
of its diameter, it shall be reinforced as provided in section
842. The restraining effect of the surrounding soil may be taken
into account.

749.4. Placement. — With approval of the building official, con-
crete may be placed through still water by means of a properly
operated tremie or pumped concrete.

749.5. Inspection. — The owner shall engage a competent in-
spector, qualified by experience and training and satisfactory
to the building official, to be present at all times while founda-
tion piers are being installed, to inspect and approve the bearing
soil and the placing of the concrete. The inspector shall make
a record of the type of bearing soil upon which the pier rests,
of the dimensions of the pier, and of the class of concrete used
in its construction. A copy of these records shall be filed in
the office of the building official.

RS7

REFERENCE STANDARD RS 7

List of Reference Standards

RS 7 AASHO 1965

Standard Specifications for Highway Bridges

AREA 1969

Specifications for Steel Railway Bridges

ASCE Paper No. 3269 1961

Wind Forces on Structures— 1961 Transactions of
the American Society of Civil Engineers, Vol. 126,
Part II

ASTM A252 1969

Specification for Welded and Seamless Steel Pipe Piles

ASTM D25 1958

Standard Specification for Round Timber Piles

AWPA CI 1968

Standard for the Preservative Treatment of all Timber

Products by Pressure Processes

AWPA C3 1969

Standard for the Preservative Treatment of Piles by

Pressure Processes

AWPA M2 1967

Standard for Inspection of Treated Timber Products

AWPA M4 1962

Standard for the Care of Pressure-Treated Wood

Products

ICBO 1967

Uniform Building Code, Vol. I, section 2314

Dead Load Requirements

Minimum Requirements for Uniformly Distributed
and Concentrated Live Loads

Minimum Wind Pressures for Height and Area
Locations

Required Nominal Thickness of Glass

RS 7-1 Dead Load Requirements

Categories PSF

Walls and Partitions (Unplastered)

Clay Brick (per inch thickness)

High absorbtion 8.5

Medium absorbtion 10.0

Low absorbtion 11.5

Concrete Brick (per inch thickness)

Lightweight aggregate 8.5

Heavyweight aggregate 11.5

Sand Lime Brick (per inch thickness) 9.5

Solid Concrete Block (per inch thickness)

Lightweight aggregate 6.5

Heavyweight aggregate 9.0

Hollow Concrete Block (per inch thickness)

Lightweight aggregate 5.0

Heavyweight 7.0

Solid Gypsum Block (per inch thickness) 6.0

Hollow Gypsum Block (per inch thickness) 3.5

Facing Tile (per inch thickness) 7.0

Glass Block (per inch thickness) 5.0

Clay Tile (per inch thickness)

Load bearing 6.0

Non-load bearing 5.0

Split Terra Cotta Furring Tile

(per inch thickness) 5.5

Wood Stud (2 inch x 4 inch) Unplastered 4.0

Combination Walls

8 inch brick and clay tile 60

12 inch brick and clay tile 80

8 inch brick and concrete block 72

12 inch brick and concrete block 90

RS7-1

Categories PSF

Walls and Partitions (Plastered)

Plaster work (to be added to values obtained
for unplastered walls above)

Gypsum (one side) 5

Cement (one side) 10

Gypsum on wood lath 8

Gypsum on metal lath 8

Gypsum on plaster board or fiber board 8

Cement on wood lath 10

Cement on metal lath 10

Gypsum, with sand aggregate, per inch 8.5
Gypsum, with lightweight aggregate, per

inch 4

Gypsum, with wood fibers, per inch 6.5

Cement, with sand aggregate, per inch 10
Cement with lightweight aggregate, per

inch 5
Lath and Plaster Partitions

2 inch solid cement on metal lath 25

2 inch solid gypsum on metal lath 18

2 inch solid gypsum on gypsum lath 18

2 inch metal studs gypsum & metal lath both
sides 18

3 inch metal studs gypsum & metal lath both
sides 19

4 inch metal studs gypsum & metal lath both
sides 20

4 inch wood studs plaster one side 12

4 inch wood studs plaster both sides 20
6 inch wood studs plaster & wood lath both

sides 18
6 inch wood studs plaster & metal lath both

sides 18
6 inch wood studs plaster & plaster boards,

both sides 18
6 inch wood studs unplastered gypsum board

both sides (dry wall) 10

Ceilings

Plaster on tile or concrete 5

Suspended metal lath & gypsum plaster 10

Suspended metal lath & cement plaster 12

Categories PSF

Plaster on wood lath

Suspended acoustical tile

Plaster board, unplastered

Plaster, 3/4 inch, and metal lath

Floor Finishes

Resilient flooring (asphalt tile, linoleum, etc.)

Asphalt block, 2 inch

Wood block, 3 inch

Hardwood flooring, per inch

Softwood subflooring, per inch

Plywood subflooring, per inch

Ceramic or quarry tile, 1 inch

Terrazzo, 1 inch

Slate, 1 inch

Cement, 1 inch

Solid flat tile on 1 inch mortar base

Cinder finish, per inch thick

Gypsum slab, per inch thick

Floor Fill

Cinder concrete, per inch thick

Cinder no cement, per inch thick

Sand per inch

Stone concrete, per inch thick

Roof and Wall Coverings

Clay tile (with mortar)

Clay tile (without mortar)

3-ply roofing and gravel

4-ply roofing and gravel

5-ply roofing and gravel

Aluminum, tin, or copper sheet

Insulation

Fiberglass per inch

1.5

Foam glass per inch

0.8

Urethane 1 inch

1.0

Urethane 2 inch

1.2

Cork per inch

1.0

Vegetable fiber boards per inch

1.5

Bats and blankets per inch

0.5

Fiberboard, per inch

1.5

Gypsum sheathing, per inch

4.0

Wood sheathing, per inch

3.0

RS7-1

Categories PSF

Wood shingles, in place 3.0

Asphalt shingles, in place 6

Asbestos-cement shingles, in place 4

Cement tile, 3/8 inch in place 16

Stucco (cement) per inch 10

Slate, 3/16 inch, in place 7

Slate, 1/4 inch, in place 10

Skylight, metal frame, 3/8 inch wire glass 10

Corrugated iron 2

Corrugated metal 2

Formed steel decking 3
Glass

Single strength 1.2

Double strength 1.6

Plate, wired or structured 1/8 inch 1.6
Insulating double 1/8 inch plates with air

space 3.5
Insulating double 1/4 inch plates with air

space 7.1

Miscellaneous Materials PCF

Cast stone masonry (cement stone sand) 144

Masonry ashlar

Granite 165

Limestone, crystalline 165

Limestone, oolitic 135

Marble ashlar 173

Sandstone ashlar 144

Masonry brick

Hard (low absorbtion) 140

Medium (medium absorbtion) 120

Soft (high absorbtion) 100

Masonry rubble mortar

Limestone crystalline 147

Limestone oolitic 138

Granite 153

Masonry dry rubble

Granite 130

Limestone (oolitic) 125

Marble 130

Sandstone (bluestone) 1 10

Categories PSF

Rubble stone masonry 156

Terra cotta architectural (filled) 120

Terra cotta architectural (unfilled) 72

Concrete, stone (plain) 144

Concrete, stone (reinforced) 150

Concrete, cinder 108

Fill, cinder 57

Earth (dry) 100

Earth (wet) 120

Cork (compressed) 14

Timber, ash 45

Timber, Douglas Fir 35

Timber, Cypress 35

Timber, hemlock 35

Timber, oak 45

Southern pine, short leaf 35

Southern pine, long leaf 35

Redwood 35

Spruce 35

Elm 45

Excavated earth 120

Quarried Stone 100
Bituminous Substances

Coal, anthracite 97

Coal, bituminous 84

Coal, lignite 78

Coal, charcoal 33

Coal, coke 75

Graphite 131

Paraffine 56

Petroleum 54

Petroleum, gasoline 42

Tar, bituminous 75

Steel 490

Iron 450

Water 62.5
Partition Loads

RS7-1

Equivalent Uniform Partition Loads

RS7-2

Partition Weight
(plf)

Equivalent Uniform Load (psf)
(To be added to floor dead and
live loads)

50 or less

51 to 100
101 to 200
201 to 350

Greater than 350

20 plus a concen-
trated live load
of the weight in
excess of 350 plf

RS 7-2 Minimum Requirements for Uniformly Distributed
and Concentrated Live Loads

Table A — Uniformly Distributed Live Loads

Occupancy or Use

Armories and Drill Spaces
Assembly Spaces:

Assembly Halls

Auditoriums

Churches

Court Rooms

Dance Halls

Exhibition Halls

Galleries

Gymnasiums

Lecture Halls

Lodge Rooms

Mess Halls

Museums

Passenger Stations

Restaurants _

Alleys (See Driveways and Yards)
Apartments (See Residential Areas)
Bakery
Balconies

Exterior

Interior and Mezzanines
Bowling Alleys (See Recreational Areas)
Catwalks

Class Rooms (See Schools)
Cornices

Live Load (PSF)

150

a) Fixed seating
— b) Movable seating
c) Other — See note b

a) 60 — See note a

b) 100

150

100
As required by use

Table A — Uniformly Distributed Live Loads

Occupancy or Use Live Loads (PSF)

Corridors

In schools (See Schools)

First floor all areas or uses, 100

Upper Floors (Same as that required for the
occupancy of the area being served, or as
noted herein)
Court Rooms (See Assembly Spaces)
Dance Halls (See Assembly Spaces)
Dormitories (See Residential Areas)
Dwellings (See Residential Areas)
Driveways and Yards

Pedestrian 100

Vehicular 250

Elevator Machine Rooms 100

Equipment Rooms (Mechanical and Electrical Equipment) 75
Exhibition Rooms (See Assembly Spaces)
Exitways 100

Fire Escapes 100

Garages

Passenger Cars 75

Trucks — Load 3 to 10 tons (Buses)

Columns 120

Beams 120

Girders 120

Floor Slab 175

Trucks — Load more than 10 tons (Buses) 250

Note: Design considerations for garages must
also include concentrated load require-
ment of Table B, and member selection
is to be based on resultant maximum
stress condition.
Grandstands, Reviewing Stands and Bleachers 100

Hospitals
Operating Rooms, Laboratories and Service Areas 60

Private Rooms, Wards, and Personnel Areas 40

X-Ray, Therapy and Similar Uses 75

Others (As Required by Use)
Hotels (See Residential Areas)
Ice Skating Rinks

Playing surface 250

Others (As Required by Use)
Libraries

Reading and Study Rooms 60

Stack Rooms 150(c)

Others (As Required by Use)
Lobbies and Similar Areas (All Buildings) '00

Locker Rooms 75

Loft Buildings !25

Laboratories (Scientific) ^®

Laundries 1*0

Manufacturing

Light 100

Heavy (Minimum as listed, but not less than
actual loads) 250

RS7-2
Table A — Uniformly Distributed Live Loads

Occupancy or Use Live Loads (PSF)

Repair Areas 100

Museums (See Assembly Spaces)

Marquees 75

Office Buildings

Office Rooms 50

Letter File Rooms 80

Card File Rooms 125

Open Parking Structures (See Garages)
Penal Institutions, Reformatories, Jails
Homes of Correction

Cell Blocks 40

Corridors 100

Plaza Areas (Open) accessible to the public

(including landscaped portions) 100

Public Dining Rooms (See Assembly Spaces)
Printing Plants

Press Rooms 150

Paper Storage (50 lb. per ft. of clear story height)
Others 100

Passenger Stations (See Assembly Spaces)
Recreational Areas
Bowling Alleys

Playing surface (excludes weight of machinery,

but includes construction of alleys) 75

Concourse 100

Others (As Required by Occupancy or Use)
Pool Rooms and Similar 75

Residential Areas
Apartments, Hotels, Motels, Tenements,

Guest Rooms, Living Areas, and Private Corridors 40
First Floor Corridors, Public Spaces and

Corridors serving public spaces 100

Public Corridors at Upper Floors 60

Dormitories

Partitioned Living Areas 40

Non-partitioned Living Areas 60

First Floor corridors, public spaces and

corridors serving public spaces 100

Public Corridors at Upper Floors 60

Dwellings

Multi-family units (Same requirements as those

for Apartments above)
One and two family units

First floor 40

Upper floors and habitable attics 30

Uninhabitable attics 20(b)

Rest Rooms

Serving places of Assembly 100

Others 50

Restaurants (See Assembly Spaces)
Roller Skating Rinks
Skating surface 100

Others (As Required by Occupancy or Use)

Table A — Uniformly Distributed Live Loads

Occupancy or Use Live Loads (PSF)

Sidewalks

250

Schools

Classrooms

Fixed seats

Movable seats

100

Corridors

100

Shops

Automotive and Press

100

Others

Others (As Required by Occupancy or Use of the

Area)

Stairs

100

Storage

Light

125

Heavy

250

Hay or Grain

300

Warehouse

150

Cold

No overhead system (250 psf plus 150 psf for

trucks)

With overhead system

Floor

150

Roof

250

Stores and Shops

Banking Rooms

100

Retail Sales

Heavy — all floors

125

Light — all floors'

100

Wholesale Sales

100

Telephone Equipment Rooms

Theaters

Balconies (As Required by Occupancy or Use)

Dressing Rooms

Lobbies, Corridors, Aisles

100

Orchestra Floors

Projection Rooms

100

Standing Space

100

Stage Floor

150

Notes:

a. Uniform load shall be applied to the gross floor area.

b. Live load need be applied to joists or to bottom chords of
trusses or trussed rafters only in those portions of attic space having
a clear height of 42 in. or more between joist and rafter in con-
ventional rafter construction; and between bottom chord and any
other member in trussed or trussed rafter construction. However,
joists or the bottom chords of trusses or trussed rafters shall be
designed to sustain the imposed dead load or using the formula
1000/net floor area per occupant, but shall not be less than 50
psf nor 10 psi, whichever is greater, uniformly distributed over the
entire span.

c. Minimum of 150 but not less than actual.

RS7-2

Table B — Concentrated Live Loads

Use or Location

Elevator machine room

floor
Gratings, checkered

plates and similar

metal decks
Floor registers and

similar floor insets

Garages

Passenger vehicles

Load (lbs.)

200 (on area

of 1.0 sq.

in.)
250 (on area

of 2 ft. x

2 ft.)

2,500 (on area
of 20 sq. in)

For slab or
deck design

1,500 (each
wheel)

Trucks, b

uses

150 per cent
of maximum

wheel load
with vehicle
loaded (on
area of 20
sq. in.)

Floor of office

2,000

areas

Resident and multi-

200 (on area

ple dwellii

igs

of 4.0 sq.

in.)

Scuttles and

sky-

200

light ribs

Steel joists —

■for

800 (for

each indiv

idual

trussed

joist

joists apply
at a panel
point)

Roofs

250 (on area
of 2 ft. x
2 ft.)

Remarks

See Reference Standard
RS 16

Nonconcurrent with uni-
form live load

The concentrated load
may be assumed to
represent the reaction
of a jack placed under
one end of the vehicle.
Omit uniform live load
in area (6 ft. x 9 ft.)
representing one half
the vehicle, adjacent
to the point of load
concentration.

To be used in lieu of
uniform live load in
stalls of mechanized
garages where there
is no slab or deck.

Same as for Garages —
Passenger Vehicles

Nonconcurrent with uni-
form live load

Nonconcurrent with uni-
form live load. Not
applicable, for aw-
nings, canopies, and
similar constructions
where access by per-
sons is difficult and
not intended.

Table B — Concentrated Live Loads

Use or Location

Stair and fire
escape treads

Boiler rooms

Remarks

Nonconcurrent with uni-
form live load

Load(lbs.)

300 (on area

1 ft. wide

by depth of

the tread

and spaced

at 3 ft.

center-to-
center)
3,000 The concentrated load

of 3,000 lbs. may be
assumed to represent
the weight of minor
items of equipment
(pumps, etc.) in tem-
porary locations dur-
ing installation. In ad-
dition provision shall
be made for support-
ing the weight of the
empty boiler at per-
tinent locations on the
floor to provide for
replacement of the
boiler.

Note a: Except when otherwise indicated loads are assumed to be
applied over an area 2-'/2 ft. x 2-'/2 ft.

RS 7-3 AASHO 1965

Standard Specifications for Highway Bridges

RS 7-4 AREA 1969

Specifications for Steel Railway Bridges

RS 7-5

RS7-3 RS7-6

Table of Minimui

m Wind Pressures

for Height and

Area Locations

Height in Feet

P in

lbs. per sq. ft.

to less than

25 to less than

50 to less than

100

100 to less than

150

150 to less than

200

200 to less than

300

300 to less than

400

400 to less than

500

500 to less than

600

600 to less than

700

700 to less than

800

800 to less than

900

900 to less than

1000

1000 and over

in ;

accordance with

sound engineering
principles approved
by the building
official

A. are the values of P for a structure on islands in
Boston Harbor (including former islands now
having causeways thereto).

B. are the values of P for a structure any part of
which lies within 800 feet of mean low water
line fas determined by mean low water at U. S.
Navy Yard at Charlestown).

C. are the values of P for every other structure.

RS 7-6 Required Nominal Thickness of Glass

The required nominal thickness of glass shall be deter-
mined from the chart within this reference standard.
The modified design wind load to be used as the
abscissa for entering this chart shall be determined
by dividing the appropriate general design wind load

from section 713 by the relative resistance value for
the glass type involved. For this purpose the relative
resistances to wind load for equal thicknesses of glass
shall be assumed as follows:

Relative
Glass Type Resistance

Regular Plate or Sheet 1.0

Laminated 0.6

Wired Glass 0.5

Heat Strengthened 2.0

Fully-Tempered 4.0

Rough-Rolled Plate 1.0

Sandblasted 0.4

Factory Fabricated Double Glazing (Use only the

thickness of the thinner of the two lights) 1.5

RS7-6

Required Nominal Thickness of Glass

2001

10 15 20 25 30 40 50 60 70 80 90 100

Modified Design Wind Load (Pounds per Square Foot)

This chart is based on minimum thicknesses allowed in Federal
Specification DD-G-451b

Design Factor - 2.5

RS 7-7

The allowable working stresses for ordinary materials
as defined in sections 701 and 722 shall be reduced
below the allowable values specified in Article 8 by
the amounts listed below. When the structural material
is identified in regard to manufacture and grade and
the identification is accompanied by satisfactory mill
tests or the strength and stress grade of the materials
are otherwise confirmed to the satisfaction of the
building official, the allowable working stresses may
be increased to comply with the provisions of Article 8.
10% Reduction

Reinforced Concrete Stresses Section 842

Reinforced Gypsum Concrete Stresses . Section 850

Steel Reinforcement Stresses Section 830

Structural Steel Stresses Section 827

Open-Web Steel Joist Stresses Section 829

Formed Steel Construction Stresses .... Section 828
Stresses for all materials not otherwise
noted in this reference standard

25% Reduction

Cast Steel Stresses Section 831

RS 7-8 ASTM A252 1969

Specification for Welded and Seamless Steel Pipe Piles

RS 7-9 AWPA CI 1968

Standard for the Preservative Treatment of all Timber
Products by Pressure Processes

AWPA C3 1969

Standard for the Preservative Treatment of Piles by

Pressure Processes

AWPA M4 1962

Standard for the Case of Pressure-Treated Wood

Products

AWPA M2 1967

Standard for Inspection of Treated Timber Products

RS 7-7 RS 7-12
RS 7-10 ASTM D25 1958

Standard Specification for Round Timber Piles

RS 7-11 ASCE Paper No. 3269 1961

Wind Forces On Structures — 1961 Transactions of
The American Society of Civil Engineers, Vol. 126,
Part II

RS 7-12 ICBO 1967

Uniform Building Code, Vol. I, Section 2314, "Earth-
quake Regulations"

MATERIALS AND TESTS

800.0

Scope

813.0

801.0

Definitions

814.0

802.0

Basic Classification of

815.0

Construction Materials

816.0

803.0

Tests

817.0

804.0

Conditions of Acceptance

818.0

805.0

Approvals

819.0

806.0

Masonry Construction Units

820.0

807.0

Brick Units

821.0

808.0

Structural Clay Tile Units

822.0

809.0

Glazed Masonry Units

823.0

810.0

Concrete Units

824.0

811.0

Gypsum Units

825.0

812.0

Structural Glass Block Units

826.0

ARTICLE

Architectural Terra Cotta

Natural Stone

Cast Stone

Mortar and Grout for Masonry

Concrete Aggregates

Ready-Mix Concrete

Structural Wood Glues

Interior Lathing and Plastering

Exterior Lathing and Stucco

Plastering Materials

Plaster Bases

Fiber Boards

Plywood

Wall Boards and Sheathing

TABLE

8-1 816.2.1. Mortar Proportions (Parts by Volume)

SECTION 800.0, SCOPE

The provisions of this article shall govern the quality, work-
manship and requirements for all materials and methods and
the minimum specifications for enclosure walls and wall thick-
ness hereafter used in the construction of buildings and structures.
All materials and methods of construction shall conform to the
approved rules, the standards for materials and tests of approved
authoritative agencies, the requirements of accepted engineering
practice and the certification requirements of reference standard
RS 8-60 as herein specified.

800.1. Accepted Engineering Practice. — The quality, use and
installation of all materials and methods of building construction
shall be controlled by the standards of accepted engineering
practice as listed in reference standard RS 8, except where other-
wise specifically provided in this code.

800.2. Material Standards. — All building units used in wall,
partition and floor construction and for fireproofing or other
insulation purposes shall comply with the applicable standards
listed in reference standard RS 8.

800.3. New Materials. — All new building materials, equipment,
appliances, systems or methods of construction not provided for
in this code, and any material of questioned suitability proposed

for use in the construction of a building or structure, shall be
subjected to the tests prescribed in this Code and in the ap-
proved rules to determine its character, quality and limitations
of use.

800.4. Used Materials. — The use of all second-hand materials
which meet the minimum requirements of this code for new
materials shall be permitted.

800.5. Alternate Test Procedure. — In the absence of approved
rules or other accepted standards, the building official shall
make or cause to be made the necessary tests and investigations,
or he may accept duly authenticated reports from recognized
testing authorities in respect to the quality and manner of use
of new materials as provided in section 116. The cost of all
tests and other investigations required under the provisions of
this code shall be borne by the applicant.

SECTION 801.0. DEFINITIONS

For definitions to be used in the interpretation of this article,
see section 201.0.

SECTION 802.0. BASIC CLASSIFICATION OF CONSTRUC-
TION MATERIALS

All materials and methods used in the design and construction
of buildings and structures shall be classified as controlled
materials or ordinary materials as defined in sections 201 and
722. The design procedures and construction shall be based on
the assumptions, limitations and methods of stress determination
of the specified reference standards.

SECTION 803.0. TESTS

All structural units and assemblies unless approved or other-
wise provided for in this code shall be tested in accordance
with the appropriate Reference Standard specified in this Code
for the particular unit or assembly. Also, the building official
may require reasonable tests from time to time similarly con-
ducted to determine quality or conformance with the provisons
of this Code. In the absence of test procedures governing any
specific material or method of construction, the building official
shall either accept authenticated reports from approved recog-

800-803

nized authoritative sources which meet the requirements of this
code or shall specify the method and manner of making the
test.

803.1. Strength Tests. — To determine the safe uniformly dis-
tributed working load, when not capable of design by accepted
engineering analysis, or to check the adequacy of the structural
design of an assembly when there is reasonable doubt as to its
strength or stability, every system of construction, sub-assembly
or assembled unit and its connections shall be subjected to
strength tests prescribed in this code, or to such other tests
acceptable to the building official that simulate the loads and
conditions of application that the completed structure will be
subjected to in normal use. Structural load determinations shall
include but not be limited to consideration of transverse floor
and roof loading, wall compression and racking, concentrated
loads, plaster bond as affected by deflections, puncture pene-
tration of materials and assemblies as specified in section
804.6, and soil tests.

803.1.1. Strength Tests for Glass. — The working strength of
glass for any location in which it is required to withstand
specific loads shall be determined as provided in reference
standard RS 7-6.

803.2. Durability and Endurance Tests. — Whenever required by
the building official or specified herein or in the approved rules,
the material or construction shall be subjected to approved
testing procedures to determine resistance to fatigue, durability,
and weather resistance. These procedures may include subjecting
the material or construction to sustained and repetitive loading
as a measure of its resistance to fatigue.

803.3. Maintenance Test. — In addition to durability and endur-
ance tests, tests of all materials shall be made to assure the
maintenance of the standards of approved materials when
reasonable doubt exists as to quality and when required by
the building official.

803.4. Workmanship Test. — Whenever there is reasonable doubt
as to the stability or structural safety of a completed building or
structure or part thereof for the intended occupancy, the building
official may require a load test of the building unit or portion
of the structure in question. Such existing structure shall be sub-
jected to its own dead load plus a superimposed load equal to
one-half (0.5) times the dead load plus one and eight-tenths
(1.8) times the live load (applied test load equals 0.5D ■+■ 1.8L),

or to a load causing a stress equal to eighty (80) per cent of
the yield point of the constituent materials whichever is less. The
test load shall be left in place for a period of twenty-four (24)
hours. If during the test, or upon removal of the test load, the
structure shows evidence of failure, the building official shall
order such reinforcement or modifications deemed necessary to
insure adequacy of the structure for the rated capacity; or in lieu
thereof, he may specify a reduced working load to which the
structure shall be limited. The structure shall be considered to
have successfully met the test requirements if the total deflection
does not exceed the theoretical deflection computed by accepted
engineering formulae. When the total deflection is greater than
such theoretical value, the structure shall be considered safe for
the design load, if it recovers seventy-five (75) percent of the
maximum deflection within twenty-four (24) hours after removal
of the test load. This provision shall in no way relieve com-
pliance with the maximum permissible deflection limitations
under working loads allowed by this code.

803.5. Tests of Service Equipment and Devices. — Tests of
service equipment and accessories shall include proscenium cur-
tain and stage ventilation, article 4; structural load tests, article
7; flues and chimneys, article 10; boilers, article 11; sprinkler
and standpipe equipment, article 12; electric installations, article
15; moving stairways, elevator interlocks and safety devices,
article 16; refrigerating equipment, article 18; plumbing systems
and devices as required by article 17 and all other service tests
required by the approved rules.

803.6. Fire Tests. — In the determination of flash points, com-
bustibility, flameresistance and fireresistance of construction
materials and methods, all tests shall be conducted in con-
formity to sections 903 and 904.

803.7. Prefabricated Construction Tests. — Prefabricated assem-
blies or sub-assemblies not capable of design by accepted
engineering analysis, shall meet all the requirements and tests
for at-site construction. The floor panels and other prefabricated
units shall be assembled to form an integrated test specimen
constructed as in practice, of not less than three (3) units in
width with two (2) longitudinal joints; and when designed on the
assumption of a simple span, such units shall be tested with
flat end supports.

803.8. Test Specimens. — The selection and construction of all
test specimens and the details of test procedure herein required

803-804

shall conform to the recognized test procedures listed in the
reference standards. All test specimens and constructions shall
be truly representative of the materials, workmanship and details
to be normally applied in practice. When structural or fire-
resistive properties of the material are dependent upon adequate
curing, the age of the concrete compression test specimens shall
be not less than seven (7) nor more than twenty-eight (28) days
and as required by reference standard RS 9-2 for fireresistive
properties, unless otherwise approved by the building official.
803.9. Conditions of Support and Loading Interaction. — Load
tests shall be performed in such a manner that the supports for
the members or assemblies being tested will simulate the condi-
tions of support in the building, except that conditions of
partial fixity may be approximated by condition of full or zero
restraint, whichever produces a more severe stress condition in
the member being tested. The test conditions shall be such as to
obviate all interaction of fills, finishes, partitions, supports, or
members whose interaction normally would be neglected in
design. Where continuous, multiple, intersecting, or connected
members are used in the test, all interacting members shall be
simultaneously and fully loaded and additional tests shall be
performed under partial live loading as necessary to produce
maximum stresses.

SECTION 804.0. CONDITIONS OF ACCEPTANCE

Where, because of practical difficulties, design calculations for
the strength or deflection characteristics of a member or assem-
bly cannot be executed, its evaluation may be based on load
tests performed and evaluated in accordance with the require-
ments of this article. These provisions shall apply only to load
tests made to assist in establishing the structural adequacy of
members or assemblies before their incorporation into the
structure. Load tests to establish the adequacy of construction
already in place shall conform to the requirements of section
803.4.

804.1. Test Load Factor.

a. The test specimen shall sustain for a period of twenty-
four (24) hours, without visible damage other than hair-
line cracks, its own weight, plus a superimposed test
load equal to the dead load to be added at the site

plus one hundred fifty (150) percent of the design live
load.

b. After completion of the test required by section 804.1. a.
and removal of all superimposed loads, the recovery
of deflection within twenty-four (24) hours shall be at
least seventy-five (75) percent of the deflection due
to the superimposed loads.

c. The test specimen shall sustain without collapse its own
weight, plus a superimposed test load equal to fifty (50)
percent of its weight plus one hundred fifty (150) per-
cent of the dead load to be added at the site, plus two
hundred fifty (250) percent of the design live load.

804.2. Working Load Deflection. -The deflection properties
of the member or assembly under working loads shall conform
to the applicable requirements of this Code and the reference
standards, as well as to any special requirements of the job
specifications. Such deflections may be predicted on the basis
of short-time tests, plus a suitable allowance, approved by the
building official, for the effects of shrinkage and creep.

804.3. Wall and Partition Assemblies. — Bearing wall and parti-
tion assemblies shall sustain the load test both with and without
window framing.

804.4. Comparative Tests. — When not available from existing
authoritative test data, the building official may require com-
parative tests of assemblies of standard traditional forms of
construction used for similar purposes to assist in determining
the adequacy of the new construction.

804.5. Concentrated Load Tests. — When not capable of design
all floor construction in the occupancy or use classification
groups specified in reference standard RS 7-2, Table B shall be
subjected to the concentrated loads therein prescribed when such
loading causes stresses greater than the uniformly distributed
load specified for such occupancies or uses in reference standard
RS 7-2 Table A.

804.6. Puncture Penetration Tests. — All finish floor constructions
in which light gage metal or other thin materials are used as the
structural floor shall withstand the application of a two hundred
(200) pound concentrated load applied to the top surface on an
area of one (1) square inch at any point or points of the con-
struction designated by the building official.

804-806
SECTION 805.0. APPROVALS

805.1. Written Approval. — Any material, appliance, equipment,
system or method of construction meeting the requirements of
this code shall be approved by the building official in writing
within a reasonable time after satisfactory completion of all
required tests and submission of required test reports.

805.2. Approval Record. — Whenever any material, appliance,
equipment, system or method of construction shall have been
approved by the building official, a record of such approval,
including all the conditions and limitations of its permitted use,
shall be kept on file in his office and shall be open to public
inspection during business hours.

805.3. Identification of Product. — When identification of a
material is necessary for structural safety, the approved material
shall be identified by the approved label and the grade mark,
trademark or other manufacturer's identification for which
official recognition is desired. A drawing of the identification
marks shall be filed with the building official and kept in the
official records.

805.4. Heretofore Approved Materials. — The use of any material
already fabricated or of any construction already erected, which
conformed to requirements or approvals heretofore in effect,
shall be permitted to continue, if not detrimental to life, health
or safety of the public.

SECTION 806.0. MASONRY CONSTRUCTION UNITS

The quality of materials assembled in masonry and the method
and manner of their assembly shall be suitable for their use and
shall conform to the minimum requirements of reference standard
RS 8.

806.1. Identification. — The materials entering into masonry shall
be classified for the purposes of this code as follows:

Brick

Structural Clay Tile

Glazed Masonry Units

Concrete Units

Gypsum Units

Structural Glass Block Units

Architectural Terra Cotta

Natural Stone

Cast Stone

Mortar for Masonry

A material of masonry other than those classified in this article,
which is incombustible and otherwise sufficiently embodies the
characteristics of one of the materials here classified, and which
satisfies the requirements of this article for that material may be
included by the building official in the classification of that
material which is most closely resembles.

806.2. Nominal Dimensions. — Dimensions and thicknesses speci-
fied herein are nominal dimensions; actual dimensions may
vary from the prescribed minimum in accordance with accepted
tolerances in the building industry.

806.3. Second-Hand Units. — Brick and other second-hand mason-
ry units may be reused subject to the requirements of this
code as to quality, condition and compliance with the require-
ments for new masonry units. The unit shall be good, whole,
sound material, free from cracks and other defects that would
interfere with its proper laying or use; and shall be cleaned free
from old mortar before reuse.

SECTION 807.0. BRICK UNITS

All clay, shale and sand-lime brick shall be selected on the
appropriate grade specified by reference standards RS 8-1 and
RS 8-2. See Section 810.0 for concrete brick. The minimum
grade permitted for brick in contact with the ground and sub-
ject to water, frost and freezing action shall be grade SW; when
subject to frost without danger of water saturation, grade MW;
and when not subject to weathering or when used as back-up
in exterior walls or for interior construction, grade NW. Under-
burned clay brick shall not be used in isolated brick piers,
nor in a bearing wall which is more than forty (40) feet in
height. Brick for fire protection, fireresistive walls or fire stop-
ping shall be of grade MW or better.

SECTION 808.0. STRUCTURAL CLAY TILE UNITS

Structural clay tile shall consist of well burned hollow units of
clay or shale classified for use as load bearing wall tile, floor
tile, or fireproofing and non-load bearing partition tile.
808.1. Load Bearing Wall Tile. — Structural clay load bearing
wall tile shall be classified for physical quality as grade LBX
or grade LB and shall be in conformance with reference standard
RS 8-4.

806-810

808.2. Floor Tile. — Structural clay floor tile shall be classified
for physical quality as grade FT1 or grade FT2 and shall
conform to reference standard RS 8-6.

808.2.1. Arches. — Structural clay floor tile used in floor and
roof arches shall be at least grade FT2.

808.3. Fireproofing and Non-Load Bearing Partition Tile. —
Structural clay non-load bearing tile, used for partitions, fire-
proofing, and furring shall be classified as grade NB and shall
conform to reference standard RS 8-5.

808.3.1. Fireresistance. — Structural clay tile in fire resistive
construction shall be of grade NB or better, and shall conform
to the requirements of section 221.1 Table 2-1.

808.4. Exposure. — Any structural clay tile exposed to the weather
shall be at least of grade LBX.

SECTION 809.0. GLAZED MASONRY UNITS

Structural clay load-bearing facing tile, facing brick, and other
solid masonry units made from clay, shale, fire-clay, or mixtures
thereof having a finish consisting of a ceramic glaze shall be in
conformance with reference standard RS 8-7.

SECTION 810.0. CONCRETE UNITS

Concrete units as classified in this code shall include concrete
bricks, solid load bearing units, hollow load bearing units and
hollow non-load bearing units of concrete made from Portland
cement, water and suitable aggregates, such as sand, gravel,
crushed stone, bituminous or anthracite cinders, expanded clay
or shale and blast furnace slag. The materials shall conform to
the specific reference standards herein noted except that cinder
aggregate for concrete blocks shall contain not more than twenty
(20) per cent of combustible matter.

810.1. Quality. — Cast concrete units shall be of sound, compact
structure, uniform in shape and free from cracks, warpage or
other defects that would impair their serviceability or strength
when laid in the wall.

810.2. Hollow Load Bearing Units. — Hollow load bearing
concrete units shall conform to reference standard RS 8-8 and
when used unprotected below grade or unprotected against the

weather by stucco, brick or other approved facings or veneers
shall be grade U; when used protected below grade or pro-
tected exterior subject to frost action, grade P or better; for
interior and protected exterior use not subject to frost action,
grade G or better.

810.3. Hollow Non-Load Bearing Units. — Hollow non-load
bearing concrete units shall conform to reference standard RS 8-9
and may be used in non-load bearing interior partitions and
non-load bearing exterior walls where effectively protected from
the weather.

810.4. Solid Load Bearing Units. — Solid load bearing units shall
conform to reference standard RS 8-10 and when used unpro-
tected below grade or unprotected against the weather by stucco,
brick or other approved facings or veneers shall be grade U;
when used protected below grade or protected exterior subject
to frost action, grade P or better; for interior and protected
exterior use not subject to frost action, grade G or better.

810.5. Concrete Brick. — Concrete brick shall conform to refer-
ence standard RS 8-3 and when exposed to severe frost action
shall be grade U; when exposed to moderate frost action shall
be grade P or better; and when used in backup or interior
masonry, or where effectively protected against moisture pene-
tration, grade G or better.

810.6. Concrete Fireproofing and Furring Units. — Concrete units
may be used for fireproofing or furring when graded for wea-
thering according to this section except that the exterior use of
hollow non-load bearing units shall not be permitted for fire-
proofing purposes. All non-load bearing units shall be clearly
marked to distinguish them from load bearing units.

810.7. Concrete Floor Tile.

810.7.1. Structural Fillers. — Structural concrete filler-block or
tile when included in strength calculations in ribbed floor
construction shall have webs and shells not less than one (1)
inch thick and shall develop an average compressive strength
on the net area not less than that of the rib concrete.

810.7.2. Other Fillers. — Removable tile and permanent fillers
which are not included in strength calculations shall be of
adequate strength to insure integrity of the unit and safety in
handling as approved by the building official.

810-815
SECTION 811.0. GYPSUM UNITS

A gypsum building unit in the form of tile or block for use in
non-loadbearing construction in the interior of buildings and for
the protection of columns, elevator shafts, etc., against fire shall
conform to reference standard RS 8-11.

811.1. Use. — Gypsum tile or block shall not be used in load
bearing masonry, in masonry exposed to weather or soil, nor
in masonry exposed to frequent or continuous wetting. Gypsum
partition tile or block shall not be used for partitions to receive
Portland cement plaster, ceramic tile, marble or structural glass
wainscots unless self-furring metal lath is placed over the gypsum
tile.

SECTION 812.0. STRUCTURAL GLASS BLOCK UNITS

Glass block may be solid or hollow. All mortar bearing sur-
faces of the block shall be precoated or prepared to insure
adhesion between mortar and glass. Glass blocks shall not be
used in fire walls, party walls or fire division walls, or for load-
bearing construction.

SECTION 813.0. ARCHITECTURAL TERRA COTTA

All approved architectural terra cotta units shall be formed
with a strong, homogeneous body of hard-burned, weather-
resisting clay which gives off a sharp, metallic ring when struck.
All units shall be formed to engage securely with and anchor
to the structural frame or masonry wall, and shall conform to
reference standards RS 8-4 and RS 8-5.

SECTION 814.0. NATURAL STONE

Natural stone for masonry shall be sound, free from loose or
friable inclusions; and shall have the characteristics of strength,
durability, fire resistance, and resistance to impact and abrasion
commensurate with the proposed use. Sandstone in masonry ex-
posed to the weather shall be laid with its natural bed horizontal.

SECTION 815.0. CAST STONE

815.1. Description. — Cast stone shall be precast of Portland

cement, aggregates, and water with or without admixtures, or
strength, durability, and fire-resistance commensurate with its
proposed use, and in accordance with reference standard RS 8-12.

815.2. Limitations. — The intended use for cast stone shall be as
a trim, veneer, or facing on a structure with no unit dimension
in excess of eighteen (18) inches. Cast stone shall not project
more than six (6) inches beyond its supporting material. Cast
stone shall have reinforcing as required for reinforced concrete
with no less than three (3) inch damp-proofing protection of
the reinforcing.

815.3. Strength. — The minimum compressive strength of cast
stone when delivered to the building site shall be sixty-five
hundred (6,500) pounds per square inch when tested as three-
inch by three-inch (3" x 3") cylinders or two-inch by two-inch
(2" x 2") cubes.

The average water absorption of cast stone when delivered to
the building site shall be not more than six (6) percent by dry
weight of the specimens when tested as three-inch by three-inch
(3" x 3") cylinders or two-inch by two-inch (2" x 2") cubes.

815.4. Exceptions. — Other precast concrete, whether fabricated
at factory or site, not in compliance with the preceding shall
be in conformance with section 1912.0.

SECTION 816.0. MORTAR AND GROUT FOR MASONRY

816.1. Materials. — All Portland, natural and masonry cements,
quicklime and hydrated lime for use in masonry mortar and
grout shall meet the minimum strength and durability require-
ments of reference standards RS 8-13 thru RS 8-17. Masonry
shall be laid in mortar, except plain concrete, plain gypsum
concrete, stone masonry in underwater masonry, and retaining
walls not in buildings which may be laid without mortar.

816.2. Mortar Types and Proportions. — Mortar for masonry
construction shall conform to one (1) of the following types and
shall be mixed to a consistent workability in the specified
proportions measured by volume with clean fresh water free
from harmful amounts of acids, alkalis, oils or organic materials;
and with approved aggregates composed of hard, strong, durable
mineral particles well graded from fine to coarse, free from
injurious amounts of acids, alkalis, oils, saline, organic and other

815-816

deleterious substances. Masonry mortars shall have a flow after
suction of not less than seventy (70) percent, and shall conform
to reference standard RS 8-18 and the following table:

816.2.1. Table 8-1

Mortar Proportions (Parts by Volume)

Masonry Hydrated Lime Damp

Mortar Portland Cement or Lime Putty Loose

Type Cement Type II Min. Max. Aggregate

Ml — — 1/4

1 1 — —

s l ~ l / 4 l / 2 Not less than 2-

*/2 * ~~ ~~ 1/4 and not more

N 1 - 1/2 1-1/4 than 3 times the

— 1 — — sum of the vol-

O — 1 — — umes of thecem-

1 — 1-1/4 2-1/2 ents and lime used.

Grout shall conform to reference standard RS 8-19.

816.2.2. Lime Putty. — Lime putty shall be made by slaking to
a smooth paste fresh and properly burned quicklime. The resul-
tant paste shall be stored in a suitable box or other receptacle
for not less than forty-eight (48) hours before being mixed with
sand. Hydrated lime may be substituted in equivalent amount
for lime putty.

816.3. Types of Mortar Permitted. — Unit masonry shall be laid
in mortar of the following types:
Type of Masonry Types of Mortar Permitted

Masonry in contact with earth M or S

Grouted and filled cell masonry M or S

Masonry above grade or interior masonry:

Piers of solid units M, S or N

Piers of hollow units M or S

Walls of solid units M, S or N

Walls of hollow units M, S or N

Cavity walls and masonry bonded
hollow walls:

Design wind pressure exceeds 20 psf M or S
Design wind pressure 20 psf or less M, S or N

Type of Masonry

Types of Mortar Permitted

Glass block masonry
Nonloadbearing partitions and fire-
proofing
Gypsum partition tile or block
Fire brick

Linings of existing masonry, above or

below grade
Masonry other than above
NOTE:

S or N

M, S, N, O or Gypsum

Gypsum

Refractory air-setting

mortar

M or S
M, S or N

Mortar or grout under metal bases of columns or
beams resting upon concrete shall be made without
lime.

816.4. Special Mortars. — The building official may approve other
special masonry mortars in place of the mortar types listed in
section 816.2, provided they develop the minimum compressive
strengths specified for the respective mortars they replace. The
strength classification of a special mortar or special mix may be
determined by compressive strength tests with the materials and
in the proportions representative of those to be used in actual
practice. In no case shall the allowable unit working stresses
in the masonry be more than one-fourth (1/4) the average
ultimate compressive strength of the assembled test samples.

816.5. Gypsum Mortar. — Gypsum mortar shall be composed of
one (1) part of unfibered calcined neat gypsum to not more
than three (3) parts sand by weight. Only gypsum mortar shall
be used with gypsum tile and block units. Gypsum shall con-
form to reference standard RS 8-20.

816.6. Mortars for Ceramic Wall and Floor Tile. — Mortars for
installing ceramic wall and floor tile shall be of the following
composition measured by volume:

1/3 hydrated lime: 4 sand
1/2 hydrated lime:

sand
sand

Walls: Scratch coat — 1 cement

Setting bed and

Leveling coat — 1 cement
Floors: Setting bed — 1 cement
Ceilings: Scratch coat and

Setting bed — 1 cement
or other mortars of comparable adhesive strength and durability,
in accordance with reference standard RS 8-21.

1/2 hydrated lime: 3 sand

816-817
816.6.1. Dry-Set Portland Cement Mortars. — Dry-set Portland
Cement Mortars to be used in the installation of ceramic tile
shall be in accordance with standard specification for dry-set
Portland cement mortar listed in reference standard RS 8-22.
816.7. Organic Adhesives. — Organic adhesives to be used in
installing ceramic tile shall have a shear bond strength in accor-
dance with commercial standard for adhesives for installations
of clay tile listed in reference standard RS 8-23.

SECTION 817.0. CONCRETE AGGREGATES

817.1. Aggregate Quality. — All concrete aggregates shall conform
to reference standards RS 8-24 and RS 8-25 for organic im-
purities, soundness, mortar strength, durability, weather-resist-
ance, fireresistance, and wearing qualities. In addition, coarse
aggregate subjected to the test for organic impurities showing
a color darker than two-thirds (2/3) the intensity of the standard
color shall be rejected.

817.2. Fireresistance. — Coarse aggregate in concrete shall be
rated in respect to the fireresistance of concrete made therewith
on the basis of performance in fire test on building elements
such as columns, floors, partitions and walls conducted in
accordance with standard fire test specifications applicable to
such test. Protective coverings of encasements of concrete for
steel in fireresistive construction shall likewise be selected on the
basis of performance in applicable standard fire tests. All con-
crete constructions shall meet the requirements of article 9 as
regulated by the provisions of section 221.1. table 2-1.

817.2.1. Grade 1 Concrete. — Grade 1 concrete shall mean
concrete made with aggregates such as blast-furnace slag, expanded
clays, and calcareous, igneous, and most silicate crushed stones
and gravels and shales, as well as any other aggregates performing
as required by this code, for the appropriate construction when
tested in accordance with standard methods of fire tests of
building construction and materials as controlled by section
903.0.

817.2.2. Grade 2 Concrete. — Grade 2 concrete shall mean con-
crete made with aggregates such as cinders and crushed stones
and gravels composed essentially of quartz and quartzite cherts
as well as any other aggregates performing as required by this
code for the appropriate construction when tested in accordance

with standard methods of fire tests of building construction and
materials as controlled by section 903.0.

817.3. Size of Aggregates. — Fine aggregates shall be well graded
from fine to coarse and shall conform to reference standards
RS 8-24 and RS 8-25. Coarse aggregates shall not exceed one-
fifth (1/5) of the narrowest dimension between sides of the form
nor three-fourths (3/4) of the minimum clear spacing between
reinforcing bars, and shall conform to reference standards
RS 8-24 and RS 8-25.

817.4. Special Aggregates. — Special aggregates, including among
others, perlite, vermiculite and other processed mica, pumice,
lava, tufa, volcanic glass, slag, coke, expanded clay and shale
used in concrete and plaster construction shall meet all the
requirements of the approved rules and shall be classified in
their respective fireresistant grades as determined by test. When
used for fire protection purposes only, the building official may
waive mortar strength requirements for such aggregates providing
the concrete is shown by test to have adequate strength for the
intended use.

SECTION 818.0. READY-MIX CONCRETE

818.1. Control. — Ready-mix concrete for use in ordinary or in
controlled materials procedure shall conform to reference standard
RS 8-26 and other appropriate portions of section 842 for
reinforced concrete.

818.2. Transportation. — Ready-mix concrete shall be transported
in approved conveyances which insure delivery of the concrete
at the site in a plastic, workable and unhardened state. The
maximum amount of concrete hauled in an agitator shall not
exceed the approved rating of the conveyance; and the period
of delivery shall not exceed the time in which loss of plasticity
may occur and generally not more than one and one-half (1-1/2)
hours, after either the introduction of the mixing water to the
cement and aggregates, or the introduction of the cement to the
aggregates.

818.3. Ordinary Materials Procedure. — When ready-mix is used
under the ordinary materials procedure, either the cement con-
tent in bags per yard of concrete together with the maximum
allowable water content, or the compressive strength and maxi-
mum permissible slump shall be specified. In no case shall the
cement factor and water cement ratio violate the requirements

817-821

of tables RS 8-45-1 or RS 8-45-2 of reference standard RS 8-45,
nor shall the specified or required twenty-eight (28) day compres-
sive strength (f'c) exceed four thousand (4,000) psi.

SECTION 819.0. STRUCTURAL WOOD GLUES

819.1. Quality of Glue. — Glues used in structural assemblies of
built-up or laminated lumber sections shall develop the full
strength of the wood, shall not produce decomposition or
deleterious chemical reaction in the wood structure, shall not be
attractive to vermin and shall conform to reference standard
RS 8-27.

819.2. Manufacturer's Requirements. — Approved structural glues
shall be handled, mixed and applied as prescribed by the
manufacturer and the gluing shall be done only in accordance
with the timber construction standards listed in reference standard
RS 8-27.

819.3. Types of Glue. — Structural glues shall be classified as dry
use and wet use in conformance with reference standard RS 8-27.

SECTION 820.0. INTERIOR LATHING AND PLASTERING

All interior lathing and plastering shall conform to the standards
for lathing, furring and accessories and gypsum and Portland
cement plastering listed in reference standard RS 8-28 through
RS 8-32 except as may be otherwise provided in this Code
for specific materials.
820.1. Installation.

820.1.1. Inspection. — The building official shall be notified not
less than twenty-four (24) hours in advance of all plastering
work, and no plaster shall be applied until after the lathing
or other plaster base has been inspected and approved by him.

820.1.2. Weather Protection. — When plastering work is in
progress, the building or structure shall be temporarily enclosed
and in freezing weather the enclosure shall be heated to protect
the plaster from injury.

SECTION 821.0. EXTERIOR LATHING AND STUCCO

All exterior lathing, plastering and stucco work shall be installed
of Portland cement or other approved mortar as provided in

the reference standard RS 8-32 or as provided in this Code
for specific materials.

821.1. Reinforcement. — All stucco work shall be reinforced
with approved metal lath or wire fabric except when applied
directly to a masonry or concrete base, or when installed on a
masonry base which is protected with bituminous surfacing.

821.2. Minimum Weight. — Metal lath, expanded metal and
wire reinforcing fabric shall weigh not less than the following:

Minimum Weight

Type of

Minimum

Maximum

Pounds per

Enforcement U.S. Gage

Mesh Inches

Square Yard

Metal lath

—

3.4

Expanded metal

—

1.8

Woven wire . . .

1.74

Woven wire . . .

1-1/2

1.41

Woven wire . . .

1.47

Welded wire . . .

4 sq. in.

0.67

Welded wire . . .

4 sq. in.

0.82

Welded wire . . .

4 sq. in.

1.10

821.3. Corrosion Resistance. — All metal lath and stucco rein-
forcing fabric shall be protected with a zinc, or other approved
rust-resistive coating or rust-inhibitive paint, or shall be manu-
factured from approved corrosion-resistive alloys.

821.4. Sheathing. — Except in back-plastered construction, the
studs shall be covered with approved sheathing complying with
section 855; or not less than No. 18 U.S. gage galvanized wire
shall be stretched horizontally at six (6) inch centers and shall
be covered with not less than fourteen (14) pound waterproof
felt or paper before applying the reinforced stucco; or an
approved paperbacked wire fabric may be used of not less
than No. 16 U.S. gage galvanized wire with stiffening ribs not
more than five (5) inches on centers to which is attached a
double layer or fibrous waterproof backing. The mesh opening
shall not exceed two by two (2 x 2) inches.

821.5. Back-Plastered Construction. — In back-plastered construc-
tion, when spacing of studs exceeds sixteen (16) inches, approved
horizontal noncombustible cross-furring at not more than sixteen
(16) inch centers shall be first applied; unless approved stiffened
lath is used and the frame is adequately stiffened as provided in
section 855.

821-822

821.6. Application on Masonry Base. — When applied directly to
masonry or monolithic concrete, the surfaces shall be com-
pletely roughened, hacked or bush-hammered to provide bond,
and a preparatory dash coat of Portland cement grout shall be
applied. The dash coat shall be kept damp for at least two (2)
days after application and before applying succeeding stucco
coats.

821.7. Protection.

821.7.1. From Freezing. — At all times during application and for
a period of not less than forty-eight (48) hours after application
of each coat, provisions shall be made to keep stucco work
above fifty (50) degrees F.

821.7.2. From Moisture. — Stucco shall be kept a sufficient
height above ground surfaces as provided in section 855 and all
sills, coping and projecting courses shall be flashed and provided
with drips as therein specified.

821.7.3. From Rapid Drying. — Stucco shall be protected from
heat, sun, and wind for the first forty-eight (48) hours to
prevent premature drying.

SECTION 822.0. PLASTERING MATERIALS

All sand, quick-lime, hydrated lime, hair binder, gypsum, Keene
and Portland cements, Pozzuolanic cements and aggregates and
other materials used in plastering shall be stored, protected and
applied in accordance with reference standards RS 8-33, RS 8-16,
RS 8-32 and RS 8-13.

822.1. Special Cements and Plasters. — Approved cements used in
plastering may have admixtures of approved plasticity agents
added in the manufacturing process or when mixing the plaster
at the site in the approved proportions. All premixed special
plasters, cements and aggregates shall be packaged and identified
with the approved label.

822.2. Lime Piaster. — Lime and hydrated lime plasters for use
in base and finish coats shall be applied in accordance with
reference standard RS 8-30 and the manufacturer's specifications.

822.3. Gypsum Plaster. — All gypsum plaster shall comply with
reference standard RS 8-28. Gypsum plaster shall not be used
on exterior surfaces.

822.4. Gypsum Plasters with Special Aggregates. — When gypsum
is used with manufactured aggregates in place of natural sand

for plaster, the mixture shall be proportioned and applied in
accordance with the manufacturer's recommendations and refer-
ence standards RS 8-28 and RS 8-31.

SECTION 823.0. PLASTER BASES

823.1. Fiber Boards. — Approved fiber boards used as plaster ^
bases shall comply with section 824. The surface of such boards
shall be of a rough, fibrous texture to insure mechanical and
suction bond; and the boards shall meet the bond and strength
tests specified by reference standard RS 8-34.

823.2. Gypsum Lath. — Except when greater thickness is required
for fireresistance under the provisions of article 9, or as herein ,
specified, gypsum lath used for plastering shall be not less than
three-eights (3/8) inch thick and shall comply with reference
standard RS 8-35.

823.3. Perforated Gypsum Lath. — Where required to provide
specified time-temperature performance, perforated gypsum lath
shall be not less than three-eight (3/8) inches thick. The openings
shall be equivalent to three-quarter (3/4) inch diameter holes for
each sixteen (16) square inches of lath surface; or the lath shall
be perforated as determined by full size tests for load, strength
and fireresistance ratings.

823.4. Metal Lath. — The dimensions and sizes of expanded,
ribbed and sheet metal lath shall comply with reference standard
RS 8-32, and shall be fabricated from not less than No. 30
U.S. gage steel sheets. It shall be manufactured from copper-
bearing steel, coated with rust-inhibitive paint after cutting, or
cut from zinc-coated steel sheets.

823.5. Wire Lath. — All types of wire lath shall comply with
reference standard RS 8-32, and shall be fabricated from woven
or welded wire of not less than No. 19 W&M gage with not
more than two and one-half (2-1/2) meshes to the inch. Woven
or welded wire reinforcement shall be coated with zinc or rust-
inhibitive paint.

823.6. Paper-Backed Lath. — Expanded metal or wire lath backed
with integral approved paper shall be fabricated from the
minimum gages and weights specified in sections 823.4 and 823.5.

823.7. Combustible Lath. — Wood lath shall be erected horizon-
tally on walls and partitions and ceiling lath shall run in one

822-824

direction only; but in neither case shall it extend through cross-
partitions from room to room. Wood lath shall be not less than
one(l) inch wide nor less than five-sixteenth (5/16) inches thick.
The lath joints shall be staggered so that not more than seven
(7) laths occur in any one continuous break.

SECTION 824.0. FIBER BOARDS

Insulating boards manufactured with wood or other vegetable
fibers used as building boards for sheathing, roof decks, plaster
bases, interior wall and ceiling finish, roof insulation or sound
deadening, shall be vermin proof, resistant to rot-producing
fungi and water-repellent and shall meet the strength and
durability tests specified in reference standard RS 8-34. When
required under the provisions of article 9, the boards shall be
protected or treated to develop the required fireresistance or
flameresistance as determined by test.

824.1. Jointing. — To insure tight-fitting assemblies, edges shall
be manufactured square or shiplapped, beveled, tongue-and-
grooved or U-jointed; and shall be installed in accordance with
reference standard RS 8-32.

824.2. Plaster Base. — When used as a plaster base, fiber boards
shall be permitted in fireresistive construction complying with
the test provisions of article 9, except where specifically pro-
hibited in fireproof (type 1) and noncombustible (type 2) con-
struction.

824.3. Roof Insulation. — When used as roof insulation in all
types of construction, fiber boards shall be protected with an
approved type of roof covering.

824.4. Wall Insulation. — When installed and firestopped to
comply with article 9, fiber boards may be used for wall
insulation in all types of construction. In firewall and fire
division construction, unless treated to be noncombustible, the
boards shall be cemented directly to the masonry or other
noncombustible base and shall be protected with an approved
noncombustible veneer anchored to the base without intervening
air spaces.

824.5. Dry Wall Construction. — Where fireresistance ratings are
required, provision shall be made for interlocking, lapping or
otherwise protecting the joints between adjacent boards to insure
smoke and flame tightness.

824.6. Insulating Roof Deck. — When used as roof decking in
open beam construction fiber board insulating roof deck shall
have a minimum nominal thickness not less than one (1) inch.

SECTION 825.0. PLYWOOD

825.1. Quality. — All plywood when used structurally shall meet
the performance standards and all other requirements of reference
standard RS 8-36 for the type, grade and identification index or
species group of plywood involved, and shall be so identified by
an approved agency. Working stresses shall conform to the
standards of accepted engineering practice as presented in refer-
ence standard RS 8-36.

825.2. Types. — Plywood for interior use may be either of the
moisture resistant or exterior type; plywood for exterior use shall
be of the exterior waterproof type. Exterior plywood may be
applied directly to the framing as a siding, provided it has a I (
nominal thickness of three-eighths (3/8) inch. Joints shall occur'
over framing members, unless wood or plywood sheathing is I
used or joints are lapped horizontally a minimum of one and i
one-half (1-1/2) inches or otherwise made waterproof to the I
satisfaction of the building official. If plywood is used as lapped I
siding without sheathing, the wall framing to which it is attached I
shall be diagonally braced.

825.3. Spans. — The maximum spans for plywood roof sheathing j
and subflooring shall be limited by the allowable stresses and
deflections for the design live load but shall have not less than I
the identification index listed in reference standard RS 8-36
item 4, provided it is continuous over two (2) or more spans
and laid with face grain perpendicular to the supports.

825.3.1. — The allowable span for plywood combination sub-
floor underlayment shall conform to the provisions of reference
standard RS 8-36 item 5.

825.3.2. Vertical Maximum Stud Spacing. — Stud spacing for
vertical sheathing and for use in stress-skin panel or other
prefabricated constructions shall be determined by accepted
engineering analysis or by the tests prescribed for prefabricated
assemblies in section 803.

824-826
SECTION 826.0. WALLBOARDS AND SHEATHING

826.1. Sheathing. — Sheathing of gypsum, processed fiber and
other approved materials shall conform to reference standards
RS 8-39 and RS 8-40. When used in frame construction, they
shall meet requirements of sections 855.1 and 855.2. When re-
quired to meet fireresistance ratings the assembled construction
shall comply with section 221.1 table 2-1 for structural elements
and article 9 for trim and finishes.

826.2. Wallboards. — Wallboard of gypsum, processed fiber and
other approved materials shall conform to reference standard
RS 8-41. When required to meet fireresistance ratings the
assembled construction shall comply with section 221.1 table 2-1
for structural elements and article 9 for trim and finishes.

ARTICLE

STEEL, MASONRY, CONCRETE, GYPSUM AND
LUMBER CONSTRUCTION

827.0

Structural Steel Construction

844.0

828.0

Cold-Formed Steel

845.0

829.0

Open Web Steel Joists

846.0

830.0

Reinforcing Steel

847.0

831.0

Cast Steel Construction

848.0

832.0

Cast Iron Construction

849.0

833.0

Special Steels

850.0

834.0

Light Weight Metal Alloys

851.0

835.0

Masonry Wall Construction

852.0

836.0

Bonding of Walls

837.0

Lateral Bracing of Walls

853.0

838.0

Chases and Recesses in Bearing

Walls

854.0

839.0

Corbeled and Projected

Masonry

855.0

840.0

Bearing on Hollow Unit Walls

856.0

841.0

Plain Concrete

857.0

842.0

Reinforced Concrete

843.0

Controlled Concrete

Ordinary Concrete

Omitted

Short Span Floor Filling

Concrete-filled Pipe Columns

Pneumatic Concrete

Minimum Concrete Dimensions

Reinforced Gypsum Concrete

Reinforced Brickwork

Reinforced Hollow Block
Construction

Lumber and Timber Con-
struction

Heavy Timber Type
Construction

Wood Frame Construction

Stress Skin Panels

Structural Glued, Laminated
and Built-Up Lumber Con-
struction

SECTION 827.0. STRUCTURAL STEEL CONSTRUCTION

Structural steel construction used in all buildings and structures
shall be fabricated from materials of uniform quality, free from
defects that would vitiate the strength or stability of the struc-
ture. Design, fabrication and erection shall conform to reference
standard RS 8-42.

827.1. Plans. — Design plans drawn to appropriate scale shall
show the size, section and relative locations of all structural
members with floor levels, column centers and all offsets fully
dimensioned; and the design loads shall be clearly indicated
for all parts of the building or structure.

827.2. Identification. — Structural steel that is required to have a
minimum yield point greater than thirty-six thousand (36,000)
psi shall at all times in the fabricator's plant, be marked,
segregated, or otherwise handled so that the separate alloys and
tempers are positively identified, and after completion of fabrica-
tion, shall be marked to identify the alloy and temper. Such

markings shall be affixed to completed members and assemblies
or to boxed or bundled shipments of multiple units prior to
shipment from the fabricator's plant.

827.3. Shop Drawings. — Shop drawings, giving complete informa-
tion necessary for the fabrication of the component parts of the
structure, including the types of material, the location, type and
size of all rivets, bolts and welds, shall be prepared in advance
of the actual fabrication. They shall clearly distinguish between
shop and field rivets, bolts and welds. Shop drawings shall be
made in conformity with the best modern practice and with due
regard to safety, speed and economy in fabrication and erection.

827.4. Welding. — All welded construction shall be designed by
engineers and shall be supervised by engineers and qualified
technicians experienced and skilled in welded construction. Welds
shall be made by welders, tackers and welding operators who
have been previously qualified to perform the type of work
required, by tests as prescribed in reference standard RS 8-73.
Unless otherwise specifically provided for in this Code or
reference standards, all provisions of reference standard RS 8-73
shall apply.

827.5. Painting and Protective Coating of Structural Steel.

827.5.1. — All structural steel, except as provided in 827.5.2,
shall receive one (1) coat of paint, zinc or bituminous coating, or
equivalent metal protection before erection. The protection shall
be applied thoroughly and evenly to dry surfaces which have
been cleaned of loose mill scale, loose rust, weld slag flux
deposit, dirt, and other foreign matter. Oil and grease deposits
shall be removed by solvent. Surfaces inaccessible after assembly
shall be treated as required above prior to assembly.

827.5.2. — Surfaces of structural steel shall not be required to
receive metal protection when the structural steel is used under
the conditions listed in a through g below. However, these
surfaces shall be cleaned of oil or grease by solvent cleaners
and be cleaned of dirt and other foreign material by thorough
brushing with a fiber brush.

a. Structural steel that is encased in concrete or surfaces
that abut concrete at interior iocations.

b. Structural steel encased in. non-corrosive fire resistive
materials that are bonded or secured to the steel surface
by an approved method that will insure a durable bond.

c. Surfaces of structural steel that are to be riveted, bolted,
or welded together.

827

d. Surfaces of structural steel within two (2) inches of field
welds shall be free of protective coatings that would
prevent proper welding or produce objectionable fumes
while welding is being done.

e. Surfaces of structural steel that have been machine
finished but shall be protected against corrosion by a
rust-inhibiting coating that can be easily removed prior
to erection of which has characteristics that make removal
unnecessary prior to erection.

f. Surfaces of types of structural steels that have been
specifically approved for use without metal protection.

g. Structural steel members that are completely concealed
by interior finish such as lath and plaster, masonry, etc.,
need not be painted except that where such members
are adjacent to piping, are in shower or steam rooms,
are exposed to chemical fumes, or are exposed to other
conditions of potentially aggresive corrosion, such mem-
bers shall be painted.

827.5.3. — Parts of structural steel members left unpainted be-
cause of welding, bolting, or riveting operations not exempted
from painting by the provisions of 827.5.2 above shall receive a
field application of metal protection as prescribed in 827.5.1
above.

827.5.4. — Structural steel that will remain exposed to the weather
or to a corrosive atmosphere shall receive an additional coat of
metal protection of another color after erection, except for types
of structural steels that have been specifically approved for use
under exposure to the weather without metal protection.

827.5.5. — All abrasions to, or deterioration of, the protective
coating shall be spot painted.

827.5.6. — Primary frame steel built into exterior masonry walls
shall have adequate protection against corrosion by encasing
in one and one-half (1-1/2) inches of Portland cement mortar
or by a mastic asphalt or pitch one-eighth (1/8) inch thick or
its approved equivalent.

827.6. Quality Control.

827.6.1. Reference. — The provisions of reference standard RS 8-60
shall apply.

827.6.2. Welding Operations. — The certification of welding opera-
tions prescribed by reference standard RS 8-60 shall include a
check to ascertain that the welders employed on the work are
qualified in accordance with the provisions of this code.

SECTION 828.0. COLD-FORMED STEEL

828.1. General Requirements. — Materials, design, and construc-
tion methods shall meet the requirements of reference standard
RS 8-43.

828.2. Deleted.

828.3. Structural Systems. — Formed steel floor, wall, and roof
systems may be designed and constructed to resist all vertical
and horizontal moments and shears resulting from lateral forces.
Such members when designed to transmit horizontal shears due
to wind or other lateral forces, shall be connected to the sup-
porting structure so as to adquately resist all primary and
secondary stresses. When concrete topping or other approved
decking is installed in a manner to insure composite action of
the assembly, the strength of the composite member may be
included in the calculations.

828.4. — Deleted.

828.5. Protection.

828.5.1. Shop Coat. — All individual structural members and
assembled panels of light gage and formed steel construction,
except where fabricated of approved corrosion-resistive metallic
steel or of steel having a corrosion-resistive or other approved
coating, shall be protected against corrosion with an approved
shop coat of paint, enamel, or other approved protection.

828.5.2. Field Coat. — After erection where directly exposed to
the weather, except when encased in concrete made of non-
corrosive aggregates, or where fabricated of approved corrosion-
resistive steel, or of galvanized or otherwise adequately protected
steel, individual structural members and assembled panels of
light gage and formed steel construction shall be given an
additional coat of approved protection.

828.5.3. Siding. — Exposed siding or sheathing shall be fabricated
of approved corrosion-resistive steel or otherwise protected at
the ground level for a height of four (4) feet above grade.

828.5.4. Protection at Exterior Walls. — Floor or roof construc-
tion which extends into an exterior wall shall be adequately
waterproofed and protected from the weather to prevent corrosion.

828.6. Tests. — When not capable of design by accepted engi-
neering analysis, the building official shall require tests of the
individual or assembled structural units and their connections
as prescribed in reference standard RS 8-43. At least three (3)
specimens truly representative of the construction to be used

828-829

in practice shall be subjected to the prescribed test and the
mean of the results shall determine the safe working value;
provided that any individual test varying more than ten (10)
per cent from the mean value shall cause rejection of the series.

SECTION 829.0. OPEN WEB STEEL JOISTS

Steel joists may be used as secondary members in floor and
roof construction, other than around stairwells, shafts and other
floor openings. The materials, design, and construction methods
shall meet the requirements of reference standard RS 8-44.

829.1. Design.

829.1.1. Loads and Stresses. — Connections of all members shall
be designed with the minimum possible eccentricity and all
secondary stresses shall be included with primary stresses in the
design. In all buildings subject to heavy concentrations or
moving loads, the construction shall be designed to resist the
vertical and lateral components of such loads in addition to the
live and dead loads specified in article 7.

829.1.2. Partitions. — The joists shall be designed to support the
dead load of partitions wherever they occur in addition to all
other imposed dead and live loads.

829.2. Protection. — Painting of steel joists shall be in accordance
with the requirements of section 828 for light gage cold-formed
steel; or the joists shall be dipped in an approved hot asphalt,
or shall be protected by painting, dipping or spraying with ap-
proved cold asphalt at the place of manufacture. The paint or
asphalt coating shall conform to the requirements of reference
standard RS 8-44 and shall have a minimum dry film thickness
of 1.0 mil. All abrasions shall be touched up at the job site
with the same material.

829.3. Height and Area Limitations. — When the main structural
frame is designed to resist all horizontal and vertical moments
and shears due to lateral forces, and the secondary system con-
sists of steel joists which are attached to the supporting beams
and girders of the frame as specified in the standard, steel joist
construction of the required fireresistance may be used in all
buildings within the height limits of section 221.2 table 2-2.

829.4. Tests. — When not subject to accepted engineering analysis
as regulated by reference standard RS 8-44, the assembly shall
meet the load test requirements specified in sections 803 and 804.

SECTION 830.0. REINFORCING STEEL

Metal reinforcement for reinforced concrete, reinforced gypsum
concrete, reinforced brickwork and reinforced hollow block
construction shall comply with the applicable standards listed in
reference standard RS 8-45.

830.1. Identification. — All reinforcing bars shall be rolled with
raised symbols or letters impressed on the metal identifying the
manufacturing mill, the bar size, and the minimum yield point.
When required by the building official, the grade of material
shall be identified by satisfactory mill tests. All bundles or rolls
of cold-drawn steel wire reinforcement and of one-quarter (1/4)
inch rounds shall be securely tagged to identify the manufacturer
and the grade of steel.

830.2. High Yield Steels.— When the yield point of reinforcing
bar steel is fifty thousand (50,000) pounds per square inch or
more, and when not otherwise provided for in reference standard
RS 8-45, the building official shall approve working stresses for
tension in bending and compression in vertical column reinforce-
ment not more than forty (40) per cent of the minimum yield
point; but such working stresses shall be not more than thirty
thousand (30,000) pounds per square inch, except when pre-
stressed reinforcement is used.

830.3. Column Reinforcement.

830.3.1. Structural Steel Sections. — The allowable unit stress on
structural steel column sections shall be not more than the values
listed in reference standard RS 8-42.

830.3.2. Cast Iron Sections. — All cast iron used as reinforcement
in combination with concrete shall be of pit-cast water pipe
grade complying with the standards listed in reference standard
RS 8-46, and the allowable unit stress shall be not more than
ten thousand (10,000) pounds per square inch.

830.3.3. Steel Pipe Sections. — The allowable unit stress on steel
pipe used in concrete-filled pipe columns shall be in conformance
with section 847.0.

830.4. Tests. — When unidentified reinforcement is approved for
use under ordinary material procedure, not less than three (3)
tension and three (3) bending tests shall be made on representa-
tive specimens of the reinforcement from each shipment and
grade of reinforcing steel proposed for use in the work.

830-832
SECTION 831.0. CAST STEEL CONSTRUCTION

831.1. Materials. — Carbon steel casting for building construction
shall be cast from open hearth or basic oxygen steel conforming
to the requirements of reference standard RS 8-47. All castings
shall be free from injurious blow holes or other defects which
would impair the structural strength.

831.2. Higher Strength Cast Steel. — Higher strength cast steel
may be used when approved under controlled material procedure.

831.3. Welding Cast Steel. — Cast steel designed for use in
welding shall be of weldable grade complying with the approved
rules.

SECTION 832.0. CAST IRON CONSTRUCTION

832.1. Materials. — Cast iron for building construction shall be
a good foundry mixture providing clean, tough, gray iron, free
from serious blow holes, cinder spots and cold shuts; con-
forming to the applicable standards listed in reference standard
RS 8-48.

832.2. Limitations of Use. — Cast iron columns shall not be
used where subject to eccentric loads which produce a net
tension in the section, nor in any part of a structural frame
which is required to resist stress due to wind. Cast iron columns
shall not be used in the primary structural frames of buildings
whose height exceeds one hundred (100) feet or twice the width
at the ground level. Cast iron shall not be used for columns
required to have four (4) hour fireresistive protection. Cast iron
columns supporting a floor shall not be longer than seventy (70)
times the least radius of gyration or twenty-four (24) times the
outside diameter or least side. Cast iron columns supporting
roof loads only shall not be longer than ninety-six (96) times the
least radius of gyration or thirty (30) times the outside diameter
or least side, cast iron columns shall not be smaller than six (6)
inches in outside diameter or side.

832.3. Multi-Story Columns. — Cores of superimposed columns
shall be of the same dimensions above and below a splice. When
a column of smaller diameter is superimposed over one of
larger diameter, the larger column shall be tapered down to the
smaller diameter over a length of not less than six (6) inches.
832.3.1. Column Bases of Steel and Iron. — Cast iron bases shall
be planed on top and bases which rest on structural steel
members shall be planed on the bottom.

832.4. Thickness of Metal. — The minimum thickness of cast
iron shall be not less than herein specified:

832.4.1. Columns. — In columns, the metal shall be not less than
one-twelfth (1/12) the smallest dimension of the cross-section
and in no case less than three-quarter (3/4) inch.

832.4.2. Bases and Brackets. — In bases and flanges, the metal
shall be not less than one (1) inch thick reinforced with fillets
and brackets. The outer edge of the ribs of ribbed bases shall
be inclined not less steeply than forty-five (45) degrees. A side
of the bed plate of ribbed bases exceeding three (3) feet in
length shall have a reinforcing flange at least three (3) inches high.

832.4.3. Lintels. — In lintels, the metal shall be not less than
three-quarter (3/4) inches thick and shall be limited to use on
spans of not more than six (6) feet.

832.5. Inspection. — No cast iron column shall be erected in place
before it has been inspected and approved by the building
official. The use of any cast iron column in which blow holes
or imperfections reduce the effective area of the cross-section
more than ten (10) per cent shall be prohibited. Where required
by the building official, hollow cast iron columns, except when
open at both ends and without flanges, shall have two (2) three-
eighths (3/8) inch holes drilled in the shell to exhibit the thick-
ness thereof. If the columns are cast on the side, both holes
shall be in the top side as cast, one hole about twelve (12)
inches toward each end from mid-length of the column. If the
columns are cast on end, both holes shall be at mid-height at
ninety (90) degrees from one another about the axis of the col-
umn. Additional holes shall be drilled when required by the
building official. If the core of a cast iron column is found to
have shifted more than one quarter (1/4) the thickness of the
shell, the strength shall be computed assuming the thickness all
around to be that of the thinnest part.

SECTION 833.0. SPECIAL STEELS

833.1. Identification. — When not otherwise provided for by
reference standard RS 8-42, silicon, nickel and other corrosion-
resistive alloy steels and high strength steels required to have a
minimum yield point greater than thirty-six thousand (36,000)
psi, may be used in the design and construction of buildings
and structures with the approval of the building official. Every
such special steel shall be marked or otherwise identified to

832-835
clearly distinguish it from all other classes of steel.
833.2. Design and Workmanship. — When not otherwise pro-
vided for by reference standard RS 8-42, design and fabrication
methods shall conform to the approval of the building official.

SECTION 834.0. LIGHTWEIGHT METAL ALLOYS

Aluminum and other approved lightweight metals and alloys
shall be used for structural purposes in buildings and structures
in accordance with the applicable standards listed in reference
standard RS 8-49.

SECTION 835.0. MASONRY WALL CONSTRUCTION

835.1. Design. — All masonry construction shall comply with the
provisions of this article governing quality of materials and
manner of construction; and shall be of adequate strength and
proportions to support all superimposed loads either within the
empirical provisions of the applicable sections of article 8 or
reference standard RS 8-51 or shall be designed in accordance
with reference standards RS 8-50 and RS 8-58.

835.2. Wetting of Masonry.

835.2.1. Clay or Shale Bricks. — All brick having an absorption
rate in excess of 0.025 oz. per square inch per minute shall be
wetted before laying. The method of wetting shall be such as
to insure that each unit is nearly saturated, surface dry when
laid. During freezing weather, units that require wetting shall be
sprinkled with warm water, immediately before layinconcrete slabs, shall be securely anchored to loadbearing
masonry walls with minimum one half (1/2) inch bolts spaced
eight (8) feet on center, or their equivalent. The bolts shall
extend and be embedded a minimum of fifteen inches (15")
vertically into the masonry, or where a continuous bond beam
is provided, shall be hooked tightly around or welded to at least
0.2 square inches of continuous longitudinal bond beam rein-
forcement placed at least six (6) inches from the top of the
wall.

SECTION 838.0. CHASES AND RECESSES IN BEARING
WALLS

838.1. Where Permitted. — Chases and recesses shall be prohibited
in any wall less than twelve (12) inches thick or in the required
area of piers and buttresses. Vertical chases adjacent to bearings
of beams or lintels, vertical chases wider than twelve (12) inches,
and all horizontal chases shall be proportioned on the basis of
the analysis of stress.

838.1.1. Exceptions for Eight Inch Walls^ — In buildings of
residential occupancy not over two (2) stories in height, vertical
chases not more than four (4) inches deep and not more than
four (4) square feet of wall area may be built in eight (8) inch
walls, except that recesses below windows may extend from floor
to sill and be the width of the opening above.

837-839

838.2. Maximum Size. — The maximum permitted depth of a
chase in any wall shall be not more than one-third (1/3) the
wall thickness, and the maximum length of a horizontal chase or
the maximum horizontal projection of a diagonal chase shall not
exceed four (4) feet except as provided in section 838.5; and
except further that the length of the apron below window sills
in all walls may equal the width of the window opening. The
aggregate area of recesses and chases in any wall shall be not
more than one fourth (1/4) of the area of the face of the wall
in any one story. Masonry directly above chases or recesses
wider than twelve (12) inches shall be supported on lintels.

838.3. Fireresistive Limitations. — It shall be unlawful to have
chases or recesses which reduce the thickness of material below
the minimum specified in article 9 for fire walls, fire divisions,
fire partitions or required fireprotective covering of structural
members.

838.4. Hollow Walls. — When chases and recesses are permitted
in hollow walls and walls constructed of hollow blocks or tile,
they shall be built-in with the wall. It shall be unlawful to cut
chases in such walls after erection.

838.5. Continuous Chases. — Horizontal chases for the bearing
of reinforced concrete floor and roof slabs may be continuous
provided anchors are installed above and below the floor con-
struction to resist the bending and uplift in the wall due to
flexure of the slab.

SECTION 839.0. CORBELED AND PROJECTED MASONRY

839.1. Limitations. — No wall less than twelve (12) inches thick
shall be corbeled except to support firestopping around floor
framing; and except that eight (8) inch foundation walls may
be corbeled to support brick-veneer frame and ten (10) inch
cavity walls as provided in section 871. The maximum total
horizontal projection of corbels shall be not more than one-half
(1/2) the thickness of the wall. The maximum projection of one
(1) unit shall neither exceed one-half (1/2) the depth of the
unit nor one-third (1/3) its width at right angles to the face
which is offset.

839.2. Hollow Walls. — Corbeling of hollow masonry or masonry
built of hollow units shall be supported on at least one (1) full
course of solid masonry.

839.3. Molded Cornices. — Unless structural support and anchor-
age is provided to resist the overturning moment, the center of
gravity of all projecting masonry or molded cornices, including
loads thereon, shall lie within the middle third of the supporting
wall. Terra cotta and metal cornices shall be provided with a
structural frame of approved noncombustible material anchored
in an approved manner.

SECTION 840.0. BEARING ON HOLLOW UNIT WALLS

840.1. Bearing Details. — Concentrated loads shall be supported
upon a solid construction of solid masonry, concrete, or masonry
of hollow units with cells filled with mortar, grout, or concrete
and of sufficient height to distribute safely the loads to the wall,
pilaster, or column, or other adequate provisions shall be made
to distribute the loads.

840.1.1. Joist Bearing. — Solid construction for support under
joists shall be at least two and one-quarter (2-1/4) inches in
height, and joists supported on such construction shall extend
into the masonry at least three (3) inches.

840.1.2. Beam Bearing. — Solid construction for support under
beams, girders, or other concentrated loads shall be at least
four (4) inches in height and the bearing of beams shall extend
into the masonry at least three (3) inches.

SECTION 841.0. PLAIN CONCRETE

Plain concrete is concrete cast in place and not reinforced, or
reinforced only for shrinkage or changes of temperature. Plain
concrete shall be designed, mixed, placed and cured in accor-
dance with the applicable requirements of section 843 for control-
led concrete, or section 844 for ordinary concrete, as applicable,
and reference standard RS 8-45 and RS 8-60. The building
official shall require an applicant for a permit involving the
structural use of concrete to have approved inspection personnel
perform inspections or other quality control duties when such
duties are required by this code.

841.1. Limitations. — Plain concrete in loadbearing masonry or
where exposed to soil or where used for fire-resistive purposes,
shall be of such proportions as to have a strength of at least
fifteen hundred (1500) pounds per square inch and where
exposed to wetting or freezing at least two thousand (2,000)
pounds per square inch.

839-842

841.2. Documentation. — Shall conform to section 842.1.

841.3. On Site Certification. — Shall conform to section 842.2.

SECTION 842.0. REINFORCED CONCRETE

Concrete materials, design, and construction shall meet the
requirements of section 843 for controlled materials or of section
844 for ordinary materials, as applicable, and shall otherwise
conform to reference standard RS 8-45. Precast concrete con-
struction utilizing a thin skin or slab stiffened or supported by a
system of ribs shall conform to the requirements of reference
standard RS 8-63. The building official shall require an applicant
for a permit involving the structural use of concrete to have
approved inspection personnel perform inspections or other
quality control duties when such duties are required by this
code. The architect or engineer responsible for the design
drawings as evidenced by his seal thereon shall prepare, super-
vise, or check said design working drawings and shop details
for the construction.

842.1. Documentation. — All required attestations shall become
a part of the documentation to be filed with the building
official and shall be subject to verification by strength tests, as
hereinafter described, by check sampling of ingredients, or by
such other inspections as the building official or the architect
or engineer responsible for the design drawings may elect. Where
automatic or semi-automatic batching equipment is used, all
recordable data including tapes, equipment readings, and truck
tickets together with the required reports certifying the mix shall
be available for inspection for a period of two (2) years.

842.2. On Site Certification. — Certification of concrete and
concrete construction shall conform to the requirements of
reference standard RS 8-60, and the provisions of this section.
842.2.1. — When elements and operations on elements which are
required by reference standard RS 8-60 to be subject to certifica-
tion, said certification shall include:

a. Strength Tests. — Strength tests shall be performed on
all structural concrete. The provisons of reference stan-
dard RS 8-45 shall apply. Test cylinders shall be made
and stored on the job site in an insulated curing box of
sufficient size and strength to contain the required
number of cylinders and to minimize the hazard of
disturbance during curing. The box shall be heated as

required to maintain proper curing conditions. Such
box shall be located in an area free from vibration such
as pile driving and traffic of all kinds. No concrete
requiring inspection shall be delivered to the site until
such storage curing box has been provided. Cylinders
shall remain in the curing box until ready for delivery
to the testing laboratory but not less than twenty-four
(24) hours. Actual preparation and testing of the cylin-
ders shall be performed by competent individuals with
demonstrated experience acceptable to the architect or
engineer responsible for the design drawings and the
building official and all concrete failing to meet the
specified minimum strength requirements shall be rejected
by said architect or engineer or building official pending
verification of the adequacy of the construction by core
testing in accordance with reference standard RS 8-68.

b. Additional Tests. — Each sample recovered for the pur-
pose of strength tests shall be additionally checked for
slump, air content, unit weight, and temperature in
accordance with the standard procedures noted in refer-
ence standard RS 8-45.

c. Forms, Reinforcement and Placing. — The size and dim-
ensions of the concrete members formed by the concrete
forms; sizes and positions of reinforcement, in place; and
the placement of concrete, including temperatures, pro-
tections against excessive temperatures, curing, the erec-
tion and connection of precast members, the amount of
water added in the field; and tensioning of all prestressed
elements shall be recorded and compliance with the pro-
visions of this code shall be certified.

842.2.2. — When elements and operations on elements are not
required by reference standard RS 8-60 to be subject to certifica-
tion, quality control and inspection shall be provided in sufficient
scope to assure conformance with the requirements of this
section (and of the cited reference standards.)
842.3. Embedded Mechanical Facilities. — Plumbing and heating
piping and electrical conduits may be embedded in reinforced
concrete floor and wall construction and in column fireproofing
as provided in section 914.3. Piping for radiant heating purposes
may be embedded in the structural floor or wall slabs, or may
be installed in a separate concrete layer placed in addition to
the required fireproof covering, as approved by the building

842-846

official. In any case, the required area of reinforcement shall be
provided in addition to such piping; and the conduits, pipes or
other embedded mechanical facilities shall be so placed as to
leave the strength and fireresistance of the construction undimin-
ished. All embedment of mechanical facilities shall conform to
reference standard RS 8-45.

SECTION 843.0. CONTROLLED CONCRETE

When controlled materials procedure is followed in the design
and construction of a concrete building or structure and certified
in conformance with reference standard RS 8-60 the allowable
working stresses shall conform to accepted engineering practice
in accordance with the building code requirements for concrete
listed in reference standard RS 8-45. The ultimate compressive
strength of the concrete shall not be limited in controlled con-
crete procedure, provided proper provision is made to limit
deflections and cracking.

SECTION 844.0. ORDINARY CONCRETE

When ordinary material procedure is followed in the construction
of a concrete building or structure and certified for compliance
with reference standard RS 8-60 (if required thereby), the design
shall conform to accepted engineering practice in accordance
with building code requirements listed in reference standard
RS 8-45. In no case shall the cement factor and water cement
ratio violate the requirements of tables RS 8-45-1 or RS 8-45-2
of reference standard RS 8-45 nor shall the specified or required
twenty-eight (28) day compressive strength (f'c) exceed four
thousand (4,000) psi.

SECTION 845.0. OMITTED

SECTION 846.0. SHORT SPAN FLOOR FILLING

For spans not exceeding ten (10) feet between steel flanges, the
safe supporting capacity of concrete floor and roof slabs built as
fireproof floor filling between steel beams shall be determined by
the provisions of reference standard RS 8-45 or in accordance
with the approved rules for stone and light weight aggregate
concrete and other approved fireresistive floor filling.

SECTION 847.0. CONCRETE-FILLED PIPE COLUMNS

Concrete-filled pipe columns shall be manufactured from stan-
dard, extra strong, or double extra strong steel pipe and tubing,
filled with concrete. Pipe or tubing for such columns may have
round, square, or rectangular cross sections.
Steel equal in quality to that described in reference standard

RS 8-42 shall be used for pipe. Pipe shall be new and full size,
shall be made by the seamless process or fully welded to develop
equivalent strength. All pipe shall be mill tested and approved.
Round pipe shall be standard weight or heavier. The wall thick-
ness of square and rectangular pipe shall not be less than three-
sixteenths (3/16) inch.

Filling shall be standard weight, machine-mixed, stone or gravel
concrete and shall have a minimum compressive strength of
thirty-five hundred (3,500) pounds per square inch when pro-
portioned and tested by procedures described in reference stan-
dard RS 8-45. Concrete while being placed shall be compacted
by a mechanical method which will ensure complete filling of
the pipe with dense concrete of homogeneous quality.
Bases, caps, web ties, brackets and shear heads shall be of
steel meeting the requirements listed in reference standard RS 8-42
847.1. Design. — The safe supporting capacity of concrete-filled
pipe columns shall be computed in accordance with the approved
rules or as determined by test, or as follows:
847.1.1. Allowable Axial Loads. — The axial load P a shall not
exceed that obtained from formulas found in reference standard
RS 8-42, multiplied by the effective transformed area A tr and
with P a substituted for F a and r tr 2 substituted for r 2 . The values
of A tr and r tr z shall be evaluated by

A = A -i- _£- r tr 2 - —

A tr A s+ — lr - "

2n Atr

in which

As = area of the pipe and reinforcing steel

Ac = area of the concrete filling

Ic = moment of inertia of the concrete filling

Is = moment of inertia of steel pipe and reinforcing

n = E_ E 483

E c 60,000 VTT " VFc
f'c = concrete compressive strength, psi

847
847.1.2. Induced Bending Moment. — The computed bending
moment in columns shall take account of the effect of the axial
load on the deflection including the deflection induced by the
axial load itself. This moment M r may be approximated by

M r =

C m M

Pc(Kl/r tr ) 2
" 149,000,000A tr

in which C m shall be evaluated in accordance with reference
standard RS 8-42, with P c substituted for f a and P a substituted
for F a .
M = bending moment neglecting the effect of the axial load on

the deflection
Pc = applied axial load

At braced points M r may be taken equal to M.
847.1.3. Combined Bending and Axial Compression. — Provided
that no part of the concrete filling is stressed in tension, col-
umns subjected to bending as well as axial load shall be so
proportioned that

P a 21,000 ^

in which f^ is the compressive bending stress based on the
moment given by section 847.1.2 at the point under consider-
ation. The above expression applies directly to columns flexed
about one principal axis and to round columns. In the latter
case moment acting about several axes shall be added vectorially
and ft, obtained from the resultant moment. For square and
rectangular columns the second (bending) term shall be treated
as

f bx + f by
21,000

At braced points P a in the above formula may be computed for

Kl h

- = and C m =l.

r tr

847.1.4. Combined Bending and Axial Compression with Net
Tension. — If bending is sufficient to cause net tension at some
point in the concrete fill the column shall be so proportioned
that

P c M r - sP c

Pb M S

In the above

P 1

P a 21,000A tr

r tr 2

s = kern distance for the uncracked section=

c =distance from centroid to extreme fiber
M ^allowable moment with P c =0 which can be approximated
as 21,000S in which S is the section modulus of the pipe
and reinforcing steel alone

The above expression applies to columns flexed about one
principal axis and to round columns. In the latter case moments
acting about several axes shall be added vectorially to obtain the
resultant movement.

For square or rectangular columns with bending about both
principal axes, the section shall be so proportioned that

P c M rx - s x P c M ry - s y P c

+ + — — < 1

P b min. M ox M oy

where the subscripts x and y indicate that the quantity is com-
puted with respect to the x or y axis independently and Pt>min.
is the smaller of P^ x and P by .

847.2. Connections. — All caps, base-plates and connections shall
be of approved types and shall be positively attached to the
shell and anchored to the concrete core. When the pipe is
slotted to accommodate webs of brackets or other connections,
the integrity of the shell shall be restored by welding to insure
hooping action of the composite section. Such fixtures and their
attachments to the pipe and reinforcement shall be such as to
ensure that the allowable stresses, under the maximum conditions
of loading, are not exceeded.

847.3. Reinforcement. — Longitudinal steel having a yield point
approximating that of the pipe may be used to increase the
strength of the columns. The steel reinforcement shall be in the

847-848

form of rods, structural shapes or pipe embedded in the concrete
core with sufficient clearance to insure the composite action of
the section, but not nearer than one (1) inch to the exterior
steel shell. Such steel shall be new, straight and continuous for
the entire length of the column with ends so detailed as to de-
velop the computed stress. The ends of such steel shall be ar-
ranged for even bearing with the pipe and milled after filling if
necessary to obtain uniform bearing. The strength of this rein-
forcement shall be calculated by adding its area to the area of
the steel pipe and including it in the calculations.

847.4. Fireresistive Protection. — Pipe columns shall be of such
size or so protected as to develop the required fireresistance
ratings specified in section 221.1 table 2-1. When an outer steel
shell is used to enclose the fireproof covering, it shall not be
considered as either load bearing or as increasing the stiffness
of the column section. The minimum diameter of pipe columns
shall be four (4) inches except that in frame structures not ex-
ceeding three (3) stories or forty (40) feet in height, three (3)
inch columns may be used in the basement and as secondary
steel members.

847.5. Approvals. — Details of column connections and splices
shall be designed and shop fabricated by approved methods and
shall be tested in accordance with approved rules as required by
the building official.

847.6. Tests. — Copies of sanctioned tests of filled pipe columns
subjected to axial loads made in accordance with this section
shall be filed with the building official for each size of column
produced by a manufacturer. These tests shall be made on
specimens the length of which approximates twenty-four (24)
times the smallest outside dimension of the pipe. Tests shall
be made in an approved laboratory. For acceptance the ratio
of the test strength to P a shall not be less than the factor of
safety used as the denominator in Formula (1.5-1) from refer-
ence standard RS 8-42, excepting that in computing P a for
sanctioned tests n rather than 2n shall be used.

847.7. Identification. — Columns shall be labeled with manufac-
turer's name and date of manufacture.

SECTION 848.0. PNEUMATIC CONCRETE

Construction methods for mortar or concrete deposited pneu-
matically (shotcrete) shall conform to the applicable provisions of
reference standard RS 8-52, and shall be protected and cured

to prevent the temperature falling below fifty (50) degrees F. and
to prevent loss of moisture at the surface. Reinforcement for
pneumatic mortar shall be adequate to meet structural require-
ments and shall consist of round bars or mesh not less than
No. 12 U.S. gage in diameter, spaced not less than two (2)
inches either way.

848.1. General Requirements. — Pneumatically placed concrete
and mortar shall consist of a mixture of aggregate and cement
pneumatically applied by suitable mechanism, and to which
water is added immediately prior to discharge from the appli-
cator for the dry mix or at a point removed from the appli-
cator as in the wet mix. Except as specified in the following
sections, pneumatically placed concrete shall conform to the
requirements of this code for reinforced concrete.

848.1.1. Proportions. — The proportion of cement to aggregate,
in loose dry volume, shall not be less than one (1) to four and
one-half (4-1/2).

848.1.2. Water. — The water content at the time of discharge,
including moisture in the aggregate, shall not exceed a water-
cement ratio of 0.50 by weight.

848.1.3. Mixing. — The cement and aggregate shall be thoroughly
mixed prior to the addition of water. At the time of mixing the
aggregate shall contain not less than three (3) per cent moisture.

848.2. Rebound. — Any rebound or accumulated loose aggregate
shall be removed from the surfaces to be covered prior to
placing the initial or any succeeding layers of pneumatically
placed concrete and mortar.

848.3. Joints. — Unfinished work shall not be allowed to stand
for more than thirty (30) minutes unless all edges are sloped
to a thin edge. Before placing additional material adjacent to
previously applied work, these sloping edges shall be cleaned
and wetted.

848.4. Damage. — Any pneumatically placed concrete which
sags after placement shall be removed.

SECTION 849.0. MINIMUM CONCRETE DIMENSIONS

The dimensions of reinforced concrete structural elements in
buildings of fireproof (types 1A and IB) construction shall be
adequate to meet the fire and strength tests of this code. Any
floor finish not placed monolithically with floor slabs, shall not
be included in the calculations for structural strength, unless
specifically approved by the building official.

848-850
SECTION 850.0. REINFORCED GYPSUM CONCRETE

Reinforced gypsum concrete for use in buildings and structures
shall consist of a mixture of calcined gypsum and water, with
or without the addition of wood chips, shavings, fiber or other
approved aggregates. The manufacture, design, and construction
of both poured in place and precast gypsum concrete shall
comply with the requirements of reference standard RS 8-53.

850.1. Limitations. — Gypsum concrete shall not be used where
exposed directly to the weather or where subject to frequent or
continuous wetting. To prevent saturation or freezing, protection
from the weather and from contact with moisture shall be fur-
nished during shipment and storage of prefabricated units, and
after erection or pouring at the site.

850.1.1. Fire Protection. — Fire protection coverage for steel
reinforcement in gypsum shall be limited to a minimum of
one-half (1/2) inch in thickness.

850.1.2. Wearing Surface. — In no case shall gypsum concrete
be used for a wearing surface in gypsum construction.

850.1.3. Prohibited Use in Floors. — Gypsum concrete shall not
be used in floors of garages, dance halls, gymnasiums, armories
or floors used for any other purpose where subject to extreme
vibration, impact, or heavy, moving load concentrations.

850.1.4. Grade Construction. — The ventilated space underneath
first floor construction shall be not less than two (2) feet high
and the underside of first floor construction shall be damp-
proofed with an approved protective covering.

850.2. Poured in Place Gypsum Concrete. — The wood aggre-
gates and gypsum shall be pre-mixed at the mill, requiring only
the addition of water at the job or site.

850.2.1. Reinforcing. — Bundles or rolls of welded wire fabric
shall be securely tagged so as to identify the type and grade
of steel, and the size.

850.3. Precast Gypsum Concrete. — Precast gypsum concrete units
may be used for floor construction and shall be of uniform
thickness except for rabbets at support and shall be solid; such
units may be used for roof construction and shall be of uniform
thickness, whether solid or hollow, or recessed on the under side.
850.3.1. Span. — The span of precast gypsum concrete shall not
exceed four (4) feet in floors and six (6) feet in roofs except in
so-called suspension construction in which the span for floors
shall not exceed six (6) feet and in roofs shall not exceed eight

(8) feet. For the purpose of this section any span over three (3)
feet shall be called long span.

850.3.2. Thickness. — Except as otherwise provided in section

850.3.3, precast gypsum concrete units shall have not less than
the following:

a. Solid units in roofs shall be not less than two (2) inches
thick, nor if long span, less than three (3) inches thick.

b. Solid units in floors shall be not less than two and one
half (2-1/2) inches thick, nor, if long span, less than four
(4) inches thick.

c. Hollow units in roofs shall be not less than three (3)
inches nor the shell in compression less than three fourths
(3/4) inch thick; if long span, the units shall be not less
than five (5) inches thick nor the shell in compression
less than one and three eighths (1-3/8) inches thick.

d. Recessed units in roofs shall be not less than five (5)
inches thick nor the panel less than one and three eighths
(1-3/8) inches thick.

850.3.3. Construction and Erection. — Precast solid reinforced
gypsum concrete units not more than fifteen (15) inches wide and
bound on the long edges with structural or pressed sheet steel
of approved design anchored to the units shall be not less than
two (2) inches thick. If the length of units is not less than one
and one half (1-1/2) times the span and the steel bearing on
the edges is designed to interlock with adjoining units in the
manner of tongue and groove, and if of sufficient strength to
transmit the load on one unit to adjoining units, the end joints
may be staggered at random provided they are not less than
two (2) feet apart and the construction may be designed as
continuous. Precast gypsum concrete units for floor and roof
construction shall be reinforced and unless the shape or marking
of the unit is such as to ensure its being placed right side up,
the reinforcing shall be symmetrical so that the unit can support
its load either side up. All units shall be metal bound or other-
wise reinforced for handling stresses and precaution shall be
observed to provide temporary anchorage to the structural frame
during erection and to prevent damage or destruction from the
weather and wind before final completion of the installation.

850.3.4. Approvals. — Precast gypsum concrete units shall not be
used structurally in floors or roofs until the manufacturer thereof
has submitted satisfactory evidence of their quality and the
building official has given his approval. Approval shall be

850-853

conditioned upon such requirements as to design, materials,
methods of manufacture, erection and support as the building
official shall determine.

850.3.5. Test Cylinders. — Not less than three (3) compression
specimens for each one hundred (100) yards of gypsum concrete
cured and stored under the same conditions as the prefabricated
member shall be tested at the age of shipment. The test speci-
mens shall develop an average compressive strength at the time
of shipment not less than twice the stress used in the design.

SECTION 851.0. REINFORCED BRICKWORK

All systems of brick masonry reinforced with steel in grouted
mortar joints for use in the design and construction of buildings
and structures shall conform to the requirements of this section
and reference standard RS 8-58. Reinforced brickwork shall
incorporate only controlled materials and be certified in con-
formance with reference standard RS 8-60.

851.1. Design. — The formulae and assumptions used in the
design of reinforced masonry shall be those contained in reference
standard RS 8-58.

851.2. Foundation Piers. — Minimum dimensions for reinforced
brick used as a foundation pier shall be as required by section
749.4.

SECTION 852.0. REINFORCED HOLLOW BLOCK CON-
STRUCTION

Walls constructed of hollow block or other hollow unit masonry
and reinforced with steel rods grouted solidly into certain
vertical cells and horizontal beams shall be designed and con-
structed in accordance with reference standard RS 8-50. Rein-
forced concrete masonry shall incorporate only controlled ma-
terials and shall be certified in conformance with reference
standard RS 8-60.

SECTION 853.0. LUMBER AND TIMBER CONSTRUCTION

853.1. Design. — Structural lumber and timber and its fastenings
shall be adequately designed and assembled to safely sustain all
imposed loads. When stress-grade lumber is used and properly
identified and controlled, working stresses may be in accordance

with the accepted engineering practice standards in reference
standard RS 8-76. All lumber used for load supporting purposes
shall be identified by the grade mark of a lumber grading in-
spection agency approved by the building official. Grading
practices and identification shall be in accordance with rules
published by an agency recognized as being competent. In lieu
of a grade mark on the material, a certificate of inspection as
to species and grade issued by a lumber grading or inspection
agency approved by the building official may be accepted for
precut, remanufactured, or rough sawn lumber; also for sizes
larger than three (3) inches nominal thickness.

853.2. Minimum Dimensions.

853.2.1. Sizes of Structural Members. — All lumber sizes spec-
ified in this code are nominal sizes. Nominal sizes may be
shown on the plans. Computations to determine the required
size of members shall be based on the net dimensions (actual
sizes).

853.2.2. Structural Posts. — Afl isolated structural posts shall
have a minimum dimension of four (4) inches:

853.3. Fabrication.

853.3.1. Connections. — All connections shall be fabricated with
approved timber connectors, bolts, lag screws, spikes, nails or
gluing or other approved connecting devices in accordance with
reference standard RS 8-76. Bolted connections shall be snugged
up tightly without crushing wood fibers under the washers. All
nailed connections shall meet the minimum requirements of
reference standard RS 8-77.

853.3.2. Cambering. — Trusses and long span girders shall be
designed with a camber or other provisions to provide for
possible deflections.

853.3.3. Cutting and Notching. — It shall be unlawful to notch,
cut or pierce wood beams, joists, rafters or studs in excess of
the limitations herein specified unless proven safe by structural
analysis, or suitably reinforced to transmit all calculated loads.
Notches in the top or bottom of joists shall not exceed one-
sixth (1/6) the depth of the member and shall not be located in
the middle one-third (1/3) of the span. Notches located closer
to the supports than three (3) times the depth of the member
shall not exceed one-fifth (1/5) the depth. Holes bored or cut
into joists for piping or electrical cables shall not be closer than
two (2) inches to the top or bottom of the joist and the dia-
meter of the hole shall not exceed one-third (1/3) the depth of

853-854

. the joist. In studs of bearing walls or partitions, notches or bored
holes made to receive piping, electrical conduit, air conditioning
or heating duct work or for other fabricating purposes shall not

• be cut or bored more than one-third (1/3) the depth of the stud.
When the stud is cut or bored in excess of one-third (1/3) its

1 depth it shall be reinforced to be equal in load carrying capacity

, to a stud notched not more than one-third (1/3) its depth.

j 853.4. Trimmer and Header Beams. — When determined neces-
sary by stress analysis, trimmer and header beams shall be hung
in approved metal or other approved non-combustible stirrups
or hangers, unless supported on a masonry wall or girder. All

I such beams shall be spiked together.

i 853.5. Bearing and Anchorage on Girders. — All members framing

\ into girders shall be anchored or tied to secure continuity. The

; ends of all wood beams or joists resting on girders shall bear
not less than four (4) inches or shall be supported in approved
metal stirrups, hangers, or on wood clips or ribbon strips. Beams
framing from opposite sides shall lap at least six (6) inches and
be bolted or spiked together; and when framing end to end,

! they shall be secured together by metal ties, straps or dogs.
853.6. Maintenance. — All connections in the joints of timber
trusses and structural frames shall be inspected periodically and
bolts and other connectors shall be maintained tight.

SECTION 854.0. HEAVY TIMBER TYPE CONSTRUCTION

854.1. Wood. — All structural wood members sawn or glued
laminated used in heavy timber type construction shall be stress-
grade timbers identified as to grade and strength by approved
authoritative manufacturing, testing or inspection agencies or

■ bureaus. All structural timber members shall have the minimum
dimensions specified in section 217 for type 3-A construction.

854.2. Other Structural Materials. — Structural steel or reinforced
concrete members may be substituted for timber in any part of
the structural frame, protected to develop the required fire-
resistance specified in section 221.1 table 2-1, but not less than
three-quarter (3/4) hour fireresistance. Structural members sup-
porting walls shall be protected to afford the same fireresistance
rating as the wall supported.

854.3. Columns. — Columns shall be continuous or superimposed
throughout all stories by means of reinforced concrete or metal
caps with brackets, or shall be connected by properly designed

steel or iron caps, with pintles and base plates, or by timber I
splice plates affixed to the columns by means of metal con- I
nectors housed within the contact faces or by other approved
methods. Girders or trusses supporting columns shall have at
least three-quarter (3/4) hour fireresistance.

854.4. Floors. — The planks shall be laid so that no continuous
line of joints will occur except at points of support and so that
they are not spiked to supporting girders. Flooring shall notjf
extend closer than one-half (1/2) inch to walls to provide an I
expansion joint, but the joint shall be covered at top or bottom !
to avoid flue action.

854.5. Beams and Girders.

854.5.1. Wall and Girder Supports. — Wall plate boxes of self- 1
releasing type or approved hangers shall be provided where
beams and girders enter masonry. An air space of one-half (1/2) IS
inch shall be provided at the top, end and sides of the member
unless approved durable or treated wood is used. Where inter- 1
mediate beams are used to support a floor, they shall rest on I
top of the girders, or shall be supported by ledgers or blocks I
securely fastened to the sides of the girders, or they may be;
supported by approved metal hangers into which the ends of I
the beams shall be closely fitted. Wood beams and girders sup- 1
ported by walls required to have a fireresistance rating of two I
(2) hours or more shall have not less than four (4) inches ofH
solid masonry between their ends and the outside face of the H
wall and between adjacent beams. Adequate roof anchorage \
shall be provided. I

SECTION 855.0. WOOD FRAME CONSTRUCTION

The exterior walls, interior partitions, floors and roofs of jj
wood frame construction shall be designed, braced and con-';
structed to develop adequate strength and rigidity to resist all »
vertical and lateral forces due to both dead and live loads \
without exceeding the stresses allowed in this section for the I
various grades and species of wood. Standard balloon, braced, I
platform, and post and beam types of construction shall be I
acceptable framing methods. Sizes of wood members stated in \
this section are nominal sizes, materials, design, and construction I
methods shall meet the requirements in those applicable sections
of reference standard RS 8-76.
855.1. Wood — Stud Frame.
855.1.1. Bearing Walls. — Posts and studs in bearing walls and

854-855

partitions shall be designed as columns, with due allowance for
lateral support furnished by sheathing, intermediate bracing,
horizontal bridging, wall coverings and the floor and roof
assemblies. The walls shall be fabricated in such a manner as
to provide adequate support for the material used to enclose
the building and to provide for transfer of all lateral loads to
the foundation, in accordance with section 804.3.

855.1.2. Non-Bearing Walls. — Studs in non-bearing walls and
partitions shall not be spaced more than forty-eight (48) inches
on centers unless otherwise approved after test as an integrated
assembly, and may be erected with the long dimension parallel
to the wall.

855.1.3. Bracing. — In buildings more than one (1) story in
height and where necessary for strength in one (1) story buildings,
the corner posts shall be the equivalent of not less than three
(3) pieces of two (2) by four (4) inch studs, braced by not less
than one (1) piece of one (1) by four (4) inch continuous dia-
gonal brace let into the studs and into top and bottom plates
or by other approved methods. Bracing may be omitted when
diagonal wood sheathing or plywood panels are used, or other
sheathing specified in section 855.2 is applied vertically in panels
of not less than four (4) feet by eight (8) feet in area with
approved nailing complying with reference standard RS 8-77.
Ledger or ribbon boards used to support joists shall be not less
than one (1) by four (4) inches in size, cut into and securely
nailed to each stud.

855.1.4. Mortise and Tenon Framing. — Where mortise and tenon
framing is used, the vertical members of the frame shall be not
less than four (4) by six (6) inches in size and shall be designed
as a column.

855.1.5. Multiple Stories. — When the frame is more than one (1)
story in height and studs and posts are not continuous from sill
to roof, the members shall be secured together with approved
clips, splices or other connections to insure a continuous, well
integrated structure. Sheet metal clamps, ties or clips shall be
formed of galvanized steel or other approved corrosion-resistive
materials equivalent to No. 20 U.S. gage steel sheets for two (2)
inch framing members and not less than No. 18 U.S. gage for
three (3) inch structural members. For four (h) inch and larger
members, column splices and beam and girder supports shall
comply with section 854.

855.1.6. Framing Over Openings. — Headers, doublejoists, trusses
or other approved assemblies of adequate size to transfer all
superimposed loads to the vertical member shall be provided
over all window and door openings in bearing walls and partitions.

855.1.7. Empirical Provisions in Lieu of Design. — The provisions
of this section may be used in lieu of structural analysis only
for those buildings in occupancy group L-3 where the specific
occupancies correspond to a live load requirement of forty (40)
psf or less. Refer to reference standard RS 8-78 for these pro-
visions.

855.2. Wall Sheathing. — Except as' provided in section 855.3
for weather boarding or when stucco construction complying
with section 821.5 is used, all enclosed buildings shall be
sheathed with one of the materials of the following nominal
thickness or any other material of equal strength and durability
approved by the building official:

Reinforced cement mortar 1 inch

Wood sheathing 1 inch

Plywood 5/16 inch

Gypsum sheathing 1/2 inch

Fiber boards 1/2 inch

855.2.1. Paper-Backed Lath Sheathing. — In one^ and two-family I
dwellings and one (1) story commercial buildings with brick or
similar veneers the sheathing may consist of a layer or paper-
backed lath complying with section 821.4 with a one (1) inch,
intermediate space which shall be mortar filled as each course of f i
veneering is applied.

855.3. Exterior Weather Boarding, Veneers and Condensation. —
To secure weather-tightness in framed walls and other unoccupied
spaces, the exterior walls shall be faced with an approved
weather-resisting covering properly attached to resist wind and
rain. The cellular spaces shall be so ventilated as not to vitiate
the firestopping at floor, attic and roof levels or shall be pro- I
vided with interior non-corrodible vapor-type barriers complying
with the approved rules; or other means shall be used to avoid
condensation and leakage of moisture. The following materials
shall be acceptable as approved weather coverings of the nominal
thickness specified:

Brick Masonry veneers 2 inches

Stone veneers 2 inches

Clay tile veneers 1/4 to 1 inch

Stucco or exterior plaster 3/4 inch

855

Precast stone facing 5/8 inch

Wood siding (without sheathing) 5/8 inch

Wood siding (with sheathing) 1/2 inch

Protected fiber board siding 1/2 inch

Wood shingles 3/8 inch

Exterior plywood (without sheathing) See sec. 825.2

Exterior plywood (with sheathing) 5/16 inch

Asbestos shingles 5/32 inch

Asbestos cement boards 1/8 inch

Aluminum clapboard siding 024 inch

Formed steel siding 29 gage

Hardboard siding 1/4 inch

855.3.1. Masonry Veneers. — Refer to section 863.3.1.

855.3.2. Metal Veneers. — Veneers of metal shall be fabricated
from approved corrosion-resistive materials or shall be protected
front and back with porcelain enamel or shall be otherwise
treated to render the metal resistant to corrosion. Such veneers
shall be not less than No. 29 gage in thickness mounted on
wood or metal furring strips or approved sheathing on the
frame construction.

855.3.3. Height of Veneers. — Refer to sections 863.2 and 863.3.1.

855.3.4. Nailing. — All weatherboarding and wall and roof cov-
erings shall be securely nailed with aluminum, copper, zinc,
zinc-coated or other approved corrosion-resistive nails in accor-
dance with reference standard RS 8-77 or the approved manufac-
turer's standards.

Shingles and other weather coverings shall be attached with
appropriate standard shingle nails to furring strips securely
nailed to studs, or with approved mechanically-bonding nails
except when sheathing is wood not less than one (1) inch nomi-
nal thickness or plywood not less than five-sixteenths (5/16) inch
thick.

Wood shingles or shakes attached with approved corrosion-
resistive annular grooved nails may be applied over fiberboard
shingle backer and fiberboard sheathing when the installation
is in accordance with the approved manufacturer's standards.
Wood shingles or shakes and asbestos shingles or siding may be
nailed directly to nail base fiberboard sheathing not less than
one-half (1/2) inch nominal thickness with approved corrosion-
resistive annular grooved nails when the installation is in accor-
dance with the approved manufacturer's standards.

855.4. Foundation Anchorage. — When required to resist wind
uplift or lateral forces as determined in conjunction with article
7, wall sills shall be anchored to the foundation walls or piers at
corners and at intermediate intervals of not more than eight (8)
feet with properly anchored one-half (1/2) inch bolts. Sill plates
shall be at least equivalent to a two (2) by six (6) inch member.

855.5. At-Grade Protection.

855.5.1. Wood Framing. — All exterior wood framework of
buildings whether structural or non-loadbearing shall be supported
on approved foundation walls at least eight (8) inches above the
finished grade.

855.5.2. Metal Siding. — Exposed metal siding or sheathing shall
be protected from corrosion at the ground level by supporting
the foundation channel at sufficient height above grade on the
concrete apron or other approved water-resisting foundation.

855.6. Floors.

855.6.1. Bridging. — Except as hereinafter noted, in all floor,
attic and roof framing, there shall be not less than one (1) line
of bridging for each eight (8) feet of span. The bridging shall
consist of not less than one (1) by three (3) inch lumber, double-
nailed at each end, or of equivalent metal bracing of equal
rigidity. A line of bridging shall also be required at supports
where adequate lateral support is not otherwise provided.

855.6.2. Flooring. — The flooring of wood frame construction
shall be of adequate strength and stiffness to support required
loads and, where necessary for strength and for lateral support
of the building, subflooring shall be provided.

855.7. Roofs.

855.7.1. Types of Decking and Sheathing. — Roof deck sheathing
shall consist of not less than one (1) inch boards or plywood
of the thickness specified in section 825.3, or other approved
materials of equivalent strength and rigidity. When open-deck
sheathing is used on pitched roofs, it shall consist of not less
than one (1) by four (4) inch roofers spaced not more than six
(6) inches on centers or material of equivalent strength and
rigidity.

855.7.2. Wood Shingles. — Wood shingles and handsplit shakes
complying with reference standard RS 8-79 may be used for
roof covering where permitted in section 928.3, and may be
installed on tight decking or on spaced roof boards.

855.8. Flashing. — Approved corrosion-resistive flashing shall be
provided at top and sides of all exterior window and door

855-856

openings in such manner as to be leakproof. Similar flashings
shall be installed at the intersection of chimneys or other masonry
construction with frame or stucco walls, with projecting lips on
both sides under stucco copings; under and at the ends of
masonry, wood or metal copings and sills; continuously above
all projecting wood trim; at wall and roof intersections; under
built-in gutters; at a junction of chimneys and roofs; in all roof
valleys and around all roof openings. When veneers of natural
or artificial stone are used, fourteen (14) pounds felt or paper
shall be attached to the sheathing with flashing wherever neces-
sary to prevent moisture penetration behind the veneer.
855.9. Interior Finish. — In all habitable spaces, interior wall
and partition surfaces shall be finished with materials which do
not exceed the combustible limitations of section 904.0 and
are of adequate strength to resist a horizontal force of not less
than five (5) pounds per square foot.

SECTION 856.0. STRESS SKIN PANELS

856.1. Integrated Assemblies. — Approved panels or other inte-
grated assemblies fabricated of dimension lumber with wood
stress-coverings glued thereto, or consisting of structural units of
metal-covered or molded plywood or other approved plastics,
formed and molded into prefabricated loadbearing members shall
be permitted for use in floors, roofs, walls, partitions and
ceilings when designed in accordance with reference standard
RS 8-54, or meeting the test requirements of sections 803, 804,
and 805.

856.2. Splices. — Splices and connections between panels shall be
weathertight and of sufficient strength to resist two and one-half
(2-1/2) times the design live load to which they will be sub-
jected in normal use. The fastenings of covering assemblies to
structural studs, ribs or joists shall provide rigidity equivalent to
approved gluing. Nailing shall not be acceptable for that purpose.

856.3. Molded Plywood Units. — Structural units of plywood or
other approved plastics of similar combustible characteristics
formed and molded into prefabricated load-bearing members
shall conform to the approved rules and shall be identified by
the approved label. The design shall be based on approved
engineering analysis confirmed by the tests prescribed in sections
803 and 804.

SECTION 857.0. STRUCTURAL GLUED LAMINATED
TIMBER AND BUILT-UP LUMBER CONSTRUCTION

Buildings and structures may be designed and erected of glued
laminated structural members of standard commercial or stress
grade lumber, or of composite members of plywood and di-
mension lumber.

857.1. Structural Glued Laminated Timber. — Structural glued
laminated timber shall be manufactured and constructed under
the controlled material procedure to meet the requirements of
reference standards RS 8-55 and RS 8-56. Structural design shall
be in accordance with reference standard RS 8-51 or with other
approved engineering standards.

857.2. Glued Lumber Members. — Built-up beam and column
sections consisting of one or more webs with glued lumber
flanges and stiffeners, shall be designed in accordance with
approved engineering analysis.

857.2.1. Gluing Surfaces. — In glued lumber constructions, the
surfaces shall be worked to a smooth, flat surface without
sanding and free from wax, grease or oil to insure a complete
glue bond over the entire contact. Factory sanded plywood shall
not be prohibited.

857.3. Mechanically Laminated Members. — Mechanically lamin-
ated members shall be designed and constructed in accordance
with reference standard RS 8-76.

ARTICLE

BUILDING ENCLOSURES, WALLS AND WALL
THICKNESS

859.0

Enclosure Walls

871.0

Foundation Walls

860.0

Protection of Wall Openings

872.0

Retaining Walls

861.0

Fire Access Panels

873.0

Isolated Piers

862.0

Structural Glass Block Walls

874.0

Waterproofing

863.0

Wall Veneers

875.0

Ratproofing

864.0

Structural Glass Veneers

876.0

Protection Against Decay and

865.0

Thin Stone and Tile Veneers

Termites

866.0

Metal Veneers

877.0

Fire Protection and Fire-

867.0

Plastic Veneers

stopping

868.0

Thickness of Solid Masonry
Walls

878.0

Thermal Insulating Materials

869.0

Thickness of Panel Walls

RS 8

Reference Standards

870.0

Parapet Walls

TABLES

8-2 859.5.9.1. Requirements for Glass Panels Subject to Impact Loads
8-3 863.2.1. Minimum Thickness of Veneer
8-4 871.2.2.a Thickness of Foundation Walls.

SECTION 859.0. ENCLOSURE WALLS

All buildings, except as may be provided for miscellaneous
structures designed for special uses, shall be enclosed on all sides
with independent or party walls or frame, masonry or other
approved construction. Such walls shall be constructed to afford
the fireresistance specified in section 221.1 table 2-1 as other-
wise required in this code.

859.1. Projections. — Exterior enclosure walls shall be constructed
entirely within property lines or building lines when established
by law, except for authorized projections beyond the street lot
line in accordance with the provisions of section 312.

859.2. Exterior Wail Pockets. — In exterior walls of all buildings
and structures, wall pockets or crevices in which moisture may
accumulate shall be avoided or protected with adequate caps or
drips, or other approved means shall be provided to prevent
water damage.

859.3. Gutters and Coping. — Unless constructed with parapet
walls and coping as required by section 870 whereby provision

would be made for interior drains, all exterior walls shall be
provided with gutters and downspouts or leaders to dispose of
roof drainage in compliance with article 17. Exceptions may be
made for:

a. Roofs with overhangs greater than twelve (12) inches in
width for one (1) story or twenty-four (24) inches in
width for two (2) story, and

b. One (1) and two (2) story buildings not over six hundred
and fifty (650) square feet in area.

Roofs of buildings and of all parts thereof shall be sloped to
drain at a pitch of not less than one (1) inch in ten (10) feet.
Means shall be provided to prevent rain water from any part
of a building except window sills, copings and cornices not
more than one (1) foot wide and awnings or marquises dis-
charging off the outer edge, from filling or flowing upon a
public way.

859.4. Exceptions. — The provisions of this article shall not be
deemed to prohibit the omission of exterior walls for all or
part of a story of a building in accordance with the provisions
of section 906.1.

859.5. Glass in Walls.

859.5.1. Scope. — The provisions of sections 859.5.2 through
859.5.5 shall apply to the use of glass in the exterior wall of a
building and shall be limited to exterior application wherein the
glass would not be subjected to any loads normal to the face of
glass other than those due to wind. For applications involving
human impact, the provisions of section 859.5.9 shall apply.
For other cases, the strength and mode of installation of glass
shall be approved by the building official.

859.5.2. Support for Glass Panels. — Glass shall be firmly held
in place. The supports shall be of adequate strength to resist
the applicable design wind loads as prescribed in article 7.

859.5.3. Glass Requirements. — Unless otherwise stated herein,
glass shall meet the requirements of reference standard RS 8-59
for the applicable type, size, thickness and quality.

859.5.4. Thickness of Glass. — Thicknesses of glass panels shall
be chosen as required by reference standard RS 7-6 and article 7.

859.5.5. Installation of Glass Panels. — Glass panels shall be
handled and installed so that their strength is not impaired by
chipping or scratching, shall be fully and firmly bedded in their
supports, and shall be mounted in a manner that will accommo-

859

date differential movements due to thermal and loading conditions.

859.5.6. Protection of Glass Panels. — Glass panels installed in
areas where they will be subject to unusual conditions of con-
struction damage, such as spatter from welds or locations near
materials hoists, shall be protected by a hardboard covering or
its equivalent during the period that such work is in progress.

859.5.7. Deflection of Support. — The deflection of members
supporting glass panels under the design wind load (measured
perpendicular to the plane of the panel) shall not exceed L/175,
where L is the span of the supporting member. In no case
shall such deflection exceed three-quarter (3/4) inch.

859.5.8. Jalousies. — In jalousie windows and doors regular
plate, float, sheet or rolled glass thickness shall be not less than
three-sixteenths (3/16) inch; glass length shall not be more than
forty-eight (48) inches; glass edges shall be smooth. Other types
of glass may be used if approved by the building official.

859.5.9. Panels Subject to Human Impact Loads. — Glass in
prime and storm doors, interior doors, fixed glass panels that
may be mistaken for means of egress or ingress, shower doors
and tub enclosures, or in similar installations wherein one (1)
or more of the following criteria apply, shall meet the require-
ments set forth in section 859.5.9.1. table 8-2 or by comparative
tests, shall be proven to produce equivalent performance:

a. Openings are located in regularly occupied spaces.

b. Lowest point of panel is less than eighteen (18) inches
above finished floor.

c. Minimum dimension of panel is larger than eighteen
(18) inches.

859.5.9.1. Table 8-2

Requirements for Glass Panels Subject to Impact Loads

1,2

Glass Type

Individual

Opening

Area

Requirements

Regular plate, sheet Over 6

or rolled (annealed) sq. ft.

Regular plate, sheet

Over 6

or rolled (annealed)

sq. ft.

surface sandblasted,

etched, or otherwise

depreciated

Regular plate, sheet

Over 6

or rolled (annealed)

sq. ft.

obscure

Laminated

Over 6

sq. ft.

Fully-tempered

Over 6

sq. ft.

Wired

Over 6

sq. ft.

All unframed glass
doors (swinging)

Not less than 3/16 in. thick.
Must be protected by a push-
bar or protective grille firmly
attached on each exposed
side 3 , if not divided by a
muntin.

Not less than 7/32 in. thick.
Must be protected by a push-
bar or protective grille firmly
attached on each exposed
side 3 .

Not less than 3/16 in. thick.
Must be protected by a push-
bar or grille firmly attached
on each exposed side 3 .
Not less than 1/4 in. thick.
Shall pass impact test re-
quirements of reference stan-
dard RS 8-75.

Shall pass impact test re-
quirements of reference stan-
dard RS 8-75.

Not less than 7/32 in. thick.
Shall pass impact test re-
quirements of reference stan-
dard RS 8-75.

Shall be fully-tempered glass
and pass impact test require-
ments of reference standard
RS 8-75.

NOTES:

i Glass less than single strength (SS) in thickness shall not
be used.

2 If short dimension is larger than twenty-four (24) inches,
glass must be double strength (DS) or thicker.

3 Building owners and tenants shall maintain push-bars or
protective grilles in safe condition at all times.

859-861
SECTION 860.0. PROTECTION OF WALL OPENINGS

860.1. Fire-Protected Openings. — Openings in exterior walls
when required to be fire-protected shall comply with the pro-
visions of article 9.

860.2. Area of Openings. — All openings facing on a street,
yard, court, or public space which are required for light and
ventilation shall comply with the provisions of article 5.

860.3. Structural Strength.

860.3.1. Against Wind Forces. — In all buildings required to
resist wind pressure under the provisions of article 7, exterior
window openings shall be designed to resist the specified wind
load.

860.3.2. Sash or Frames. — The glass or other approved glazing
material and when used, metal frames or other reinforcement,
shall be adequate to resist the wind loads specified in article 7
blowing both inwardly and outwardly.

SECTION 861.0. FIRE ACCESS PANELS

Completely enclosed buildings, without exterior openings in the
enclosure walls, or without ready access for the purpose of
fighting fire, shall be provided with access panels as required
herein.

Access panels shall be not less than thirty-two (32) inches by
forty-eight (48) inches in size.

When required to be fireresistive, access panels shall be equip-
ped with approved opening protectives, complying with article 9,
which are readily openable from both the outside and the inside.

861.1. Multi-Story Buildings. — In all exterior walls of the
building required to have thirty (30) foot wide open space
adjacent thereto (see sections 307.1 and 308.1) each floor below
a height of one hundred (100) feet shall be provided with access
panels spaced not more than fifty (50) feet apart in each story.

861.2. Single-Story Buildings. — In one (1) story buildings, not
more than eighty-five (85) feet in height:

a. Roof vents shall be provided, spaced not more than
one hundred twenty-five (125) feet apart; and

b. Grade level doors, or fire access panels shall be provided
spaced not more than one-hundred (100) feet apart in all
exterior walls of the building required to have thirty (30)

foot wide open space adjacent thereto (see sections 307.1
and 308.1).

861.3. Construction of Access Panels. — Access panels:

a. Shall have a sill height of not more than thirty-six (36)
inches; and

b. Shall be readily identifiable from the outside, and;

c. Shall be readily openable from the outside or shall be
glazed with plain flat glass.

861.4. Location. — Wherever practicable, one access opening in
each story shall provide access to a stairway, or where there is
no stairway at the exterior wall, one access opening in each
story shall be located as close as practicable to a stairway.

861.5. Exemptions. — The provisions of this article shall not
apply to any story that is completely protected by an automatic
sprinkler system conforming to the construction requirements of
article 12.

SECTION 862.0. STRUCTURAL GLASS BLOCK WALLS

Masonry of glass blocks may be used in non-loadbearing
exterior or interior walls and in openings that might otherwise
be filled with windows, either isolated or in continuous bands,
provided the glass block panels have a thickness of at least
three and one-half (3-1/2) inches, at the mortar joint and the
mortared surfaces of the blocks are satisfactorily treated for
mortar bonding.

862.1. Exterior Wall Panels. — The maximum dimensions of
glass block wall panels in exterior walls when used singly or
in multiples forming continuous bands of structural glass blocks
between structural supports shall be twenty-five (25) feet in
length and twenty (20) feet in height between structural supports
and expansion joints; and the area of each individual panel
shall be not more than two hundred and fifty (250) square
feet. Intermediate structural supports shall be provided to
support the dead load of the wall and all other superimposed
loads. When individual panels are more than one hundred and
forty-four (144) square feet in area a supplementary stiffener
shall be provided behind the panels, anchored thereto and to
the structural supports. Panels shall be set in recesses at the
jambs and panels exceeding ten (10) feet in horizontal dimension
between supports shall be set in recesses at the head so as
to provide a bearing surface at least one (1) inch wide along
the panel edges.

861-862

862.2. Joint Materials. — Glass blocks shall be laid up in type S
or N mortar with approved galvanized or other non-corrosive
metal wall ties in the horizontal mortar joints of exterior panels.
The sills of glass block panels shall be coated with approved
asphaltic emulsion, or other elastic waterproofing material previous
to laying the first mortar course and the perimeter of the panels
shall be caulked to a depth of not less than one-half (1/2) inch
with nonhardening caulking compound on both faces; or other
approved expansion joints shall be provided. When laid up in
joint materials other than mortars herein defined, no single
panel shall be more than one hundred (100) square feet in area
nor more than ten (10) feet in either length or height. Both
vertical and horizontal mortar joints shall be at least one-
fourth (1/4) inch and not more than three-eighths (3/8) inch
thick and shall be completely filled.

862.3. Wind Loads. — Exterior wall panels shall be held in
place in the wall opening to resist both the internal and external
pressures due to wind specified in sections 713 and 714.

862.4. Interior Wall Panels. — Structural glass blocks shall not be
used in fire walls or party walls or for load-bearing construction.
Blocks in interior walls shall be erected with mortar in metal
frames or reinforcement as provided in this section for exterior
walls or other approved joint materials, except that wood strip
framing may be used in partitions not required to be fire-
resistive. For interior walls, glass block panels shall not exceed
two hundred - fifty (250) square feet of unsupported area nor
twenty-five (25) feet in one direction between supports.

862.5. Fireresistance Rating. — Nothing herein contained shall
be construed to prohibit the use of glass blocks in an opening
protective assembly or nonbearing partition or wall when re-
quired to afford a specific fireresistance, provided approval of
the building official is secured after satisfactory time-temper-
ature performance under the prescribed test procedure of article 9.

862.6. Access Panels. — Access panels shall be provided in ex-
terior glass block walls for fire department use to comply with
section 861.

862.7. Reinforcement. — Glass block panels shall have approved
reinforcement in the horizontal mortar joints, extending from
end to end of mortar joints but not across expansion joints,
with any unavoidable joints spliced by lapping the reinforcement
not less than six (6) inches. The reinforcement shall be spaced
at not more than two (2) feet vertically. In addition, reinforce-

ment shall be placed in the joint immediately above and below
all openings within a panel.

862.8. Expansion Joints. — Every exterior glass block panel shall
be provided with expansion joints at the sides and top. Expan-
sion joints shall be entirely free of mortar, and shall be filled
with resilient material.

SECTION 863.0. WALL VENEERS

Veneer as used in this section refers to an exposed facing
wythe or brick, tile, ceramic, terra cotta, concrete masonry
units, cast stone, precast concrete, natural stone, or other
weather-resistant noncombustible units securely attached to a
surface for the purpose of providing ornamentation, protection
or insulation, but not intentionally so bonded as to exert
common action under load.

863.1. Backing Surfaces for Veneers. — Veneers for other than
frame buildings, shall be attached only to substantial, rigid,
noncombustible surfaces which are plumb, straight and of true
plane; and no wood backing surfaces shall be used except in
frame construction. The backing shall provide sufficient rigidity,
stability and weather resistance; and the veneer shall be installed
and anchored as required in this code for the specific material.

863.2. Limitations, — Veneer shall not be assumed to add to the
strength of any wall, nor shall it be assumed to support any
load other than its own weight. No veneer shall be less than
the thicknesses specified in the following table. The height and
length of veneer areas shall be unlimited, except as required to
control expansion and contraction.

863.2.1. Table 8-3

Minimum Thickness of Veneer

Ceramic veneer (architectural terra cotta — anchored type) 1 inch

Brick 2 inches

Stone (natural) 2 inches

Stone (cast artificial) 1-1/2 inches

Clay tile (structural) 1-3/4 inches

Clay tile (flat slab) 1/4 to 1 inch

Marble slabs 1 inch

Precast Stone Facing 5/8 inch

Structural Glass 11/32 inch

Aluminum Clapboard Siding 024 inch

Metal (approved corrosion-resistive) 29 U.S. gage

Aluminum 03 inch

862-863

863.3. Design. — All anchor attachments shall be designed to
resist a positive or negative horizontal force of thirty (30) psf,
and adhesion type veneer shall be designed to have a bond
sufficient to withstand a shearing stress of fifty (50) psi. In
lieu of design, veneer may be installed in accordance with the
requirements of sections 863.3.1. and 863.3.2.

863.3.1. Veneer on Wood. — Anchored masonry veneer attached
to wood frame structures shall be supported on footings or
foundation walls. Where anchored veneer exceeding twenty (20)
feet in height is applied, it shall be supported in a manner that
will provide for movement between the veneer and its backing.
Veneer of unit masonry shall be attached directly to wood studs,
by one of the following means:

a. With at least twenty-two (22) gage corrosion-resistance
corrugated steel ties at least seven-eighths (7/8) inch wide
at vertical intervals of not more than twenty-four (24)
inches and horizontal intervals of not more than thirty-
two (32) inches, but in no case less than one (1) tie for
each three and one-half (3-1/2) square feet of wall area.

b. Directly to a one (1) inch reinforced cement mortar base.

863.3.2. Veneer on Masonry. — Veneer attached to masonry or
concrete backing shall not be limited in height other than by
compressive stresses. Veneer shall be securely attached to the
masonry or concrete backing by one of the following means
or by a means that is equivalent in strength:

a. Metal ties conforming to section 836.0.2 except that ties
shall be spaced not more than twenty-four (24) inches
apart either horizontally or vertically.

b. Corrosion-resistant dovetail slot anchors where the backing
and the veneer have been designed for this type of at-
tachment. Such anchors shall be formed from at least
sixteen (16) gage steel at least one (1) inch wide.

c. Adhesion type masonry veneer shall be installed in
accordance with the manufacturer's recommendations
and setting plans.

d. Where anchored veneer is not grouted to the backing, it
shall be supported in a manner that will provide for
movement between the veneer and its backing.

863.4. Support. — The weight of all anchored type veneer shall be
supported upon footings, foundation walls, or other supports
without dependence upon anchors for vertical support. Veneer
above openings shall be supported upon lintels.

SECTION 864.0. STRUCTURAL GLASS VENEERS

864.1. Dimensions. — The minimum thickness of glass veneer
shall be eleven thirty-seconds (11/32) inch and the area of
individual panels shall not exceed ten (10) square feet, with a
maximum length of four (4) feet. The edge of each unit shall be
ground square with a slight arris; and all exposed, external
corners and angles shall be rounded to a radius of not more
than three-sixteenths (3/16) inch.

864.2. Construction.

864.2.1. Backing Surface. — The glass veneer shall be set in
mastic cement on a float coat of one (1) inch thick cement
mortar reinforced with wire lath attached to non-combustible
furring spaced not more than twelve (12) inches on centers or
the veneer may be set by other approved methods.

864.2.2. Support of Veneer. — The base course of glass units
shall be supported on a corrosion-resistive metal frame anchored
to the backing and caulked with a waterproof compound at
grade.

864.3. Reinforcement. — Metal reinforcing of cold formep 1 cor-
rosion-resistive angles of not less than No. 16 U.S. gage or
other approved reinforcement shall be provided in all horizontal
joints anchored into the wall with expansion or toggle bolts.

864.4. Expansion Joints. — Expansion joints shall be provided
at ends and intermediate sections caulked with an approved
waterproofing compound. Where necessary for water-tightness,
exposed edges shall be protected with corrosion-resistive metal
or other approved noncombustible flashing.

864.5. Other Loads. — No signs, awning brackets or other loads
shall be hung directly from glass veneers, but shall be supported
on framing anchored to or otherwise supported by the wall,
free from contact with the glass.

SECTION 865.0. THIN STONE AND TILE VENEERS

865.1. Size Limitation. — Where subject to frost and freezing
temperatures, tile and terra cotta units shall be frostproof and
shall not be more than two hundred and eighty-eight (288)
square inches in area; and where not subject to frost action, the
size of the tile may be increased not more than fifty (50) per
cent in area.

864-868

865.2. Construction. — One (1) inch thick marble, terra cotta,
and similar materials; or ceramic tile one-quarter (1/4) to one (1)
inch in thickness shall be set in accordance with reference stan-
dards RS 8-21 and RS 8-61.

865.3. Jointing. — All joints shall be grouted and pointed with
an approved waterproofed cement compound.

SECTION 866.0. METAL VENEERS

866.1. Materials. — Veneers of metal shall be fabricated from
approved corrosion-resistive alloys, or shall be covered front and
back with approved porcelain enamel, or otherwise treated to
render the metal resistant to corrosion.

866.2. Construction. — The metal veneer shall be securely attached
to the masonry or supported on approved metal framing pro-
tected by painting, galvanizing or other approved protection
or on wood studs and furring strips, treated with an approved
preservative process.

866.3. Waterproofing. — All joints and edges exposed to the
weather shall be caulked with approved durable waterproofing
material or by other approved means to prevent penetration of
moisture.

866.4. Grounding Metal Veneers. — Grounding of metal veneers
on all buildings shall comply with the requirements of Article 15,
and Massachusetts State Law.

SECTION 867.0. PLASTIC VENEERS

Veneers of approved weather-resisting, noncombustible plastics
shall be erected and anchored on an approved substrate water-
proofed or otherwise protected from moisture absorption and
sealed with a coat of mastic or other approved waterproof
coating in accordance with the approval of the building official
and the applicable portions of articles 9 and 20.

SECTION 868.0. THICKNESS OF MASONRY WALLS

All masonry walls shall be of the minimum thickness specified
by reference standard RS 8-51, unless designed in accordance
with reference standard RS 8-50. In no case shall the combined
stress due to all loads exceed the allowable working stresses
specified for the materials of construction in this code and
reference standard RS 8-50.

SECTION 869.0. THICKNESS OF PANEL WALLS

869.1. Solid Panel Walls. — Panel, apron or spandrel walls as
defined in article 2 supported at vertical intervals not exceeding
thirteen (13) feet in height, shall not be limited in thickness,
provided they meet the fireresistive requirements of article 9
and section 221.1 table 2-1 and are constructed of approved
noncombustible weather-resisting materials of adequate strength
to resist the wind loads specified in sections 713 and 714.

869.2. Hollow Panel Walls. — Unless constructed of the materials
and thickness specified by this code for masonry, hollow panel
walls shall be tested and approved in the assembled unit as
constructed in normal practice to develop the required fireresist-
ance ratings specified in section 221.1 table 2-1 for exposure
on each face.

869.3. Weather Resistance. — When the construction as tested
and approved for fireresistance does not possess the required
weather resistance, it shall be covered on the exterior with
approved corrosion-resistive metal facings or other approved
noncombustible weather-resisting veneers.

869.4. Anchorage. — All panel walls shall be anchored to the
structural frame to insure adequate lateral support and resistance
to wind.

SECTION 870.0. PARAPET WALLS

Unless specifically provided for in sections 906.4, 907 or other
provisions of this code, required parapets for exterior masonry
walls shall extend not less than two (2) feet above the roof.
Nothing in this section shall be construed as requiring parapets
for masonry exterior walls in one- and two-family dwellings and
structures where the roof overhangs the wall or in places where
such walls are capped with cornices or gutters.

870.1. Minimum Thickness and Height. — Parapet walls shall be
the same thickness as the wall below; but in no case shall the
required thickness exceed twelve (12) inches, nor shall the height
be more than four (4) times the thickness unless laterally sup-
ported by noncombustible bracing or buttresses.

870.2. Coping. — The top of all parapet walls exposed to the
weather shall be coped with approved noncombustible and
weather-resisting materials.

870.3. Construction Requirements. — All cells in the hollow
masonry units and all joints in solid, cavity, or masonry bonded

869-871

hollow wall construction shall be filled solid with mortar. All
corners of masonry parapet walls shall be reinforced with
joint reinforcement or its equivalent at vertical intervals not
greater than twelve (12) inches. Such reinforcement shall extend
around the corner for at least four (4) feet in both directions
and splices shall be lapped at least six (6) inches.

SECTION 871.0. FOUNDATION WALLS

871.1. Design. — Foundation walls shall be designed to resist frost
action and to support safely all vertical and lateral loads as
provided in article 7. The maximum compressive stress due to
combined load shall be within the values specified for the
materials used in the construction. Unless properly reinforced,
tensile stresses shall be eliminated in the masonry insofar as
practicable; but in any case shall not exceed those permitted by
this code for plain masonry.

871.2. Minimum Thickness. — The thickness of foundation walls
shall be not less than the thickness of the wall supported and
the minimum thickness shall be limited for the various materials
of construction as herein specified. Eight (8) inch foundation
walls may be permitted under brick-veneered frame and under
ten (10) inch cavity walls when the total height of wall supported
including gables is not more than twenty (20) feet.

871.2.1. Concrete. — When reinforced concrete is required to
resist stresses, foundation walls shall be not less than eight (8)
inches thick. Concrete in foundation walls shall have a minimum
compressive strength at twenty-eight (28) days of two thousand
(2,000) psi, when tested in accordance with reference standard
RS 8-61.

871.2.2. Hollow and Solid Masonry and Mass Concrete. — The
thickness of masonry foundation walls shall not be less than
shown in the following table. The combined height of eight (8)
inch foundation wall and the wall supported shall not exceed
thirty-five (35) feet.

871.2.2.a. Table 8-4

THICKNESS OF FOUNDATION WALLS

Foundation Wall

Construction

Maximum Depth Below Grade (feet) 1 - 2

Type

Thickness
(Inches)

Frame

Masonry
Veneer

Masoni

Hollow
masonry

10
12

4 (6)

5 (7)
7

4.5 (6)

5.5 (7)
7

5 (7)

6 (7)

Solid
masonry

10
12

5 (7)

6 (7)
7

5.5 (7)
6 (7)
7

6 (7)
6.5 (7)

Mass

concrete

NOTES:

1. Depth below grade may be increased up to those shown in parentheses when
such increase is warranted by soil conditions and is required by the building
official.

2. Where height of unbalanced fill (height of finish grade above basement flooi
or inside grade) exceeds seven (7) feet for coarse sands and gravel or four (4
feet for other soils, foundation wall thickness shall be determined by structura
analysis as required in section 871.1.

871.2.3. Hollow Unit Walls. — Foundation walls of approved
hollow masonry units shall be provided with not less than four
(4) inches of solid masonry at girder bearings or shall be
strengthened with buttresses; and shall only be allowed for
support of one (1) and two (2) story buildings.

871.2.4. Rubble Stone. — Foundation walls of rough or random
rubble stone shall be not less than sixteen (16) inches thick
Rough or random rubble stone masonry without level beds
shall not be used for foundation walls more than ten (10) feet
high or supporting buildings more than forty-five (45) feet high.

871.2.5. Bonding. — All masonry foundation walls shall be bonded
as required for superstructure walls in section 836.

871-872

871.3. Increased Thickness With Depth. — When any foundation
;wall, other than a wall that is designed as a retaining wall,

extends more than twelve (12) feet below the top of the first
floor beams, the thickness of the wall shall be increased four (4)
inches for each additional twelve (12) feet or fraction thereof in
depth.

871.4. Corbels on Eight Inch Foundation Walls. — Where an
eight (8) inch wall is corbeled, the top course shall be a full

f header course at least six (6) inches in length, extending not

[ higher than the bottom of the floor framing. The maximum

projection of one (1) unit shall neither exceed one-half (1/2)

: the depth of the unit nor one-third (1/3) its width at right

angles to the face which is offset; unless specifically provided

for herein the provisions of section 839 shall apply.

871.5. Lateral Stability. — Foundation walls of buildings and
structures which serve as retaining walls shall conform to the
applicable requirements of section 872.

871.6. Lateral Bracing. — The equivalent unbraced height of a
wall supported by lateral soil pressure shall be determined by a
recognized method of elastic analysis.

871.7. Restrictions. — Sand lime brick or gypsum tile shall not be
used in foundation walls nor as part of the required thickness
thereof. Wood shall not be used in the foundations of permanent
structures, except as may be provided in article 7.

SECTION 872.0. RETAINING WALLS

Walls built to retain or support the lateral pressure of earth or
water or other superimposed loads shall be designed and con-
structed of approved masonry, reinforced concrete, steel sheet
piling or other approved materials within stresses allowed by
this code.

872.1. Design. — Retaining walls shall be designed subject to the
requirements of section 872.1.1 to resist the pressure of the
retained material including both dead and live load surcharges
to which they may be subjected, and to insure stability against
overturning, sliding, excessive soil pressure and water uplift.
Particular attention shall be paid to the type of backfill and
drainage.
872.1.1. Factor of Safety.

a. Overturning. — The minimum factor of safety against
overturning of the structure as a whole shall be one

and one-half (1-1/2). Stability against overturning shall be
provided by the dead load of the structure by the allow-
able uplift capacity of piling, by anchors, by the weight
of soil directly overlying footings provided that such soil
cannot be excavated without recourse to major modifica-
tion of the structure or by any combination of these
factors,
b. Sliding. — The minimum factor of safety against sliding
of the structure under lateral load shall be one and one-
half (1-1/2). Resistance to lateral loads shall be provided
by friction between the foundation and the underlying
soil, by passive earth pressure, by batter piles, or by
plumb piles, subject to the following.

1. The resistance to lateral loads due to passive earth
pressure shall be discounted where the abutting soil
could be removed, inadvertently, by excavation.

2. In the case of pile supported structures, frictional
resistance between the foundation and the underlying
soil shall be discounted.

3. The available resistance to friction between the foun-
dation and the underlying soil shall be predicated on
an assumed friction factor of 0.5 for soils of classes
1 through 9. A greater value of coefficient of friction
may be used subject to verification by analysis and
test. For soils of poorer classes, the stability shall be
analyzed by approved procedures of soil mechanics.

872.2 Hydrostatic Pressure. — In addition to earth pressure, walls
shall be designed and constructed to resist hydrostatic pressures
corresponding to the maximum probable ground water level.

872.3. Coping. — All masonry retaining walls other than rein-
forced concrete walls shall be protected with an approved coping.

872.4. Wood Retaining Walls. — Wood retaining walls may be
used subject to the requirements of section 876.4.

SECTION 873.0. ISOLATED PIERS

Isolated masonry piers shall be bonded as required for solid
walls of the same thickness and shall be provided with adequate
means for distributing the load on the top of the pier.
873.1. Construction. — Isolated piers shall be built of solid units,
for which hollow units filled with concrete shall not be sub-
stituted unless designed and constructed in conformance with

872-875

jequirements for columns in reference standard RS 8-50. The
unsupported height of isolated piers shall not exceed twelve
112) times their least dimension.

'373.2. Piers Within Walls. — When the clear horizontal distance
between piers in masonry walls exceeds ten (10) feet they shall
be considered isolated piers.

573.2.1. Exceptions. — Thickening of portions of walls for non-
structural purposes whether or not directly under concentrated
loads shall not necessarily be construed as creating an isolated
pier.

SECTION 874.0. WATERPROOFING

374.1. Steel Frame. — Exterior steel columns and girders before
mbedment in masonry of the required fireresistance specified

in section 221.1 table 2-1 shall be protected from moisture by
approved waterproofing material, a parging coat of cement
mortar or by a minimum of eight (8) inches of weathertight
masonry.

874.2. Chases. — The backs and sides of all chases in exterior
walls with less than eight (8) inches of approved masonry to
the exterior surface shall be insulated and waterproofed.

874.3. Foundations. — Exterior walls and floors in contact with
earth below grade enclosing habitable or occupiable rooms or
spaces shali be made waterproof. Floors and portions of exterior
walls below grade shall be reinforced to withstand water pres-
sure as prescribed in sections 710 and 871 if required.

874.4. Types of Waterproofing. — Portions of exterior walls below
grade, required herein to be made waterproof shall be protected
with not less than a one-coat application of approved water-
proofing paint, or a one-half (1/2) inch thick parging coat of
Portland cement mortar or other approved waterproof covering;
and if furred shall be done so with impervious material. The
processes and methods used to render buildings, structures or
parts thereof watertight, as herein required, shall meet with the
approval of the building official.

874.5. Protection From Heat. — Under boilers, furnaces, and
other heat-producing apparatus, suitable insulation shall be
installed to protect the waterproofing against damage from heat.

SECTION 875.0. RATPROOFING

All buildings and structures and the walls enclosing habitable
or occupiable rooms and spaces in which persons live, sleep or

work; or in which feed, food or foodstuffs are stored, prepared,
processed, served or sold shall be constructed rat and vermin-
proof in accordance with the provisions of this section. Every
basement or cellar in buildings hereafter erected shall be com-
pletely covered with a ratproof floor of concrete, or solid masonry
laid in cement mortar, not less than two (2) inches thick, or
other approved flooring.

875.1. Grade Protection.

875.1.1. Apron. — When required for protection against rodents,
all exterior walls at and near grade shall be constructed or as-
sembled of component materials, or chemically or otherwise
treated to render the construction rat or vermin-proof. When
not provided with a continuous masonry foundation wall, a
masonry or reinforced concrete apron, not less than four (4)
inches in thickness or of other approved noncombustible, water-
resisting and rat-proofing material of required strength, shall be
installed around the entire perimeter of the buildings.

875.1.2. Height of Apron. — The apron shall extend sufficiently
above grade to provide for the average snow fall, but not less
than eight (8) inches above, nor less than twenty-four (24)
inches below grade level; and, if serving as a foundation bearing
wall, to sufficiently greater depth to assure protection from
frost action as required in section 729. When the superstructure
walls are not constructed of masonry, the spaces between studs
shall be filled to a height of two (2) feet above grade with
concrete or other material indestructible by rats.

875.2. Grade Floors. — Where continuous concrete grade floor
slabs are provided, no open spaces shall be left between slab
and walls, and all openings in the slab shall be protected.

875.3. Opening Protection.

875.3.1. Wall Openings. — Openings in the apron required for
ventilation or other purposes shall be guarded with corrosion-
resistive rodent-proof shields of not less than No. 22 U.S. gage
perforated steel sheets, or No. 20 B & S gage aluminum or No.
16 U.S. gage expanded metal or wire mesh screens, with no
more than one-half (1/2) inch mesh openings.

875.3.2. Slab Openings. — Access openings in grade floor slabs
shall be protected with concrete, masonry, metal or other
corrosion-resistive non-combustible covers of adequate strength
to support the floor loads.

875.3.3. Pipes and Conduits. — All openings for pipe, conduit,
cable and similar purposes at or near grade shall have snugly-
fitted collars to eliminate all open spaces.

875-876
SECTION 876.0. PROTECTION AGAINST DECAY AND
TERMITES

876.1. Where Conditions are Favorable to Decay.

876.1.1. Wood in Contact with the Ground. — All wood in con-
tact with the ground and supporting permanent structures shall
be approved treated wood.

876.1.2. Untreated Wood. — Untreated wood may be used where
entirely below ground water level or continuously submerged in
fresh water and may be used in contact with the ground for
detached accessory buildings not intended for human occupancy,
for temporary structures and for fences.

876.2. Wood Joists or the Bottom of Wood Structural Floors.—
When wood joists or the bottom of wood structural floors with-
out joists are closer than eighteen (18) inches or wood girders
are closer than twelve (12) inches, to exposed ground located
within the periphery of the building over crawl spaces or un-
excavated areas, they shall be approved durable species or
treated wood. Ventilation 'shall be provided as required in section
508.0.

876.2.1. Additional Requirements. — Positive drainage shall be
provided for all areas under the building not occupied by base-
ments or cellars, and the ground surface shall be covered with a
vapor barrier. All loose wood and debris including wood forms
shall be removed from spaces under the building. All stumps
and roots shall be grubbed to a minimum depth of twelve (12)
inches.

876.3. Sills. — All sills which rest on concrete or masonry exterior
walls and are less than eight (8) inches from exposed earth shall

be of approved durable species or treated wood.

876.3.1. Sleepers and Sills. — Sleepers and sills on a concrete or
masonry slab which is in direct contact with earth shall be raised
by masonry or concrete at least three (3) inches above the top
of such slab except when approved durable species or treated
wood is used.

876.3.2. Posts or Columns. — Wood posts or columns in cellars
shall be supported by piers projecting at least three (3) inches
above the finish floor and separated therefrom by an approved
impervious barrier except when approved durable species or
treated wood is used. Posts or columns used in damp locations
below grade shall be of approved durable species or treated wood.

876.3.3. Wall Pockets. — Ends of wood girders entering masonry
or concrete walls shall be provided with a one-half (1/2) inch

air space on top, sides and end unless approved durable species
or treated wood is used.

876.3.4. Clearance Between Wood Siding. — Clearance betweer
wood siding and earth on the exterior of a building shall be noi
less than six (6) inches.

876.4. Wood Used in a Retaining Wail. — Wood used in a re-
taining wall shall be approved durable species or treated wood.
Retaining walls of wood shall be limited to the following:

a. When the wall is not more than two (2) feet in height
and is located on the property line.

b. When the wall is not more than four (4) feet in height
and is separated from the property line by a minimum
distance equal to the height of the wall.

c. The wall shall not exceed six (6) feet in height. A wood
retaining wall shall be separated from any permanent;'
building by a minimum distance equal to the height oil
the wall.

876.5. Where Approved Durable Species or Treated Woods!
are Required. — Where approved durable species or treated woods
are required in this code, the building official may require;
identification by an approved mark of certificate of inspection. 1

876.6. Treatment. — Where treatment of wood members is re-l
quired by this code, preservatives and methods of treatment^
shall conform to the standards for treatment and preserving of
lumber listed in reference standards RS 8-62 and RS 7-9.

SECTION 877.0. FIRE PROTECTION AND FIRESTOPPING

To prevent the free passage of flame through concealed spaces
or openings in event of fire, provision shall be made to trim all
combustible framing away from sources of heat, to provide
effective fire barriers against the spread of fire between all sub-
divisions and all stories of the building, to provide adequate fire
separation against exterior exposure, and to firestop all vertical
and horizontal draft openings as specified herein.
877.1. Beam Separation in Ordinary Construction (types 3-B
and 3-C). — All wood and other combustible floor, roof and
other structural members framing into masonry walls shall be
cut to a bevel of three (3) inches in the depth and shall project
not more than four (4) inches into the wall; and the distance
between embedded ends of adjacent beams or joists entering j
into the wall from opposite sides shall be not less than four (4)
inches.

876-877

877.2. Girder Separation in Heavy Timber Construction (type
3-A). — Wood girders framing into masonry or concrete walls
shall have at least eight (8) inches of masonry or concrete
between their ends and the outside face of walls and at least
eight (8) inches of masonry between adjacent beams entering
the wall from opposite sides. The girders shall be fire-cut,
supported in pockets or in self-releasing metal boxes, or other-
wise supported to minimize destruction of the wall in the
event of fire.

877.3. Flues and Chimneys. — The space about a chimney shall
be firestopped at each floor and ceiling level with noncombustible
material, unless such space is treated as a vertical opening and
is enclosed as provided in article 9. Combustible framing or
other woodwork shall be trimmed not less than two (2) inches
away from all flues, chimneys and fireplaces, and six (6) inches
away from flue openings.

877.4. Fireplaces. — Hearths of noncombustible construction and
fireboards, mantels and other combustible trim shall comply
with section 1013 governing fireplace construction.

877.5. Concealed Roof Spaces. — Concealed roof spaces enclosed
by combustible ceiling and roof construction shall be subdivided
into areas of not more than three thousand (3,000) square feet
as provided in section 219.0.

877.6. Exterior Cornices. — Exterior cornices where permitted of
combustible construction in section 926, or when erected with
combustible frames shall be firestopped at maximum intervals
of twenty (20) feet. If noncontinuous, they shall have closed
ends, with at least four (4) inches separation between adjoining
sections.

877.7. Wall Furring. — In masonry wall construction (types 3-A,
3-B and 3-C) and in frame construction (types 4-A and 4-B)
where walls are furred, the space between the inside of the
furring and the face of the wall for the full depth of the com-
bustible floor or roof joists shall be firestopped.

877.8. Combustible Trim and Finish. — The space behind com-
bustible trim and finish where permitted under this code and all
other hollow spaces where permitted in fireresistive construction
shall be back-filled with noncombustible materials or firestopped
as required in section 921.0.

877.9. Firestopping. — Firestopping meeting the requirements of
section 921 shall be provided in stud walls and partitions at
each floor level and between the ceiling of the top story and

roof space; in all furred spaces of frame walls and studded
off spaces of masonry walls at maximum intervals of eight (8)
feet; at the top and bottom and at least once in the middle
of each run of stairs; in concealed wall pockets for sliding
doors; for chases at floor and ceiling levels; at openings for
pipes, belts, shafting, chutes and conveyors passing through
combustible floors or partitions with close-fitting noncombustible
caps or metal shutters or other approved noncombustible means;
and in all other locations that would permit the free travel of
flame.

877.10. Steel Framing. — Where structural steel beams or other
metal members frame into exterior, party, fire or enclosure walls
of reinforced concrete, the ends shall have protection against
fire of the rating specified for the wall.

SECTION 878.0. THERMAL INSULATING MATERIALS

Insulating batts, blankets, fills or similar types of materials,
including vapor barriers and breather papers or other coverings
which are a part of the insulation, incorporated in construction
elements shall be installed and used in a manner that will not
increase the fire hazard characteristics of the building or any part
thereof.

878.1. Exposed Installation. — Such materials when exposed as
installed shall comply with the interior finish requirements as
regulated in section 922.

878.2. Deleted.

878.3. Facings and Coverings. — Vapor barriers, breather papers
or other coverings of insulating materials, when installed adjacent
to or not more than one and one-half (1-1/2) inches from the
unexposed surface of ceiling or sidewall interior finish, or when
installed in completely enclosed wall, ceiling joist or rafter
spaces, firestopped as required in section 877 are not required to
have a flame resistance rating.

RS8

List of Reference Standards

AA 1967

Aluminum Construction Manual

AASHO 1965

Standard Specifications for Highway Bridges

ACI 214 1965

Recommended Practice for Evaluation of Compres-
sion Test Results of Field Concrete

ACI 318 1963

Building Code Requirements for Reinforced Concrete

ACI 506 1966

Recommended Practice for Shotcreting

ACI 525 1963

Minimum Requirements for Thin-Section Pre-Cast

Concrete Construction

ACI 211.2 1969

Recommended Practice for Selecting Proportions for

Structural Lightweight Concrete

AISC 1969

Specification for the Design, Fabrication and Erection

of Structural Steel for Buildings

AISI 1968

Specification for the Design of Cold-Formed Steel

Structural Members

AISI 1968

Design of Light Gage Cold-Formed Stainless Steel

Structural Members

AITC 1966

Timber Construction Manual Section 4

AITC 100-65 1965

Timber Construction Standards

AITC 103-65 1965

Standard for Structural Glued Laminated Timber

ANSI A42.1 1964
Specifications for Gypsum Plastering

ANSI A42.2 1946

Specifications for Portland Cement Stucco

ANSI A42.3 1946

Specifications for Portland Cement Plastering

ANSI A42.4 1967

Specifications for Interior Lathing and Furring

ANSI A42.5 1960

Specifications for Lime Cement Stucco

ANSI A59.1 1968

Specifications for Reinforced Gypsum Concrete

ANSI A94.1 1961
Specifications for Interior Marble

ANSI A94.2 1961

Specifications for Thin Exterior Marble Veneer (Two

Inches and Less in Thickness)

ANSI A94.3 1961

Specifications for Thin Exterior Marble in Curtain

or Panel Walls

ANSI A97.1 1965

Specifications for Application and Finishing of

Wallboard

ANSI A108.1 1967

Specifications for (Including Requirements of Related
Divisions) Installation of Glazed Ceramic Wall Tile
in Cement Mortars

RS 8

ANSI A108.2 1967

Specifications for (Including Requirements of Related
Divisions) Installation of Ceramic Mosiac Tile in
Cement Mortars

ANSI A108.3 1967

Specifications (Including Requirements of Related
Divisions) for Installation of Quarry Tile and Pavers
in Cement Mortars

ANSI A108.5 1967

Specifications for Installation of Ceramic Tile with

Dry Set Portland Cement Mortar

ANSI A118.1 1967

Specifications for Dry-Set Portland Cement Mortar

ANSI Z26.1 1950

Safety Glazing Materials for Glazing Motor Vehicles

Operating on Land Highways

APA 1967

Design and Fabrication of Flat Plywood Stressed

Skin Panels

APA 1967

Design and Fabrication of Plywood Beams

APA 1967

Design and Fabrication of Plywood Curved Panels

APA 1967

Fabrication of Plywood Folded Plates

APA 1964

Lab. Bulletin 58-B — Plywood Folded Plate Design

Method

APA 1966

Plywood Design Specifications

ASTM A27 1965

Specifications for Mild-To-Medium Strength Carbon-
Steel Castings for General Application

ASTM A48 1964

Specifications for Gray Iron Castings

ASTM A 148 1965

Specifications for High-Strength Steel Castings for

Structural Purposes

ASTM A377 1966

Specifications for Cast Iron Pressure Pipe

ASTM C5 1959

Specifications for Quicklime for Structural Purposes

ASTM C6 1949

Specifications for Normal Finishing Hydrated Lime

ASTM CIO 1964

Specifications for Natural Cement

ASTM C22 1950

Specifications for Gypsum

ASTM C28 1968

Specifications for Gypsum Plasters

ASTM C31 1969

Making and Curing Concrete Compression and

Flexure Test Specimens in the Field

ASTM C33 1969

Specifications for Concrete Aggregates

ASTM C34 1962

Specifications for Structural Clay Load Bearing Wall

Tiles

ASTM C35 1967

Specifications for Inorganic Aggregates for Use in

Gypsum Plaster

RS 8

ASTM C36 1968

Specifications for Gypsum Wall Board

ASTM C37 1967

Specifications for Gypsum Lath

ASTM C39 1968

Test for Compressive Strength of Molded Concrete

Cylinders

ASTM C42 1968

Method of Obtaining and Testing Drilled Cores and

Sawed Beams of Concrete

ASTM C52 1954

Specifications for Gypsum Partition Tile or Block

ASTM C55 1966

Specifications for Concrete Building Brick

ASTM C56 1962

Specifications for Structural Clay Non-Load Bearing

Tile

ASTM C57 1957

Specifications for Structural Clay Floor Tile

ASTM C61 1964

Specifications for Keene's Cement

ASTM C62 1966

Specifications for Building Brick (Solid Masonry Units

Made from Clay or Shale)

ASTM C73 1967

Specifications for Calcium Silicate Face Brick (Sand-
Lime Brick)

ASTM C79 1967

Specifications for Gypsum Sheathing Board

ASTM C90 1966

Specifications for Hollow Load-Bearing Concrete Ma-
sonry Units

ASTM C91 1969

Specifications for Masonry Cement

ASTM C94 1969

Specifications for Ready-Mixed Concrete

ASTM C126 1969

Specifications for Ceramic Glazed Structural Clay

Facing Tile, Facing Brick, and Solid Masonry Units

ASTM C129 1964

Specifications for Hollow Non-Load Bearing Concrete

Masonry Units

ASTM C143 1966

Test for Slump of Portland Cement Concrete

ASTM C145 1966

Specifications for Solid Load-Bearing Concrete

Masonry Units

ASTM C150 1968
Specifications for Portland Cement

ASTM C172 1968
Sampling Fresh Concrete

ASTM C192 1969

Making and Curing Concrete Compression and

Flexure Test Specimens in the Laboratory

ASTM C206 1949

Specifications for Special Finishing Hydrated Lime

ASTM C207 1949

Specifications for Hydrated Lime for Masonry Pur-
poses

RS8

ASTM C208 1960

Specifications for Structural Insulating Board Made

from Vegetable Fibers

ASTM C270 1968

Specifications for Mortar for Unit Masonry

ASTM C330 1969

Specifications for Lightweight Aggregates for Struc-
tural Concrete

ASTM C331 1969

Specifications for Lightweight Aggregates for Concrete

Masonry Units

ASTM C332 1966

Specifications for Lightweight Aggregates for Insu-
lating Concrete

ASTM C476 1963

Specifications for Mortar and Grout for Reinforced

Masonry

ASTM C494 1968

Specifications for Chemical Admixtures for Concrete

ASTM C595 1968

Specifications for Blended Hydraulic Cements

ASTM D2277 1966

Specification for Fiberboard Nail-Base Sheathing

AWPA C2 1969

Standard for the Preservative Treatment of Lumber,

Timbers, Bridge Ties and Mine Ties by Pressure

Processes

AWPA C4 1969

Standard for Preservative Treatment of Poles by

Pressure Processes

AWPA C9 1967

Standard for the Preservative Treatment of Plywood

by Pressure Processes

AWS D 1.0-69 1969

Code for Welding in Building Construction

NCMA 1968

Specification for the Design and Construction of

Loadbearing Concrete Masonry

NFoPA 1966

Simplified Spans for Joists and Rafters in Residential

Construction

NFoPA 1968

National Design Specification for Stress Grade Lum-
ber and Its Fastenings

NFoPA 1957

Wood Structural Design Data

SCPI 1966

Recommended Building Code Requirements for En-
gineered Brick Masonry

SJI-AISC 1966

Standard Specifications and Load Tables for Long

Span Steel Joists, LJ-Series and LH-Series

SJI-AISC 1965

Standard Specifications and Load Tables for Open

Web Steel Joists, J-Series and H-Series

USDC CS31 1952

Wood Shingles (Red Cedar, Tidewater, Red Cypress

and California Redwood)

USDC CS181 1952

Adhesive, Water Resistant Organic, for Installation

of Clay Tile

RS8-1 RS8-4

USDC CS253 1963

Structural Glued — Laminated Lumber

US Fed. Specification DD-G-451c 1968

Glass, Flat and Corrugated, for Glazing Mirrors,

and Other Uses

US Fed. Specification SS-S-721c 1964
Stone, Architectural Cast

VI 1963

Standard Specifications for Vermiculite Plastering

Empirical Provisions for Wood Frame Construction

Minimum and Empirical Thickness Requirements for
Masonry Walls

Minimum Nailing Schedule

On Site Quality Control

Plywood Construction

RS 8-1 ASTM C62 1966

Specifications for Building Brick (Solid Masonry Units
Made from Clay or Shale)

RS8-2 ASTM C73 1967

Specifications for Calcium Silicate Face Brick (Sand-
Lime Brick)

RS 8-3 ASTM C55 1966

Specifications for Concrete Building Brick

RS8-4 ASTM C34 1962

Specifications for Structural Clay Load Bearing Wall
Tile

RS8-5 ASTM C56 1962

Specifications for Structural Clay Non-Load Bearing
Tile

RS 8-6 ASTM C57 1957

Specifications for Structural Clay Floor Tile

RS8-7 ASTM CI 26 1969

Specifications for Ceramic Glazed Structural Clay
Facing Tile, Facing Brick, and Solid Masonry Units

RS 8-8 ASTM C90 1966

Specifications for Hollow Load-Bearing Concrete
Masonry Units

RS8-9 ASTM CI 29 1964

Specifications for Hollow Non-Load Bearing Concrete
Masonry Units

RS8-10 ASTM C145 1966

Specifications for Solid Load-Bearing Concrete Ma-
sonry Units

RS8-11 ASTM C52 1954

Specifications for Gypsum Partition Tile or Block

RS 8-12 U.S. Federal Spec. SS-S-721c 1964
Stone, Architectural, Cast

RS8-13 ASTM CI 50 1968

Specifications for Portland Cement

RS8-14 ASTM CIO 1964

Specifications for Natural Cement

RS8-15 ASTM C91 1968

Specifications for Masonry Cement

RS8-16 ASTM C5 1959

Specifications for Quicklime for Structural Purposes

RS 8-5 RS 8-26
RS 8-17 ASTM C207 1969

Specifications for Hydrated Lime for Masonry
Purposes

RS 8-18 ASTM C270 1968

Specifications for Mortar for Unit Masonry

RS 8-19 ASTM C476 1963

Specifications for Mortar and Grout for Reinforced
Masonry

RS8-20 ASTM C22 1950

Specifications for Gypsum

! RS 8-21 ANSI A108.5 1967

Specifications for Installation of Ceramic Tile with
Dry Set Portland Cement Mortar

RS8-22 ANSI Al 18.1 1967

Specifications for Dry-Set Portland Cement Mortar

RS8-23 USDC CS181 1952

Adhesive- Water Resistant Organic, for Installation of
Clay Tile

RS8-24 ASTM C33 1969

Specifications for Concrete Aggregates

RS 8-25 ASTM C330 1969

Specifications for Lightweight Aggregates for Struc-
tural Concrete

ASTM C331 1969

Specifications for Lightweight Aggregates for Concrete

Masonry Units

ASTM C332 1966

Specifications for Lightweight Aggregates for Insulat-
ing Concrete

RS 8-26 ASTM C94 1969

Specifications for Ready-Mixed Concrete

RS8-27 AITC 103-65 1965

Standard for Structural Glued Laminated Timber

RS8-28 ANSI A42.1 1964

Specifications for Gypsum Plastering

RS 8-29 ANSI A42.4 1967

Specifications for Interior Lathing and Furring

RS 8-30 ANSI A42.5 1960

Specifications for Lime Cement Stucco

RS 8-31 VI 1963

Standard Specifications for Vermiculite Plastering

RS 8-32 ANSI A42.2 1946

Specifications for Portland Cement Stucco

ANSI A42.3 1946

Specifications for Portland Cement Plastering

RS 8-33 ASTM C35 1967

Specifications for Inorganic Aggregates for Use in
Gypsum Plaster

ASTM C6 1949

Specifications for Normal Finishing Hydrated Lime

ASTM C206 1949

Specifications for Special Finishing Hydrated Lime

ASTM C28 1968

Specifications for Gypsum Plasters

ASTM C61 1964

Specifications for Keene's Cement

ASTM C595 1968

Specifications for Blended Hydraulic Cements

RS 8-34 ASTM C208 1960

Specifications for Structural Insulating Board Made
from Vegetable Fibers

RS 8-27 RS 8-36

RS8-35 ASTM C37 1967

Specifications for Gypsum Lath

RS8-36 PLYWOOD CONSTRUCTION

1.1 DEFINITIONS —

1.1.1. Plywood. — Plywood is a laminated board or
panel, consisting of an odd number of veneer sheets
placed alternately crosswise and bonded together with
either a water-resistant or waterproof adhesive that
forms a bond stronger than the wood itself.

1.1.2. Plywood Component. — A plywood component,
for the purposes of this standard, shall be defined as
an element of a structural member formed by the
assembly of plywood parts or of plywood parts with
parts of wood or other materials so as to form an
integral assemblage.

1.2. Conformance With Standard. — Materials, design,
and fabrications shall conform to reference standard
RS8-37 except that the word "should" in that stan-
dard shall be mandatory.

1.3. Exterior Use. — All plywood when permanently
exposed in outdoor applications shall be of exterior
type. Plywood used for covering the exterior of out-
side walls and applied directly to supports shall be
at least 3/8 inch nominal thickness. Panel joints shall
be backed solidly by studs or by nailing pieces at
least 2 inches wide (nominal), except over sheathing
or where applied as lapped siding, or when other-
wise made waterproof. Plywood siding applied over
sheathing shall be not less than 1/4 inch thick.

1.4. Roof Sheathing. — Where plywood is used as
roof sheathing the spans shall not exceed the values
given in table RS8-36-1.

Table RS 8-36-1

Maximum Spans For Plywood Roof and Floor

Sheathing a

(Plywood continuous over two or more spans and face
grain perpendicular to supports)

qpf

Maximurr

i Span

(In X h.

es)

Load

, / '

(psf)

Floor

Panel

Identi-

Edges

Maximum

fication

Blocked

Un-

Total

Live

Spand

Index

Blocked

Load

(Inches)

12/0

130

100

16/0

20/0

24/0

24 ,e

30/12

12 f

32/16

50 c

168

36/16

50 c

35 c

168

42/20

45 c

35 c

208

48,24 .

40 c

Notes —

a These values apply for Structural I and II,
Standard Sheathing, and C-C grades only. Spans shall
be limited to values shown because of possible effect
of concentrated loads.

b Identification Index appears on all panels in the
construction grades listed in footnote a.

c For roof live load of 40 psf or total load of 55
psf, decrease spans by 13 per cent or use panel with
next greater Identification Index.

d Plywood edges shall have approved tongue and
groove joints or shall be supported with blocking,
unless 1/4 inch minimum thickness Underlayment is
installed, or finish floor is 25/32 inch wood strip.
Allowable uniform load based on deflection of 1/360
of span is 100 psf.

e 1/2 inch Structural I, when continuous over one
support, may be laid with face grain parallel to sup-
ports provided all panel edges are blocked or other
approved type edge support is provided, the spacing
of the supports does not exceed 24 inches oh center,
and the live load does not exceed 30 pounds per
square foot. For other grades, a thickness of 5/8
inch is required.

RS 8-36

f May be 16 inches if 25/32 inch wood strip
flooring is installed at right angles to joists.

g May be 24 inches if 25/32 inch wood strip
flooring is installed at right angles to joists..

1.5. Plywood Subfloors. — Where plywood is used as
structural subflooring the maximum spans shall not
exceed the values given in. table RS8-36-1. If resilient
flooring or carpeting is to be applied directly to a
plywood subfloor without separate underlayment, the
panels shall be underlayment grade C-C plugged, or
any sanded grade of exterior type plywood. This
thickness shall not be less than the values prescribed
for the given spans and loads shown in Table RS8-36-2.

Table RS 8-36-2

Minimum Thickness For Plywood Combination Sub-
Floor— Underlayment a

(Plywood continuous over two or more spans and
face grain perpendicular to supports)

Maximum Spacing Of Supports (In.)
Species Group 16 20 24

1 1 2 in. 5 8 in. 3 4 in.

2,3 5/8 in. 3 4 in. 7/8 in.

4 3 4 in. 7 8 in. 1 in.

Note —

a Applicable to Underlayment Grade, C-C (Plug-
ged) and all grades of sanded Exterior type plywood.
Spans limited to values shown because of possible
effect of concentrated loads. Allowable uniform load
based on deflection of 1 /360th of span is 100 psf.
Plywood edges shall have approved tongue and groove
joints or shall be supported with blocking unless
1/4 inch minimum thickness Underlayment is installed,
or finish floor is 25/32 inch wood strip. If wood strips
are perpendicular to supports, thickness as shown for
16- and 20-inch spans may be used on 24 inch span.

1.6. Special 1-1/8 Inch Plywood Subflooring for 48
Inch Span. — Such material, if conforming to design
specifications of the American Plywood Association
special 2-4-1 panel may be used over girders spaced
not more than 48 inches on centers, with edges on
2 inch x 4 inch blocking securely attached to main
girders, provided the total floor load does not exceed
80 psf. A tongue and groove joint may be used in
lieu of blocking.

1.7. Plywood Wall Sheathing. — Plywood may be ap-
plied either horizontally or vertically and as indicated
in building code provisions for the bracing of exterior
walls.

1.8. Fastening. — Plywood sheathing and subflooring
— Plywood sheathing and subflooring shall have the
maximum fastener spacing on framing as prescribed
in Table RS8-36-3.

Table RS 8-36-3
Fastening Schedule

Fastener

Spacing

(in,) 3

Plywood

Inter-

Thickness

Common Nail and Staple

Panel

mediate

(in.)

Size Type

Edges

Support

Plywood Roof

and Wall Sheathing

1/2 or less

6d Smooth or deformed

5/8 or greater

8d Smooth or deformed

5/16, 3/8, 1/2

16 gage galvanized wire sta-
ples, 3/8 in. minimum crown.
Length of one in. plus ply-
wood thickness except 1-1/4

inch, for 5/16 in. plywood

Plywood Subfli

aoring

1/2

6d Smooth or deformed

5,8, 3,4, 7,8

8d Smooth or 6d deformed ..

1, 1-1 8

lOd Smooth or 8d deformed..

1,2

16 gage gahanized wire sta-

ples, 3 8 in. minimum crown.

5 8

1-5 8 in. long

2-1,2

NOTE —

a Where spans are 48 inches or more nails shall
be spaced at 6 inches at all supports.

RS 8-36
1.9. Plywood Siding. — Plywood siding shall be applied
and nailed as prescribed in Table RS8-36-4.

Table RS 8-36-4

Plywood

Siding

Plywoodb,c
Thickness

Nail

/
Nail

Nail Sp
Panel

lacing (in.)
A

Type of

Intermediate

Siding

(in.)

Size

Type

Edges 2

Supports

Panel

Siding

3 8 e

1 2, 5 8 and

Corrosive
resistant box

thicker

or casing
nails

Lap

Siding

3 8

Corrosive
resistant box

One nail per
stud for

1 2 and

or casing
nails

width 12 in.
or less.

thicker

8 in. for
width

greater than
12. in.

NOTES —

a Minimum edge distance of 3/8 in.

b In direct-to-stud applications 5-ply panels of
1/2 in. nominal thickness or more may be used over
studs 24 in. o.c. if texturing does not penetrate
through the face veneer. All other panels must be
used over studs spaced not more than 16 in. on
center.

c Special requirement: Nails on ship-lap edges of
5/8 in. and thicker panel siding 3/8 in. from exposed
edge and slant driven towards edge; do not set.

e When separate sheathing is applied, 3/8 in.
panel and 303 siding may be used over supports
spaced 24 inches on center, 1/4 inch over supports
16 inches on center.

1.10. Plywood Diaphragms. — Plywood diaphragms
may be used to resist horizontal forces when designed
and constructed in accordance with reference standard
RS8-57.

RS 8-37 APA 1966

Plywood Design Specifications

RS 8-38 APA 1967

Design and Fabrication of Plywood Beams

APA 1967

Design and Fabrication of Plywood Curved Panels

APA 1964

Lab. Bulletin 58-B — Plywood Folded Plate Design

Method

APA 1967

Fabrication of Plywood Folded Plates

RS8-39 ASTM C79 1967

Specifications for Gypsum Sheathing Board

RS8-40 ANSI A97.1 1965

Specifications for Application and Finishing of Wall-
board

RS8-41 ASTM C36 1968

Specifications for Gypsum Wall Board

RS 8-42 AISC 1969

Specification for the Design, Fabrication, and Erection
of Structural Steel for Buildings

Modifications. — Unless otherwise specifically dated,
national standards cited within this reference standard
shall be those current on June 1, 1969. The provisions
of AISC 1969 Specification for the Design, Fabrica-
tion, and Erection of Structural Steel for Buildings
shall be applied in conformance with the AISC 1969
Commentary on the Specification for the Design,
Fabrication and Erection of Structural Steel for Build-
ings and shall be subject to the following modifica-
tions: (The section and paragraph numbers are from
that standard.)

RS8-37 RS8-42

1.3. Loads and Forces. —

Delete this section and substitute the following:
"The provisions of the Boston Code for loads shall
apply."

1.4. Material.—

General. — The provisions relating to certification as
the term is used in this section shall be only as re-
quired and approved by the building official.

1.4.1.3. Add the following new subsection:

"Steels of higher strength than are covered by the
above mentioned ASTM Specifications may be used
provided the design is based upon the minimum prop-
erties of such higher strength steel as certified by the
manufacturer's test reports and approved by the
building official."

1.4.1.4. Add the following new subsection:
"Structural steel members installed in buildings in the
year 1924 or earlier shall not be stressed in excess of
16,000 psi. Similar members installed after 1924 and
prior to the year 1943, and after 1942 and prior to
October 1963 shall not be stressed in excess of 18,000
psi and 20,000 psi respectively.

Structural steel which has previously been used in a
building or other structure or which has been fabri-
cated for such use, shall not be used in another
building or structure except with the approval of the
building official and under such conditions as he may
in each case specify."

1.4.2. Add the following sentence at the end of this
subsection:

"The building official may require reasonable tests
from time to time of metals and alloys to determine
their quality and whether they conform to the re-
quirements of this section."

1.4.6. Add the following new subsection:
"Pipe Steel.

Pipe steel shall conform to the following specifications:
Welded and Seamless Steel Pipe, ASTM A53-65."

1.5. Allowable Unit Stresses

1.5.1.3. Compression. — Add the following subsection:
"1.5.1.3.6. The above formulas (1.5-1) and (1.5-2)
shall be used in conjunction with section 847.0 of the
Boston code (Concrete Filled Pipe Columns)."

1.5.5. Masonry Bearing. — Delete this section and
substitute the following:

"The applicable provisions of the Boston Code shall
apply."

1.5.6. Wind and Seismic Stresses. — Delete and sub-
stitute the following:

"The applicable provisions of article 7 of the Boston
Code shall apply."

1.6. Combined Stresses

1.6.1. Axial Compression and Bending. — At the end

of this subsection add the following sentence:
"This section shall be used in conjunction with sec-
tion 847.0 of the Boston Code (Concrete Filled Pipe
Columns.)"

1.10. Plate Girders and Rolled Beams

1.10.9. Horizontal Forces. — Delete reference to sec-
tion 1.3.4 and substitute applicable provisions of the
Boston Code for loads.

1.11. Composite Construction

1.11.1. Definition. — Add the following paragraph:
"Concrete materials shall meet the applicable require-
ments of the building code. Where concrete having
aggregates other than those in accordance with RS8-24
is used, the capacity of the shear connectors to resist

RS 8-42

the applied load under the proposed conditions of use
shall be investigated. Composite construction used for
members subject to heavy vehicle loads (except where
the applied vehicle load is limited to passenger cars),
shall be proportioned in accordance with the require-
ments of reference standard RS8-74."

1.20. Expansion

Delete this text and substitute the following:
"The provisions of section 710.8 of the Boston Build-
ing Code shall apply."

1.24. Shop Painting

Delete this section. The provisions of section 827
shall apply.

1.25. Erection

Delete section 1.25.5 and add the following:
"1.25.5. Field Connections.—

Field connections shall meet the requirements for cor-
responding types of shop connections as described in
section 1.23. No holes, copes, or cuts of any type
shall be made to facilitate erection unless specifically
shown on the shop drawings or authorized in writing
by the party or parties designated for inspection of
said work."

Add Section as follows:

"Section 1.27. Minimum Thickness of Metal. — All

exterior members of structural steel, except roofing and
siding, that are exposed to the weather shall have a
protective coating as required by the provisions of
Section 1.24 and shall have a minimum thickness of
metal of 0.23 inch. Exception: The minimum thickness
of metal need only conform to the requirements for
stress under the following conditions:

( 1 ) Exterior members exposed to the weather. — An
approved type of atmospheric corrosion resistant
steel is used or exposed surfaces are zinc coated

with a minimum weight of coating of approximately
0.6 ounces per square foot of exposed surface and
covered with a protective coating as required by
section 1.24 or exposed surfaces are protected by
other approved means.

(2) Members not exposed to the .weather. — All
members except that members located where they
would be subject to accidental impact shall be
stiffened to resist such impact.

(3) Roofing and siding. — All members provided
that surfaces which are exposed to the weather
shall have a protective coating.

(4) Temporary construction that will be in place
for a period of one year, or less, provided that all
surfaces which are exposed to the weather shall
have a protective coating.

(5) Joists or purlins that are exposed to the
weather but which are spaced not more than 30
inches center-to-center, do not support more than
200 square feet of floor or roof area, and which
have a protective coating as required by section
1.24."

AISI 1968

Specification for the Design of Cold-Formed Steel
Structural Members

Modifications. — The provisions of AISI 1968 specifi-
cation for the design of cold-formed steel structural
members shall be subject to the following modifica-
tions. The section and paragraph numbers are from
that standard.

3.1.2. Wind, Earthquake and Combined Forces. — De-
lete sections 3.1.2.1 and 3.1.2.2 and substitute the
following:

"The provisions of the Boston Building Code for
loads shall apply."
4.2. Welds.—

4.2.1. Fusion Welds. — In the last paragraph delete
the words "Code for Welding in Building Construc-
tion or the Special Ruling on Gas-Metal Arc Welding
with Carbon Dioxide Shielding of the American
Welding Society," and substitute "Reference Stan-
dard RS8-73."

RS8-42 RS8-43
Section 6 Tests for Special Cases. —

1. Add to paragraph 6.1(e) the following sentence:

"All laboratories shall be subject to the approval of

the building official."

Add the following section:

"Section 7. Fabrication and Erection. —

The applicable provisions of reference standard RS8-42

shall apply, supplemented as follows:

7.1 Fabrication. —

(a) Straightening and flattening. — All material shall
be clean and straight. If straightening or flattening is
necessary, it shall be done by a suitable process or
method and in a manner that will not injure the
material.

(b) Profiles and distortion. — Profiles used struc-
turally shall conform to the specified dimension. Care
shall be taken not to stretch, bend, or otherwise dis-
tort parts of the sections unless such forming is an
integral part of the design.

(c) Cutting and punching. — Components may be
cut by slitting, shearing, sawing, or flame cutting. All
punched holes and sheared or flame cut edges of ma-
terial in members subject to calculated stress shall be
clean and free from notches and burred edges.

(d) Bolted and riveted connections. — Holes for
bolts or rivets shall be 1/16 inch larger than the
nominal diameter of the bolt and rivet when the
diameter of bolt or rivet is 1/2 inch and larger, and
1/32 inch larger than the nominal diameter of the
bolt or rivet when the diameter is less than 1/2 inch.

7.2 Erection. — Care shall be taken to avoid damage
when loading, unloading, and handling members."

AISI 1968

Specification for the Design of Light Gage Cold-
Formed Stainless Steel Structural Members
Modifications. — The provisions of AISI 1968 specifi-
cation for the design of light gage cold-formed stain-
less steel structural members shall be subject to the
following modifications. The section and paragraph
numbers are from that standard.

3.9. Wind or Earthquake Stresses. — Delete section

3.9.1 and 3.9.2 and substitute the following:
"The provisions of the Boston Building Code for
loads shall apply."
4.2. Welds.—

4.2.1. Fusion Welds. — In the third paragraph delete
the words "Code for Welding in Building Construc-
tion, D1.0 of the American Welding Society, of
latest edition, " and substitute "Reference Standard
RS8-73."

Section 6 Tests for Special Cases. —

1. Add to paragraph 6.2.1(c) the following sentence:
"All laboratories shall be subject to the approval
of the building official."
Add the following section:

"Section 7. Fabrication and Erection. —

The applicable provisions of reference standard RS8-42
shall apply, supplemented as follows:

7.1 Fabrication. —

(b) Profiles and distortion — Profiles used struc-
turally shall conform to the specified dimension. Care
shall be taken not to stretch, bend, or otherwise dis-
tort parts of the sections unless such forming is an
integral part of the design.

(d) Bolted and riveted connections. — Holes for
bolts or rivets shall be 1/16 inch larger than the
nominal diameter of the bolt and rivet when the dia-
meter of bolt or rivet is 1/2 inch and larger, and
1/32 inch larger than the nominal diameter of the
bolt or rivet when the diameter is less than 1/2 inch.

7.2 Erection. — Care shall be taken to avoid damage
when loading, unloading, and handling members."

RS 8-43 RS 8-45
SJI-AISC 1965

Standard Specifications and Load Tables for Open
Web Steel Joists, J-Series and H-Series

SJI-AISC 1967

Standard Specifications and Load Tables for Long
Span Steel Joists, LJ-Series and LH-Series
Modifications. — The provisions of the standard speci-
fications for open web steel joists as listed above shall
be subject to the following modifications. The section
and paragraph numbers are from those standards.
Minimum thickness of metal. — The provisions of refer-
ence standard RS8-42 shall apply.
Specific Modifications — Open Web Steel Joists
5.10 Inspection. —
Delete this section.

Specific Modifications — Longspan Steel Joists
104.11 Inspection. —
Delete this section.

ACI 318 1963

Building Code Requirements for Reinforced Concrete
Modifications. — The provisions of ACI 318 1963
shall be subject to the following modifications. The
section and paragraph numbers are from that stan-
dard, unless otherwise noted.
101 Scope. —

(a) Insert the words "plain and" after the words
"construction of in the second line.

(b) Delete this paragraph.

104 Approval of special systems of design or construc-
tion. — Delete this section and substitute the following:
"Nothing in this article shall be construed to prohibit
the use of any system of design, alternate to those in-
dicated, provided that it can be demonstrated to the
satisfaction of the building official that such system
of design will provide a factor of safety against struc-
tural failure, fire safety, and such other characteristics
pertinent to the safety of life, health, and property as
prescribed in the Boston Code or as may be required
by the building official. The building official may
approve any system of construction which is not

covered by or which conflicts with the requirements
of the Boston Code, on the basis of satisfactory ex-
perience records and tests as prescribed by sections
803 and 804 and sections 903 and 904. Whenever the
code prescribes the use of a particular material, the
building official may permit the use of any material
shown to be equivalent for the use intended, in terms
of health, fire, and/or structural safety. Nothing
contained in this code shall be construed to require
the use of any particular material for the purpose of
meeting performance requirements of this code."

402 Add the following new paragraph:

(c) Special cements may be used subject to the ap-
proval of the building official. Such cements shall
meet the requirements for Portland cement in regard
to soundness, setting time and strength of the Ameri-
can Society for Testing and Materials for the particular
type. Air-entraining cements shall produce a resultant
air content in field mixtures at point of deposit not
in excess of 5.0% when measured by means of an
air meter in conformity with Standard Methods of
Test for Determination of Air Content of Freshly
Mixed Concrete by Pressure Method of the American
Society for Testing and Materials.

403 Add the following new paragraph:

(c) Concrete aggregates for which there are no stan-
dard specifications also may be employed in concrete
for particular uses subject to the approval of the
building official. Very lightweight aggregates such as
pumice, expanded perlite, exfoliated vermiculite,
weighing less than 40 pounds per cubic foot dry and
loose may be employed only in non-structural concrete.
406, 407 and 408 Admixtures. — The requirements
for the use of admixtures shall be in accordance with
the three (3) previously cited sections as modified
by the following:

"Admixtures, other than air-entraining and water-
reducing agents, may be used only when batch plant
observations are made by a representative of, or em-
ployee of, or other qualified individuals responsible
to the architect or engineer who prepared the design
drawings with said individual subject to the approval
of the building official and the architect or engineer.

RS 8-45

When admixtures are used, the provisions of reference
standard RS8-45 shall apply except that water-reducing
agents shall conform to reference standard RS8-69.
Type A or D, with the requirements for compressive
strength increased to one hundred ten (110) per cent
(all ages) and for durability increased to one hundred
(100) per cent. In addition, no anti-freeze agents shall
be used. Admixtures shall be added only through
calibrated dispensing devices. These dispensers shall
be regularly inspected and certified as to accuracy by
the manufacturer of the admixture.
410 Specifications cited in this code*.—
(a) Delete the asterisk and note applying to same.

501 Add the following new paragraph:

(e) The provisions of this section apply to site-mixed
concrete, ready-mixed concrete (either central or tran-
sit mixed) and to precast concrete made at a casting
plant.

502 Method of determining the proportions of concrete.
— Delete the entire contents of this section except for
the title and first sentence labeled "( a )" an d substi-
tute the following text whose section and paragraph
numbers are not from the referenced national standard:
502.1. Method I — Mixes with Minimum Cement
Factor.

502.11. Minimum Cement Factor. — The cement factor
used in the work shall not be less than the factor
given in table RS8-45-1 for the corresponding strength
of concrete.

Table RS8-45-1 Minimum Cement Factor
Specified Compressive Minimum Bags of Cement

Strength in 28 Days Cubic Yard of Concrete

(f'c)-psi (all aggregates)

2,000 5.00

2,500 5.25

3,000 5.75

3,500 6.50

3,750 6.75

4,000 7.00

5,000 7.50

Over 5,000 Permitted only by

Method II

502.12. Water-Cement Ratio. — The concrete used in
the work, whether proportioned on the basis of pre-
liminary tests or of prequalified mix designs, shall be
produced by using a water-cement ratio corresponding
to a point on the strength vs. water-cement ratio
curve representing (at a slump of five (5) inches ± one
(1) inch for concrete manufactured with gravel or
stone aggregate and at a slump of four (4) inches
± one (1) inch for concrete manufactured with light-
weight aggregate) a strength of concrete at least
twenty-five (25) per cent higher than the specified
strength called for on the plans. The cement factor
shall not be less than the factor shown in table
RS8-45-1. The water-cement ratio shall not exceed
the ratio shown in table RS8-45-2.
Table RS8-45-2

Maximum Permissible Water-Cement Ratios For Concrete (Method

No. 1)

Maximum permissible water-cement ratio*

Specified

Non-air-entrained

Air-entrained

compressive
strength in

concrete

28 days,

I .S. gal.

Absolute

U.S. gal.

Absolute

psi f'c

per 94-

ratio bv

per 94-

ratio bv

lb. bag

weight

1b. bag

weight

of cement

2500

7-1 4

0.642

6-1 4

0.554

3000

6-1 2

0.576

5-1 4

0.465

3500

5-3 4

0.510

4-1 2

0.399

4000

0.443

0.354

*Including free surface moisture on aggregates.

502.13. Preliminary Tests. — Except as provided in )
section 502.14, preliminary tests of concrete shall be i
made in advance of the beginning of any concreting J
operation and shall be subject to certification. Pre- |
liminary tests shall consist of compressive strength \\
tests of molded concrete cylinders made in accordance '
with reference standards RS8-64 and RS8-65. A curve |
representing the relation between the average strength ,
of the concrete at twenty-eight (28) days, or at earlier y
periods, and the water-cement ratio shall be established j
for the range of strength values required for the work.
The tests shall include at least four (4) different

RS 8-45

water-cement ratios and at least four (4) cylinder
specimens for each water-cement ratio. The cylinder
strength tests shall be supplemented by tests to con-
firm that the cement and aggregates conform to the
provisions of reference standard RS8-45.
502.14. Prequalified Mixes. — In lieu of the making of
preliminary tests for individual buildings or groups of
buildings, a concrete producer may provide concrete
proportioned on the basis of prequalified or previously
accepted mix designs, which designs, including the
applicable batching weights and results of applicable
preliminary tests and of tests to confirm that the
cement and aggregates conform to the provisions of
reference standard RS8-45, shall be submitted not less
often than once a year to the building official for re-
view and prequalification. The preliminary tests shall
be made under the supervision of an architect or
engineer engaged by the producer. Concrete propor-
tioned according to prequalified mixes shall be pro-
duced only from batch plants satisfactory to the build-
ing official. Separate prequalification shall be required
for mixes utilizing different combinations of aggregates
and admixtures from all sources which are to be
utilized.

502.15. Quality Control and Certification of Materials
and of Batching. — Where concrete materials are used
for structural elements, quality control and certifi-
cation shall be provided at the batch plant for con-
formance to reference standards RS8-60 and in suffi-
cient scope to:

( 1 ) Determine and record the actual batched weights
and the water-cement ratios used;

(2) Verify that such weights and ratios conform
to the weights and proportions required by the pre-
liminary test mix (or the prequalified mix) adjusted
for moisture content and graduation of aggregates;

(3) Verify conformance of the quality and condi-
tion of the materials to reference standard RS8-45.

(4) Verify that the ingredients are the same or
equal to those used for the preparation of the pre-
liminary test or prequalifying mixes;

(5) For all concrete, attestation of the results of
the quality control and certification at the batch plant

shall appear on a ticket accompanying each load ofj
concrete.

502.2. Method II — Mixes Determined From Perfor-
mance Data Performance Concrete.

502.21. Preliminary Tests. — Preliminary tests of con-
crete shall be performed in accordance with the pro-
visions of section 502.13. Mixes with performance data
from previous projects, similarly proportioned, maybe
accepted in lieu of preliminary tests for the proposed
project, subject to approval of the architect or engi-
neer responsible for the design drawings and to
approval by the building official, provided that ac-
ceptable performance data from such previous projects
are submitted and the conditions of paragraph 502.24
below, are met.

502.22. Performance Cement Factor. — The cement
factor used in the work shall be as determined in

502.23 below.

502.23. Strength.—

(1) Concrete manufactured with stone or gravel
aggregate. — The concrete used in the work shall be
produced using a water-cement ratio corresponding
to a point on the strength vs. water-cement ratio
curve representing a strength of concrete, at the de-
sign slump, at least twenty-five (25) per cent higher
than the specified strength called for on the plans.
However, if the producer demonstrates to the satis-
faction of the architect or engineer responsible for
the design drawings and the building official, on the
basis of job performance records of the coefficient
of variation (described in reference standard RS8-66)
that the quality control exercised in the producer's
plant warrants a change in the twenty-five (25) per
cent factor, the change may be permitted. In no case,
however, shall the concrete used in the work be pro-
duced using a water-cement ratio in excess of, or a
cement factor less than, that corresponding to a point
in the strength vs. water-cement ratio curve representing
a strength of concrete, at the design slump, fifteen
(15) per cent higher than the specified strength called
for on the plans. The design slump shall be as speci-
fied by the architect or engineer responsible for the
design drawings and the concrete shall be placed at
a slump equal to or less than the design slump.

RS 8-45

(2) Concrete manufactured with lightweight aggre-
gate. — The concrete used in the work shall be pro-
portioned on a strength vs. cement content basis at
a given consistency in accordance with reference stan-
dard RS8-67 for a strength, at the design slump, at
least twenty-five (25) per cent higher than the specified
strength called for on the plans. The provision of (1)
above relating to reduction in the strength requirement
for demonstrable quality control shall apply.

502.24. Materials. — The cement, aggregates, admix-
tures and other ingredients of the concrete used for
the individual building or group of buildings shall be
the same and from the same sources as those in the
preliminary tests or previously used mixes.

502.25. Batching. — The concrete shall be produced in
a plant acceptable to the building official and con-
crete produced according to previous performance
data shall be produced in a plant with automatic
or semi-automatic batching maintaining documentation
as required in section 842.1 of the Boston Building
Code for all ingredients.

502.26. Quality Control and Certification of Materials
and of Batching. — The provisions of 502. 15 shall apply.

502.27. — Subaqueous concrete shall contain twenty
(20) per cent more cement than previously required.
504. Strength tests of concrete. —

Delete paragraphs (a), (b) and (c) and substitute the
following:

"(a) Whenever strength tests of concrete specimens
are required by the provisions of the Boston building
code, compression test samples shall be taken directly
from the mixer in accordance with reference standard
RS8-70 and cured in accordance with reference stan-
dard RS8-71 and tested at the age of 28 days in
accordance with reference standard RS8-64. Three
test cylinders shall be molded for each 150 cubic
yards or fraction thereof of each class of concrete
placed in any one day's concreting. Additional speci-
mens may be molded and tested where there is a
question as to the required interval between placing
of concrete and stripping of forms or placing the
structure into use.

(b) The test cylinders shall be tested by an approved
concrete testing laboratory. The testing of each batch

of three test cylinders shall be considered as one
strength test. The strength of such test shall be the
average of the breaking strengths of the three cylinders
comprising the test except that, if one of the speci-
mens shall show manifest evidence of improper sam-
pling, molding, handling, or testing, it shall be dis-
carded and the remaining two averaged. If more than
one cylinder must be discarded, the entire strength
test shall be voided.

(c) The average of any three consecutive strength
tests representing each class of concrete shall be equal
to or greater than the specified strength (f'c) and not
more than 10 per cent of the strength tests shall have
values less than the specified strength, but no test
shall show an average strength less than 85 per cent
of the specified strength (f # c)."

(e) In the 6th line, change the words "as outlined
in chapter 2" to the words "as described in the Bos-
ton Code for core tests and load tests of concrete
construction."

Add new paragraph "(f) All strength tests of concrete
and testing of concrete materials required by the
provisions of the Boston Code shall be performed
by approved concrete testing laboratories."'

604. Depositing. —

At the end of paragraph (a), delete the words "unless

approved by the engineer."

Add the following new paragraph:

(e) Subaqueous concrete shall be placed carefully by

Tremie, covered bottom-dump-bucket, or other suitable

means to minimize "wash" of cement or segregation

of constituents. Subaqueous construction equipment,

materials, and methods shall have the approval of

the building official.

605. Add the following new paragraph:

(b) No blasting shall be carried out in the vicinity
of the construction which will affect the resultant
quality of the concrete after deposit.
608. Add the following new section:
"Concrete Utilizing Preplaced Aggregate. —
(a) The use of concrete formed by the injection of
grout into a mass of preplaced coarse aggregate will
be permitted where it can be demonstrated by success-
ful prototype installation that the proposed mix, ma-

RS 8-45

terials, and method of placement will produce a
concrete of the specified strength and free of areas or
inclusions of uncemented aggregate.

1. Prototypes. — At least two (2) prototypes, from
either previous work or samples prepared for the
proposed project shall be prepared. The forms shall
be stripped, and a minimum of six (6) cores recovered
and tested to demonstrate the strength of the concrete
produced by the proposed materials and methods of
installation. In addition, the homogeneity of the pro-
totypes shall be demonstrated by demolishing the pro-
totypes in the presence of the building official or his
agent.

2. In-Place Concrete. — The concrete, as finally
placed in the work, shall be prepared using the same
materials, mix, equipment, and procedures utilized to
prepare the successful prototype installations.

3. Cylinders. — All preparation and placement of
structural concrete utilizing pre-placed aggregates shall
be subject to certification. Compression test cylinders
shall be prepared and tested as required for premixed
concrete, except that the cylinders shall be prepared
under conditions that will simulate the conditions
under which the concrete in the work is installed."
703. Conduits and pipes embedded in concrete. — Add
the following paragraph:

"(c) No conduits, pipes, or other similar embedded
items will be permitted in prestressed or post-tensioned
concrete members other than as shown on the ap-
proved plans. Computations demonstrating the effects
of such embedded items on the structural adequacy
of prestressed or post-tensioned concrete members
shall be submitted to the building official."
808. Add the following sentence:
(a) The specified minimum coverage applies also at
the bottom of rustications.

902. Design loads, and 903. Resistance to wind,
earthquake and other forces. —

Delete these sections. Building code requirements for
loads shall apply.

907. Effective depth of beam or slab.—
At the end of paragraph (b) add the words "or pro-
vision shall be made to inhibit wear."

909. Control of deflections.—

Add the following to paragraph (b):
"For flexural members of lightweight concrete the
fractions given in table 909(b) shall be multiplied by
the cube root of the ratio of 3,000,000 to the modu-
lus of elasticity of the concrete being used."
912. Limiting dimensions of columns.—
(a) Add the introductory phrase "Except for precast
members,"

1004. Allowable stresses. — wind and earthquake forces.
— Delete this section. Boston Code requirements for
combination of loads shall apply.
Add the following paragraph to chapter 22:
2204. Plain Concrete Walls —

(a) The ratio of unsupported height to thickness
or the ratio of unsupported length to thickness (which-
ever is the greater) for plain concrete walls shall not
exceed 20.

(b) Plain concrete walls shall be proportioned so
that the tensile stress does not exceed the allowable
stress in concrete given in table 1002(a), and the
allowable stress in compression shall be 0.25f # c for
walls having a ratio of height to thickness of 10 or
less, and shall be reduced proportionally to 0.15f'c
for walls having a ratio of height to thickness of 20.
2401. Scope.—

Add the following paragraph:

"(b) The provisions of reference standard RS8-63
shall apply for thin-section precast members."

RS 8-46 ASTM A377 1966

Specifications for Cast Iron Pressure Pipe

RS 8-47 ASTM A27 1965

Specifications for Mild-To-Medium Strength Carbon-
Steel Castings for General Application

ASTM A 148 1965

Specifications for High-Strength Steel Castings for

Structural Purposes

RS 8-48 ASTM A48 1964

Specifications for Gray Iron Castings

RS 8-49 A A 1967

Aluminum Construction Manual

RS 8-50 NCMA 1968

Specification for the Design and Construction of

RS 8-45 RS 8-51

Load-Bearing Concrete Masonry. Where conflict arises
between this reference standard and the Boston Code,
the more stringent requirements of the two shall
apply.

Minimum and Empirical Thickness Requirements for
Masonry Walls

1.1. Minimum Thickness Requirements. — Whether

proportioned on the basis of analysis of stresses in

accordance with reference standards RS 8-50 and

RS 8-58 or empirical rules contained herein, in no

case shall the thickness of masonry construction be

less than the dimensions shown in table RS 8-51-1.

The minimum thickness of a wythe shall be two (2)

inches.

Table RS 8-51-1

Minimum Thickness of Masonry

Type of Masonry Nominal Thickness

(Inches)
Loadbearing walls (exterior or
interior) —

Solid masonry 6

Grouted or filled cell masonry ... 6

Hollow masonry 6

Cavity or masonry bonded hollow

walls 8a

Stone ashlar masonry 12

Stone rubble masonry 16 c

Non-loadbearing walls —

Exterior walls 4

Partitions 3

Columns —

Solid unit masonry 6

Hollow unit masonry 8

Facing of faced walls 2 D

Notes —

a Overall wall thickness including cavity.

b In no case less than 1/8 the height of the facing

unit,
c Twelve (12) inches for one story buildings.

1.11. Decrease in Thickness. — Whether proportioned
on the basis of empirical provisions or the analysis
of stresses, where walls of hollow units or masonry

bonded hollow walls are decreased in thickness, a
course or courses of solid masonry shall be inter-
posed between the wall below and the thinner wall
above, or special units or construction shall be used
that will adequately transmit the loads from the
shells of the units above to the shells of those below.
Except for window-paneled backs, -and permissible
chases and recesses (section 838.0) walls shall not
vary in thickness between their lateral supports. When
a change in thickness, resulting from minimum thick-
ness requirements, would occur between floor levels,
the greater thickness shall be carried up to the higher
floor level.

2.1. Empirical Thickness Requirements for Loadbear-

ing Walls. — Where the height of exterior or interior
loadbearing masonry walls does not exceed the fol-
lowing requirements, such walls, if they meet the
provisions of reference standards RS 8-50 and RS 8-58
with regard to compressive stress and of table RS 8-51-1
with regard to minimum thickness, may be considered
to be adequate to resist the applied wind loads and
other shearing forces. All other provisions of this
reference standard shall apply only to that masonry
not designed under the provisions of reference stan-
dards RS 8-50 and RS 8-58.

2.11. Multi-story Buildings. — For limitations on 8 inch
walls see (6) below.

(1) Exterior solid walls. — The thickness of solid ex-
terior masonry bearing walls shall be at least 8 in-
ches for the top floor and 12 inches for a maximum
of 55 feet, measured downward from the top floor
level. Any additional height shall be provided by
16 inch lower walls up to a maximum building
height of 104 feet. Buildings taller than 104 feet
shall be structurally analyzed and designed. The
slenderness ratio shall not exceed 20.

(2) Interior solid walls. — Interior solid walls shall
be at least 8 inches thick for the uppermost 55 feet
of wall height and 12 inches for the lower walls for

RS 8-51

a maximum building height of 104 feet. Taller walls
shall be designed by structural analysis.

(3) Cavity walls. — Cavity walls or masonry bonded
hollow walls shall be at least 8 inches thick for the
top floor and 12 inches thick for the lower walls
up to a maximum total height of 40 feet except that
10 inch cavity walls may be used for a maximum
total height of 25 feet. Taller walls shall be designed
by structural analysis.

(4) Walls of hollow units. — Loadbearing walls of
hollow units shall be at least 8 inches thick for the
top floor and at least 12 inches for the lower walls
for a maximum building height of 40 feet. Hollow
unit walls 40 feet high may be supported by solid
masonry walls whose height is no more than 35
feet above the first tier of beams.

(5) Stiffened walls. — Where solid masonry bearing
walls are stiffened by, and tied to, reinforced concrete
floors or masonry cross walls at distances not greater
than 20 feet apart, they may be 12 inches thick for
the uppermost 70 feet, measured downward from the
top of the wall.

(6) Eight inch walls. — Notwithstanding other pro-
visions in this section, the thickness of masonry bear-
ing walls may be 8 inches where: (a) the toal height
of the wall above its support does not exceed 35
feet except for cavity walls for which (3) above shall
apply; and (b) the distance from floor-to-floor or
floor-to-roof does not exceed 12 feet; and (c) the
floor live load does not exceed 60 psf; and (d) the
roof is designed so that the dead load imparts no
lateral thrust to the wall.

2.12. One-Story Buildings. —The bearing walls of
one story buildings except as otherwise specifically
provided for herein shall be at least 6 inches thick
provided the vertical loads on the roof impart no
lateral thrust to the wall.

2.13. Walls of Residence Buildings. — In residence
buildings not more than three stories high, bearing
walls other than coursed or rough or random rubble

stone, may be 8 inches thick when not over 35 feet
high and the roof is designed so that the dead load
imparts no lateral thrust to the wall. Such walls in
one story residence buildings, and in one story private
garages, may be 5-1/2 inches thick.

2.14. Walls above Roof Level. — Masonry walls above
roof level, 12 feet or less in height, enclosing stair-
ways, machinery rooms, shafts, or penthouses, may
be 8 inches thick and may be considered as neither
increasing the height nor requiring any increase in
the thickness of the wall below. Parapet walls shall
conform to the provisions of section 870.0.

2.15. Faced or Composite Walls. — Neither the thick-
ness or height of faced or composite walls, nor the
distance between lateral supports, shall exceed that
prescribed for masonry of either of the types forming
the facing or the backing.

2.16. Cavity or Masonry Bonded Hollow Walls. —

Where both the facing and backing wythes are con-
structed of solid masonry units, the wythes may be
3 inches thick. Otherwise, the wythes of cavity walls
shall each have a thickness of at least 4 inches and
the cavity shall be at least 2 inches but not more
than 4 inches wide. Wythes less than 4 inches thick
shall not have raked joints and the backing wythe
of cavity or masonry bonded hollow walls shall be
at least as thick as the facing wythe. A cavity or
masonry bonded hollow wall may be constructed to
its maximum permissible height on top of a solid
masonry wall whose maximum height is 35 feet
above the first tier of beams. Roof construction shall
be designed so that the dead load imparts no lateral
thrust to the wall.

2.17. Rubble Stone Walls. — Rough, random, or
coursed rubble stone walls shall be 4 inches thicker
than is required for other types of masonry, but in
no case less than 12 inches thick.

2.18. Wall Thickness Increase Due to Span Length. —

When the clear span between bearing walls or between
a bearing wall and an intermediate support is more
than 26 feet, the effects of temperature, of rotation
of end supports, and of eccentricity shall be investi-
gated. In lieu of such investigation, the thickness of

RS8-51 RS8-59

such walls shall be increased 4 inches for each 12-1/2
feet or fraction thereof, that such span is in excess
of 26 feet.

2.2. Empirical Thickness Requirements forNon-Load-
bearing Walls. — Provided that they conform to the
provisions of section 837.0, non-loadbearing masonry
walls, including curtain walls and panel walls, may
be 4 inches less in thickness than required in section
2.1 for loadbearing walls, except as provided below.

2.21. Partitions. — The minimum thickness for parti-
tions shall be as follows:

Height of Walls Thickness

8 feet and under 3 inches

Over 8 feet to 1 1 feet 4 inches

Over 11 feet to 16 feet 6 inches

V Over 16 feet to 21 feet 8 inches

Over 21 feet to 27 feet 10 inches

ACI 506 1966

Recommended Practice for Shotcreting

RS 8-53 ANSI A59.1 1968

Specifications for Reinforced Gypsum Concrete

RS 8-54 APA 1967

Design and Fabrication of Flat Plywood Stressed
Skin Panels

RS 8-55 USDC CS253 1963

Structural Glued-Laminated Lumber

AITC 100-65 1965
Timber Construction Standards

AITC 1966

Timber Construction Manual Section 4

SCPI 1966

Recommended Building Code Requirements for Engi-
neered Brick Masonry. Where conflict arises between
this reference standard and the Boston Code, the
more stringent requirements of the two shall apply.

US Federal Spec. DD-G-451c 1968

Glass, Plate, Sheet, Figured (Float, Flat for Glazing,

Corrugated, Mirrors and Other Uses.)

RS 8-60 ON SITE QUALITY CONTROL

The minimum extent of required on site certifica-
tion of materials and methods of construction shall
be as outlined in this reference standard. The certi-
fication shall be by an individual acceptable to the
architect or engineer responsible for the design draw-
ings and approved by the building official unless
otherwise provided for in this Code. The certification
when required shall be for conformance with all
requirements of this Code and the reference standards.

1.0. Materials.—

1.1. Controlled Materials. — Evidence of the certifi-
cation of all controlled materials furnished and used
under the provisions of sections 201 and 722 shall
be verified at the job site.

1.2. All Other Materials and Assemblies. — Evidence

of all attestations, documents, and all other off site
quality controls as may be required by any portion
of the code shall be available and verified at the job
site.

2.0. Methods of Construction. —

2.1. Structural Steel. — Welding operations and the
tensioning of high strength bolts in connections where
the calculated stresses in the welds or bolts are 50
per cent or more of basic allowable values and any
other special connections as the building official may
require.

2.2. Concrete. — All operations relating to the con-
struction of all structural elements and assemblies.

2.2.1. Exceptions. —

.1 Operations relating to the construction of mem-
bers and assemblies (other than prestressed members)
which involve the placement of a total of less than

RS 8-60

50 cubic yards of concrete and provided that the con-
crete is used at levels of calculated stress less than
70 per cent of basic allowable values.

.2 Placing of concrete for all:

.2.1 Short span floor and roof construction as per
section 846.

.2.2 Walls and footings for buildings in occupancy
group L-3.

.3 Size and location of reinforcement for walls
and footings for buildings in occupancy group L-3.

2.3. Aluminum. — Welding operations in connections
where the calculated stresses in the welds are 50
per cent or more of the basic allowable values and
any other special connections as the building official
may require.

2.4. Wood. — Fabrication of glued-laminated assem-
blies and of plywood components.

2.5. Reinforced Masonry. — Placement and bedding
of units; sizes of members, including thickness of
walls and wythes; sizes of columns; the size and
position of reinforcement, in place, and provisions
for curing and protection against freezing for all
reinforced masonry construction; fabrication of pre-
fabricated units.

2.5.1. Exceptions. —

.1 All operations relating to the construction of
members and assemblies which involve the placement
of a total of less than 50 cubic yards of masonry
and provided that this masonry is used at levels of
calculated stress 70 per cent or less of basic allowable
values.

.2 All masonry work for buildings in occupancy
group L-3.

.3 All mixing of mortar.

2.6. Unreinforced Masonry. — Placement and bed-
ding of units and sizes of members including thick-
ness of walls and wythes; sizes of columns; and pro-
visions for curing and protection against freezing for
all masonry construction proportioned on the basis
of structural analysis as described in reference stan-
dard RS 8-50.

2.6.1. Exceptions.—

.1 All operations relating to the construction of J
members and assemblies which involve the placement
of a total of less than 50 cubic yards of masonry j
and provided that this masonry is used at levels of
calculated stress 70 per cent or less of basic allowable
values.

.2 All masonry work for buildings in occupancy
group L-3.

.3 All mixing of mortar.

2.7. Other. — Requirements as may be established
in other articles of this code or by the building
official.

RS 8-61 ANSI A108.1 1967

Specifications for (Including Requirements of Related
Divisions) Installation of Glazed Ceramic Wall Tile
in Cement Mortars

ANSI A108.2 1967

Specifications for (Including Requirements of Related
Divisions) Installation of Ceramic Mosaic Tile in
Cement Mortars

RS8-60 RS8-63

ANSI A108.3 1967

Specifications for (Including Requirements of Related
Divisions) Installation of Quarry Tile and Pavers in
Cement Mortars

ANSI A94.1 1961
Specifications for Interior Marble

ANSI A94.2 1961

Specifications for Thin Exterior Marble Veneer (Two

Inches and Less in Thickness)

ANSI A94.3 1961

Specifications for Thin Exterior Marble in Curtain or

Panel Walls

AWPA C2 1969

Standard for the Preservative Treatment of Lumber,

Timbers, Bridge Ties and Mine Ties by Pressure

Processes

AWPA C9 1967

Standard for the Preservative Treatment of Plywood

by Pressure Processes.

AWPA C4 1969

Standard for Preservative Treatment of Poles by

Pressure Processes

ACI 525 1963

Minimum Requirements for Thin-Section Precast Con-
crete Construction

Modification. — The provisions of ACI 525 1963 shall
be subject to the following modification. The section
and paragraph number is from that standard.
Admixtures. —

Delete last sentence of paragraph 8 and substitute the
following:

"The use of other admixtures will be permitted pro-
vided they do not alter the intent of any section of
these requirements or of reference standard RS8-45,

and provided their use is in accordance with pertinent
information in "Admixtures for Concrete" reported
by ACI Committee 212.

RS 8-64 ASTM C39 1966

Test for Compressive Strength of Molded Concrete
Cylinders

RS 8-65 ASTM C192 1969

Making and Curing Concrete Compression and Flexure
Test Specimens in the Laboratory

RS 8-66 ACI 214 1965

Recommended Practice for Evaluation of Compression
Test Results of Field Concrete

RS 8-67 ACI 211-2 1969

Recommended Practice for Selecting Proportions for
Structural Lightweight Concrete

RS 8-68 ASTM C42 1968

Method of Obtaining and Testing Drilled Cores and
Sawed Beams of Concrete

RS 8-69 ASTM C494 1968

Specifications for Chemical Admixtures for Concrete

RS 8-70 ASTM CI 72 1968

Sampling Fresh Concrete

RS 8-71 ASTM C31 1969

Making and Curing Concrete Compression and Flexure

Test Specimens in the Field

To section 6. (a) add the following:

The following size cylinders will be permissible for the

following nominal size aggregate:

Size Cylinder Size Aggregate

6" x 12" 2" and smaller

4" x 8" 1" and smaller

3" x 6" 1/2" and smaller

RS 8-63 RS 8-76

For cylinders smaller than 6" x 12", evidence must
be presented to relate their compressive strength num-
ber to that of the standard 6" x 12" cylinder.

RS 8-72 ASTM C143 1969

Test for Slump of Portland Cement Concrete

RS 8-73 AVVS D 1.0-69 1969

Code for Welding in Building Construction

RS 8-74 AASHO 1965

Standard Specifications for Highway Bridges

RS 8-75 ANSI Z26.1 1966

Safety Glazing Materials for Glazing Motor Vehicles
Operating on Land Highways

RS 8-76 NFoPA 1957

Wood Structural Design Data

NFoPA 1968 (As amended 1967)

National Design Specification for Stress-Grade Lumber
and Its Fastenings.

Modifications. — The provisions of NFoPA 1968 Na-
tional Design Specification for Stress-Grade Lumber
and Its Fastenings shall be subject to the following
modifications. The section and paragraph numbers
are from that standard.

Part I. General Requirements for Structural Design.—
100-A Practice defined. — Delete the second paragraph
of 100-A-l and substitute the following:
"In this specification the word "should" is to be
considered as mandatory unless otherwise indicated
in these modifications."

Part II. Allowable Unit Stresses for Stress-Grade
Lumber. —

200-F Grade identification. — Delete this section in
its entirety.

200-H-l Other species and grades. — Add the following
standards:

"Machine stress rating as approved by the American
Lumber Standards Committee."

203-A Increase in unit stresses. — Add the following
introductory paragraph:

"In lieu of the building code provisions for combina-
tion of loads, the provisions of this section shall
apply."

Part III. Design Loads.—

Delete this part in its entirety and substitute the
following:

"The loads provisions of the Boston building code
shall apply."

Part IV. Design Formulas and Provisions. —
400-C-6 Delete the first three sentences and substitute
the following:

"Beams with notches shall be checked for stress at
the notched section on the basis of net depth. Beams
containing bored holes within 1-1/2 diameters of the
top or bottom of the beam shall be treated as though
notched to the depth of the inner extreme of the
hole. In all cases the effects of notches or holes shall
be accounted for in the design and reinforcement shall
be supplied if required."

400-C-7 Change this section to read as follows:
"The lateral distribution of a concentrated load for
moment from a critically loaded beam to adjacent
parallel beams may be calculated by the method in-
dicated in appendix A."

400-1-2 Delete this part and substitute the following:
"For bridging see section 855.6.1. of the Boston
building code."

405 Timber-concrete composite construction. — Delete
this section in its entirety and substitute the following:
"405 Composite timber-concrete construction — Where
the tensile strength of wood and the compressive
strength of concrete are to be used compositely, the
joining of the two materials shall be such as to resist
all horizontal shear at the plane of junction and pro-
visions shall be made to prevent separation of the
wood from the concrete by the use of nails, grooves,
or other suitable devices. The design shall be executed
in accordance with the principles applicable to com-
posite steel-concrete construction, as set forth in refer-
ence standard RS8-42. The resistance of shear con-

RS 8-76

nectors shall be determined in accordance with the
applicable provisions of the Boston building code
requirements for load tests."
Part V. Timber Connector Joints. —
500-D-5 Change this paragraph to read:
"For connectors used in lumber, pressure-impregnated
with fire-retardant chemicals, where the treated wood
is kiln dried after treatment, the tabulated loads shall
be reduced 10 per cent. Where the treated wood is
not kiln dried after treatment, the load adjustments
applicable to unseasoned wood shall apply."
Part VIII. Nail, Spike, Drift-Bolt, and Wood-Screw
Joints. —

800-C-l The "should" in this paragraph is advisory.
Part IX. Mechanically Laminated Members.—
The provisions of Part I to VIII shall be supple-
mented, as follows:

a. General. —

(1) Beams loaded perpendicular to the edges of the
laminations (wide faces of laminations parallel to the
direction of the load) — Mechanically laminated beams
with full length laminations all of the same grade,
shall be assumed to be as strong and stiff as sawn
beams of the same external net dimension. Allowable
stresses for members laminated of combinations of
grades shall be limited to the allowable stress of the
values assigned for the lowest grade used.

(2) Beams loaded perpendicular to wide faces of
laminations. — Mechanically laminated beams with
laminations horizontal shall be designed on the basis
of specific placement of butt joints and test data per-
taining to the particular construction with respect to
butt joints, and on the basis of fastenings used to
transfer shear between laminations.

b. Laminated trusses. —

(1) End joints in laminations. — End joints in out-
side laminations shall be located at panel points only.
End joints shall not be located closer than 2 feet in
adjacent laminations; they shall not be permitted in
the first panel; and end joints in a given cross section
shall be separated by at least two unspliced lamina-
tions. In chords of only four laminations, only one of

the outside laminations may have an end joint at a
given panel point.

(2) Lamination bolts. — One or more 1/2 inch
minimum diameter bolts, extending through all lam-
inations, shall be placed at each panel point in order
to distribute the loads, introduced by the web mem-
bers, to all laminations.

(3) Axial compression. — The axial compression
in a mechanically laminated chord shall be assumed
to be resisted by simple column action of the in-
dividual laminations, or the entire section may be
assumed to act as a mechanically laminated column.
In the latter case for 2 inch nominal thickness lam-
inations in panels up to 5 feet, full column action
may be assumed; and for panel lengths of 5 feet to
8 feet, a straight line reduction from full column
strength to 50 per cent of this value shall be used.
Panel lengths over 8 feet shall not be used with 2
inch nominal thickness laminations. Proportionately
longer panel lengths may be used with 3 inch nominal
thickness laminations.

The type and amount of nails shown in the schedule
below are the minimum amount required and shall be
increased where necessary for structural adequacy.

MINIMUM NAILING SCHEDULE

Number and
Building Element Nail Type Distribution

Stud to sole plate Common-toe-nail 4 — 8d

Stud to cap plate Common-toe-nail 2— 16d

Double studs Common-direct lOd 12" o.c. or

16d 24" o.c.

Corner studs Common-direct 16d 24" o.c.

Sole plate to joist or

blocking Common 16d 16" o.c.

Double cap plate Common-direct 16d 16" o.c.

Cap plate laps Common-direct 3— 16d

Ribbon strip — 6" or less Common-direct 2 — lOd ea. bearing

Ribbon strip — over 6". Common-direct 3 — lOd ea. bearing

Roof rafter to plate Common-toe-nail 3 — 16d

Roof rafter to ridge Common-toe-nail 2— 16d

Jack rafter to hip Common-toe-nail 3 — lOd

Floor joists to studs.

(no ceiling joist) Common-direct 5 — lOd or 3— 16d

RS 8-76 RS 8-77

Number and
Building Element Nail Type Distribution

Floor joists to studs Common-direct 2 — lOd

(with ceiling joists) ... Common-direct 2 — lOd

Floor joists to sill or

girder Common-toe-nail 3 — 8d or 2 — 16d

Double joist to joist Common-direct lOd stgd. (a 16" o.c.

Ledger strip Common-direct 3 — 16d at ea. joist

Ceiling joists to plate ... Common-toe-nail 2 — 16d
Ceiling joists (laps over

partition) Common-direct 3 — 16d

Collar beam Common-direct 4 — lOd

Bridging to joists Common-direct 2 — 8d ea. end

Bridging to studs Common-direct

or toe 2 — lOd ea. end

Diagonal brace (to stud

and plate) Common-direct 2 — 8d ea. bearing

Tail beams to headers
(when nailing permit-
ted) Common-end 1 — 20d ea. 4 sq. ft.

floor area
Header beams to trim-
mers (when nailing

permitted) Common-end 1 — 20d ea. 8 sq. ft.

floor area
1" Sub-flooring (6" or

less) Common-direct 2 — 8d ea. joist

1" Sub-flooring (8" or

more) Common-direct 3 — 8d ea. joist

2" Sub-flooring Common-direct 2 — 16d ea. joist

1" Wallsheathing(8"or

less in width) Common-direct 2 — 8d ea. stud

1" Wall sheathing (over

8" in width) Common-direct 3 — 8d ea. stud

Plywood Roof and Wall
Sheathing

1/2" or less Common-direct 6d — 6" o.c. edges and

12" o.c. intermediate

5/8" or greater Common-direct 8d — 6" o.c. edges and

12" o.c. intermediate
5/16", 3/8", 1/2" 16 ga. galvanized 4" o.c. edges and

wire staples. 3/8" 8" o.c. intermediate
minimum crown.
Length of 1" plus
plywood except
1-1/4" for 5/16"
plywood.
Plywood Sub-flooring

1/2" Common-direct 6d — 6" o.c. edgesand

10" o.c. intermediate

5/8", 3/4", 7/8" Common-direct 8d — 6" o.c. edges and

10" o.c. intermediate

Building Element Nail Type

1", 1-1/8" Common-direct

1/2" 16 ga. galvanized

wire staples. 3/8"
min. crown

5/8" 1-5/8" length

1" Roof decking (6" or

less in width) Common-direct

1" Roof decking (over

6" in width) Common-direct

Built-up girders and

beams Common-direct

Continuous header to

stud Common-toe-nail

Continuous header —

two pieces Common-direct

1/2" Fiberboard

sheathing 1-1/2" galvanized

Roofing Nail
6d Common Nail
16 gage galvan-
ized staple. 1-1/8'
long with mini-
mum crown of
7/16"

Number and
Distribution

lOd or 8d ring shank
— 6" o.c. edges and
6" o.c. intermediate
4" o.c. edges and 7"
7" o.c. intermediate

2-1/2" o.c. edges and
4" o.c. intermediate

2 — 8d ea. rafter

3 — 8d ea. rafter
20d at 32" o.c.

4 — 8d

16d at 16" o.c.

3" o.c. exterior edge
6" o.c. intermediate

25/32" Fiberboard
sheathing

1-3/4" Galvani- *
zed Roofing Nail
8d Common Nail
16 gage galvan-
ized staple, 1-1/2"
in. long with min-
imum crown of
7/16"

■^3" o.c. exterior edge
6" o.c. intermediate

Gypsum sheathing 12 gage 1-1/4"

Large head Cor-
rosion-resistive 4" o.c. on edge

8" o.c. intermediate

Shingles — wood Corrosion-resistive 2 — No. 14 B&S each

bearing
Weather boarding Corrosion-resistive 2 — 8d ea. bearing

RS 8-77 RS 8-78

Ceiling Joist Nailing To Every Rafter
(Number of 16d Nails)

Slope of Roof

4/12

5/12

6/12

7/12

9/12

12/12

Rafter spacing,

o.c. (in.)

16 24

Width of building

Up to 24 ft

5 8

4 7

3 5

3 4

3 3

24 to 30 ft

7 11

6 9

4 7

3 6

3 4

3 3

Shingle nails shall penetrate not less than 3/4 inch
into nailing strips, sheathing or supporting construc-
tion except as otherwise provided in section 855.3.4.

RS 8-78 EMPIRICAL PROVISIONS FOR WOOD FRAME
CONSTRUCTION

Empirical Provisions in Lieu of Design. — The pro-
visions of this reference standard may be used in lieu
of structural analysis only for those buildings in oc-
cupancy group L-3 where the specific occupancies
correspond to a live load requirement of 40 psf, or
less, and to constructions wherein the supporting
framing consists of multiple, closely spaced members,
such as joists, studs, platform or balloon frames. All
requirements established in this reference standard
may be reduced when an analysis of stresses, executed
in accordance with reference standard RS8-76 indi-
cates such reduction is feasible.
1.1. Stud Walls and Partitions.—

1.1.1. Studs shall be of equivalent or better grade
than the minimum grades for the various species as
established in reference standard RS8-76.

1.1.2. Corner posts shall be 3-stud members or mem-
bers of equivalent strength.

1.1.3. Load bearing studs shall be set with the larger
cross section dimension perpendicular to the wall or
partition. Studs in exterior walls of one story build-
ings of construction class type 4 shall be at least 2
inches x 4 inches spaced not more than 24 inches
on center. Studs for other classes of construction or
multiple story buildings shall be at least 2 inches x 4
inches spaced not more than 16 inches on center.

1.1.4. Stud walls resting on concrete or masonry
shall have sills at least 2 inches in nominal thickness.
Where such sills bear on concrete, they shall be
fastened with minimum 1/2 inch bolts embedded at
least 6 inches. Each sill piece shall have at least two
anchor bolts, with one bolt located at least 1 inch
from each end of the plate, and with intermediate
spacing not more than 8 feet. Where such sills bear
on masonry, they shall be anchored in accordance
with the applicable provisions of article 8.

1.1.5. Stud partitions that rest directly over each other
and are not parallel to floor joists or beams may
extend down between the joists and rest on the top
plate of the partition, partition girder, or foundation
below, or may be constructed on sill plates running
on top of the beams or joists.

1.1.6. All load bearing stud partitions shall be sup-
ported on walls, other partitions, double joists or
beams, solid bridging, or on beams at least as wide
as the studs. Joists supporting a partition parallel to
the joists wherein the joists are spaced apart to permit
the passage of piping or duct work shall be provided
with solid blocking at intervals of not more than
16 inches.

1.1.7. Load bearing partitions perpendicular to joists
shall not be offset from supporting girders, walls, or
partition by more than the depth of the joists unless
the joists are proportioned on the basis of analysis
of stress.

1.1.8. In interior walls and in bearing partitions,
double studs shall be provided at the sides of openings
that are greater than 3 feet-6 inches up to 6 feet in
width, and triple-studs shall be provided at the sides
of openings of greater width.

1.1.9. Headers shall be provided over each opening
in exterior walls and bearing partitions. Where the
opening does not exceed 3 feet each end of the
header shall be supported on a stud or framing
anchor. Where the opening exceeds 3 feet in width
each end of the header shall be supported on one
stud and where the opening exceeds 6 feet each end
shall be supported on two studs.

RS 8-78
1.1.10. All studs in exterior walls and in bearing
partitions shall be capped with double top plates in-
stalled to provide overlapping at corners and at
intersections with other walls and bearing partitions.
End joints in double top plates shall be offset at
least 24 inches. In lieu of double top plates, a con-
tinuous header of similar dimensions may be used.
For platform frame construction, studs shall rest on
a single bottom plate.

1.2. Bracing of exterior walls. — Exterior stud walls
shall be braced by 1 inch x 4 inch continuous diag-
onal strips let into the face of the studs and into the
top and bottom plates at each corner of the building.
Bracing may also be provided by one of the following
means:

1.2.1. Wood board sheathing of 1 inch nominal
thickness, applied diagonally.

1.2.2. For one and two-story dwellings, plywood
sheathing at least 4 feet x 8 feet (except where cut to
fit around openings and for similar purposes) and at
least 5/16 inch thick on studs spaced 16 inches or
less on centers and at least 3/8 inch thick on studs
spaced more than 16 inches but not exceeding 24
inches on centers.

1.2.3. For one story dwellings and for the upper
story of two story dwellings, fiberboard sheathing
applied vertically in panels at least 4 feet x 8 feet (ex-
cept where cut to fit around openings and for similar
purposes). Fiberboard sheathing shall be at least 1/2
inch in thickness and shall conform to the provisions
of reference standard RS8-80.

1.2.4. For one story dwellings and for the upper
story of two story dwellings, gypsum board sheathing
applied horizontally in panels at least 2 feet x 8 feet
(except where cut to fit around openings and for
similar purposes). Gypsum boards shall be at least
1/2 inch thick and shall conform to the provisions
of reference standard RS8-39.

1.3 Floor and roof framing. —

1.3.1. Span tables. — Joists and rafters may be used
in accordance with reference standard RS8-81.

1.3.2. Bridging. — See section 855.6.1.

1.3.3. Notches. — See section 853.3.3. In addition, for
stair stringers, the minimum effective depth of the
wood at any notch shall be 3-1/2 inches unless the
stringer is continuously supported on a wall or
partition.

1.3.4. Support.—

.1 Floor or roof framing may be supported on
stud partitions.

.2 Tail beams over 12 feet long and all header
and trimmer beams over 6 feet long shall be hung in
metal stirrups having anchors, or by other methods
providing adequate support. Trimmers and headers
shall be doubled where the header is 4 feet or more
in length.

.3 Except where supported on a 1 inch x 4 inch
ribbon strip and nailed to the adjoining stud, the ends
of floor joists shall have at least 1-1/2 inch of bearing
on wood or metal, nor less than 4 inches on masonry.

.4 Joists framing from opposite sides of and sup-
ported on a beam, girder, or partition shall be lapped
at least 4 inches and fastened, butted end-to-end and
tied by metal straps or dogs, or otherwise tied to-
gether in a manner providing adequate support.

.5 Joists framing into the side of a wood girder
shall be supported by framing anchors, on ledger
strips at least 2 inches x 2 inches, or by equivalent
methods.

.6 Wood joists and rafters bearing on masonry
walls shall be anchored to such walls in accordance
with the applicable provisions of article 8.

1.3.5. Rafters and Ceiling Joists. —

.1 Where rafters meet to form a ridge, they shall
be placed directly opposite each other and nailed to a
ridge board at least 1 inch thick, and not less than
the cut end of the rafters in depth.

.2 Provisions shall be made to resist the thrust
from inclined rafters by connection of collar beams
at least 1 inch x 6 inches, by connection to joists,
or by equivalent means.

RS8-78 RS8-81

.3 Where ceiling joists are not parallel to rafters,
subflooring or metal straps attached to the ends of
the rafters shall be installed in a manner to provide
a continuous tie across the building.

.4 Ceiling joists shall be continuous, or where
they meet over interior partitions, shall be securely
joined to provide a continuous tie across the building.

.5 Valley rafters shall be double members. Hip
rafters may be single members. Valley and hip rafters
shall be 2 inches deeper than jack rafters.

.6 Trussed rafters shall be designed in accordance
with the provisions of reference standard RS8-76.

1.3.6. Built-up members shall be securely spiked or
bolted together and provision shall be made to resist
the horizontal shear between laminations.

1.3.7. Nailing schedule. — The size and number of
nails for connections shall be in accordance with
reference standard RS8-77.

RS 8-79 USDC CS31 1952

Wood Shingles (Red Cedar, Tidewater, Red Cypress
and California Redwood)

RS 8-80 ASTM D2277 1966

Specifications for Fiberboard Nail-Base Sheathing

RS 8-81 NFoPA 1966

Simplified spans for Joists and Rafters in Residential
Construction

ARTICLE
FIRERESISTIVE CONSTRUCTION REQUIREMENTS

900.0 Scope

901.0 Definitions

902.0 Fire Hazard Division

Classification
903.0 Fireresistance Tests

904.0 Flame Resistance Tests

905.0 Special Fireresistive

Requirements
906.0 Enclosure Walls

907.0 Fire Walls and Party Walls

908.0 Fire Wall or Vertical Type A

Fire Division Openings
909.0 Fire Partitions

910.0 Fireresistive Partitions and

Type B Fire Divisions
911.0 Vertical Shafts and

Hoistways
912.0 Wall Lintels
913.0 Beams and Girders

914.0 Columns

915.0 Trusses

916.0 Exterior Opening

Protectives

TABLES

9-1 902.4 Type B Fire Divisions (Separations)

9-2 902.4 Type A Fire Divisions

9-3 908.3.1 Opening Protectives for Fire Walls and Fire Divisions

9-4 922.1.2 Interior Finish Flame Spread Limit Requirements

917.0
918.0
919.0
920.0

921.0
922.0
923.0

924.0

925.0
926.0

927.0
928.0
RS 9

Fire Doors

Fire Windows and Shutters

Wired Glass

Fireresistive Requirements
for Plaster

Firestopping

Interior Finish and Trim

Application of Interior
Finish

Combustible Materials
Permitted in Floor
Construction of Type 1
and Type 2 Buildings

Omitted

Restrictions of Exterior
Appendages and Trim

Roof Structures

Roof Coverings

Reference Standards

SECTION 900.0. SCOPE

The provisions of this article shall govern the use and assembly
of all materials of construction with respect to fireresistance,
flame spread resistance, and smoke and toxic fume limitation.
The provisions shall also control the location and function of
integral structural and fire protective elements of buildings, and
provide for the installation of safeguards against the spread of
fire within buildings and between buildings. The provisions of
the reference standards RS-9 shall be a part of this article.
900.1. Performance Standards. — The requirements of this article
shall constitute the minimum functional performance standards
for fire-protection purposes; and shall not be deemed to decrease

or waive any strength provisions or in any other manner de-
crease the requirements of this code in respect to structural
safety.

900.2. Use of Combustibles. — All materials and forms of con-
struction that develop the fireresistance required by this code
shall be acceptable for fireproofing and structural purposes;
except that the use of combustible component materials in
structural units or structural assemblies shall be limited to type
3 and type 4 construction except as follows:

900.2.1. Combustible Components. — Combustible aggregates
may be incorporated in concrete mixtures approved for fire-
resistive construction as provided in sections 811 and 850 for
gypsum concrete, in section 845 for cinder concrete and any
other approved component material or admixture may be used
in assemblies that meet the fireresistive test requirements of this
code; and wood nailing strips or any other material of similar
combustible characteristics may be embedded in concrete and
masonry construction for securing trim and finish.

900.2.2. Filler Units. — When not included in strength calcula-
tions, filler units that contain component combustible materials
may be used in all fireresistive floor construction provided the
complete assembly meets the required fire test performance.

900.3. Reinforced Concrete. — All reinforced concrete mixtures
which meet the requirements of section 817 for concrete aggre-
gates and the provisions of this article for time-temperature
performance shall be accepted in fireresistive construction and
shall be classified in accordance with the degree of fireresistance
required in article 2 and in section 221.1 table 2-1 and section
221.2 table 2-2.

900-902
SECTION 901.0. DEFINITIONS

For definitions to be used in the interpretation of this article,
see section 201.0.

SECTION 902.0. FIRE HAZARD DIVISION
CLASSIFICATION

Fire hazard division classification of buildings and structures
for the segregation of occupancies or spaces by fire divisions
as prescribed in section 213 shall be as specified in sections
below except as modified in article 6.

902.1. Segregation by Type A Fire Divisions. — When different
occupancies are to be segregated by fire divisions under the pro-
visions of section 213, the occupancies shall be separated from
each other, vertically and horizontally, by Type A fire divisions
having at least the fire-resistance ratings listed in section 902.4
table 9-2 for the occupancy groups involved. Every building sec-
tion shall be constructed of elements having at least the fire-
resistance rating of a construction class required for the area
and height of the building section as listed in section 221.1
table 2-1 and section 221.2 table 2-2.

902.2. Segregation by Type B Fire Divisions. — When different
spaces are to be segregated under the provisions of section 213,
the occupancies shall be separated from each other, vertically
and horizontally, by fire separations having at least the fire-
resistance ratings listed in section 902.4 table 9-1. In buildings
of construction types I and II, Type B Fire Divisions shall be
constructed of noncombustible materials.

902.3. Unclassified Uses. — The building official shall determine
the fire hazard classification of a building or structure designed
for a use not specifically provided in section 902.4 tables 9-1
and 9-2 in accordance with the fire characteristics and potential
fire hazard of the occupancy group which it most nearly re-
sembles; or its designation shall be fixed by the approved rules.

902.4. Required Fireresistance Rating for Fire Divisions.

Cl
J

<~i

-j

(-1

«N

rr>

■a

(—>

■*

■"fl-

■<t

■*

I-

■*

3 U

O a

-1

O a.

c
g '-5
iZ 2

<~j

(-1

E 2
O

«-s

902-903
902.5. Notes for Table 9-1.

902.5.1. An office, or group of offices, whose use is accessory
to an occupancy, and totals four hundred (400) square feet or
less in area shall not be required to be separated with a type
B Fire Division. Such office, or group of offices, totalling more
than four hundred (400) square feet in area shall not be re-
quired to be separated with a type B Fire Division if such
offices exit directly without having to pass through the area of
the related occupancy.

902.5.2. Counters and backbars for the sale of publications,
tobacco products, liquors, or candies, or for making of reser-
vations for travel, car rental, or theatre, or otherwise involving
similar business and mercantile activities that are accessory to
an occupancy and are limited in area to one hundred (100)
square feet within the area of the occupancy, need not comply
with the requirements of this table.

902.5.3. The provisions of this table shall not apply to closets
seventy-five (75) square feet or less in area.

902.5.4. Nonresidential kitchens shall be separated by fire divi-
sions from adjoining dining spaces except when the following
conditions are complied with:

a. The cooking equipment is vented directly to the out-
doors, and

b. A draft curtain of noncombustible material, at least
twenty-four (24) inches down from the ceiling, is pro-
vided to separate the cooking facilities from dining
spaces, and

c. Sprinkler heads constructed in accordance with the pro-
visions of article 12 are provided on the cooking facil-
ities side of the curtain, or any opening between the
kitchen and dining space, located within twenty-four (24)
inches of the curtain or opening, and spaced not more
than forty-eight (48) inches on centers if the opening is
more than sixty (60) inches wide. When fire separations
consisting of type B fire divisions are provided, double-
action doors may be permitted.

SECTION 903.0. FIRERESISTANCE TESTS

All fire tests of building materials and construction shall be
conducted in accordance with the applicable fire test procedure
as specified herein; except that the hose-stream test therein pre-

scribed for one (1) hour construction shall be required for all
assemblies and constructions approved for a fireresistance rating
of three-quarter (3/4) hours. The fireresistance rating of mate-
rials and assemblies listed in reference standard RS 9-1 may be
used to determine conformance with the fireresistance require-
ments of this code. In addition to the performance results, test
reports shall give all technical data pertaining to the nature of
the constituent materials, such as the physical properties, chem-
ical composition and properties, coefficient of expansion, thick-
nesses of materials, etc. Except as listed in reference standard
RS 9-1, any assembly using a component having a structural
base of noncombustible material covered with an integrally
manufactured combustible surfacing material, shall have an
approved fireresistance rating.

903.1. Structural Building Assemblies. — Built-up masonry units
and composite assemblies of structural materials including walls,
partitions, columns, girders, beams and slabs and assemblies
of slabs and beams or other combinations of structural units
for use in floor and roof construction shall be regulated by the
fireresistance ratings of section 221.1 table 2-1 based on the
test procedures of reference standard RS 9-2.

903.2. Protection of Unoccupied Space. — Where a fireresistance
rating is required for floor and roof assemblies, the ceiling may
be omitted over unusable space and flooring or decking of the
tested assembly may be omitted where unusable enclosed space
occurs above provided the fireresistance of the assembly is not
reduced to less than one (1) hour.

903.3. Column, Beam and Girder Protection. — To evaluate
column, beam and girder protection for structural units when
the fireproofing is not a structural part of the element, in lieu
of full size tests of loaded specimens, the structural sections
encased in the material proposed for use as insulation and fire
protection may be subjected to the standard test procedure
without load.

903.4. Roof Coverings.

903.4.1. Size of Specimen. — Roof coverings shall be tested in
a complete assembly of roof deck and roof covering constructed
and applied as in practice with a panel area of not less than
twelve (12) square feet and no dimension less than thirty-two
(32) inches.

903.4.2. Test Procedure. — The tests shall be conducted to de-
termine ability to resist ignition, duration of flaming and sus-
ceptibility to fire spread.

903

903.5. Classification of Roof Coverings. — Roof coverings shall
be classified as A, B or C on the basis of their resistance to
exterior fire exposure as listed in reference standard RS 9-3
or as determined by tests made in conformance with reference
standard RS 9-4 for those not listed.

903.5.1. Limitations of Use. — Every roof placed on a building
shall be covered with Class A or B roof covering, except that
Class C roof covering may be placed on buildings classified in
Occupancy Group L when not more than three (3) stories or
forty (40) feet in height, and on buildings permitted by this code
to be of type 4 A or 4B construction.

903.5.2. Combustible Roof Decking. — Unless attached directly
to noncombustible framework, all roof covering shall be applied
to a closely fitted deck.

903.5.3. Roof Insulation. — Approved combustible roof insula-
tion may be applied on top of roof decking or slab provided
that it is protected with the roof covering applied directly
thereto.

903.5.4. Wood Shake or Wood Shingle. — Roofing shall be
limited to use in areas outside of the fire limits where the ex-
terior fire exposure hazard is reduced by required fire separa-
tions as provided in section 928.3 and on frame (type 4B)
construction.

903.6. Opening Protectives.

903.6.1. Structural Integrity. — Opening protectives, including
frames, self-closing devices, and hardware, shall be classified as
to fire-protection rating in accordance with the test procedures
of reference standards RS 9-5 and RS 9-6, and shall be in-
stalled, maintained, and operated in accordance with the pro-
visions of reference standard RS 9-7. All opening protectives
shall bear the identification of an approved testing laboratory
or agency certifying to the performance rating thereof, in accor-
dance with the acceptance requirements of article 1.

903.6.2. Smoke and Flame Barrier. — Tests of door and window
assemblies shall be considered unsuccessful unless the assembly
prevents the passage of smoke or flames in considerable volume
and remains securely in the opening during the fire exposure
and following the hose-stream test.

903.6.3. Labeled Fire Doors. — Opening protective assemblies
including the frames, hardware and operation which comply
with the standards and accepted practice, including shop inspec-
tion, of an approved testing laboratory or agency, shall be

deemed to meet the requirements of this code for their recom-
mended and approved locations and use as listed in section 917.

903.6.4. Door Openings More Than 120 Square Feet. — Labeled
fire doors for openings which are more than one hundred and
twenty (120) square feet in area may be approved as conforming
to all the standard construction requirements of tested and ap-
proved fire door assemblies except as to size.

903.6.5. Labeled Fire Windows and Shutters. — Fire window
assemblies and shutters which comply with section 918, and
the standards and accepted practice of the Underwriters'
Laboratories, Inc., or other approved testing authorities shall
be deemed to meet the requirements for their recommended
and required locations under this code.

903.6.6. Labeled Fire Dampers. — Only fire dampers which
have been tested, listed and labeled by Underwriters' Labora-
tories, Inc., or an equivalent test and labeling by other approved
testing laboratories shall be deemed to meet the requirements
of this code for the recommended locations and use as listed
in section 1812.1.

903.7. Combustibility Tests. — Where the behavior of materials
under exposure to fire is specified in this Code the character-
istics of materials shall be determined by the following tests
and criteria.

903.7.1. Noncombustible Materials. — A noncombustible material
is one which, in the form in which it is used, meets any of the
following requirements:

a. Materials which pass the test procedure for defining
noncombustibility of elementary materials listed in refer-
ence standard RS 9-8 when exposed to a furnace temper-
ature of thirteen hundred eighty-two (1382) degrees F.
for a period of five (5) minutes, and do not cause a
temperature rise of the surface or interior thermocouples
in excess of fifty-four (54) degrees F. above the furnace
air temperature at the beginning of the test and which
do not flame after an exposure of thirty (30) seconds.

b. Materials having a structural base of noncombustible
material as defined in paragraph a., with a surfacing not
more than one-eighth (1/8) inch thick which has a flame-
spread rating not greater than fifty (50) when tested in
accordance with the method of test for surface burning
characteristics of building materials listed in reference
standard RS 9-9.

903

c. Materials other than defined in paragraphs a. and b.,
having a flame-spread rating not greater than twenty-
five (25) without evidence of continued progressive com-
bustion, and of such composition that surfaces that
would be exposed by cutting through the material in
any way would not have a flame-spread rating greater
than twenty-five (25) when tested in accordance with
method of test for surface burning characteristics of
building materials listed in reference standard RS 9-9.

d. The term noncombustible does not apply to the flame-
spread characteristics of interior finish or trim materials.
No material shall be classed as noncombustible building
construction material which is subject to increase in com-
bustibility or flamespread rating beyond the limits herein
established through the effects of age, moisture or other
atmospheric conditions.

903.7.2. Fire-Retardant Treated Wood Tests. — Where permitted
for use as a structural element, fire-retardant treated wood shall
be tested in accordance with the standard method of test for
surface burning characteristics of building materials (tunnel test)
listed in reference standard RS 9-9 and shall show a flame-
spread rating not greater than twenty-five (25) when exposed
for a period of not less than thirty (30) minutes, with no evi-
dence of significant progressive combustion. The material shall
bear the identification of an approved authoritative testing
agency showing the performance rating thereof.
903.8. Fire-Retardant Treated Wood. — Wood that has been
pressure treated with fire-retardant chemicals in accordance with
reference standards RS 9-10 or RS 9-11 may be used in type
1 and 2 constructions for non-bearing partitions, structural ele-
ments, roof framing and sheathing, in accordance with Note
6, as indicated by note in section 221.1 table 2-1 provided that
the assembly in which such material is used shall produce the
required fireresistance when tested in accordance with reference
standard RS 9-2.

903.8.1. Limitations. — Fire-retardant treated wood may not
be used where exposed to the weather or in interior spaces
where the relative humidity is normally eighty (80) per cent or
more. There shall be no fabrication of the material after treat-
ment, such as cutting, shaping or grooving for splines or ring
connectors so as to expose untreated surfaces, except that the
material may be cut to length, shaped, or grooved if the ex-

posed surfaces or edges are tightly butted against other material
that is noncombustible or that is fire retardant treated, so that
no untreated wood is left exposed to danger of ignition. Holes
may be bored or cut for plumbing or heating pipes and for
electric outlets only if the openings are covered with tightly-
fitted noncombustible escutcheons or cover plates. The allowable
working stresses of the material shall be ninety (90) per cent of
the allowable stresses for untreated lumber of like classification.

903.8.2. Structural Elements. — Where used as a structural ele-
ment or as furring, such material shall meet the requirements of
section 903.7.2.

903.8.3. Interior Finish. — Where used as interior finish or trim,
such material shall meet the requirements of section 904.1.

903.8.4. Area Increase. — Fire-retardant treated wood may be
used in construction types 3A, 3B and 4A buildings in lieu
of untreated wood for wall studs, bearing partition studs,
columns, beams, girders, joists, rafters, trusses, sole and cap
plates, subflooring and roof decks and when so used, the area
limitations of section 221.1 table 2-1 for buildings of construc-
tion type 3A, 3B and 4A may be increased by thirty-three and
one-third (33-1/3) per cent.

SECTION 904.0. FLAME RESISTANCE TESTS

All materials which are required to restrict the spread of flame
or to be flame resistant under the provisions of this code, in-
cluding but not limited to interior finish materials, fireretardant
treated wood, tents and tarpaulins, and interior hangings and
decorations, shall meet the requirements for their respective use
and classifications as determined by the applicable test pro-
cedures listed herein.

904.1. Interior Finish Materials. — All materials used for interior
finish shall be classified in accordance with the surface flame-
spread rating obtained as prescribed in the provisions of reference
standard RS9-9. Where an interior finish material is comprised
of two (2) or more materials, laminated, glued, nailed or other-
wise secured together, the test rating for flame spread shall be
based upon the composite of the materials in the form in which
it will be used in construction. Interior finish materials shall

903-905

be grouped in the following classes, in accordance with their

surface flame spread characteristics:

Interior Finish Class Flame-Spread Rating

A to 25

B 26 to 75

C 76 to 225

D 226 to 500

SECTION 905.0. SPECIAL FIRERESISTIVE REQUIREMENTS

In buildings or parts thereof of the occupancies and types of
construction herein specified, the general fireresistive require-
ments of section 221.1 table 2-1 and the height and area limi-
tations of section 221.2 table 2-2 shall be subject to the following
exceptions and modifications, and to Massachusetts Department
of Public Safety, Board of Fire Prevention Regulations Form
FPR No. 4.

905.1. Public Garages. — Subject to the approval of the building
official, existing buildings and structures altered or converted
for use to a garage, motor vehicle repair shop or gasoline
service station, more than one (1) story in height, unless of
fireproof (type 1) construction, or heavy timber (type 3-A)
construction, shall have the partitions, columns and girders and
all floor and roof construction protected and insulated with
noncombustible materials or assemblies of component materials
having a fireresistance rating of not less than three-quarter (3/4)
hours; except that existing roof trusses shall be exempt from
all fireproofing requirements.

905.2. Open Parking Structures. — For general construction re-
quirements, see section 430.

905.2.1. — Open parking structures shall be provided with stand-
pipe in accordance with the requirements of Article 12.

905.2.2. — When a sprinkler system is installed in accordance
with section 1213 in types 2A, and 2B construction, the area
maybe unlimited.

905.3. Petroleum Bulk Storage Buildings. — Warehouses for the
bulk storage of not more than fifty thousand (50,000) gallons
of lubricating oils with a flash point of not less than three
hundred (300) degrees F. in approved sealed containers may be
erected outside the first and second fire zones of masonry
wall (type 3) construction not more than five thousand (5,000)
square feet in area and not more than one (1) story or twenty
(20) feet in height; or to proportionate areas in other types

of construction as regulated by section 221.2 table 2-2. Not
more than one (1) motor vehicle may be stored in such build-
ings unless separately enclosed with a Type A fire division of
two (2) hours fireresistance.

905.4. Packing and Shipping Rooms. — Every packing or shipping
room located on or below a floor occupied for mercantile uses
shall be separated therefrom by fire divisions of not less than
the fireresistance of the type of construction of the building
but in no case less than three-quarter (3/4) hours fireresis-
tance.

905.5. Truck Loading and Shipping Areas. — Truck loading and
shipping areas shall be permitted within any business building
provided such areas are enclosed in construction of not less
than the fireresistance of the type of construction of the build-
ing but in no case less than three-quarter (3/4) hours; and
direct access is provided therefrom to the street.

905.6. Residential Buildings.

905.6.1. Protected Ordinary Construction. — Multi-family dwel-
lings (occupancy group L-2) of protected ordinary (type 3-B) con-
struction may be increased to six (6) stories or seventy-five
(75) feet in height when the first floor above the basement
or cellar is constructed of not less than three (3) hour fire-
resistive construction, the floor area is subdivided by two (2)
hour fire walls into fire areas of not more than three thousand
(3,000) square feet, and the stairways, public hallways and
exitways are enclosed in two (2) hour fireresistive construction.

905.6.2. Protected Noncombustible Construction.— When of three-
quarter (3/4) hour protected noncombustible (type 2-B) con-
struction, multi-family dwellings (use group L-2) may be in-
creased to nine (9) stories or one hundred (100) feet in height
when separated not less than fifty (50) feet from any other
building on the lot and from interior lot lines, the exitways
are segregated in a fire area enclosed in a continuous fire
wall of two (2) hour fireresistance and the first floor is not
less than one and one half (1-1/2) hours fireresistive construction.

905.6.3. Retail Business Use. — Subject to the restrictions of the
zoning laws, the first floor of buildings of unprotected non-
combustible (type 2-C), masonry wall (type 3-C) or frame
(type 4-B) construction may be occupied for retail store use,
provided the ceilings and enclosure walls are protected to afford
three-quarter (3/4) hour fireresistance and the exitways from
the residence floors are separately enclosed in accordance with
the requirements of section 909.5 and article 6.

905-906
905.7. Grade Floor Protection.

905.7.1. Non-Fireproof Construction. — In all buildings other
than one- and two-family dwellings (occupancy group L-3) and
other than fireproof (types 1A and IB) construction with hab-
itable or occupiable stories or basements below grade, the
ceilings, partitions and supports below the grade floor shall
be protected with noncombustible materials or assemblies of
component materials having a fireresistance rating of not less
than three-quarter (3/4) hours or shall be of heavy mill (type
3A) construction, or shall be equipped with automatic sprinklers;
but in no case less than the required fireresistance of the occu-
pancy group and type of construction required by section 221.1
table 2-1 and section 221.2 table 2-2.

905.7.2. Protected Noncombustible Construction. — In all build-
ings of one and one-half (1-1/2) hour protected noncombustible
(type 2-A) construction, more than four (4) stories or fifty
(50) feet in height, in other than residential occupancy groups,
the floor above the basement or cellar shall be constructed with
a fireresistance of not less than two (2) hours.

905.7.3 One- and Two-Family Dwellings. — One- and two-family
dwellings (occupancy group L-3), not more than (2) stories
and attic or thirty-five (35) feet in height, shall be exempt
from the requirements of section 905.7.

905.7.4. Below Grade Assembly Uses. — No dance hall, skating
rink or similar places of public assembly for amusement, enter-
tainment, instruction, or service of food or refreshment shall
be located in rooms or spaces, the floor levels of which are
more than three (3) feet below grade unless the floor construc-
tion above and below is of not less than one and one-half
(1-1/2) hours fireresistance.

SECTION 906.0. ENCLOSURE WALLS

All exterior masonry ?nd other enclosure walls shall comply
with the structural provisions of articles 7 and 8 and with the
fireresistance requirements of section 221.1 table 2-1 as regulated
by the location and type of construction. Where other provisions
of this code require a space or facility to be enclosed, the con-
struction requirements for the enclosure shall not apply to any
exterior wall that forms part of the enclosure.
906.1. Exceptions. — The provisions of this code shall not be
deemed to prohibit the omission of enclosure walls for all or

part of a story when required for special uses and occupancies;
except that when so omitted, the open areas shall be separated
from the rest of the area and from the upper and lower stories
of the building by wall and floor construction of the fireresistance
required in section 221.1 table 2-1; and except as otherwise
specifically permitted in this code, and the piers, columns and
other structural supports within the open portion shall be con-
structed with the fireresistance required for exterior bearing walls
in section 221.1 table 2-1.

906.2. Stone Masonry Piers. — In buildings of fireproof (types 1A
and IB) construction, stone masonry shall not be used for in-
terior isolated piers, columns, arches or vaultings, that support
loads in addition to their dead weight except in church and
similar monumental buildings; but this shall not prohibit the use
of stone facings on loadbearing piers installed in accordance with
the provisions of sections 863 and 873.

906.3. Fire Canopies. — All fire canopies required by section
918.5.1 shall be constructed of noncombustible materials ex-
tending out at least two (2) feet horizontally from the wall and
at least as long as the width of the lower opening and constructed
to provide a fireresistance rating required for the exterior wall.

906.4. Parapets. — Parapets shall be provided on all exterior
walls of buildings of construction types 3A, 3B or 3C that have
roof construction of combustible materials, shall be at least
two (2) feet high, shall be of materials and assembly having at
least the fireresistance rating of the wall below and shall other-
wise conform to the requirements of section 870.0. Exceptions
where parapets need not be provided on the exterior walls shall
be made for the following buildings:

906.4.1. One (1) story buildings less than twenty-two (22) feet
high; or

906.4.2. A building whose roof has a pitch of more than twenty
(20) degrees to the horizontal and whose overhang, fascia,
cornice or gutter is of noncombustible construction, or if of
combustible construction, is separated from the roof and ceiling
construction by construction having the fireresistance rating
required for the exterior wall of the building. Combustible
members, including roof sheathing, shall not extend through this
construction, but shall have at least four (4) inches of solid non-
combustible material below, at the sides, and at the ends of
such members; or

906-907

906.4.3. A building is provided with a fire canopy, or not more
than two (2) feet below the roof level, continuous around that
portion of the wall that is without a parapet, constructed as
required by section 906.3; or

906.4.4. A building whose roof has a class A roof covering,
and any overhangs, cornices, or gutters are constructed as re-
quired by section 906.4.2 above.

SECTION 907.0. FIRE WALLS AND PARTY WALLS

Fire walls, party walls and other Type A Fire Divisions shall
be constructed of noncombustible materials or assembly of non-
combustible materials or form of construction of the required
strength and fireresistance rating specified in section 221.1 table
2-1 for the type of construction but not less than the fire-
resistance rating required in section 902.4 table 9-2 for the
occupancies involved. The construction shall comply with all
the structural provisions for bearing and nonbearing walls of
this code.

907.1. Solid Brick. — In other than frame buildings, when con-
structed of solid brick masonry, the wall thickness shall conform
to the requirements of section 868; except that in all buildings
more than twenty-five (25) feet in height used for moderate fire
hazard storage (occupancy group B-l) and all high hazard uses
(occupancy group A), no part of an unplastered masonry fire
wall shall be less than twelve (12) inches thick.

907.2. Reinforced Concrete. — When constructed of reinforced
concrete, the wall thickness shall be not less than six (6) inches
for the uppermost twenty-five (25) feet or portion thereof and
shall increase two (2) inches for each additional twenty-five (25)
feet or portion thereof measured down from the top of the wall;
except that in buildings more than twenty-five (25) feet in height
used for storage of moderate fire hazard (occupancy group B-l)
and high hazard (occupancy group A), no part of an un-
plastered reinforced concrete fire wall shall be less than eight
(8) inches thick.

907.3. Frame Dwellings. — In one- and two-family dwellings
(occupancy group L-3), of frame (type 4) construction, party
walls shall be not less than three-quarter (3/4) hour fireresistive
construction and shall extend through intersecting walls of frame
construction to the outside of all combustible wall and roof
sheathing.

907.4. Other Frame Buildings. — In frame buildings, in occupancy
groups other than one- and two-family dwellings, all fire walls,
party walls and type A fire divisions shall not be less than two
(2) hour fireresistive construction, but in no case less than rating
required in section 902.4 table 9-2. These divisions shall project
at least twelve (12) inches through the exterior wall which pro-
jection may be eliminated where the exterior walls are constructed
of noncombustible materials for a distance of at least eighteen
(18) inches on each side of the fire division and their junction
is smoke tight.

907.5. Cutting Fire Walls. — Chases or recesses shall not be cut
into fire divisions so as to reduce their thickness below that
required for all fireresistance rating, except that no chases,
recesses or pockets for insertion of structural members subse-
quent to erection shall be cut in walls of eight (8) inches or
less in thickness.

907.5.1. Where combustible members such as joists, beams, or
girders bear on, or frame into, vertical fire divisions, such mem-
bers shall not extend through the wall and shall have at least
four (4) inches of solid noncombustible material below, at the
sides, and at the ends of each such member.

907.6. Hollow Fire Walls and Type A Fire Divisions. — Vertical
fire divisions and walls that are hollow shall be firestopped with
at least four (4) inches of noncombustible material so as to
prevent passage of flame, smoke, or hot gases through the
hollow spaces to the story above or below, or to hollow spaces
within connecting floor or roof construction.

907.7. Combustible Insulation. — The building official may
permit the application of cork or fiber board or other com-
bustible insulation if laid up without intervening air spaces and
cemented or attached directly to the face of the fire wall and
protected on the exposed surface as provided in section 824.

907.8. Continuity of Fire Walls and Type A Fire Divisions.—
Fire walls and other vertical type A fire divisions shall be con-
tinuous between foundation, roof, or horizontal type A fire
divisions and through any concealed space in floor or roof con-
struction. Horizontal type A fire divisions shall be continuous
between exterior walls and/or vertical type A fire divisions.
907.8.1. When roof construction is combustible on both sides of
a type A vertical fire division, the division shall extend through
the roof construction to a height of at least four (4) inches
above the high point at the roof framing. Decking shall tightly

907-908

butt the fire division. Above the decking of roofs that are flatter
than twenty (20) degrees to the horizontal blocking shall be
constructed to form cants on both sides of the fire division
with slopes not steeper than 1:4. Combustible decking shall not
extend over the top of the fire division.

907.8.2. Except as required in 907.8.3 below, when roof construc-
tion is noncombustible on one (1) or both sides of a vertical
fire division, the vertical fire division may terminate at the
underside of the noncombustible roof construction provided the
junction of the wall and roof construction is made smoke tight.

907.8.3. When a vertical type A fire division is required by
section 902.4 table 9-2 to have a fireresistance rating of three (3)
or four (4) hours, and the roof construction has a fireresistance
rating of less than two (2) hours, the fire division shall extend
above the roof construction to form a parapet at least three (3)
feet high.

907.8.4. Fire walls and Type A fire divisions shall be so con-
structed that the removal or collapse of construction on one side
will not endanger the support of construction on the other side.

907.8.5. Fire walls and fire divisions shall be made smoke tight
at their junction with exterior wails.

907.9. Offset Fire Walls and Divisions. — Fire walls and other
type A fire divisions may be offset if the construction between
the offset divisions, including their supports, has at the same
fireresistance rating as the fire division, with all hollow spaces
within the construction firestopped with noncombustible material.

SECTION 908.0. FIRE WALL OR VERTICLE TYPE A
FIRE DIVISION OPENINGS

Openings in said walls and fire divisions shall not exceed the
limits in size and area herein prescribed and the opening pro-
tectees shall conform to the provisions of sections 903, 904
and 917.

908.1. Size of Openings. — In buildings without sprinkler system
no opening through a fire wall or verticle type A fire division
shall exceed one hundred and twenty (120) square feet in area,
with no dimension greater than twelve (12) feet, and the aggre-
gate width of all openings at any level shall not exceed twenty-
five (25) per cent of the length of the wall. Where the areas on
both sides of a fire division are sprinklered in accordance with
article 12, the size of the opening may be one hundred and fifty
(150) sq. ft. in area, with no dimension greater than fifteen (15)

feet. In buildings fully sprinklered in compliance with the pro-
visions of article 12, the size and aggregate width of openings
through fire divisions and walls shall be unlimited.

908.2. First Story Exceptions. — In buildings of all types of con-
struction, when the entire areas on both sides of a fire wall
are protected with an approved automatic sprinkler system com-
plying with article 12, openings designed for the passage of
trucks may be constructed not more than two hundred and
forty (240) square feet in area with a minimum distance of
three (3) feet between adjoining openings. Such openings shall be
protected with approved automatic opening protectives of three
(3) hour fire resistance and provided with an approved water
curtain for such openings in addition to all other requirements.

908.3. Opening Protectives. — Except as section 917.1 may re-
quire, every opening in a fire wall or vertical type A fire
division shall be protected by opening protectives having the
fireresistance rating prescribed in section 908.31 table 9-3.
908.3.1. Table 9-3 Opening Protectives for Fire Walls and Fire
Divisions.

Fire-Resistance Rating of Fire Fire Protection Rating of

Wall or Division in which Opening Protection*

opening occurs
3 or 4 hours 3 hours (Class A)

2 or 1-1/2 hours 1-1/2 hours (Class B)

1 hour 3/4 hour (Class C)

*When not a part of a means of egress, the opening protective
shall be applied on each face of the opening, with each pro-
tective individually having the required rating except that only
a single protective shall be required when it is installed wholly
within the thickness of the wall.

908.4. Horizontal Exitway. — Door openings in a fire wall ser-
ving as a horizontal means of egress shall be protected with an
approved one and one-half (1-1/2) hour self-closing swinging
fire door or its labeled equivalent when designed as an exitway
from one side. When serving as a dual exitway, there shall be
adjacent openings with swinging fire doors opening in opposite
directions. Signs shall be provided indicating as an exit, the
door which swings in the direction of travel from that side. The
size of openings shall comply with section 616. An automatic
fire door, fire curtain, or water curtain shall be provided on
the opposite side of each such opening.

908-909
SECTION 909.0. FIRE PARTITIONS

909.1. Construction. — Fire partitions required for the enclosure
of exitways and areas of refuge shall be constructed of approved
masonry, reinforced concrete or other approved noncombustible
materials having the minimum fireresistance prescribed by sec-
tion 221.1 table 2-1, except that partitions constructed of com-
bustible materials to provide the required fireresistance may be
accepted for use in exitways of buildings of types 3 and 4 con-
struction as regulated by section 221.1 table 2-1 and the pro-
visions of section 618.9.

909.2. Bearing Partitions. — When fire partitions are used as
bearing walls, they shall comply with all the structural provi-
sions of article 8 governing height and thickness.

909.3. Continuity. — When fire partitions around vertical shafts
are not continuous from floor to floor, the offset in the floor
construction shall be of construction with a fireresistance rating
not less than that of the partition construction, nor less than
that of the fireresistance rating required in section 902.4 table
9-2 for the specific occupancy involved.

909.4. Openings.

909.4.1. Size. — No other openings shall be permitted in fire
partitions except exitways doors, and the aggregate permissible
width of such doorways shall not exceed twenty-five (25) per
cent of the length of the wall, nor shall the maximum area of
any individual opening exceed forty-eight (48) square feet.

909.4.2. Protectives. — All opening protectives in fire partitions
in other than one- and two-family dwellings shall comply with
the provisions of sections 903 and 918 for construction, except
as provided in section 618.93 for buildings not more than three
(3) stories in height.

909.5. Combustible Stair Enclosures.

909.5.1. Construction. — Stair enclosures constructed of approved
combustible assemblies protected with component materials to
afford the required fireresistance ratings shall be continuous
through combustible floor construction and shall provide an
unbroken fire barrier in combination with protected floors,
ceilings and fire doors, separating the exitways from the un-
protected areas of the building. Such enclosures shall be fire-
stopped to comply with sections 877.9 and 921.

909.5.2. Openings for Lighting. — Openings for the purpose of
providing light in such enclosures may be protected with wired
glass with single panes not more than three hundred and sixty

(360) square inches in area and a total area in one story of
not more than seven hundred and twenty (720) square inches.
Such light panels shall comply with the provisions of section
919 and shall be contained in stationary sash and frames of
steel or other approved noncombustible materials.

SECTION 910.0. FIRERESISTIVE PARTITIONS AND TYPE
B FIRE DIVISIONS

910.1. Construction. — Type B fire divisions shall be constructed
of materials or assembly of materials having at least the firere-
sistance ratings required by section 902.4 table 9-1, except that
when used to separate different tenant apartments, suites, stores,
offices or other spaces from each other the fireresistance rating
prescribed shall be that indicated in section 902.4 table 9-1 but
in no case less than one (1) hour and shall continue through
any concealed spaces of the floor or roof construction above.

910.2. Supports — All fireresistive partitions shall extend from
the top of the fireresistive floor below to the fireresistive ceiling
above, and shall be securely attached thereto. They shall be
supported on fireproofed steel or reinforced concrete construc-
tion; except that the supporting beams and girders of fireresis-
tive partitions constructed of combustible materials shall be pro-
tected with component materials or assemblies to afford the
required fireresistance of the partitions supported. All hollow
vertical spaces shall be firestopped at every floor level as re-
quired in sections 877 and 921.

910.3. Openings. — Door openings shall not exceed one hundred
and twenty (120) square feet in area and where required to be
fire protected, they shall comply with the provisions of sections
904 and 917.

910.4. Exceptions.

910.4.1. Non-Fireproof Construction. — In buildings and struc-
tures of masonry enclosed (type 3) and frame (type 4) construc-
tion, protected wood studs or other combustible assemblies
constructed with component materials to afford the required fire-
resistance specified in section 221.1 table 2-1 shall be approved
for enclosures of exitways where permitted in section 618.93
and for all nonbearing partitions.

910.4.2. Fireproof Construction. — In buildings and structures
of fireproof (type 1) or of protected noncombustible (type 2)
construction:

909-911

a. Of other than group H, L-l and L-2 occupancies, parti-
tions of a single thickness of wood or approved com-
posite panels, and glass or other approved materials of
similar combustible characteristics, may be used to sub-
divide rooms or spaces into offices, entries, or other
similar compartments, provided they do not establish a
public corridor or a private corridor serving an occupant
load of fifty (50) or more in areas occupied by a single
tenant and not exceeding five thousand (5,000) square
feet between fireresistive partitions and fireresistive floors,
or type A fire divisions.

1. Larger areas may be subdivided with fireretardant
wood or with materials of similar combustible
characteristics when complying with section 903.72,
but not to exceed fifty (50) per cent increase in area.

b. Nonbearing partitions that are not required to have a
fireresistance rating may be constructed of fireretardant
treated wood and furring as provided in section 903.8,
and except that such partitions and furring may be con-
structed of combustible materials in spaces classified in
class E, L-2 or L-3 occupancies provided the space
containing the combustible portions does not exceed
five thousand (5,000) square feet in area within a non-
combustible enclosure having a fireresistance rating of at
least one (1) hour, is of a single tenancy and glass or
approved light transmitting plastic is used for glazing.

SECTION 911.0. VERTICAL SHAFTS AND HOISTWAYS

The provisions of this section for the enclosure shafts shall
apply to all shafts except that floor openings accommodating
a slide pole in a fire house shall be exempt from these provisions
and except as provided for stairway enclosures in section 618,
flue enclosures in section 1008, incinerator chutes in sections
1016 and 1017, duct shafts in sections 1018 and 1019, pipe
shafts in section 1117 and elevator and dumbwaiter hoistways
in article 16.

911.1. Wall Enclosure. — The shafts shall be enclosed with
materials having at least the fireresistance rating required by
section 221.1 table 2-1 and as supplemented herein.

911.1.1. Open Shafts. — The enclosing wall of shafts that are
open to the outer air at the top shall be constructed of materials
specified in article 8 for exterior walls of buildings and structures.

911.1.2. Closed Shafts. — The enclosing walls of interior covered
shafts shall be constructed of approved masonry, reinforced con-
crete or other approved construction with a fireresistance rating
of not less than two (2) hours, except as provided in section 911.

911.1.3. Shafts in Residential Buildings. — In one- and two-
family dwellings of other than fireproof or noncombustible
construction, shafts may be supported on and constructed of
combustible materials or assemblies having a fireresistance rating
of not less than three-quarter (3/4) hours, and shall extend not
less than three (3) feet above the roof with a ventilating skylight
of noncombustible construction as specified in section 927.2.

911.2. Top Enclosure.

911.2.1. Not Extending to Roof. — A shaft that does not extend
into the top story of the building shall be enclosed with top
construction of the same strength and fireresistance as the floors
of the building or structure in which it occurs, but in no case
less than that of the fireresistance rating of the shaft enclosure.

911.2.2. Extending to Roof. — A shaft that extends through or
serves the top most story of a building shall extend through the
roof at least thirty-six (36) inches above any combustible roof
construction. Where the roof construction is of noncombustible
materials, the shaft shall extend through any concealed space
within the roof construction and may terminate at the underside
of the roof deck. Pipes and ducts penetrating shaft construction
shall comply with the requirements of this code.

911.3. Bottom Enclosure. — All shafts that do not extend to the
bottom of the building or structure shall be enclosed at the
lowest level with construction of the same strength and fire-
resistance as the lowest floor through which it passes, but in
no case with a fireresistance rating less than that of the shaft
enclosure.

911.4. Shaft Openings. — No openings other than necessary for
the purpose of the shaftway shall be constructed in shaft en-
closures; and except in shafts that contain only one opening
below the roof terminus, all openings shall be protected with
approved fire doors, curtains, shutters or fixed metal sash with
wired glass complying with the provisions of sections 917, 918
and 919.

911
911.4.1. Where a window is located in a shaft wall that is an
exterior wall and is ten (10) stories or less above grade or three
(3) stories or less above a roof, it shall be protected against
entrance by a permanently secured grille consisting of five-eighths
(5/8) inch diameter bars ten (10) inches o.c. vertically, or by a
stationary metal sash window having one-eighth (1/8) inch thick
solid section steel muntins, eight (8) inches o.c. one way.
911.5. Venting of Closed Shafts. — All closed shafts having an
area exceeding four (4) square feet shall be provided with a
smoke vent having an area of at least three and one half (3-1/2)
per cent of the maximum shaft area at any floor, but in no
event less than one half (1/2) square foot. Smoke vents may be
windows, louvers, skylights, vent ducts, or similar devices. Vent
ducts shall be enclosed by construction having the same fire-
resistance rating as required for the shaft enclosure. Such vent
ducts 'shall extend vertically, diagonally, or horizontally as
follows:

911.5.1. Through any roof of the building provided the vent
opening is at least ten (10) feet from any window, door, outside
stairway, or interior lot line. This dimension may be reduced to
five (5) feet if the vent duct is extended up to at least the level
of the top of the window or door. A vent that is required to
extend above a roof shall extend at least eight (8) inches above
a roof assembly constructed of noncombustible materials, and
at least thirty-six (36) inches above a roof assembly constructed
of combustible materials that are within a horizontal distance
of ten (10) feet.

911.5.2. Through an exterior wall of the building, provided
there are no openings in the wall within a distance of thirty (30)
feet vertically above the vent opening, and within five (5) feet
either side of the vent opening. When a side of a shaft is an
exterior wall or a wall of a roof bulkhead, the required vent
may be a louver or window. Any window or louver located in
a shaft wall above a roof constructed of combustible materials
shall have its sill at least thirty-six (36) inches above the roof.

911.5.3. Of the total required vent area for shafts, at least one-
third (1/3) shall be clear opening to the outdoors, either in the
form of fixed louvers, ridge vents, or hooded or goosenecked
openings. In lieu thereof, skylights or trap doors may be used
if constructed and arranged to open automatically by fusible link
or other mechanical device when subjected to a temperature of
one hundred and sixty (160) degrees F. or to a rapid rise in

temperature at a rate of fifteen (15) to twenty (20) degrees F.
per minute. The remaining portion of the required vent area may
be a window or skylight glazed with plain glass not more than
one eighth (1/8) inch thick or slow burning plastic.

911.6. Equipment Rooms. — Any room, space, or compartment
containing equipment or machinery that communicates with a
shaft enclosure shall comply with all requirements for shafts.
The required louver or glazing shall not be located in any door
leading into such room, space or compartment.

911.7. Existing Shaftways. — In all existing shaftways of buildings
of assembly (occupancy groups Fl, F2, F3 and F4), institutional
(occupancy groups HI and H2) and residential (occupancy
groups LI and L2) classifications, which are not already en-
closed as herein required, the building official shall direct such
construction as he may deem necessary to insure the safety of
the occupants.

SECTION 912.0. WALL LINTELS

912.1. Fire Protection. — Lintels over openings wider than four
(4) feet in masonry walls, other than in walls of masonry veneer
on wood frame structures, shall be fire protected as required by
section 913 for structural members, when the full load over the
opening is not relieved by a masonry arch of required strength.
The members of an assembled metal lintel that support only
outer face masonry that is securely bonded or anchored to
backing, need not be fire protected, provided that the inner
members of the assembly support the full load imposed upon
the lintel and are fire protected as required for structural mem-
bers supporting masonry.

912.2. Stone Lintels. — The use of stone lintels on spans exceed-
ing four (4) feet shall not be permitted unless supplemented by
fire protected structural members or masonry arches of the re-
quired strength to support the superimposed loads.

SECTION 913.0. BEAMS AND GIRDERS

All beams and girders shall be protected with noncombustible

materials or assemblies of component materials to afford the

fireresistance specified in section 221.1 table 2-1 and as herein

modified.

913.1. Protection of Beams and Girders. — Beams and girders

that are required to be fire protected, and that support only

911-913

one (1) floor or a roof, and/or a nonbearing wall not more

than one (1) story high, shall be individually encased on all
sides with materials having the required fireresistance rating; or
shall be protected by a ceiling as specified in section 913.2
having the required fireresistance rating; or shall be protected
by a combination of both a ceiling and individual encasement
which, together, provide the required fireresistance rating. Beams
and girders that are required to be fire protected, and that
support more than one (1) floor or a nonbearing wall more
than one (1) story high, or a bearing wall, shall be individually
encased on all sides for their entire length or height with ma-
terials having the required fireresistance rating. Similar indi-
vidual encasement shall be provided for all structural elements
supporting stairway enclosures.

913.1.1. Ceilings that contribute to the required fireresistance
rating of a floor or roof assembly shall be continuous between
exterior walls, vertical fire divisions, or vertical partitions having
at least the same fireresistance rating as the ceiling.

913.2. Ceiling Fixtures. — Ceilings required to have a fireresis-
tance rating may be pierced to accommodate noncombustible
electric outlet boxes or recessed lighting fixtures, if the aggre-
gate area of such openings does not exceed sixteen (16) square
inches in each ninety (90) square feet of ceiling area and the
electrical outlet boxes or recessed lighting fixtures are con-
structed of steel at least .022 inches thick and sealed tightly at
the ceiling. Noncombustible pipes, ducts, and additional or
larger electrical or other service facilities may pierce ceilings
that are required to have a fireresistance rating only when the
type of ceiling to be used has been tested with such types of
facilities installed in pla ^ind the proportionate area of open-
ings for such facilities to be installed in the ceiling does not
exceed the proportionate area of such openings in the assembly
tested, and provided no opening is larger than that in the
assembly tested. Protection for such openings shall be the same
as provided in the test. Duct openings installed in accordance
with the foregoing shall be protected by fire dampers comply-
ing with the requirements of article 18.

913.3. Firestopping of Ceiling Spaces. — Floor or roof assem-
blies required to have a fireresistance rating shall have any con-
cealed spaces therein firestopped as outlined below.

913.3.1. Firestopping of Non-Combustible Construction. — The
concealed space above fireresistive ceilings shall be firestopped

into areas not exceeding three thousand (3,000) square feet with
materials listed in section 921.0 for the full height of the con-
cealed space. Access to each such concealed space may be
through one (1) or more openings not exceeding nine (9) square
feet and protected by self-enclosing opening protectives having
the fire protection rating required by section 221.1 table 2-1.
Fire-stopping shall not be required where the structural members
within the concealed space are individually protected with
materials having the required fireresistance rating, or where
the ceiling is not an essential part of the fireresistance assembly.
Fire-stopping shall not be required where a concealed space is
sprinklered in accordance with the construction requirements
of article 12. Concealed spaces over boiler rooms and under
roofs may be ventilated to the outer air.

913.4. Firestopping of Wood Joist Construction. — Where the
ceilings are suspended below wood joist flooi; construction, the
space between the ceiling and the floor above shall be fire-
stopped in areas of not more than one thousand (1,000) square
feet with materials meeting the requirements of section 921.0.

913.5. Wall Supports. — Structural members which support walls
shall be protected in conformance with section 913.1 to afford
not less than the required fireresistance of the wall construction
supported thereon.

913.6. Exterior Exposed Beams and Girders. — Beams and
girders exposed to the outdoors on buildings that do not ex-
ceed two (2) stories or thirty (30) feet in height, which are re- ,
quired by section 221.1 table 2-1 to have a fireresistance rating I
not exceeding one (1) hour need not be protected on any face I
of the member that has an exterior separation of thirty (30) j
feet or more, provided the outdoor area within the thirty (30) I
foot separation distance is not used for storage of materials,
or for motor vehicle parking.

913.7. Beams and Girders in Cavity Walls. — Where beams and
girders occur within exterior cavity walls, portions of such I
structural members facing the exterior need not be individually
fire protected if the outer wythe of the cavity wall provides the
required fireresistance rating and is located not more than two
and one-half (2-1/2) inches from such structural members, and
if all surfaces of the structural members are fire protected from I
the interior of the building by materials having the required ±
fireresistance rating.

913-914

913.8. Elevators. — Beams and girders located wholly within the
shaft and not an integral part of the support of the shaft need
not be fire protected.

913.9. Embedments and Enclosures. — Pipes, wires, conduits,
ducts, or other service facilities shall not be embedded in the
required fire protection of a structural member that is required
to be individually encased; except that pipes, wires, and conduits
may be installed in the space between the required fire protec-
tion and the structural member protected, provided that where
such facilities pierce the required fire protection, the area of the
penetrations does not exceed two (2) per cent of the area of the
fire protection, on any one (1) face, the penetrations are closed
off with close-fitting metal escutheons or plates and the con-
cealed space shall be fire-stopped at each story in accordance
with the provisions of section 913.3.

913.10. Impact Protection. — Where the fire protective covering
of a structural member is subject to impact damage from mov-
ing vehicles, the handling of merchandise, or other activity, the
fire protective covering shall be protected by corner guards or
by a substantial jacket of metal or other noncombustible ma-
terial to a height adequate to provide full protection. Where
applicable, such protection shall be designed in accordance with
the requirements of section 710.

SECTION 914.0. COLUMNS

All steel, iron and other approved metal columns and rein-
forcement in concrete columns shall be protected with noncom-
bustible materials or assemblies of component materials to afford
the fireresistance specified in section 221.1 table 2-1 and as here-
in modified. Columns that are required to be fire protected, and
that support only one floor or a roof, and/or a non-bearing
wall not more than one (1) story high, shall be individually en-
cased on all sides with materials having the required fireresis-
tance rating; or shall be protected by a ceiling as specified in
section 913.2 having the required fireresistance rating; or shall
be protected by a combination of both a ceiling and individual
encasement which, together, provide the required fireresistance
rating. Columns that are required to be fire protected, and that
support more than one (1) floor or support a bearing wall or
non-bearing wall more than one (1) story high, shall be indi-
vidually encased on all sides for their entire length or height

with materials having the required fireresistance rating; (or shall
be protected by a combination of both a ceiling and individual
encasement which, together, provide the required fireresistance
rating.)

914.1. Exterior Columns. — Columns located in exterior walls
or along the outer lines of a building or structure -shall be fire-
protected as required by this section and shall be protected
against corrosion by cement parging, waterproofing, or other
approved methods complying with section 874.

914.2. Columns in Cavity Walls. — Where columns occur within
exterior cavity walls, portions of such structural members facing
the exterior need not be individually fire protected if the outer
wythe of the cavity wall provides the required fireresistance
rating and is located not more than two and one half (2-1/2)
inches from such structural members, and if all surfaces of the
structural members are fire protected from the interior of the
building by materials having the required fireresistance rating.

914.3. Embedments and Enclosures. — Pipes, wires, conduits,
ducts, or other service facilities shall not be embedded in the
required fire protection of a structural member that is required
to be individually encased; except that pipes, wires, and conduits
may be installed in the space between the required fire protec-
tion and the structural member protected, provided that where
such facilities pierce the required fire protection, the area of the
penetrations does not exceed two (2) per cent of the area of the
fire protection on any one face, the penetrations are closed off
with close-fitting metal escutcheons or plates and the concealed
space shall be firestopped at each story in accordance with the
provisions of section 913.3.

914.4. Mechanical Protection. — Where the fire protective cover-
ing of a structural member is subject to impact damage from
moving vehicles, the handling of merchandise, or other activity,
the fire protective covering shall be protected by corner guards
or by a substantial jacket of metal or other noncombustible
material, to a height adequate to provide full protection. Where
applicable, such protection shall be designed in accordance with
the requirements of section 710.

914.5. Exterior Exposed Columns. — Columns exposed to the out-
doors on buildings that do not exceed two (2) stories or thirty
(30) feet in height, which are required by section 221.1 table 2-1
to have a fireresistance rating not exceeding one (1) hour
need not be protected on any face of the member that has an

914-915

exterior separation of thirty (30) feet or more, provided the
outdoor area within the thirty (30) foot separation distance is
not used for storage of materials, or for motor vehicle parking.
The interior faces of exterior columns shall be protected and
insulated as otherwise required.

914.6. Anchors, Bands and Ties.

914.6.1. Concrete Reinforcement. — Concrete fire protection on
structural metal columns shall be reinforced and anchored by
wire mesh, metal caging, metal clips or spirally wound wire of
approved types. Wire fabric shall be not less than No. 12 U.S.
gage, four (4) by four (4) inch mesh or its equivalent; spirally
wound wire shall be not less than No. 10 U.S. gage with not
over four (4) inch pitch or equivalent heavier wire at a maxi-
mum pitch of eight (8) inches.

914.6.2. Gypsum Concrete Reinforcement. — Poured-in-place
gypsum fire protection shall be reinforced and anchored by wire
fabric of not less than No. 16 U.S. gage, two (2) by two (2)
inch mesh or No. 14 U.S. gage, four (4) by four (4) inch mesh.

914.6.3. Masonry Unit Ties. — Block and tile fireproofing units
shall be securely anchored or bounded by wall ties, metal mesh
or metal u-clips in the horizontal joints, or by outside tie wires
not less than No. 16 U.S. gage with at least one (1) tie around
every block course; or shall consist of special masonry units
designed to furnish positive anchorage to the structural member
and to each other.

914.6.4. Exposed Ties. — When outside tie wires are used, they
shall be protected by not less than one-half (1/2) inch of ce-
ment mortar, or gypsum plaster or the equivalent fireresistive
covering.

914.7. Reinforced Concrete Columns.— The thickness of pro-
tection required outside of reinforcing steel in the concrete
columns shall be proportioned by test to meet the fireresistive
requirements of section 221.1 table 2-1 based on the fireresistive
classification of concrete aggregates.

SECTION 915.0. TRUSSES

All trusses shall be protected with noncombustible materials
or assemblies of component materials to afford the fireresistance
specified in section 221.1 table 2-1 and as herein modified.
915.1. Protection of Trusses. — Trusses that are required to be
fire protected, and that support only one floor or a roof, and/or

a non-bearing wall not more than one (1) story high, shall be
individually encased on all sides with materials having the re-
quired fireresistance rating; or shall be protected by a ceiling as
specified in section 913.2 having the required fireresistance
rating; or shall be protected by a combination of both a ceiling
and individual encasement which, together, provide the required
fireresistance rating. Trusses that are required to be fire pro-
tected, and that support more than one floor or support a bear-
ing wall or non-bearing wall more than one story high, shall be
individually encased on all sides for their entire length or height
with materials having the required fireresistance rating.
With the use of a continuous ceiling of the specified firere-
sistance rating, the enclosed truss space shall have an access
doorway with maximum dimensions of three (3) by three (3)
feet, equipped with an opening protective of the same fire-
resistance rating as the required truss protection. When the
trusses or the roof decking are permitted to be constructed of
combustible materials, the space above the required fireresistive
ceiling shall be subdivided into maximum areas of three thousand
(3,000) square feet as required for attic spaces in section 219.

915.2. One Story Buildings. — In all one (1) story buildings re-
quired to be of fireresistive construction, no protection shall be
required for the members of roof trusses, purlins or roof beams
when the height to the lowest chord is twenty (20) feet or more
from the floor.

915.3. Roofs Less Than Twenty (20) Feet High. — In multi-
story buildings of types of construction in which fire protected
coverings of the structural framework are required by section
221.1 table 2-1 and the provisions of this code, the fire protec-
tion of individual members of the roof truss may be omitted
when the clear height of the lower chord of the truss is more
than fifteen (15) and less than twenty (20) feet above the floor,
gallery or balcony immediately below and a three-quarter (3/4)
hour continuous ceiling is installed.

915.4. Roofs Twenty (20) Feet or Higher. — When every part of
the structural framework is twenty (20) feet or more above the
floor immediately below, all fire protection of the structural
members may be omitted, including the protection of roof beams
and purlins.

915.5. Roof Slabs and Arches. — Where the omission of fire
protection from roof trusses and purlins is permitted, the hori-
zontal or sloping roofs in fireproof (type 1) and noncombustible

915-916

(type 2) construction, immediately above such trusses, shall be
constructed of noncombustible materials of the required strength
without a specified fireresistance rating, or of mill type con-
struction in buildings not over five (5) stories or sixty-five (65)
feet in height.

SECTION 916.0. EXTERIOR OPENING PROTECTIVES

Where specified herein, the exterior openings of all buildings
and structures, more than three (3) stories or forty (40) feet in
height, other than churches (occupancy group F4), residential
buildings (occupancy groups L2 and L3) and buildings of frame
(type 4) construction, shall have approved opening protectives
meeting the requirements of section 903.6 and the provisions
of article 4 for special uses and occupancies.

916.1. Horizontal Exposure. — Approved protectives shall be
provided in every opening facing a street thirty (30) feet or
less in width, or within thirty (30) feet horizontally in a direct
line not in the same plane of any unprotected noncombustible
(type 2-C), unprotected frame (type 4-B) structure, or within
thirty (30) feet horizontally of any opening in another building
of any type of construction.

916.2. Vertical Exposure. — Approved protectives shall be pro-
vided in every opening which is less than fifty (50) feet vertically
above the roof of an adjoining structure within a horizontal dis-
tance of thirty (30) feet of the wall in which the opening is
located, unless such roof construction affords a fireresistance of
not less than one and one-half (1-1/2) hours.

916.3. General Exposure.

916.3.1. Interior Lot Line Exposure. — Opening protectives shall
be provided in every permissible wall opening in buildings of
high hazard (occupancy group A) within eleven (11) feet of an
interior lot line; in buildings of moderate hazard (occupancy
group Bl) within six (6) feet of such lot lines; and in wall
openings of frame buildings which are erected within six (6)
feet of interior lot lines, except for store fronts and window
and door openings in dwellings of occupancy groups L2 and L3.

916.3.2. Exterior Opening. — Exterior openings above the third
floor level of a building or above a height of forty (40) feet,
except buildings in occupancy group L3, open parking structures
and buildings of construction types 4A and 4B, shall have
opening protectives when:

a. any part of the opening is less than thirty (30) feet dis-
tant in a direct unobstructed line not in the same plane,
from an opening in another building or from a wood
frame building, or

b. any part of the opening is above and less than thirty
(30) feet in a direct unobstructed line from any roof
construction that has a fireresistance rating of less than
one (1) hour or that has unprotected openings therein
within this distance, whether the roof construction is on
the same building or on an adjacent building.

916.4. First Story Openings. — The required fireresistive opening
protectives may be omitted in show windows or other openings
on the lowest story of a building facing on a street or public
space not less than thirty (30) feet in width.

916.5. Non-Automatic Protectives. — Required opening protec-
tives in exterior openings, if not self-closing or automatic, shall
be kept closed by the occupants at all times when not required
for light or ventilation under the provisions of article 5.

916.6. Opening Protective Required Ratings. — In a building or
space classified in occupancy group A, all opening protectives
shall be three-quarter (3/4) hour (Class E) opening protectives
meeting the requirements of reference standard RS 9-7. Such
protectives shall be fixed self-closing or automatic. Alternately,
these openings may be protected with three-quarter (3/4) hour
(Class F) protectives together with outside sprinklers installed
in accordance with construction requirements of article 12. In
such cases, there shall be an automatic dry pipe sprinkler head
centered over each opening with the orifice directed against the
opening. All opening protectives required by section 221.1
table 2-1 or by section 916.3.2 above in buildings classified in
other than occupancy group A shall be three-quarter (3/4) hour
(Class F) openings.

916.6.1. Exterior windows and doors, including their frames
and glazing, that are not required by this code to have a fire-
protection rating, may be of combustible materials. Glazing in
balcony doors shall comply with the requirements of section
612.7.4.

SECTION 917.0. FIRE DOORS

917.1. Fire Door Assemblies. — Approved fire door assemblies
as defined in this Code shall be constructed of any material or

916-917

assembly of component materials which meet the test require-
ments of sections 903 and 904 and the fireresistance rating here-
in required.

Fireresistance
Location Rating in Hours

Fire walls and fire divisions of 3 or more
hour construction 3

Fire walls and fire divisions of 2 hour
construction 1-1/2

Shaft enclosures and elevator hoistways of
2 hour construction 1-1/2

Stairway and exitway enclosures of 1 hour
or less except fire towers and grade

passageways 3/4

Doors in exitways of residential and business use buildings not
more than three (3) stories for forty (40) feet in height with an
occupancy load of not more than forty (40) below or seventy
(70) above grade and doors from hotel rooms (occupancy group
LI), from hospital rooms (occupancy group H2), and from
school rooms (occupancy group G) to corridors providing access
to an exitway may be of noncombustible construction or of one
and three-quarter (1-3/4) inch bonded solid-core wood doors.

917.2. Labeled Protective Assemblies.— Labeled protective as-
semblies meeting the requirements of sections 903.6.3 and 903.6.5,
and reference standards RS 9-5, RS 9-6 and RS 9-7, including
shop inspection, shall be approved for use in the following
typical and special situations:

917.2.1. Typical Situations.

Class A Doors — Fire wall openings in accordance with section
908.

Class B Doors — Verticle shafts and openings in fire partitions
in accordance with sections 909 and 911.

Class C Doors — Openings in corridor, room and fireresistive
partitions in accordance with section 910.

Class D Doors and Windows — Openings in exterior walls in
exposing and exposed buildings of high hazard use (occupancy
group A) in accordance with article 4 and along exterior
stairways in accordance with section 621.

Class E Doors and Windows — Openings in exterior walls and
along fire escapes except where. class D protectives are re-
quired in accordance with section 624.

917.2.2. Special Situations. — Approved labeled opening pro-
tective assemblies shall be accepted as complying with the re-
quired time-temperature performance ratings specified in this
code including the following special situations:
Class A Doors — High pressure boiler room walls in accordance
with sections 618 and 1115.
Volatile flammables, film, pyroxylin products and fur storage

vaults in accordance with sections 403, 408 and 409.
Grinding and grain processing rooms in accordance with

section 411.
Paint and flammable storage rooms in accordance with sec-
tion 412.
Dry cleaning rooms of high and moderate hazard in accor-
dance with section 413.
Proscenium walls of theatres in accordance with section 418.
Transformer room walls in accordance with article 15.
Class B Doors — Motion picture studios in accordance with
section 409.
Dressing rooms in accordance with section 418.
Show rooms in public garages in accordance with section 415.
Theatre exits and property rooms in accordance with section

418.
Fire and smokeproof towers in accordance with section 620.
Horizontal exits in accordance with sections 616 and 908.
Class C Doors — Projection and trial exhibition rooms in ac-
cordance with section 409.
Paint spray rooms in accordance with section 412.
Service stations and repair shops in accordance with sections

416 and 417.
Kitchen and service pantries in places of assembly in accor-
dance with section 419.
Corridor rooms and all fireresistive partitions in accordance
with section 910.
Class D Doors — Attached garages in accordance with sections
414 and 917.
Switchboard rooms where required by article 15.

917.3. Deleted.

917.4. Glass Panels. — Wired glass panels shall be permitted in
fire doors within the limitations of section 919 and as herein
specifically prescribed.

917.5. Alternate Closing Devices. — Except as may be otherwise
provided for openings in fire enclosures and fire division walls,

917-918

all fire doors shall be self-closing. Fire doors shall be kept
closed at all times, except that approved fail-safe electromagnetic
holders activated by approved rate of temperature rise and
smoke detection devices (installed in compliance with their
listing) located on both sides of opening and capable of con-
nection to a local or central fire alarm may be used on exit
doors and smoke screen doors in horizontal hallways, exitways
and corridors. Holders shall not be used on fire doors con-
necting to stairways or other vertical openings.

SECTION 918.0. FIRE WINDOWS AND SHUTTERS

918.1. Fireresistance Rating. — Approved assemblies of fire win-
dows and fire shutters shall meet the test requirements of sections
903 and 904, or shall be approved labeled assemblies meeting
the requirements of section 903.6.5.

Steel window frame assemblies of one-eighth (1/8) inch minimum
solid section or of not less than No. 18 U.S. gage formed
sheet steel members fabricated by pressing, mitering, riveting,
interlocking or welding and having provision for glazing with
one-quarter (1/4) inch wired glass as required in section 919.0,
when securely installed in the building construction and glazed
with one-quarter (1/4) inch wired glass, shall be deemed to meet
the requirements for a three-quarter (3/4) hour fire window
assembly.

918.2. Window Mullions. — All metal mullions which exceed
a nominal height of twelve (12) feet shall be protected with
insulating materials to afford the same fireresistance as required
for the wall construction in which the protective is located.

918.3. Swinging Fire Shutters. — When fire shutters of the swing-
ing type are used in exterior openings, not less than one (1)
row in every three (3) vertical rows shall be arranged to be
readily opened from the outside and shall be identified by dis-
tinguishing marks or letters not less than six (6) inches high.

918.4. Rolling Fire Shutters. — When fire shutters of the rolling
type are used, they shall be approved counter-balanced construc-
tion that can be readily opened from the outside.

918.5. Vertical Separation of Windows.

918.5.1. Where Required. — In all buildings and structures ex-
ceeding three (3) stories or forty (40) feet in height, openings
located vertically above one another in exterior walls which are
required to have a firesistance rating of more than three-quarter

(3/4) hours shall be separated by apron or spandrel walls not
less than three (3) feet in height extending between the top of
any opening and the bottom of the opening next above, or j
the floor above shall be protected by fire canopies conforming J
to provisions of section 906.3, set backs or other means of
preventing vertical spread of fire. No vertical separation is re-
quired between exterior openings when the building is of un-
protected construction (types 2C, 3C, and 4B), or when the
lower of any two (2) successive exterior openings under con-
sideration opens onto a room or space used for assembly,
business, educational or residential occupancy.
918.5.2. Fireresistance Rating. — The apron or spandrel walls
shall be constructed with the same fireresistance required for the
exterior wall in which located as specified in section 221.1
table 2-1; except that when such required rating exceeds three-
quarter (3/4) hours, approved wired glass construction in fixed
noncombustible sash and frames not exceeding one-third (1/3)
of the area of such apron or spandrel may be located therein,
and except further that in exterior non-bearing enclosure walls
which are not required to be of more than three-quarter (3/4)
hour fireresistance, the provisions of this section in respect to
apron or spandrel walls shall not apply.

SECTION 919.0. WIRED GLASS

Wired glass in approved opening protective assemblies shall
be not less than one-quarter (1/4) inch thick and shall be
limited in area and location as herein required.

919.1. Fire Wall Protectives. — Wire glass in fire doors located
in fire walls shall be prohibited, except that when serving as a
functioning element in a required means of egress, the self-
closing swinging door may be provided with a vision panel of
not more than one hundred (100) square inches with no dimen-
sion exceeding twelve (12) inches.

919.2. Fire Partition Protectives. — Wired glass vision panels
may be used in fire doors of one and one-half (1-1/2) hour
fireresistance rating intended for use in fire partitions; but in
no case shall the glass panels be more than one hundred (100)
square inches in area with no dimension exceeding twelve (12)
inches.

918-920

919.3. Fireresistive Partition Protectives.— Wired glass panels
in three-quarter (3/4) hour fire doors, smoke stop partitions
and fixed vision panels in corridor enclosures of one (1) hour
fireresistance rating or less, shall not exceed a total exposed
area of one thousand two hundred and ninety-six (1,296) square
inches; except as provided in section 917.3.2.

919.4. Wired Glass in Labeled Doors and Windows. — One-
quarter (1/4) inch wired glass may be used in approved labeled
opening protectives with the following maximum sizes:

Limiting Size of Wired Glass Panels

Area in Height Width

Square In In

Inches Inches Inches

Class A door per opening....

Class B door per door* 100 12 12

Class C door per light 1296 — —

Class D door per light

Class E door per light 720 54 44

Class E window per light 720 54 54

Class F window per light 2916 54 54

♦Listed values shall be permitted in a single door or in each
door of a pair of doors.

919.5. Exitway Protectives. — Unless specifically required in
article 4 to be solid in such locations where unusually hazardous
conditions prevail, fire doors in stairway shaft enclosures may
be equipped with vision panels which shall be so located as to
furnish clear vision of the passageway or approach to the stair-
way. Such vision panels shall not exceed the size limitations
specified for class B doors, or the required protective which-
ever is less.

SECTION 920.0. FIRERESISTIVE REQUIREMENTS FOR
PLASTER

920.1. Thickness of Plaster. — The required thickness of fire-
resistive plaster protection shall be determined by the prescribed
fire tests for the specified use and type of construction and in
accordance with the provisions of section 820 for interior plas-
tering and section 821 for exterior plastering. The thickness in
all cases shall be measured from the face of the plaster base
when applied directly to masonry walls or from the face of the

lath when applied to fiber board, wood, or gypsum lath and I
from the back of metal lath.

920.2. Plaster Equivalents. — For fireresistive purposes, one-half I
(1/2) inch of neat gypsum plaster shall be deemed equivalent I
to three-quarter (3/4) inches of one (1) to three (3) sanded
gypsum or one (1) inch portland cement plaster.

920.3. Noncombustible Furring. — In fireproof (type 1) and non-
combustible (type 2) construction, plaster shall be applied
directly on masonry or on an approved noncombustible plas-
tering base and furring.

920.4. Double Reinforcement. — Except in solid plaster parti-
tions, or when otherwise determined by the prescribed fire tests,
plaster protections more than one (1) inch in thickness shall be
reinforced with an additional layer of approved lath imbedded
at least three quarter (3/4) inch from the outer surface and
fixed securely in place.

920.5. Plaster Alternates for Concrete. — In reinforced concrete
construction, gypsum or portland cement plaster may be sub-
stituted for one-half (1/2) inch of the required poured concrete
protection, except that a minimum thickness of three-eighth
(3/8) inches of poured concrete shall be provided in all rein-
forced concrete floors and one (1) inch in reinforced concrete
columns in addition to the plaster finish and the concrete base
shall be prepared in accordance with section 821.6.

SECTION 921.0. FIRESTOPPING

921.1. Where Required. — Firestopping shall be designed and
constructed to close all concealed draft openings and to form
effectual fire barriers against the spread of fire between stories
of every building and in all open structural spaces therein,
including the following locations: for the subdivision of attic
spaces in section 219; for combustible wall, partition and
floor framing in section 877; for ceiling spaces in section 913;
for open spaces behind acoustical and other finishes in section
923; for floor sleeper spaces in section 924; for pipe, duct and
flue openings in section 1119 and for fire dampers and curtains
in section 1812.

921.2. Firestopping Materials. — All firestopping shall consist
of noncombustible materials including asbestos, brick, terra
cotta, concrete, fibrous glass, gypsum, mineral wool, rock wool,
steel, iron, metal lath and cement or gypsum plaster, formed

920-922

steel of not less than No. 20 U.S. gage, or other approved
noncombustible materials, securely fastened in place; except that
firestops of two (2) thicknesses of one (1) inch lumber with
broken lap joints or of two (2) inch lumber installed with tight
joints shall be permitted in open spaces of wood framing.

921.3. Inspection of Firestopping. — No firestopping shall be
concealed or covered from view until inspected and approved
by the building official.

SECTION 922.0. INTERIOR FINISH AND TRIM

Interior finish and interior trim shall for the purpose of com-
plying with the provisions of this section mean those materials
that form the exposed interior surfaces of a building and that
are part of or affix to walls, fixed or folding partitions, ceilings
and other construction elements.

922.1. Interior Finish. — Interior finishes and exposed structural
or construction materials when classified as provided in section
904.1, shall have a flame-spread rating not greater than that
designated by the class prescribed for the various occupancy
groups in which they are used, as listed in section 922.1.2. table
9-4. They shall have a smoke density rating not greater than
the limits provided for in section 922.1.3.

922.1.1. Exceptions to the Flame-Spread Requirements of Sec-
tion 922.1.

a. Finish flooring and floor coverings provided for in
section 924.

b. Vinyl wall coverings less than .006 inch total thickness
and other wall coverings and coatings of paper or other
materials less than .036 inch total thickness, when applied
directly to a noncombustible, or fireretardant treated
wood substrate.

c. Exposed structural members and planking in buildings
of type 3A construction, which may be left exposed in
any room or space, except in exitways.

d. These regulations shall not be considered as requiring
the installation of interior finish.

e. When a sprinkler system is provided in any room or
space, and is installed in compliance with the construc-
tion provisions of article 12, interior finish materials

may be one class higher in flame-spread rating than re-
quired by section 922.1.2 table 9-4, but in no case higher
than class "C".

922.1.2. Table 9-4 — Interior Finish Flame Spread Limit Require-
ments.

Occupancy Group
Classification
of the Space

Exitways

and

Shafts

Corridors

Providing

Access to

Exitways(b)

Rooms more Rooms Less
than 1500 than 1500
sq. ft.(a) sq. ft.(a)

High Hazard

Storage

B(c)

Mercantile

B(c)

Industrial

B(c)

Business

Assembly

Fla

B(d)

Assembly

Fib

B(c)

B(c,d)

Assembly

B(c)

Assembly

B(c)

B(c,d)

Assembly

B(c)

B(c,d)

Institutional

HI, H2

B(d)

Residential

LI, L2

B(f)

Residential

D(e)

Notes for table 9-4

a. In determining the applicable requirements for rooms or
enclosed spaces, the occupancy group classification of the
room or enclosed space shall be the governing factor,
regardless of the occupancy group classification of the
building. For the purposes of this table, the area of a
room shall be that floor area contained within enclosing
construction in which interior doors or other interior
openings represent not more than ten (10) per cent of
the area of the enclosing construction. Interior doors or
windows that are constructed of noncombustible mate-
rials and that are self-closing or automatic may be
ignored in computing door or opening area. Rooms or
spaces that have unprotected openings constituting more
than ten (10) per cent of the area of enclosing construc-
tion shall not be considered as a room. Interior finish

922

requirements for rooms are based upon rooms being
enclosed in ceiling high partitions. Partitions, to be con-
sidered ceiling high, shall extend up to the floor or roof
construction above or to a ceiling having at least a
three-quarter (3/4) hour fireresistance rating. Partitions
that do not comply with this requirement shall not be
considered as enclosing the spaces, and the rooms or
spaces on both sides thereof shall be considered as one.

b. Rooms or spaces through which it is necessary for
occupants of an adjacent room to pass in order to reach
the only exitway shall, for the purposes of this table,
be considered as corridors. Where used in corridors,
class B finish material shall not extend more than fifty
(50) feet between separations of class A finish material
that are at least two (2) feet wide.

c. On the street floor one (1) story buildings in construction
type 3 and 4, ceilings, beams, trusses, etc. that are
twenty (20) feet or more in height from the floor to
their lowest part, may have a class C finish.

d. Class C interior finish may be used in offices, or groups
of offices, whose use is accessory to an occupancy, pro-
vided such offices are separated from the occupancy by
construction having at least a two (2) hour fireresistance
rating.

e. Class C interior finish may be used in the residential
rooms of one (1) and two (2) story motels when there
is a direct exitway from each room to the exterior.

f. Interior finish when used in the following spaces shall
be at least Class B:

1. Kitchens, cooking spaces, and pantries in buildings
classified in occupancy groups other than L2 and L3.

2. Repair and maintenance rooms.

3. Boiler rooms and incinerator combustion rooms.

922.1.3. Smoke Density Limitations. — No material shall be used
for interior finish in the following locations if the material
develops smoke in greater density than the rating shown, based
upon a test conducted in accordance with the provisions of
reference standard RS 9-9. Materials used for interior finish that
cover not more than twenty (20) per cent of the wall or ceiling
area of any room, space, or corridor shall be exempt from the
above requirements.

Smoke
Location or Occupancy Developed Rating

Exitways, Corridor providing exitway

access, places of public assembly 25

Occupancy groups HI and H2 50

Rooms in which the net floor area per

occupant is ten (10) square feet or

less except places of public assembly 100

922.2. Interior Trim. — Baseboards, chair-rails, mouldings, trim
around openings and other interior trim, not more than twelve
(12) inches in width, may be of Class A, B or C materials
except trim around fire windows and fire doors shall comply
with the requirements of section 917 and section 918 and ex-
cept that only class A or B materials shall be used for interior
trim where interior finish is restricted to class A material. Class
D trim having a flame-spread rating not greater than five
hundred (500) shall be allowed for trim only where class D ma-
terial is permitted for interior finish.

922.3. Coatings. — Coatings applied in the field by brush or
spray shall not be used as flame-spread retardants except on
existing surfaces of buildings existing on the effective date of
this code, and then only with the express permission of, and in
a manner directed by, the building official.

922.4. Ceiling Construction. — Ceilings may be suspended below
floor or roof construction by means of a framing system of
supporting hangers and carrying channels and a supporting grid
of strength adequate to support the ceiling material. The hangers
and supporting grid shall be of noncombustible materials. In
buildings of construction class types 3 and 4, every other hanger
supported from wood members shall be attached by a through
bolt or clinched through nail. Where, in section 221.1 table
2-1, floor or roof construction is required to have a fireresis-
tance rating, a ceiling having no fireresistance rating may be
suspended below the fireresistive construction.

922.4.1. Luminous Ceilings. — For the purpose of this section,
a luminous ceiling shall be defined as a ceiling consisting of
translucent, louvered, egg-crated, mesh, or similar light-diffusing
material suspended from the ceiling or structural framework.
A suspended ceiling containing less than twenty (20) square
feet of translucent, louvered, egg-crated, mesh or similar material
in any one hundred (100) square feet of ceiling area shall not
be considered a luminous ceiling, and shall be constructed and

922-923

installed in accordance with requirements of article 15 for
lighting fixtures. Luminous ceilings shall, in addition to the
requirements of this section, conform to all of the requirements
of sections 923.0 through 925.0.

922.4.2. Luminous Ceilings of Noncombustible Material. — Lum-
inous ceilings constructed of glass and/or metal or other non-
combustible materials may be used in any location.

a. Glass used in luminous ceilings, unless it is wire glass
or heat-resistant glass as specified below, shall not weigh
more than two (2) psf, nor shall any pane be larger
than eight (8) square feet in area. If glass used in lu-
minous ceilings is wire glass, or is heat resistant by
reason of having a maximum coefficient of expansion
of 36x10-7 inches per inch per degree C, the glass may
be of any weight and any size, limited only by considera-
tions of structural safety.

b. Luminous ceilings installed below sprinkler heads shall
be constructed of a type of noncombustible louver mesh
or other open material that will not impede the flow of
water from the sprinkler heads over the intended area of
coverage. The luminous ceiling shall be constructed so as
to provide access to all heads and valves.

922.4.3. Luminous Ceilings of Combustible Material. — Lumi-
nous ceilings constructed of combustible materials shall not
be installed in:

a. Any exitway or corridor providing access to exitways.

b. Any room classified in occupancy group H, or any room
leading therefrom as defined in section 922. 1. 2. b.

c. Any room in which the net floor area per occupant is
twenty (20) square feet or less, or any room leading
therefrom as defined in section 922. 1. 2. b.

d. Luminous ceilings constructed elsewhere than in the
spaces listed in a., b. and c. above shall be exempt
from the provisions of section 922.1 provided that they
comply with the provisions of section 2007.

SECTION 923.0. APPLICATION OF INTERIOR FINISH

Where interior finish is regulated by the requirements of this
Code, interior finish materials shall be applied or otherwise
fastened in such a manner that they will not fall off when sub-
jected to room temperatures of two hundred (200) degrees F.

or less for thirty (30) minutes, or otherwise become loose
through changes in the setting medium from the effects of time
or conditions of occupancy.

923.0.1. Attachment of Interior Finish. — To be credited with
the same rating, interior finish materials that were applied to
a substrate when tested shall be applied at the building to an
equivalent substrate and shall be cemented or otherwise secured
in place in the same manner and with materials equivalent to
those used in flame-spread tests conducted in accordance with
section 904.1 for the applicable classification.

923.1. Application to Structural Elements. — Interior finish mate-
rials applied to walls, ceilings or structural elements of a build-
ing or structure which are required to be fireresistive or to be
constructed of noncombustible component materials, shall be
applied directly against the exposed surface of such structural
elements