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BUILDING CODE
OF THE
CITY OF BOSTON
Consisting of Chapter 479 of the Acts of 1938, As Amended
by Chapter 217 of the Acts of 1939, With the
Amendments by Ordinance Incorporated.
CITY OF BOSTON
ADMINISTRATIVE SERVICES DEPARTMENT
PRINTING SECTION
1964
46>S
CITY OF BOSTON,
Office of the City Clerk.
August 15, 1964.
I hereby certify that Chapter 479 of the Acts of 1938,
as amended by Chapter 217 of the Acts of 1939, was
accepted by order passed by the City Council on
May 10, 1943, and approved by the Mayor on May 15,
1943.
I hereby further certify that pages 5 to 284, inclusive,
of this volume contain a true copy of Chapter 479 of
the Acts of 1938 as amended by Chapter 217 of the
Acts of 1939 and by ordinances of the City of Boston
adopted in the period from May 15, 1943, to date.
Attest :
J. M. Dunlea,
City Clerk.
(2)
CONTENTS.
PAGB
Part 1 — Administration 5
2 — Fire Limits 32
3 — Special Requirements for Group A Occupancy: Theatres . 34
4 — Special Requirements for Group B Occupancy: Halls . . 43
5 — Special Requirements for Group C Occupancy: Schools . 50
6 — Special Requirements for Group D Occupancy: Hospitals
and Detention Buildings 55
7 — Special Requirements for Group E Occupancy: Commercial
Buildings of Hazardous Occupancy 59
8 — Special Requirements for Group F Occupancy: Offices and
Commercial Buildings 62
9 — Special Requirements for Group G Occupancy: Commercial
Buildings of Non-Hazardous Occupancy .... 66
10 — Special Requirements for Group H Occupancy: Unlimited
Habitations and Large Dwellings 69
11 — Special Requirements for Group I Occupancy: Limited
Habitations and Small Dwellings 77
12 — Special Requirements for Group J Occupancy: Miscellaneous
Structures 79
13 — Separation of Occupancies 82
14 — Walls and Partitions 86
15 — Protection of Vertical Openings 100
16 — Floor Construction . . 104
17 — Roof Construction and Covering 109
18 — Exits Ill
19 — Doors, Windows and Skylights 123
20 — Penthouses and Roof Structures 126
21 — Chimneys and Heating Apparatus 128
22 — Fire-Resistive Construction 138
23 — Dead and Live Loads 156
24 — Masonry 163
25 — Wood 171
26 — Reinforced Concrete 183
27 — Precast Gypsum Concrete 224
28 — Steel and Iron 227
29 — Excavations and Foundations 297
30 — Fire Extinguishing Apparatus 319
31 — Plumbing 327
32 — Validity 350
33 — War Provision 350
34 — Fall Out Shelters . 350
Gasfitting Regulations 351
Fire Zones 352
Index 354
(3)
Digitized by the Internet Archive
in 2010 with funding from
Boston Public Library
http://www.archive.org/details/buildingcodeofci1964bost
&Jje Commontoealtfj of JWa&sacljtigette
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.
Be it enacted by the Senate and House of Representatives in General Court
assembled, and by the authority of the same, as follows:
PART I.
ADMINISTRATION.
Section
101 —Title.
102 — Repeals.
103 — Pending Actions.
104 — Other Statutes.
105 — Effective Date.
[10SA — Amendment by Ordinance.]
106 — Definitions.
107 — Scope.
108 — Maintenance.
109 — Organization.
110 — Application for Permit.
111 — Permits.
112 — Fees.
113 — Inspection.
114 — Posting Floor Loads.
115 — Annual Report.
116 — Powers and Duties of Building Commissioner.
117 — Board of Appeal.
118 — Appeals.
119 — Decisions of the Board of Appeal.
120 — Board of Examiners.
121 — Board of Examiners of Gas Fitters.
122 — Penalties.
123 — Enforcement Jurisdiction.
124 — Classification of Buildings by Types of Construction.
125 — Types of Construction.
126 — Type I, Fireproof Construction.
127 — Type II, Semi-Fireproof Construction.
128 — Type III, Heavy Timber and Masonry Construction.
129 — Type IV, Light Wood and Masonry Construction.
(5)
Sees. 101-105
Section
130 — Type V, Metal Frame Construction.
131 — Type VI, Wooden Frame Construction.
132 — Occupancies Classified.
133 — Change of Occupancy.
134 — Multiple Occupancies.
135 — Elevators and Escalators.
136 — Building Height.
Section 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 hundred 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; sections 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 effective 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 complaint
or indictment for the violation of any of such provisions, or for the violation
of any ordinance, rule or regulation established 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 depart-
ments 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 thereunder
whether before or after the effective date of this code, shall apply to the
building department and to the boards established 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
(6)
Sees. 105-106
provision of its charter. If an application for a permit is filed before said
effective date, and a permit is issued thereon and the work is actually com-
menced within ninety days after the issuance of the permit, the applicant
notwithstanding any provision to the contrary in section one hundred 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. 1948, ch. 2 ]
fSect. 105A. [Amendment by Ordinance.] — The city of Boston,
for the purposes of the prevention of fire and the preservation 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 com-
missioner or the board of appeal, regulate the inspection, materials, con-
struction, alteration, repair, height, area, location and use of buildings and
other structures in said city, except such buildings or structures 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 said purposes may from time to time, by
ordinance upon like written recommendation, alter, amend, extend or render
ineffective any provision or provisions of this code regulating building and
other structures as aforesaid.
[ fAs inserted by Stat. 1939, ch. 217 ]
JSect. 106. Definitions. — (a) For the purposes of this code the words
and phrases defined in this section shall be construed as so defined except
when the context clearly indicates that another meaning is intended.
"Abut", touch, be contiguous. A building abuts upon a street when some
part of the building touches or extends to the line of the street. A building
shall be construed to abut upon a street if it is nearer at any point than ten
feet from the street or when the space between the building and the side line
of the street is used wholly or chiefly for the purposes of a street or sidewalk.
"Apartment", a room or suite of rooms occupied by one person or one
family for living and sleeping purposes.
"Apartment hotel", a building containing four or more apartments without
kitchens, primarily for persons who have their residences therein.
"Apartment house", a building containing four or more apartments with
kitchens, primarily for persons who have their residences therein.
"Approved", approved by the building commissioner of the city of
Boston.
"Area of a building", see "Building, area of",
"Assembly hall", a hall or room, including the balconies thereof, if any,
in which persons may assemble in a manner as permitted in Group B, Part 4.
"Attic", finished or unfinished story situated within a sloping roof, the
area of which at a height of four feet (4) 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 attic in any building, and it shall be considered as a
half story.
"Auditorium", an assembly hall in which persons may assemble to hear or
see concerts, plays, lectures, athletic or sports events or similar performances.
(7)
Sec. 106
"Automatic sprinklers", 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.
"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 balcony of an auditorium has exits at two or more
levels opening into separate foyers, one above another, each portion thereof
served by such a foyer shall be considered a separate balcony for the purpose
of this code.
"Basement", a story of a building below the first story.
"Building", a structure forming a shelter for persons, animals or property,
and having a roof The word "building" shall be construed, where the con-
text allows, as though followed by the words "or part thereof." The word
"building" shall not include such frame-works and tents as are customarily
used exclusively for outdoor carnivals, lawn parties or like activities.
"Building, area of", the maximum horizontal projected area of a building,
above ground, within the property lines, including exterior walls one or more
of which may be party walls and including covered porches but excluding
terraces, steps and cornices.
"Building, height of", in linear measure, the vertical distance of the
highest point of the roof, excluding pent houses and roof structures, above
the mean grade of the sidewalk at the line of the street or streets on which
the building abuts; and, if the building does not abut on a street, above the
mean grade of the ground around and contiguous to the building; and provided,
further, that for the purposes of establishing said mean grade, the ground
bounded by the lot lines and contiguous to the building and within twenty
feet of it, shall be considered to slant toward the building not more than one
foot upward or downward in two horizontal feet. In stories, the number of
stories above the floor of the first story.
"Building, pre-code", a building already erected on the effective date of
this code, or thereafter erected, as provided in section one hundred and five,
under permit for its construction subject to the provisions of law in effect prior
to such effective date.
"Building, post-code", a building erected after the effective date of this
code and subject to the provisions thereof.
"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 purpose.
"Cellar", see basement.
"Chimney", a vertical structure of masonry with one or more flues in
which smoke or the products of combustion are conducted upward for dis-
posal in the open air at a height above the ground.
"Code", "this code", the Boston Building Code, consisting of this act
and the regulations established thereunder.
"Commissioner", the building commissioner of the city of Boston.
"Corridor", an enclosed passageway.
"Dead load", the weight of materials built into the construction of a
(8)
Sec. 106
building including walls, permanent partitions, floors, roofs, framing and all
other permanent stationary construction entering into and becoming part
of a building.
"Department", the building department of the city of Boston.
"Exit", a means of egress; a way out.
"Exit from a room", a doorway or other means of egress from the room
on the way toward an exit from the building.
"Exit from a story", a stairway, ramp, ladder or other means of egress
from the story on the way toward an exit from the building.
"Exit from a building", a doorway or other means of egress from the build-
ing opening upon a street or upon an open space with unobstructed access to
a street.
"Exit, path of", the continuous series of doorways, connecting rooms,
corridors, passages, stairways, ramps and the like, which leads from any
exit from a room through an exit from the building,
"Family", a group of persons living together who share at least in part
their living quarters and accommodations.
"Fire division", a portion of a building so separated from the rest by
separations as specified in Part 13, that it may be erected to the maximum
height and area allowed for its principal occupancy and type of construction,
independently of adjoining occupancies. A portion of a building separated
from the rest by fire walls. A fire division may not be larger than a maximum
unit of occupancy and may be further limited by the application of require-
ments of Table A, (2), section thirteen hundred and two.
"Fire division, area of", the maximum horizontal projected area of the
division within the property lines including exterior walls, one or more of
which may be party walls, and in the case of separation walls within the
property lines to the center of the separation wall.
"Fire door", a door of fire-resistive construction as described in Part 22.
"Fire extinguisher", a portable device the contents of which are for ex-
tinguishing a fire.
"First aid hose station", a hose connection with valve in a system of piping
adequately supplied with water, hose and nozzle for use of occupants of a
building in extinguishing a fire.
"Floor area", of a room, the area of the floor contained within the walls.
"Foundation", that portion of a building or structure of which the sole
or chief purpose or use is to transmit the weight of the building or structure to
the earth; the support of the lowest portions of columns, walls, piers or other
vertical members.
"Foyer", a foyer, lobby, corridor or passage, one 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 or more exits therefrom
open, in the path of normal egress from the building.
"Front", a building or wall fronts upon a street when a wall of the building
or the wall faces the street and is parallel thereto or makes an angle of less
than forty-five degrees therewith.
(9)
Sec. 106
"Fusible link", a device consisting of two pieces of brass or other suitable
metal connected by solder or other metal fusible at a moderate temperature,
arranged to release in the presence of fire or excessive heat; or any equivalent
approved device.
"Gage", for sheet metal, United States Standard Gage; for brass and
copper tubing, Stubs Gage; for wire, Washburn & Moen or Roebling Steel
wire gage.
"Garage", a building or portion thereof in which is housed or stored one or
more motor vehicles containing or using a volatile flammable fluid for fuel or
power, or in which such motor vehicles are painted, repaired or serviced.
"Gasfitting", the art of installing, repairing or altering pipes, fittings,
fixtures and other apparatus for distributing gas for heat, light, power or other
purposes; the system of pipes, fittings, fixtures and other apparatus for
distributing gas for heat, light, power or other purposes.
"Grade", elevation with reference to Boston city base, namely, a hori-
zontal plane of reference established and used by the city of Boston.
"Grade, mean", the average of the grades of mid-points of successive equal
distances of not over ten feet measured along the line or lines along which
the mean grade is to be determined.
"Hotel", a building containing four or more apartments without kitchens,
or sleeping accommodations for ten or more persons, primarily the temporary
abode of persons who have their residences elsewhere.
"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 watts.
"Lintel", a beam in a masonry wall supporting the masonry above an
opening.
"Live load", the load or weight to be supported on floors or other portions
of buildings incidental to their occupancy; the pressure of wind, the weight
of snow, and all loads other than dead loads.
"Masonry", construction of assembled units of stone, brick, concrete,
gypsum or other similar incombustible materials separated from one another
and held in place by mortar.
"Masonry, dry", masonry, except that the units are not separated or held
in place by mortar.
"May", a term giving permission but not, except in the negative, making a
requirement. "May" is used in this code to emphasize that specified con-
struction is not prohibited by the code when such prohibition might other-
wise be implied or construed ; or to limit the scope of a prohibition by except-
ing specified construction from its effect. A permission so expressed in this
code in specific terms shall not be construed as a prohibition of other con-
struction. "May not" is prohibitive.
"Mezzanine floor", a floor within a story between the floor and ceiling
thereof, having an area not over forty per cent of the area of the building at
the level at which the mezzanine floor occurs. A floor of larger area separates
two stories.
(10)
Sec. 106
"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 determined by the commissioner.
"Occupancy", use or occupancy of a building, character of use, or desig-
nated purpose of a building or structure or portion thereof.
"Occupancy, unit of", that portion of one building within separations
within which the occupancy, whether of one or more tenants, falls in a single
group and division as classified in section one hundred and thirty-two and
Parts 3 to 12, inclusive, of this code.
"Or", providing an alternative at the option, unless the contrary is clearly
indicated, of the applicant for a permit.
"Owner", the owner of the land as recorded in the registry of deeds for
Suffolk county, or as registered in the land court, except as otherwise provided
in paragraph (d) of this section.
"Partition", see Wall.
"Passageway", a continuous way, of required width, kept clear for use
as an exit, whether enclosed or not.
"Pier", a vertical body of masonry used as a column, the portion of a
masonry wall between thinner portions or between openings when the hori-
zontal dimension parallel to the wall does not exceed four times the thickness.
"Plan or plans". The word plan or plans shall be construed to mean
drawing or drawings illustrating the work involved.
"Plumbing", the art of installing, repairing or altering the pipes, fixtures
and other apparatus for distributing the water supply and removing liquid
and water-carried wastes; the system of pipes, fixtures and other apparatus
installed in buildings for distributing the water supply and for the disposal
of liquid and water-carried wastes, including valves, traps and soil, waste and
vent pipes; provided, that nothing herein contained shall include the work
of steamfitting.
"Projection room", a room in a theatre or assembly hall containing a
projector of moving pictures.
"Remote", in reference to two or more exits, removed or distant from one
another in such manner that a person in any place served by such exits may
choose either of two directions in a path toward an exit and in such manner
that a single fire could not, in its early stages, block both paths toward an
exit.
"Seating capacity", the number of seats within an auditorium or other
hall when fastened to the floor; the number of persons who may be seated
within an auditorium or hall allowing six square feet of floor area per person
unless fixed seats are provided.
"Separation", a system of walls, floors or other construction serving to
separate or cut off one unit of occupancy from another.
"Shaft", an enclosure of a vertical opening in two or more stories.
"Smoke pipe", a flue, approximately horizontal, of metal or other material,
in which smoke or the products of combustion are conducted from a furnace
to a chimney or stack.
(11)
Sec. 106
"Smoke stack", a vertical flue of metal or reinforced concrete, whether'or
not lined with masonry or other protective material, in which smoke, or the
products of combusion, are conducted upward for disposal in the open air
at a height above the ground.
"Soil", the softer matter mostly inorganic composing part of the surface
of the earth in distinction from the firm rock; including gravel, clay, loam
and the like, and filling materials of similar nature.
"Sprinklers, automatic", a system of automatic sprinklers installed in
accordance with this code.
"Stair, rise of", the vertical distance between successive treads or steps
measured always from the same relative position thereon.
"Stair, tread of", the horizontal distance from one riser to the next or from
one nosing to the next.
"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, except that a space
used exclusively for the housing of mechanical services of the building shall
not be considered to be a story if access to such space may be had only for
maintenance of such services.
"Story, first", the lowest story of which sixty-five per cent or more of the
height is above the mean grade from which the height of the building is
measured.
"Structure", a combination of materials assembled at a fixed location to
give support or shelter, such as a building, bridge, trestle, tower, frame-work,
retaining wall, tank, tunnel, tent, stadium, reviewing stand, platform, bin,
fence, sign, flag-pole or the like. The word "structure" shall be constructed,
where the context allows, as though followed by the words "or par thereof".
"Unit of occupancy", see "Occupancy, unit of".
"Unit of occupancy, area of", the maximum horizontal projected area of a
unit of occupancy.
"Vertical opening", an opening in a floor or roof for giving access vertically
from the story below or above for light, ventilation, the movement of persons
or materials or for any other purpose.
"Wall, bearing", a wall which supports a floor, roof or other vertical load
in addition to its own weight.
"Wall, curtain", an exterior, non-bearing wall more than one story high
and not supported at each floor level, which is laterally stayed by masonry
piers or by the frame of the building.
"Wall, enclosure", an interior wall, bearing or non-bearing, which encloses
a stairway, elevator shaft or other vertical opening.
"Wall, fire", a wall separating two fire divisions of a building.
"Wall, non-bearing", a wall which supports only its own weight.
"Wall, panel", a non-bearing exterior wall not over one story high, or
supported at each floor level.
"Wall, parapet", a wall or part of a wall above the roof of a building.
"Wall, partition", an interior bearing or non-bearing wall, not over one
story in height the chief function of which is to separate two rooms.
"Wall, party", a wall used or adapted for use in common as a part of two
buildings.
(12)
Sees. 106-107
"Wall, retaining", a wall used to resist the lateral displacement of liquid,
granular or other materials.
(b) In conformity with the purposes of this code, to prescribe the minimum
requirements for structures and the maximum utility of structures consonant
with safety, the phrases "at least", "not less than" or "not more than"
shall be construed to precede quantitative specifications, as determined
by the commissioner.
(c) Wherever in this code a public official is referred to by the title of his
office without mention of any municipality, unless the context otherwise
requires, such reference shall be to an official of the city of Boston.
(d) 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 commissioner 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 en-
forcing this code.
[ tAs amended by Ord. 1948, ch. 2 and Ord. 1945, ch. 6 ]
*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 elevated 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 buildings. A pre-code building damaged by fire or other-
wise 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
(13)
Sec. 107
be made to conform to such requirements in the portions so altered or repaired
to such extent as the commissioner may determine. For the purposes of this
paragraph physical value shall mean the reproduction cost of the building
less physical deterioration as determined by the building commissioner.
(e) When occupancy of a pre-code building, or portions thereof separated
from the remainder as required in Part 13, is so changed that the hazard is
Increased, the commissioner 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 building 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 demonstrate such structural safety by actual
load tests made as directed by him.
3. Adequate resistance to the spread of fire shall be construed 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
demonstrated to the commissioner.
4. Safe egresses not less than two in number shall be construed to
mean egress facilities sufficient to evacuate the building in three minutes.
Owners of buildings shall, if directed by the building commissioner, demon-
strate 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 require-
ments 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 materials 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,
(H)
Sees. 107-109
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 ]
fSect. 108. Maintenance. — All buildings or structures, and all parts
thereof, shall be maintained in a safe condition. All devices 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.
[ \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 department, 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 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 commissioner 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 consti-
tuted immediately prior thereto, shall become the members of the board of
appeal established by paragraph (a) of section one hundred and seventeen,
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
immediately prior thereto, shall become the licensed master gasfitter member
of the board of examiners of gasfitters established 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,
immediately 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 re-
(15)
Sees. 109-110
appointment, shall retain all rights to retirement with pension that shall
have accrued or would thereafter accrue to them, and their services shall be
deemed to have been continuous 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 construction who has not had at least five years' experience
as a builder, civil engineer or architect, or as a superintendent, foreman 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 absence 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 employee
shall engage in any work which is inconsistent with his duties or with the
interests of the department. The provisions of this paragraph shall not
apply to the members of boards established by this code.
(g) The commissioner shall keep a record of the business of the depart-
ment. The records of the department shall be open to public inspection.
The commissioner shall not, however, be required 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 fee as the commissioner, with the approval of the mayor, 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 pro-
ducing apparatus 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.
No engine, dynamo, boiler or furnace shall be placed in any building
without a permit from the commissioner. Every application for such permit
shall be in writing, shall be filed with the commissioner and shall set forth
the character of the building, the size, power and purpose of the apparatus,
and such other information as the commissioner may require. The com-
missioner may, after an examination of the premises described in the applica-
tion and after hearing the applicant and any objectors, issue a permit for
placing a boiler or furnace on such premises, upon such conditions as he
shall prescribe, or he may refuse such permit. If the application is for
anything other than a boiler or furnace, the applicant shall publish in at
least two daily newspapers published in the city of Boston, and on at least
(16)
Sec. 110
three days in each, and, if so directed by the commissioner, shall also post
conspicuously on the premises a copy of the application, and shall deliver
copies thereof to such persons as the commissioner may designate.
If no objection is filed with the commissioner before the expiration of
ten days after the time of the first publication of notice, or within ten days
of the delivery and first posting of the notice, if such delivery or posting is
required, the commissioner shall if the arrangement, location and construction
of the proposed apparatus is proper and in accordance with the provisions
of this code, issue a permit for the same. If objection is filed, the application
shall be referred to the board of appeal which may in its discretion require
the deposit by the objector of a reasonable sum as security for the payment
of the costs.
After such notice as the board shall order it shall hear the same and shall
direct the commissioner to issue a permit under such conditions as it may
prescribe, or to withhold the same. If the permit is refused, the applicant
and if it is granted the objectors shall pay such costs as the board may order.
The commissioner may, from time to time, after public notice and hearing,
prescribe the conditions on which furnaces, boilers, or other steam generators
and hot water heaters may be maintained in buildings, and, if any person
interested objects to such conditions and appeals from his decision establishing
the same, the appeal shall be referred to the board of appeal, and thereupon
said board shall prescribe the conditions.
(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.
(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
b> the building, and shall contain such other information as may be required
by the commissioner.
(d) The commissioner may require the material facts contained 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 application, and shall be filed in duplicate with
the commissioner. Such plans shall contain information, in the form of
notes or otherwise, 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 construction 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
(17)
Sees. 110-111
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 issued; 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 indicated 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 requirements of this code and of all other pertinent laws
or ordinances.
[ *As amended by Ord. 1943, ch. 2 ]
fSect. 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 desig-
nated 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 therewith describe
work which does not conform to the requirements of this code or other per-
tinent laws or ordinances, the commissioner 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 presentation 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 building has been
filed, and pending issuance of such permit, the commissioner may, in his
discretion, upon payment of the required 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
(18)
Sec. 1 1 1
of the provisions 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 misrepresentation of a
material fact in the application for the permit or in the plans or computations
filed therewith, or if the work authorized 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 provision
of this code or other provision of law, or if after commencement 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 representative.
(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 com-
missioner 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 required fee, and
shall contain or be accompanied by a description of the proposed work with
plans sufficient to enable the commissioner to form an opinion. The com-
missioner shall make reply in writing within thirty days after receipt of the
request either that 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 provision will not allow the proposed construction for
reasons which he shall state. If the commissioner shall interpret such pro-
vision 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 involves construction under conditions which,
in the opinion of the commissioner, are hazardous or complex, the commis-
sioner shall require that the architect or engineer who signed the affidavit
or made the plans or computations shall supervise such work, be responsible
for its conformity with the approved plans, and forthwith upon its completion
(19)
Sees. 111-114
make and file with the commissioner 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 engineer is not available
a competent person whose qualifications are approved by the commissioner
shall be employed by the owner in his stead.
[f As amended by Ord. 1943, ch. 2 and Ord. 1953, ch. 7]
JSect. 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 para-
graph (d) of section one hundred and eleven.
(3) For written interpretation of this code given for the purpose of an
appeal from a disallowance as provided in paragraph (g) of said section one
hundred and eleven.
(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 inspection and of all violations of this
code. The publication of such records shall be privileged.
(b) No building operation requiring a permit shall be commenced 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 completion 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 specified in this code; provided, that
the commissioner may permit occupancy of a building for mercantile, com-
mercial 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*
(20)
Sees. 1 14-116
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 removed 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. 1948, ch. 2 ]
fSect. 115. Annual Report. — The commissioner shall annually, not
later than May first, submit a report to the mayor, covering the work of the
department during the preceding calendar year, and shall incorporate in said
report a summary of the decisions of the board of appeal, a summary of the
proceedings of the board of examiners and of the board of examiners of gas
fitters, during said year, and his recommendations as to desirable amende
ments of this code.
[ f^-s amended by Ord. 1943, ch. 2 ]
JSect. 116. Powers and Duties of Building Commissioner. — (a)
The commissioner and the health commissioner shall severally enforce the
provisions of this code relative to his powers and duties and they may, them-
selves or by their respective duly authorized representatives, enter any build-
ing or premises in said city to perform any duty imposed upon them, respec-
tively, 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 conditions
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, struc-
ture or enclosure, or part thereof, in the performance of his duty in the
enforcement of any provision 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
offence.
(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 order shall be in writing and shall be addressed and de-
livered, 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 con-
spicuous place upon an external wall of the building, and shall state the con-
ditions 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 commipsioner, with the approval of the mayor, may at once enter
the building or other structure which he finds unsafe or dangerous, or land
Sec. 116
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 account 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 assistant
recorder for the Suffolk district, of a statement of the claim, signed by the
commissioner, setting forth the amount claimed without interest. Such lien
ehall 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 statement of said lien was filed
in the registry of deeds or with said assistant recorder, as the case may be,
may appeal to the municipal court of the city of Boston, which shall hear and
determine 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 specif-
ically 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
(22)
Sees. 116-117
oiie 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 appliances in any and all buildings in Boston and to compel
compliance in Boston with the rules and regulations aforesaid.
(j) The commissioner shall make and issue rules and regulations 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 construction 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 qual-
ities of the material and shall make such additional tests or present satis-
factory 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 construc-
tion cannot be satisfactorily determined by the application of accepted en-
gineering principles, its safe strength shall be determined as one sixth of the
ultimate strength evidenced by tests 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 provide substantially as much safety from fire as materia
meeting such fire-resistive and fire-protective requiremtns.
[ As amended by Ord. 1948, 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
(23)
Sees. 117-118
the Building Trades Employers' Association and one by the Building Con
tractors 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 remain
ing members shall designate a substitute.
Note — Chapter 6 of the Ordinances of 1952 provides: " Each member of
the board of appeal shall receive for every day or part thereof of actual
service twenty-five dollars, but in no event shall any member of said board
receive in any one year more than thirty-five hundred dollars in the ag-
gregate for services rendered by him under the building code and the
zoning law. . . ." Effective January 1, 1953.
(c) Members of said board shall be residents of or engaged in business in
the city of Boston.
(d) Said board shall cause to be made a detailed record of all its pro-
ceedings, which shall set forth the reasons for its decisions, the vote of each
member participating therein, the absence 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 com-
missioner to incur expense may so appeal therefrom within thirty uays of the
date of such order, except that, in case of a building or structure which, in
the opinion of the commissioner, is unsafe or dangerous, the commissioner
may in his order limit the time for such appeal to a shorter period. A person
aggrieved by an adverse interpretation 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 within thirty days
after the date thereof. Appeals hereunder shall be on forms provided by the
commissioner and shall be accompanied by such fee as may be established by
the commissioner, 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.
(24)
Sees. 119-12G
fSect. 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 particular 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 inspec-
tion; 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 commas-*
sioner'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 officer 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 county 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 execution shall issue therefor.
[ fAs amended by Ord. 194$, ch. 2 ]
{Sect. 120. Board of Examiners. — (a) There is hereby established
in the City of Boston a Board of Examiners to consist of three members
appointed by the Mayor. The Board shall consist of an engineer or architect
with at least five years' experience 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
appointments to said Board shall be for terms of three years each. Vacancies
(25)
Sec. 120
ehall be filled by appointments by the Mayor for the remainder of the un-
expired term. Each member of the board of examiners shall receive ior
every day or part thereof of actual service ten 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 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 6 of the Ordinances of 1952 provides: "Each member of
the board of examiners, and the appointive member of the board of ex-
aminers of gasfitters, shall receive for every day or part thereof of actual
service fifteen dollars, but in no event more than fifteen hundred 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 construction, alteration, removal or tearing
down of buildings or structures. Due notice of the time and place for such
examinations 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 Depart'
ment 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 examina-
tion 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, moving and demolishing
of buildings or structures and installing and repairing of elevators and es-
calators 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 examination, 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
(26)
Sees. 120-121
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 pro-
vided in chapter two hundred and ninety-seven of the acts of nineteen hun-
dred 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 com-
missioner, 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 con-
tain a copy of the charges. At such hearing the licensee may be represented
by counsel, and the commissioner may be assisted by a representative of the
law department of the city.
(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.
[ tAs amended by Stat. 1952, ch. 212 and Ord. 1943, ch. 2 ]
[ *As amended by ch. 227, Acts of 1959 }
*Sect. 121. Board of Examiners of Qasfitters. — (a) There is hereby
established in the city of Boston a board of examiners of gasfitters, to consist
of three members, who shall be the building commissioner, the health com-
missioner and a licensed master gasfitter. The member of the board of
examiners of gasfitters who is a licensed master gasfitter shall be appointed
annually by the mayor for a term ending on the first day of May of the year
next ensuing; and he shall receive for every day or part thereof of actual
service ten dollars or such other sum as may from time to time be fixed by
the city council with the approval of the mayor. He shall have been con-
tinuously engaged in business as a master gasfitter during the five years
next preceding his appointment.
Note — See note under Sect. 120, par. (a).
(27)
Sees. 121=122
(b) Said board shall hold examinations, under rules and regulations
adopted by it, of persons desiring to engage in business as master gasfitters
or to work as journeyman gasfitters. Due notice of the time and place for
such examinations shall be posted in the office of the department and published
in the City Record.
(c) Said board shall determine the qualifications required for registration
as master gasfitter and as journeyman gasfitter, and after examination shall
register as such the persons found to possess the requisite qualifications.
Said board shall, without re-examination, register as qualified master gas-
fitters or journeyman gasfitters, as the case may be, persons desiring so to be
registered who were so licensed before the effective date of this code. The
name and address of each person so found to be qualified and registered,
and the place of business of each person qualified as a master gasfitter, shall
thereupon be certified by said board to the commissioner who shall, upon
payment of the required fee. issue to each person so registered and certified a
license to engage in business as a master gasfitter or to work as a journeyman
gasfitter, as the case may be.
(d) Every original license issued under this section shall take effect upon
its issuance and shall expire on such date, not later than one year after its
effective date, as said board shall determine. Upon the expiration of any
license issued under this section, the commissioner shall, upon payment of
the required fee, renew the same except that, unless otherwise ordered by said
board, he shall not renew the license of any person whose registration has been
cancelled or whose license has been revoked or suspended. Every renewal
license issued under this section shall take effect on such date, not later than
one month after its issuance, and expire on such date, not later than one year
after its effective date, as said board shall from time to time determine. The
registration of any person whose license has not been renewed within one year
after its expiration shall be cancelled.
(e) The fee for issuance or renewal of a master gasfitter's license shall be
two dollars and that for issuance or renewal of a journeyman gasfitter's
license shall be fifty cents; provided, that such fees may be changed from
time to time by the building commissioner, with the approval of the mayor.
(f) Except as otherwise provided in this section all gas fitting in buildings
shall be done by licensed master gasfitters, either themselves or through
licensed journeymen gasfitters employed by them. A firm or corporation
employing journeymen gasfitters shall be deemed to be licensed for the
pur-pose of this section if a member of the firm or an officer of the corporation
is duly licensed as a master gasfitter. A permit for gas fitting in buildings
shall be issued only to licensed master gasfitters.
(g) No person shall connect, disconnect or remove a gas meter, except
the duly authorized representative of the gas company owning such meter.
Nothing in this section shall be construed to affect the operations of a gas
company upon its own premises or upon its mains and service pipes.
(h) Whoever violates any provision of this section shall be punished
by a fine of not more than one hundred dollars, and, in addition, if the offender
is licensed under this section, his license shall be revoked or suspended by
the commissioner, when so ordered by said board after a hearing.
[*As amended by Stat. 1952, ch. 212, Stat. 1955, ch. 4, and Ord. 1943, ch. 2)
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.
(28)
Sees. 122=124
(b) Except as otherwise provided in this code, whoever violates any
provision thereof, or whoever builds, alters, or maintains a structure or a
part thereof in violation of any provision thereof, shall be punished by a
fine of not exceeding five hundred dollars. Each day during any portion
of which such violation is allowed to continue, or is permitted by the owner,
shall be considered a separate offence.
Section 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 unlaw-
fully 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, advance the case, so that it
may be heard and determined with as little delay as possible.
♦Sect. 124. Classification of Buildings by Types of Construction. —
(a) Buildings shall be classified by types of construction representing
varying degrees of resistance to fire. All buildings required to be of a given
type of construction shall conform to the minimum requirements of this code
for that type, but materials and combinations of materials which offer greater
resistance to fire than those specified for minimum requirements may be
used. Every building shall be classified as of the most fire-resistive type
all of the minimum requirements of which it fully meets. No building or
portion thereof shall be required to conform to a type of construction more
fire-resistive than that specified for its occupancy and size, or for its location
in the fire zones, in this code.
(b) When two or more types of construction occur in the same building
and are separated as provided in this code, each portion so separated may be
classified as of the type of construction to which it conforms; otherwise the
entire building shall be classified as of the least fire-resistive type of con-
struction used, and shall be subject to the restrictions of this code imposed
upon that type.
(c) A pre-code building which cannot be definitely classified as one of
the types defined in sections one hundred and twenty-five to one hundred and
thirty-one, inclusive, shall be deemed for the purpose of this code to belong
to the less fire-resistive of the two types to which it most nearly conforms.
[ *As amended by Ord. 1943, ch. 2 ]
(29)
Sees. 125-132
Sect. 125. Types of Construction. — All buildings shall be classified
for the purpose of this code in the following types of construction: —
Type I. Fireproof.
Type II. Semi-Fireproof.
Type III. Heavy Timber and Masonry.
Type IV. Light Wood and Masonry.
Type V. Metal Frame.
Type VI. Wooden Frame.
Sect. 126. Type I, Fireproof Construction. — Buildings of Type I
construction shall be of incombustible materials in all structural parts; their
exterior bearing walls and frames shall be of four-hour fire-resistive construc-
tion and their floors and roofs shall be of three-hour fire resistive construction
and shall furnish protection of three-hour fire-resistive rating against the
spread of fire.
Sect. 127. Type II, Semi-Fireproof Construction. — Buildings of
Type II construction shall be of incombustible materials in all structural
parts; their exterior bearing walls shall be of four-hour fire-resistive con-
struction, their columns and frames shall be of two-hour fire-resistive con-
struction and their floors and roofs shall be of one-hour fire-resistive construc-
tion and shall furnish protection of one-hour fire-resistive rating against the
spread of fire.
Sect. 128. Type III, Heavy Timber and Masonry Construction. —
Buildings of Type III shall have exterior bearing walls of masonry or other
construction of incombustible materials of four-hour fire-resistive construc-
tion, and their frames, floors and roofs shall be of heavy timber construction
without concealed air spaces.
Sect. 129. Type IV, Light Wood and Masonry Construction.—
Buildings of Type IV shall have exterior bearing walls of masonry or other
construction of incombustible materials of four-hour fire-resistive construction
and their frames, floors and roofs may be of wood.
Sect. 130. Type V, Metal Frame Construction. — Buildings of Type
V shall have walls, frames, floors and roofs of metal or other incombustible
materials which may be without protection against fire.
Sect. 131. Type VI, Wooden Frame Construction, — Buildings of
Type VI may have walls, frames, floors and roofs of wood.
*Sect. 132. Occupancies classified. — (a) Every building, whether
pre-code or post-code, shall, for the purpose of this code, be classified according
to its principal occupancy, as follows: —
Group A. Theatres.
Group B. Halls.
Group C. Schools.
Group D. Hospitals and detention buildings.
Group E. Commercial buildings of hazardous occupancy.
Group F. Offices and commercial buildings.
Group G. Commercial buildings of non-hazardous occupancy.
Group H. Unlimited habitations and large dwellings.
Group I. Limited habitations and small dwellings.
Group J. Miscellaneous structures.
(30)
Sees. 132=136
(b) An occupancy not mentioned specifically in this section or in the
definitions of groups and sub-divisions of groups contained in Parts 3 to 12,
inclusive, of this code, or about which there is any question, shall be classified
by the commissioner and included in the group which it most nearly resembles,
as regards fire hazard and danger to the lives of persons.
[ *As amended by Ord. 1943, ch. 2 ]
fSect. 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.
[ fAs amended by Ord. 1948, ch. 2 ]
Sect. 134. Multiple Occupancies. — When a building contains two or
more units of occupancy, whether of the same or of different occupancy
classifications, the separations between such units and the aggregate area of
such units within the building shall be as provided in this code.
Sect. 135. Elevators and Escalators. — No elevator or escalator shal
be installed in a building or structure except under the provisions of sections
sixty-two to seventy-one, inclusive, of chapter one hundred and forty-three
of the General Laws and the regulations issued thereunder, and in conformity
with section one hundred and twenty of this code.
Sect. 136. Building Height. — (a) No building or structure shall be
so erected or altered that any part thereof shall be higher above the ground
than two and one half times the shortest horizontal distance of that part from
the further side of the street upon which it fronts ; provided, that, in case of a
building at the intersection of two streets, within one hundred and fifty feet
measured along the streets from the intersection of the nearer side lines thereof,
the width of each street shall for the purpose of this section be taken as the
width of the wider street.
(b) No building or structure shall be erected or altered to a greater height
measured to the highest point of the roof thereof than one hundred and fifty-
five feet except as provided in this paragraph. If a building or structure shall
be erected or altered to a greater height than one hundred and fifty-five feet
every part of such building shall not be higher above the ground than one
hundred and twenty-five feet plus two and one half times the shortest hori-
zontal distance of that part from the nearest lot or street line. No building
shall be erected or enlarged to contain a volume above the grade of the ground
greater than the buildable area of the lot multiplied by one hundred and
fifty-five feet.
(c) In determining the height of any part of a building for the purposes
of this section, the grade of the ground from which measurement shall be made
shall be that from which the height of the building is measured as defined in
section one hundred and six. Flag poles and weather vanes shall not be
considered a part of a building for the purposes of this section.
(31)
Sees. 201-203
PART 2.
FIRE LIMITS.
Section
201 — Fire Limits.
202 — Boundaries.
203 — Construction within the Fire Zones.
Section 201. Fire Limits. — For the purposes of this code there shall
be established in the city of Boston two fire districts or zones within which
building construction shall be limited as provided in this part of the code.
Outside of the boundaries of the zones no limitation is placed by this part
of the code upon the construction of buildings.
Sect. 202. Boundaries. — (a) The boundaries of the first fire zone
shall be the boundaries of the building limits as they existed prior to the
twenty-second day of September in the 3^ear nineteen hundred and thirteen.
(b) The boundaries of the second fire zone shall be the boundaries of
the building limits as they were established on and after the twenty-second
day of September in the year nineteen hundred and thirteen.
(c) The city council of the city of Boston may by ordinance from time
to time extend either fire zone and re-establish its boundaries.
*Sect. 203. Construction within the Fire Zones. — (a) Buildings
hereafter erected in the first or second fire zone shall be of Type I, Type II,
Type III or Type IV construction except as hereinafter provided.
(h) The limitations of this section shall not apply to buildings not over
twenty-seven feet high on wharves and buildings for the storage and handling
of coal or grain in bulk, of Type V or Type VI construction, in either fire
zone, if the exterior thereof is covered with slate, tin, sheet metal or other
equally fire-resistive construction, erected with the approval of the com-
missioner and subject to such conditions as he may in each case specify.
(c) Temporary structures to be used in connection with construction
work and temporary reviewing stands, frame-works and tents, as are cus-
tomarily 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 commissioner, and to such conditions and for such time
as he may in each case specify.
(d) Buildings of Type VI construction for dwellings for one or two families
may be erected or enlarged in the second fire zone where the area of each does
not exceed sixty per cent of the area of the lot on which it is located and the
roof is pitched at not less than thirty degrees with the horizontal.
(e) Buildings of Type V construction may be erected or enlarged for use
as garages in the second fire zone providing they are equipped with fire win-
dows and are not within two feet of a lot line or within five feet of a building
of Type VI construction and the height does not exceed one story and the
area six hundred square feet and the capacity two cars.
(32)
Sec. 203
(f ) Buildings of Type V construction for other occupancies may be erected
in the second fire zone providing the location and the occupancy are approved
by the building commissioner.
(g) Buildings in the first or second fire zone erected, enlarged or con-
verted to use as a garage for more than four cars shall be of Type I or Type II
construction and if such garage be more than one story in height it shall be
of Type I construction.
(h) Every building in Group C in the first or second fire zone shall be of
Type I or Type II construction.
[ *As amended by Ord. 1945, ch. 6 ]
(33)
Sees. 301-303
PART 3.
SPECIAL REQUIREMENTS FOR GROUP A OCCUPANCY:
THEATRES.
Section
301 — Group A Occupancy: Type, Height, Area.
302 — Separation of Occupancies.
303 — Exterior Walls.
304 — Enclosure of Vertical Openings.
305 — Exits and Entrances.
306 — Aisles and Seating.
307 — Exit Lights.
308 — Light and Ventilation.
309 — Stage Ventilators, Group A Occupancy.
310 — Proscenium.
311 — Stage Construction.
312 — Dressing Rooms and Workshops.
313 — Fire=Extinguishing Apparatus.
314 — Projection Room.
Section 301. Group A Occupancy: Type, Height, Area. — (a)
Group A shall include every building containing an auditorium and a per-
manent stage equipped with a gridiron or other means of hanging scenery,
and primarily adapted for the giving of plays, operas or similar forms of
entertainment.
(b) Buildings or parts of buildings, classified for occupancy in Group A,
shall be of Type I construction, except that portion of the stage which, under
the provisions of section three hundred and eleven, may be of wood or un-
protected metal, and they shall not hereby be limited as to seating capacity,
area or height.
Sect. 302. Separation of Occupancies. — Portions of a building of
Group A occupancy may be used for purposes other than the giving of plays,
operas and the like, but the parts given to such other occupancies shall be
separated from that devoted to Group A occupancy by separations specified
in Part 13.
♦Sect. 303. Exterior Walls. — (a) Exterior walls or parts of walls,
except where fronting on a street, which are less than five feet from a property
line, shall be without openings, except that openings in such walls at the ends
of courts shall be allowed when protected by fire windows or Class B fire
doors. Openings in such walls or parts of walls which are five feet or more
but less than ten feet from a property line shall be protected by fire windows
or Class B fire doors.
(b) In an exterior wall, every opening which faces, at a distance of less
than twenty feet, the further side of a street or a combustible wall or roof
or an unprotected opening in a wall or roof of another building on the same
lot, shall be protected by fire windows or Class B fire doors.
(34)
Sees. 303-305
(c) The commissioner may waive the requirements of this section, for
protection or prohibition of openings in walls, temporarily pending construc-
tion on an adjoining lot or across a street, provided the owner agrees in a
writing recorded in the registry of deeds for Suffolk county to comply with the
said requirements on demand of the commissioner.
[ *As amended by Ord. 1943, ch. 2 ]
Sect. 304. Enclosure of Vertical Openings. — (a) Stair or ramp
exits from only the first or lower balcony need not be enclosed. Stair or ramp
exits from smoking rooms, lounges or other public rooms in the basement
shall be enclosed in the basement or first story, and the doors shall be self-
closing but need not be fire doors. Other stairways and ramps which pierce
only one floor shall be enclosed in the story above or below but such stairway
or ramps which serve as required exits from one story shall be enclosed in the
other story. Stairways or ramps serving dressing rooms need not be enclosed
above the stage or first floor if separated from the stage by a two-hour separa-
tion. Other stairways and ramps shall be enclosed in all stories in which they
occur. There shall be no openings in stair or ramp enclosures except entrance
and exit doorways and the openings required for ventilation.
(b) Vertical openings for elevators serving dressing rooms need not be
enclosed above the stage or first floor if they are separated from the stage by a
two-hour separation. Vertical openings for elevators serving the gridiron
and fly galleries need not be enclosed above the stage level. All other vertical
openings for elevators and vertical openings for ventilation or other purposes,
except as otherwise specified in this section, shall be enclosed.
fSect. 305. Exits and Entrances. — (a) Group A buildings shall be
so located that the main entrances shall open directly from a public street or
streets not less than thirty feet wide. The main entrance or entrances, which
may also serve as exits, shall have in the aggregate twenty inches of un-
obstructed width for each one hundred persons to and including one thou-
sand persons, with an additional ten inches for each additional one hundred
persons to and including one thousand additional persons, and an additional
five inches for each additional one hundred persons over two thousand, all
based on the total seating capacity of the building served by said entrances.
No main entrance shall be less than fifteen feet in clear width between walls
or in aggregate width of doorways and of passageways but such width shall
not be required to exceed forty feet in width. Doorways and passageways in
such entrances shall be not less than five feet in clear width.
(b) Adjacent to the main floor and each balcony of the auditorium and
between the auditorium and the main entrance, in the path of normal entrance
and egress, there shall be a foyer consisting of a lobby, corridor or passageway,
one or more, the aggregate floor area of which shall be at least equal to one
square foot for each seat in such division of the auditorium.
(c) There shall be at least two remote exits from the main floor and from
each balcony of the auditorium. One of these exits from the main floor and
one from each balcony shall open into the foyer required therefor in this
section. Both such exits may open into the required foyer if it has two remote
exits.
(35)
Sec. 305
(d) From the main floor and each balcony of the auditorium there shall
be at least two paths of exit independent of one another. Stairways or ramps
serving balconies above the first or lowest balcony shall be enclosed and shall
discharge directly into a street or open court independently of the other
required exit serving the same balcony or balconies and independently of the
paths of exit from the main floor. Such stairways or ramps may serve also
as exits from the first or lowest balcony. A stairway or ramp serving as an
exit only from the first or lowest balcony need not be enclosed and the path
therefrom may join a path of exit from the main floor. Where a path of exit
joins another at an angle, the common path of exit shall be at least as wide as
the sum of the widths of the paths so joined, and the partition or railing which
bounds a path so joining another shall either be stopped back from the nearer
side of the common path a distance equal to the width of the joining path or
shall extend such distance beyond the side of the common path, thus enabling
persons either to join the common path before turning or to enter and turn
before joining the common path.
(e) Exit stairways or ramps from balconies shall not extend below the
level at which they discharge from the building.
(f ) Exits and paths of exit, except from boxes seating less than twenty-five
persons, shall be not less than five feet wide at any point. The aggregate
width of the paths of exit specified heretofore in this section which serve one or
more divisions of the auditorium shall be at least twenty inches for every one
hundred persons for whom seats are provided in the division or divisions so
served. In calculating the required width of each path of exit, persons seated
in the auditorium shall be allotted to those exits therefrom which they can
most quickly reach in an emergency, assuming that the emergency exits
hereinafter specified are not used, and upon any other reasonable assumption.
(g) In addition to the exits specified in paragraphs (c), (d), (e) and (f)
of this section, hereinafter called normal exits, there shall be provided a system
of emergency exits as specified in this paragraph and in paragraphs (h) and (i).
Emergency exits from the auditorium shall be at least five feet wide and
there shall be at least one such exit from each side of the main floor and of
each balcony as remote as practicable from the normal exits. Emergency
exits from the main floor shall be exits from the building or shall be con-
nected by passageways with exits from the building independent of the
normal exits. The paths of emergency exit from the main floor shall be
not less than five feet wide, nor shall the aggregate width be less than five
inches for every one hundred persons served. The paths of exit from the
emergency exits from balconies shall be either of inside type as specified in
paragraph (h) or of outside type as specified in paragraph (i) of this section,
or a combination of the two types; provided, that the aggregate width of
the paths of emergency exit shall have five inches in width of inside path or
ten inches in width of outside path for every one hundred seats in the balcony
or balconies served.
(h) An inside path of emergency exit, referred to in the preceding para-
graph, shall consist of a foyer with at least fifty square feet of floor for each
emergency exit served, and an enclosed stairway or ramp with outside ventila-
(36)
Sec. 305
tion, with a direct exit from the building, or an enclosed passageway leading
to such an exit, independent of normal exits, or an exit to another building
or fire division of Type I or Type II construction. An exit to another build-
ing or fire division shall be through a lobby or vestibule of at least one
hundred square feet in floor area with outside ventilation and with self-
closing Class A fire doors at entrance and exit and shall lead, through ade-
quate corridors, stairways and passageways, to the street. No such exit
shall be made through a building or fire division of Group E occupancy.
Inside emergency exits shall be not less than three feet wide.
(i) An outside path of emergency exit, referred to in paragraph (g) of
this section, shall consist of an exterior fire escape balcony not less than
four feet wide at each emergency exit from a balcony and not more than
six inches below the sill thereof. Such balconies at the highest level shall
be at least eight feet long and at lower levels at least twelve feet long. Fire
escape stairs of rise not exceeding eight and one half inches and tread not
less than nine and one half inches and not less than thirty inches wide shall
lead from all such balconies to the ground. The lowest runs may be hinged
and counterweighted. Exterior fire escapes shall be located either in a
street or in an open court. Such courts shall be at least six feet wide and
open to the sky for the full depth of the auditorium and shall be connected
with a street by an open court or an enclosed passageway ten feet high,
either of which shall be at least six feet wide. Every such court or passage-
way shall have such additional width as may be necessary, if any, to pro-
vide, when the fire escape stairs are in position for use, the clear width
required for it as a path of emergency exit and as a path of normal exit if so
used.
(j) At least one exit, three feet wide, shall be provided on each side of
the stage. These exits shall open directly upon a street, or on a passageway
or court not less than three feet wide, leading to a street. Ladders may
be provided as exits from fly gallery and gridiron. Each tier of dressing
rooms shall be provided with at least two remote exits not less than thirty
inches wide.
(k) All exit and entrance doors or gates in any path of exit shall swing
in the direction of egress and if provided with latches, such latches shall be
of self-releasing type such as panic bolts or similar devices, of non-corrodible
metal, which will permit the door to open when pressed against. All doors
shall be so installed as not in any position to decrease the width of any door-
way (except that in which it is installed), stairs, landing, passageway or
corridor below the width required.
(1) No mirrors, false doors or windows shall be so placed as to give the
appearance of a doorway or exit, hallway or corridor.
(m) In buildings of Group A the rise of stairs shall not exceed seven
and one half inches nor shall the tread be less than ten and one half inches.
There shall be no flights of stairs of more than fifteen or less than three risers
between landings.
(n) A landing between two flights of stairs in the same direction shall
be at least as wide as the stairway and at least four feet long in the direction
of travel. Stairs turning at a right angle shall have a square or rectangular
(37)
Sees. 305-306
landing the full width of the respective stairways, except that the outer line
of the landing shall be curved to a radius not less than two feet, or bevelled
two feet, to avoid a deep corner. Where stairs return directly on them-
selves, a landing without steps shall be provided at least as wide as the stairs,
and the outer corners shall be curved or bevelled. Winders may be provided
only in stairs from boxes seating less than twenty-five persons. Where
two side nights of stairs join and continue in a common flight, a landing
without winders shall be provided and the width of the common flight shall
be equal to the sum of the widths of the side flights. A door opening into a
stairway shall not open immediately upon a flight of stairs, but a landing
at least three feet long in the direction of travel shall intervene.
(o) All stairways shall have, on both sides, strong hand rails firmly
secured about three feet high above the upper tread at each riser, except
that stairs less than three feet wide need have a rail only on one side.
(p) Stairways over eight feet wide shall be provided with a central rail,
not less than two inches in diameter, placed at a height of about three feet
above the upper tread at each riser, firmly supported on metal standards.
Stairways over twelve feet wide shall have such intermediate rails dividing
the stairs into equal runs not over six feet wide. Where hand rails are
fastened to walls, there shall be a minimum clearance of two inches between
the rail and the wall, and the upper ends of wall hand rails shall be returned
to wall or posts. At the head of each flight of stairs there shall be a post or
standard at least six feet high, to which the intermediate rail or rails shall
be fastened.
(q) Except as otherwise specified in this section, the provisions of Part
18 shall apply to exits from Group A buildings.
[ f As amended by Ord. 1943, ch. 2 ]
♦Sect. 306. Aisles and Seating. — (a) In auditoriums, aisles having
seats on both sides shall be not less than thirty inches in width at the end
remote from an exit and shall be widened by two inches for each ten feet in
length measured toward the exit. Aisles having seats on one side only shall
be not less than twenty-four inches wide at the end remote from an exit, and
shall be widened toward the exit by two inches for each ten feet in length.
Side aisles serving more than one exit shall be of uniform width between exits
and such width shall be not less than that required by this paragraph at a
point midway between the extreme exits.
(b) Aisles shall be so arranged that not more than six seats shall intervene
between any seat and the nearest aisle.
(c) There shall be no obstructions of any kind in an aisle. Aisles on the
main floor and in balconies may be sloped or stepped. When sloped, the
slope shall not exceed two inches vertical in ten inches horizontal. Where
stepped the rise shall not exceed twenty-one inches in a horizontal distance of
thirty-two inches. Stepped aisles shall not be construed to be stairways.
(d) The main floor of auditoriums shall have a cross-over aisle, either
open or enclosed, at the rear extending from side to side of auditorium. Fur-
thermore, if there are more than thirty-five rows of seats, there shall be in
addition at least one cross-over aisle extending from side to side of the audi-
(38)
Sees. 306=308
torium, and in no case shall there be more than thirty-five rows of seats
between cross-over aisles. Balconies with more than five rows of seats shall
have at least one cross-over aisle extending from side to side of balcony,
and in no case shall there be more than twenty rows of seats between cross-
over aisles. Cross aisles shall be not less than three feet wide in the clear
and shall lead to exits that are easily accessible. Vomitories shall be considered
entrances and exits.
(e) Seats shall be spaced not less than thirty-two inches except that
seats with backs less than one inch thick may be spaced not less than thirty
inches back to back. Seats in stepped balconies shall be spaced not less than
thirty-two inches back to back. No seats shall be less than eighteen inches
in width center to center. All seats shall be securely fastened to the floor,
except as otherwise provided in this section.
(f) Seats in boxes accommodating less than twenty-five persons need
not be fastened to the floor. Boxes accommodating twenty-five persons or
more shall be considered balconies.
[ *As amended by Ord. 194$, eh. 2 ]
fSect. 307. Exit Lights. — Over every exit doorway in any path of exit,
on the inside, and over every opening to a fire escape, on the inside, there
shall be an illuminated sign bearing the word "EXIT" or "FIRE ESCAPE",
respectively, in letters not less than four inches high. Each sign shall be
provided with two electric lamps.
[ jAs amended by Ord. 1943, ch. 2 ]
{Sect. 308. Light and Ventilation. — (a) Dressing rooms, work
shops, toilet rooms, auditoriums, foyers, and other public rooms shall be
provided with light and ventilation by means of windows and skylights with
an area not less than one eighth the floor area in each room, or they shall be
provided with artificial light and a mechanically operated ventilating system.
The mechanically operated ventilating system shall provide for four complete
air changes per hour in rooms where required and in the auditorium shall
supply at least fifteen cubic feet of fresh air per minute for each occupant
thereof. If the velocity of the air entering the room exceeds five feet per
second, the opening must be placed more than eight feet above the floor
directly beneath. Adequate means shall be provided for the removal of
foul air.
(b) Light shall be electric. Auditorium lights shall be on circuits separate
from those of the stage and the remainder of the building, and shall be so
arranged that they can be turned on from the stage and from at least one other
approved point in the front of the house, with approved indicators to show
when the lights are on.
(c) Lights in foyers, stairways, corridors and other paths of exit shall be
on circuits separate from those of the stage, auditorium and the remainder
of the building and shall be so arranged that they can be turned on from the
stage and from at least one other approved point in the front of the house,
with approved indicators to show when the lights are on.
(d) Exit sign lights and selected lights in foyers, auditoriums, stairways,
corridors and other paths of exit sufficient to provide illumination for egress
(39)
Sees. 308-310
of the audience in case of emergency shall be wired on separate circuits, and
these lights, hereinafter referred to as emergency lights, shall be kept lighted
when the building is occupied, except that outside balconies and fire escapes
need not be lighted before sunset nor auditorium lights during a performance.
The emergency lights may also include lights on switchboards, in projection
rooms, in boiler rooms and at other critical points. Emergency lights shall
be protected from possible physical damage.
(e) The 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 per cent 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 per cent of the nominal lamp voltage. The emergency
source of current shall be either: —
(1) A separate feeder of the service company other than that from
which the normal service is taken, or
(2) A separate feeder from a reliable generating plant independent of
that from which the normal service is taken, or
(3) An approved storage battery, or
(4) Illuminating gas.
(f) Glass in lighting fixtures hung in auditoriums, lobbies or other public
places shall be secured from falling by an approved method.
[ J As amended by Ord. 1948, ch. 2 and 9 ]
Sect. 309. Stage Ventilators, Group A Occupancy. — (a) There
shall be one or more ventilators, constructed of metal or other non-combustible
material, near the center and above the highest part of the stage. Such
ventilator or ventilators shall be raised above the stage roof and shall have a
total ventilating area at least equal to ten per cent of the floor space behind
the proscenium wall, at the stage floor level, not separated from the stage by
a two-hour separation.
(b) Doors or covers for ventilators shall open by gravity. Doors or
covers shall be held closed and manually operated by means of cords extending
to each side of the stage. These cords shall each be equipped with three
fusible links one of which shall be placed in the ventilator above the main
roof level and the other two at approved points not affected by sprinkler
heads. Fusible links shall be of an approved type which will release at a
temperature of one hundred and sixty degrees Fahrenheit. Each ventilator
shall be opened and closed at least once before each performance.
(c) Glass, if used in ventilators, may be either plain or wired. If plain
glass is used, a suitable wire netting shall be placed both above and below
the glass.
Sect. 310. Proscenium. — (a) The stage portion shall be separated
from the auditorium by not less than four-hour fire-resistive construction, as
specified in Part 22. Such separation shall be known as the proscenium wall.
This wall may be offset as desired, but such offset shall also be of not less
(40)
Sees. 3 1 0-3 1 1
rhan four-hour fire-resistive construction. The proscenium wall shall not be
finished or covered with combustible materials.
(b) The proscenium opening, the main opening for the viewing of per-
formances, shall be provided with a proscenium curtain as follows : —
(1) The proscenium curtain shall be of incombustible and fire-resistive
material. If of fabric, it shall be of asbestos cloth containing not over ten
per cent by weight of cotton or other combustible fibre, shall be reinforced
by wire and shall weigh not less than three pounds per square yard.
(2) Proscenium curtains of other materials than fabric, which are able
to withstand a standard fire test, as specified in Part 22, for thirty minutes
may be used with the approval of the commissioner.
(3) If the proscenium opening is not more than thirty-five feet wide
the curtain shall have a rigid metal member at the top and at the bottom
edge protected by the fabric on both stage and auditorium sides. If the
proscenium opening is more than thirty-five feet wide the curtain shall
have a rigid steel frame on all sides braced and constructed to the satis-
faction of the commissioner and protected from fire on both stage and audi-
torium sides.
(4) The proscenium curtain shall extend into non-combustible grooves
at the side a distance of at least twelve inches and the edges of the curtain
shall be retained in the groove by means of a taut steel cable or by other
approved means. The curtain shall overlap the top of the proscenium
opening not less than eighteen inches. At the bottom edge the curtain
shall be padded for a depth of at least four inches with flexible incombustible
material.
(5) The proscenium curtain shall be so rigged, counter balanced, and
operated that it can be quickly released to descend by gravity, and com-
pletely close the opening in case of fire. The releasing device and its
location shall be approved by the commissioner.
(6) The proscenium curtain shall be raised and lowered at least once
before every performance and shall be lowered at the close of every per-
formance. The operation of the curtain by means of the releasing device
shall be tested at intervals as required by the commissioner.
(c) The proscenium wall may have, in addition to the proscenium opening
not more than two openings at the orchestra pit level and two openings at
about the auditorium floor or stage level, none of which shall be more than
twenty-five square feet in area. Each such opening shall be protected on
each side of the wall by a Class A fire door as specified in Part 22. Ventilating
ducts may pass through the proscenium wall, provided they are equipped
with automatic-closing shutters of approved fire-resistive construction with
fusible links.
Sect. 311. Stage Construction. — (a) The portion of the stage
floor used in the working of scenery, traps or other mechanical apparatus,
may be of Type III floor construction, and steel beams need not be protected
against fire. This construction shall not extend beyond the proscenium
wall or the proscenium curtain, and shall not exceed the width of the pro-
scenium opening by more than three feet on each side. All other portions
of the stage shall be of Type I construction as specified in Part 16. The room
(41)
Sees. 311-314
or rooms under a stage of other than Type I construction shall not be used
for storage or for any purpose other than the working of traps and mechanical
apparatus necessary for a performance on the stage.
(b) Gridirons, fly galleries, and pin rails shall be constructed of incom-
bustible materials, but fireproofing of metal shall not be required.
(c) A protecting hood of incombustible material shall be provided over
and the full length of the stage switchboard. The switchboard shall be
protected on the sides and back by a grille of three-sixteenths inch wire with
not more than two-inch mesh, or by partitions of incombustible materials
having a one-hour fire-resistive rating, and on the front by a railing not
less than three feet high.
Sect. 312. Dressing Rooms and Workshops. — The dressing rooms,
workshops and storerooms shall be separated from the stage by a two-hour
separation as specified in Part 13.
Sect. 313. Fire=Extinguishing Apparatus. — (a) Automatic sprinklers
shall be provided throughout, except in auditoriums, foyers, lounges, entrances,
exits and projection rooms.
(b) The proscenium opening shall be equipped with an effective water
curtain by means either of automatic sprinkler heads of suitable design, or
open heads controlled by either of two valves on the stage, one on each side
of the proscenium opening.
(c) A portable fire extinguisher or extinguishers of approved type shall
be provided on the outside of each projection room near the door or doors.
(d) Portable extinguishers, not less than one for every two thousand square
feet of floor area, shall be provided throughout except in entrances and exits.
(e) First aid hose stations shall be provided throughout, except in pro-
jection rooms, auditoriums, foyers, lounges, entrances, exits and other rooms
used by the public. There shall be one station each side of the stage.
(f) Fire department standpipes shall be provided in buildings more than
seventy feet high.
Sect. 314. Projection Room. — The size, construction, arrangement
and equipment of a projection room shall conform to the requirements of
sections seventy-two to eighty-eight, inclusive, of chapter one hundred and
forty-three of the General Laws, and to the regulations established thereunder
by the commissioner of public safety of the commonwealth of Massachusetts.
(42)
Sec. 401
PART 4.
SPECIAL REQUIREMENTS FOR GROUP B OCCUPANCY:
HALLS.
Section
401 — Group B Occupancies: Type, Height, Area.
402 — Separation of Occupancies.
403 — Exterior Walls.
404 — Enclosure of Vertical Openings.
405 — Exits and Entrances.
406 — Aisles and Seating.
407 — Exit Lights.
408 — Light and Ventilation.
409 — Stage and Proscenium.
410 — Dressing Rooms, Workshops and Boiler Rooms.
411 — Fire-Extinguishing Apparatus.
412 — Projection Room.
♦Section 401. Group B Occupancies: Type, Height, Area. —
(a) Group B shall include places where persons may assemble for such
and similar purposes as are indicated in the following list of categories, where
the main floor exceeds nine hundred square feet in area or where the total
floor area, including a balcony, exceeds one thousand square feet.
(1) Churches in the commonly accepted sense of religious societies.
(2) Rooms and halls where people may engage in any form of dancing.
(3) Auditoriums, Entertainment and Exhibition Halls without gridiron
equipped stages as defined in Group A.
(4) Moving picture theatres without gridiron equipped stages as
defined in Group A.
(5) Gymnasiums and sports events halls.
(6) Meeting and gathering places of fraternal, social, civic, and philan-
thropic organizations.
(b) Buildings or parts of buildings classified for occupancy in Group B,
and of the several types of construction, shall not exceed in height and area of
units of occupancy the following limits: —
Type of
Construction.
Stories.
Maximum Area of Unit (Square Feet).
I
Not hereby limited.
4
1
4
1
3
1
Not allowed.
1
Not hereby limited.
II
18,000
Ill
Not hereby limited. Maximum distance in path
of exit, 175 feet.
17,000
IV
Not hereby limited. Maximum distance in path
of exit, 150 feet.
12,000
V
Not hereby limited. No structure of combustible
material to support seats or aisles to be super-
imposed on the floor construction. Maximum
distance in path of exit, 100 feet.
Not allowed.
VI
5,000
(43)
Sees. 401=405
The maximum area may be increased proportionately within the limits
given as the number of stories is decreased from the maximum.
(c) The first floor of all buildings more than two stories in height shall be
of Type I construction. No assembly hall of floor area exceeding thirty-six
hundred square feet and no group of assembly halls of aggregate floor area
exceeding forty-eight hundred square feet shall be above the first story unless
the building is of Type I or Type II construction.
(d) The maximum area provided in this section may be increased fifty
per cent if the entire floor area is protected by automatic sprinklers.
[ *As amended by Ord. 1943, ch. 2 ]
Sect. 402. Separation of Occupancies. — Group B occupancies shall be
separated from other occupancies, and fire divisions of Group B occupancy
shall be separated from adjoining fire divisions as specified in Part 13.
fSect. 403. Exterior Walls. — (a) Exterior walls or parts of walls,
except where fronting on a street, which are less than five feet from a property
line, shall be of four-hour fire-resistive construction without openings, except
that openings in such walls at the ends of courts shall be allowed when pro-
tected by fire windows or Class B fire doors. Such walls or parts of walls
which are five feet or more, but less than ten feet from a property line shall
be of at least two-hour fire-resistive construction and all openings therein shall
be protected by fire windows or Class B fire doors.
(b) Every portion of an exterior wall which faces, at a distance of less than
twenty feet, the further side of a street, or a combustible wall or roof or an
unprotected opening in a wall or roof of another building on the same lot,
shall be of at least two-hour fire-resistive construction, and all openings in
such portions shall be protected by fire windows or Class B fire doors.
(c) The commissioner may waive the requirements of this section, for the
protection or prohibition of openings in walls, temporarily pending construc-
tion on an adjoining lot or across a street, provided the owner agrees in a writing
recorded in the registry of deeds to comply with the said requirements on
demand of the commissioner.
[ fAs amended by Ord. 1943, ch. 2 ]
Sect. 404. Enclosure of Vertical Openings. — (a) Main stair or ramp
exits from only the second story need not be enclosed. Stairways or ramps
which extend only from a balcony in a hall to the main floor level need not be
enclosed. Other stairways and ramps which pierce only one floor shall be
enclosed in the story above or below but such stairways which serve as re-
quired exits from one story shall be enclosed in the other. Other stairways
and ramps shall be enclosed in all stories in which they occur.
(b) Elevator shafts, ventilation shafts and other vertical openings except
stairways and ramps, shall be enclosed.
JSect. 405. Exits and Entrances. — (a) Group B buildings shall front
upon a public street not less than twenty feet wide or upon an open area not
less than twenty feet wide leading to a public street. In this front shall be
located the main entrance of the building. The main entrance or entrances,
which may also serve as exits, shall have in the aggregate twenty inches of
clear width for each one hundred persons to and including one thousand per-
(44)
Sec 405
song, with an additional ten inches for each additional one hundred persons
to and including one thousand additional persons, and an additional five
inches for each additional one hundred persons over two thousand persons.
In a one story or two story building the width of entrance shall be based upon
the total seating capacity of the halls served by it. In a building of three or
more stories the width of entrance shall be based upon the maximum total
seating capacity of the halls served by it which are contained in any two
stories. (See definition of "seating capacity.")
(b) Adjacent to the main floor and to each balcony, if any, of an assembly
hall and between the hall and its main entrance in the path of normal entrance
and egress, except in the first story, there shall be a foyer, consisting of a lobby,
corridor or passageway, one or more, the aggregate floor area of which shall
be at least equal to one square foot for each seat in the seating capacity of the
hall or balcony so served; provided, that one such area may serve two or more
halls or balconies on the same floor level if large enough for the largest two halls
so served. A hall, with a balcony seating not more than one hundred and
fifty persons, may have a common foyer. A foyer shall have a width of at
least ten inches for each one hundred seats in the seating capacity of the
largest two halls served by it.
(c) Assembly halls having a seating capacity of fifteen hundred or less
shall have exits with an aggregate width of at least twenty-four inches for
each one hundred seats thereof and no exit shall be less than three feet wide.
Halls having a seating capacity of five hundred or less shall have at least two
remote exits. Halls having a seating capacity of more than five hundred, but
not more than eight hundred, shall have at least three remote exits. Halls
having a seating capacity of more than eight hundred, but not more than one
thousand, shall have at least four remote exits of which two shall be at least
five feet wide. Halls having a seating capacity exceeding one thousand shall
have at least four remote exits five feet wide. Every assembly hall shall have
at least two remote and independent paths of exit. Halls having a seating
capacity of more than fifteen hundred shall have exits meeting the require-
ments for normal and emergency exits from the auditoriums of Group A
buildings. Every balcony seating more than twenty-five persons shall have
two remote exits.
(d) At least one exit from every hall or balcony shall lead into the foyer
thereof and all such exits may lead into the foyer if it has two remote exits.
Exterior stairways and ramps shall not serve as required exits of Group B
buildings except the emergency exits required for halls seating more than
fifteen hundred. Exits from foyers and all paths of exit from doorways
from assembly halls shall be at least forty-four inches wide and shall have
an aggregate width at least equal to twenty inches for each one hundred
seats in the seating capacity of the halls of any one story served by them.
No point on the main or balcony floor of an assembly hall shall be further
from the nearest exit from the story than one hundred and fifty feet along a
path of exit.
(e) Enclosed stairways or ramp exits shall discharge directly through an
exit from the building or through an enclosed corridor leading to an exit from
the building.
(45)
Sees. 405-406
(f ) Doorways from a room leading into a stair enclosure shall have single
acting, self-closing doors opening in the direction of any path of exit.
If doors in exit doorways in any path of exit have latches, such latches shall
be panic bolts or similar approved devices, of non-corrodible metal.
(g) Stairs shall have a handrail on each side. The upper ends of handrails
shall return to the wall or to a post.
(h) Except as otherwise specified in this section the provisions of Part 18
shall apply to exits from Group B buildings.
[% As amended by Ord. 1943, ch. 2 ]
♦Sect. 406. Aisles and Seating. — (a) Aisles having seats on both
sides shall be not less than thirty inches in width at the end remote from an
exit and shall be widened by two inches for each ten feet in length measured
toward the exit. Aisles having seats on one side only shall be not less than
twenty-four inches wide at the end remote from an exit, and shall be widened
toward the exit by two inches for each ten feet in length. Side aisles serving
more than one exit shall be of uniform width between exits and such width
shall be not less than that required by this paragraph at a point midway
between the extreme exits.
(b) Aisles shall be so arranged that not more than six seats shall interve:.^
between any seat and the nearest aisle
(c) There shall be no obstructions of any kind in an aisle. Aisles on the
main floor and in balconies may be sloped or stepped. When sloped, the slope
shall not exceed two inches vertical in ten inches horizontal. When stepped,
the rise shall not exceed twenty-one inches in a horizontal distance of thirty-
two inches. Stepped aisles shall not be construed to be stairways.
(d) The main floor of auditoriums shall have a cross-over aisle, either
open or enclosed, at the rear extending from side to side of auditorium. Fur-
thermore, if there are more than thirty-five rows of seats there shall be in
addition at least one cross-over aisle extending from side to side of the audi-
torium, and in no case shall there be more than thirty-five rows of seats
between cross-over aisles. Balconies with more than five rows of seats shall
have at least one cross-over aisle extending from side to side of balcony, and
in no case shall there be more than twenty rows of seats between cross-over
aisles. Cross aisles shall be not less than three feet wide in the clear and
shall lead to exits that are easily accessible. Vomitories shall be considered
extrances and exits.
(e) Seats shall be spaced not less than thirty-two inches except that
fixed seats with backs less than one inch thick may be spaced not less than
thirty inches back to back. Seats in stepped balconies shall be spaced not
less than thirty-two inches back to back. No seats shall be less than eighteen
inches in width center to center.
(f) In a hall or balcony seating more than one hundred and fifty persons,
seats shall either be fastened to the floor or approved means shall be provided
so that the relative position of seats shall be maintained. In smaller halls
or balconies, unless the seats are so secured, the aisles shall be four inches wider
than as provided in paragraph (a) of this section.
[ *As amended by Ord. 1943, ch. 2 ]
(46)
Sees. 407-408
*Sect. 407. Exit Lights. — Over every exit doorway in any path of exit
on the inside, there shall be an illuminated sign bearing the word "EXIT"
in letters not less than four inches high. Each sign shall be provided with
two electric lamps.
[ *As amended by Ord. 1948, ch. 2 ]
fSect. 408. Light and Ventilation. — (a) Assembly halls, foyers t
toilet rooms and other public rooms shall be provided with light and ventilation
by means of windows or skylights with an aggregate area not less than one
eighth the floor area in each room, or they shall be provided with artificial
light and a mechanically operated ventilating system. The mechanically
operated ventilating system shall provide for four complete changes of air
per hour, and in assembly halls shall supply at least fifteen cubic feet of fresh
air per minute for each occupant thereof. If the velocity of the air entering
the rooms exceeds five feet per second, the opening must be placed more than
eight feet above the floor directly beneath. Adequate means shall be provided
for the removal of foul air.
(b) Registers or ventilating ducts for supplying air to or exhausting air
from stages shall be equipped with automatic-closing shutters with fusible
links.
(c) Lights for stages shall be on circuits separate from the lights of
the remainder of the building. Lights in corridors, stairways, and other
parts of exits shall be suitably protected.
(d) In an assembly hall having a seating capacity in excess of eight
hundred the exit sign lights and selected lamps in foyers, auditoriums, stair-
ways, corridors and other paths of exit therefrom sufficient to provide illu-
mination for egress in case of emergency shall be wired on a separate
emergency circuit with a second source of current as provided for in Group A
occupancy. Exit sign lights shall be kept lighted when the hall is occupied,
and other emergency lights, except auditorium lights, when the hall is
occupied except before sunset in rooms, corridors and stairways sufficiently
lighted by windows.
(e) The 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 per cent 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 per cent of the nominal lamp voltage. The emergency
source of current shall be either: —
(1) A separate feeder of the service company other than that from which
the normal service is taken, or
(2) A separate feeder from a reliable geaerating plant independent
of that from which the normal service is taken, or
(3) An approved storage battery, or
(4) Illuminating gas.
[ fAs amended by Ord. 1948, ch. 2 and 9 }
(47)
Sees. 409-412
Sect. 409. Stage and Proscenium. — (a) Where a stage or platform
is without provisions for scenery, no separation from the auditorium shall
be required, and such stage or platform may be of the same type of con-
struction as the auditorium floor; or it may be constructed of wood, if the
auditorium floor extends under the full area of such stage or platform.
(b) Where a stage has provisions for standing scenery only, such stage
shall be separated from the auditorium by a proscenium wall of not less
than two-hour fire-resistive construction. Each opening through this wall
other than the proscenium opening, shall not exceed twenty-five square
feet in area, and shall be protected by a Class A fire door. Where such
stage exceeds fifteen feet in depth, or where the proscenium opening exceeds
twenty-five feet in width or twelve feet in height, the proscenium opening
shall be provided with a proscenium curtain as specified for theatres in Part 3.
Where such stage is less than fifteen feet in depth, and the proscenium open-
ing is less than twenty-five feet in width and twelve feet in height, the pros-
cenium curtain shall be either of asbestos fabric or of cotton or other fabric
flame-proofed by approved chemical process.
Sect. 410. Dressing Rooms, Workshops and Boiler Rooms. —
Dressing rooms, workshops and store rooms near the stage shall be separated
therefrom by a two-hour separation as defined in Part 13. Every boiler
room or room containing a heating plant shall be separated from the rest of
the building by a two-hour separation.
♦Sect. 411. Fire Extinguishing Apparatus. — (a) Cellars and base-
ments, stages with proscenium walls, accessible areas — other than the
Assembly Hall, entrances and exits, and projection rooms shall be equipped
with Automatic Sprinklers. Attics, the space under stages and other such
paces, if available for storage, shall be equipped with Automatic Sprinklers.
(b) In buildings where Group B occupancy is located above occupancy
of other grouping or groupings, the areas of the other grouping or groupings
shall be equipped with Automatic Sprinklers.
(c) In every Assembly Hall where stage shall have a proscenium wall as
required by Section 409 (b), the proscenium opening shall be equipped with a
water curtain as specified in Part 3.
(d) A portable fire extinguisher of approved type shall be provided out-
side of every projection room near each projection room door.
(e) In buildings more than two stories high, either portable extinguishers,
not less than one for every two thousand square feet of floor area, or first
aid standpipes, shall be provided in spaces other than projection rooms, but
first aid standpipes shall not be provided in assembly halls, corridors, foyers,
exits and other rooms used by persons assembled in such halls.
(f) Fire department standpipes and first aid standpipes shall be provided
in buildings more than seventy feet high.
[ *As amended by Ord. 1948, ch. 2 ]
fSect. 412. Projection Room. — A projection room shall have a floor
of incombustible material supported on a concrete base not less than three
(48)
Sec. 412
inches in total thickness which may be supported by a floor of the same
type of construction as that of the building, or of other materials having
equivalent fire-resistance. A projection room shall have walls and ceiling
of not less than one-hour fire-resistive construction of incombustible materials.
In other respects a projection room shall conform to the requirements of
sections seventy-two to eighty-eight, inclusive, of chapter one hundred and
forty-three of the General Laws, and to the regulations established there-
under by the commissioner of public safety of the commonwealth of
Massachusetts.
[ tAs amended by Ord. 1948, ch. 2\
(49)
Sec. 501
PART 5.
SPECIAL REQUIREMENTS FOR GROUP C OCCUPANCY:
SCHOOLS.
Section
501 — Group C Occupancy: Type, Height, Area.
502 — Separation of Occupancies.
503 — Exterior Walls.
504 — Enclosure of Vertical Openings,
505 — Exits.
506 — Aisles and Seating.
507 — Light.
508 — Ventilation and Heating.
509 — Fire-Extinguishing Apparatus,
510 — Special Requirements.
511 — Toilet Accommodations.
♦Section 501. Group C Occupancy: Type, Area. — (a) Group C shall
Include every post-code building used wholly or in part as a school.
(b) Buildings or parts of buildings classified for occupancy in Group C
shall be limited as to type of construction, height and area of units, as follows:—
Type of Construction.
Stories.
Maximum Area of Unit (Square Feet).
I
Not hereby limited.
4
1
2
1
2
1
Not allowed.
1
Not hereby limited.
II
18,000
Ill
24,000
17,000
IV
20,000
12,000
V
18,000
VI
5,000
The maximum area may be increased proportionately within the limits
given as the number of stories is decreased from the maximum.
(c) The maximum area provided in this section may be increased fifty
per cent if the entire floor area is protected by automatic sprinklers.
(d) Assembly halls with seating capacity of more than one hundred and
fifty persons shall conform with the requirements of Part 4 and, in addition,
the width of exits shall be computed in multiples of twenty inches for each
one hundred seats.
(e) Every Group C post-code building in the first or second fire zone
shall be of Type I or Type II construction.
(50)
Sees. 501-504
(f) When school usage involves special conditions such as the use of
hazardous, highly inflammable or explosive materials or liquids or any other
special occupancy that is a hazard, they shall also conform to the special
requirements of that occupancy or hazard.
(g) Pre-code buildings or parts of buildings involving a change of occu-
pancy to Group C, whether or not altered or enlarged shall conform to the
general requirements of this section as they shall be interpreted by the com-
missioner as delineated in Section 107, paragraph (e), and they shall be limited
as to type of construction, (number of stories,) and area of units as follows:
Type of Construction.
Stories.
Maximum Area of Unit (sq. ft.)
I
Not hereby limited.
4
1
5
5
Not allowed.
2
Not hereby limited.
II
18,000
Ill
24,000
5,000
IV
5,000
V
VI
4,000
[ *As amended by Ord. 1948, ch. 8 ]
Sect. 502. Separation of Occupancies. — Group C occupancies shall
be separated from other occupancies, and fire division of Group C occupancy
shall be separated from adjoining fire divisions as specified in Part 13.
fSect. 503. Exterior Walls. — (a) Exterior walls or parts of walls,
except where fronting on a street, which are less than five feet from a property
line, shall be of four-hour fire-resistive construction without openings. Such
walls or parts of walls which are five feet or more, but less than ten feet from
a property line, shall be of at least two-hour fire-resistive construction and
all openings therein shall be protected by Class B fire doors or fire windows.
(b) Every portion of an exterior wall which faces, at a distance of less
than twenty feet, the further side of a street, or a combustible wall or roof,
or an unprotected opening in a wall or roof of another building on the same
lot, shall be of at least two-hour fire-resistive construction, and all openings
in such portions shall be protected by Class B fire doors or fire windows.
(c) The commissioner may waive the requirements of this section, for
protection or prohibition of openings in walls, temporarily pending con-
struction on an adjoining lot or across a street, provided the owner agrees
in a writing recorded in the registry of deeds for Suffolk county to comply
with the said requirements on demand of the commissioner.
[ fils amended by Ord. 1948. ch. 8 ]
JSect. 504. Enclosure of Vertical Openings. — (a) Elevator shafts,
ventilating shafts, dust chutes and other vertical openings shall be enclosed.
(b) Stairways and ramps which pierce only one floor shall be enclosed in
the story above or below, but such stairways or ramps which serve as required
(51)
Sees. 504-505
exits from one story shall be enclosed in the other story. Other stairways
and ramps shall be enclosed in all stories in which they occur.
[ %As amended by Ord. 1948, ch. 3 ]
♦Sect. 505. Exits. — (a) All rooms used for the instruction of pupils*
shall have at least two means of egress; one of which shall open into a corridor,
stairway, ramp or other egress enclosure; the other shall lead to another
separate corridor, stairway, ramp or other egress enclosure through intervening
rooms and intercommunicating doors. The width of exit doors shall be not
less than thirty-six inches nor less than twenty inches for each one hundred
occupants thereof.
(b) Corridors shall have uniform width between exits and shall have a
clear exit-width not less than six feet, nor less than twenty inches for each one
hundred persons or fraction thereof allotted to it as a path of exit; provided,
that the exit-width of a corridor shall not be required to exceed ten feet.
If classroom doors on one or both sides of a corridor project into it when
in open position, the width of the corridor shall be increased over its required
exit-width by one half the sum of such projections. If lockers are installed
in the walls of corridors on one or both sides, the width of the corridor shall be
increased over its required exit-width by eighteen inches for each side on
which lockers are installed. No obstruction shall be placed in corridors
except that the drip of a recessed drinking fountain or a radiator may project
into a corridor. If a radiator less than six feet six inches above the floor ia
placed in a path of exit and is not fully recessed, the width of the corridor
shall be measured from the face of the radiator.
(c) Each corridor shall have at least two remote exits which shall be
exits from the story as specified in Part 18. Such exits shall be so located,
that every doorway from a room for pupils to a corridor shall be not more
than seventy feet from an exit from the corridor. The persons in each room
having an exit to a corridor shall be allotted to a path of exit through the
corridor to the nearest exit therefrom for the purpose of computing the
width of corridors and their exits; provided, that if the mid-length point of
a corridor between its exits lies in an exit from a room or between two exits
from a room, the persons in such room may be allotted to either exit from the
corridor. The width of every exit from a corridor shall be not less than
forty inches, nor less than twenty inches for each one hundred persons or
fraction thereof allotted to it.
(d) Each story of a Group C building shall have at least two remote
exits. The width of stairs and ramps and of exits from them shall be not less
than forty inches nor less than twenty inches for each one hundred persons
or fraction thereof allotted to them and shall be based upon the largest
number of persons from any one story whom they serve as exits. If doors,
in exit doorways more than four feet wide have latches, such latches shall be
panic bolts or similar devices of non-corrodible material.
(e) No intake for a dust or waste paper chute shall open directly upon a
corridor or enclosed exit, but may open in a closet off a corridor.
(f) All stairs shall have a handrail on each side. Stairs eighty inchef-
or more in width shall have one or more intermediate rails dividing the stairs
(52)
Sees. 505-508
into widths less than eighty inches but not less than forty inches; provided,
that in calculating the capacity as an exit of a stair so divided, each division
shall be considered an exit. The upper ends of handrails shall be returned
to the wall or shall so terminate at a post as not to leave a free or projecting
end.
(g) Stair landings shall have a width at least equal to that of the stairs.
No run of stairs shall have more than fifteen nor less than three risers. The
rise shall not exceed seven and one half inches nor shall the tread be less
than ten inches. Winders shall not be permitted.
[ *As amended by Ord. 1943, ch. 3 ]
Sect. 506. Aisles and Seating. — (a) Classrooms with fixed seats
shall have aisles at least thirty inches wide next to the windows and at least
thirty-six inches wide on other sides, and intermediate aisles at least sixteen
inches wide.
(b) Unless definitely fixed on the plans the normal seating capacity of
classrooms shall be determined by dividing the floor area of each room as
follows: —
Elementary Schools by 15 square feet
Intermediate Schools by 17 square feet
High Schools and Colleges by 19 square feet
fSect. 507. Light. — (a) Rooms used by pupils for study and class
work shall have outside windows with a total sash area not less than one
fifth the floor area of each such room. The windows shall preferably be
on the long side of a room. The clear height of a room shall be not less
than ten feet. No room shall be used for class work where an exterior wall
outside and opposite the required windows shall extend above a line from
the window sills at thirty degrees above the horizontal unless such wall is
at least sixty feet from the windows. The possibility of a building on an
adjoining lot shall be provided for.
(b) Corridors, stairways and other exits shall have artificial illumination
which, if electric, shall be on circuits and control separate from other lighting
in the building.
ffAs amended by Ord. 1943, ch. 3 and Ord. 1955, ch. 1]
Sect. 508. Ventilation and Heating. — (a) In all rooms used by
pupils for school purposes shall be installed a positive system of ventilation
that will supply fresh air, heated when necessary, and adequately remove
the foul air. In class, recitation and study rooms there shall be provided
at least six complete air changes per hour but not less than twenty cubic
feet of fresh air per minute per pupil normally seated, and in assembly rooms,
gymnasiums, lunch rooms and vocational rooms at least four complete
changes of air per hour but not less than fifteen cubic feet per minute per pupil
for whom seating or work space is provided. In toilets, shower and locker
rooms at least eight complete air changes per hour shall be provided and
these rooms shall be ventilated by an exhaust system.
(b) The heating and ventilating system shall be capable of maintaining,
when the outside temperature is zero, in gymnasiums and toilets a temperature
(53)
Sees. 508-511
of sixty degrees, in shower and locker rooms appurtenant to gymnasiums
seventy-five degrees, and in other rooms used by pupils or teachers seventy
degrees, all by Fahrenheit scale.
Sect. 509. Fire-Extinguishing Apparatus. — (a) Cellars and base-
ments, except those portions used for classes, shall be equipped with auto-
matic sprinklers. Mechanical trade shops, storage rooms and attics available
for storage shall have automatic sprinklers where required by the commissioner.
(b) A portable fire-extinguisher of approved type shall be provided out-
side every projection room near the door.
(c) In buildings more than two stories high, either portable fire-extin-
guishers, not less than one for every thirty-five hundred square feet of floor
area and not less than one in each story, or first aid standpipes shall be pro-
vided, but first aid standpipes shall not be provided in assembly halls or in
exits therefrom.
(d) Fire department standpipes and first aid standpipes shall be provided
in buildings more than seventy feet high.
Sect. 510. Special Requirements. — Every boiler room shall be sepa-
rated from the remainder of the building by a two-hour separation as speci-
fied in Part 13.
Sect. 511. Toilet Accommodations. — (a) Adequate toilets shall be
provided for pupils, with fixtures in accordance with the following table: —
Number of Puph-s of Either Sex.
Girls.
Boys.
Water Closets.
Water Closets.
Urinals.
4
6
9
12
14
16
18
20
22
24
43
61
3
4
6
8
9
10
11
12
13
14
25
36
4
6
8
10
12
14
16
18
20
22
40
56
(b) For intermediate numbers of pupils, fixtures shall be provided by
interpolation in the table and for numbers in excess of fifteen hundred at the
rate provided for fifteen hundred.
(c) Separate toilets shall be provided for the teachers and for the janitors.
(54)
Sec. 601
PART 6.
SPECIAL REQUIREMENTS FOR GROUP D OCCUPANCY:
HOSPITALS AND DETENTION BUILDINGS.
Section
601 — Group D Occupancy: Type, Height, Area.
602 — Separation of Occupancies.
603 — Exterior Walls.
604 — Enclosure of Vertical Openings.
605 — Exits.
606 — Light and Ventilation.
607 — Fire-Extinguishing Apparatus.
608 — Special Requirements.
609 — Exceptions.
610 — Emergency Lights.
*Section 601. Group D Occupancy: Type, Height, Area. — (a
Group D shall include such occupancies as —
Division 1. Jails, prisons, reformatories, houses of correction, asylums
for the insane or feeble minded, the parts of police stations wherein more than
ten persons may be detained, and similar buildings.
Division 2. Hospitals, sanitariums, orphanages, nurseries, homes for the
aged and similar buildings, with sleeping accommodations for ten or more
persons.
(b) Buildings or parts of buildings classified for occupancy in Group T>
shall be limited as to type of construction, height and area of units, as follows : —
Type of Construction.
Stories.
Maximum Area of Unit (Square Feet)
I
Not hereby limited.
4
1
2
1
2
1
Not allowed.
1
Not hereby limited.
II
17,000
Ill
20,000
12,000
IV
18,000
10,000
V
15,000
VI
2,500
The maximum area may be increased proportionately within the limits
given as the number of stories is decreased from the maximum.
(c) Division 1 buildings of Group D shall be of Type I construction
throughout. The ceilings and partitions of Division 2 buildings of Group D
(55)
Sees. 601-605
more than one story in height shall be of not less than one-hour fire-resistive
construction and the first floor of such buildings more than two stories in
height shall be of Type I construction.
(d) The provisions of this section and of Part 16 shall not be held to pro-
hibit cell block mezzanine floor construction of unprotected metal without
limitation as to number and area of such floors provided the entire cell block
construction is of incombustible materials.
[ *As amended by Ord. 1943, ch. 3 ]
Sect. 602. Separation of Occupancies. — Group D occupancies shall
be separated from other occupancies, and fire divisions of Group D occupancy
shall be separated from adjoining fire divisions as specified in Part 13.
Sect. 603. Exterior Walls. — (a) Exterior walls or parts of walls,
except where fronting on a street, which are less than five feet from a property
line, shall be of four-hour fire-resistive construction without openings, except
that openings in such walls at the ends of courts shall be allowed when pro-
tected by Class B fire doors or fire windows. Such walls or parts of walls
which are five feet or more, but less than ten feet from a property line shall be
of at least two-hour fire-resistive construction and all openings therein shall be
protected by Class B fire doors or fire windows.
(b) Every portion of an exterior wall which faces, at a distance of less than
twenty feet, the further side of a street, or a combustible wall or roof, or an
unprotected opening in a wall or roof of another building on the same lot,
shall be of at least two-hour fire-resistive construction, and all openings in such
portions shall be protected by Class B fire doors or fire windows.
(c) The commissioner may waive the requirements of this section, for
protection or prohibition of openings in walls, temporarily pending con-
struction on an adjoining lot or across a street, provided the owner agrees in
a writing recorded in the registry of deeds for Suffolk county to comply
with the said requirements on demand of the commissioner.
(d) In buildings of Type V construction exterior walls of unprotected
metal may be considered to meet the requirements of this section for two-
hour walls.
Sect. 604. Enclosure of Vertical Openings. — (a) Elevator shafts,
ventilating shafts and other vertical openings, except stairways and ramps,
shall be enclosed.
(b) Stairways and ramps which pierce only one floor shall be enclosed
in the story above or below but such a stairway or ramp which serves as
required exit from one story shall be enclosed in the other story. Other
stairways and ramps shall be enclosed in all stories in which they occur.
(c) This section and Part 15 shall not be held to require enclosure of
mezzanine floors in Group D buildings nor of vertical openings in such
floors, nor of cell block floors if such cell blocks are constructed entirely of
incombustible materials.
fSect. 605. Exits. — (a) Every portion of a building shall be provided
with exits as specified in Part 18.
(56)
Sees. 605=609
(b) In buildings of Division 2 exits from a story, as specified in Part 18,
shall be so located that no bed shall be more than seventy feet distant from
at least one such exit measured along the path of exit.
(c) In buildings of Division 2 exit doorways from patients' rooms shall
be not less than forty-two inches wide. In such buildings corridors, stair-
ways, ramps, doorways in stair or ramp enclosures and doorways from the
building, which serve as required exits, shall be not less than sixty inches
wide. In such stairways the tread shall not be less than eleven inches nor
the rise more than six and one half inches; stair landings at turns shall be
not less than sixty inches wide.
(d) Except in places of detention, exit doors shall not be fastened against
egress except by self-releasing latches, panic-bolts or similar devices which
can readily be opened from the inside at all times without the use of keys
or anj'- special knowledge or effort. Revolving doors shall not be installed
in required exit doorways from buildings of Group D occupancy
[ fAs amended by Ord. 1948, ch. 8 ]
{Sect. 606. Light and Ventilation. — Rooms ordinarily occupied by
human beings shall be provided with light by means of windows in exterior
walls or skylights in roofs, the area of which shall not be less than one-eighth
of the floor area, and the same shall be ventilated by windows in exterior
walls the area of which when open shall not be less than one-sixteenth of the
floor area of the room, or by mechanically operated ventilating system sup-
plying at least fifteen cubic feet of fresh air per minute per occupant or
four complete changes of air each hour, whichever is greater. Rooms accom-
modating a bed shall be provided with light and ventilation by means of
windows in exterior walls, the area of which shall not be less than one-eighth
of the floor area for light and when opened for ventilation not less than
one-sixteenth of the floor area.
[ JAs amended by Ord. 1948, ch. 8 ]
Sect. 607. Fire-Extinguishing Apparatus. — (a) All cellars, base-
ments and shafts shall be protected by automatic sprinklers. Store rooms,
kitchens and utility rooms in buildings of other than Type I or Type II
construction shall be protected by automatic sprinklers.
(b) In all buildings either portable fire extinguishers, not less than one
for every twenty-five hundred square feet of floor area and at least one in
each story, or first aid standpipes shall be provided.
(c) Fire department standpipes and first aid standpipes shall be provided
in buildings more than seventy feet high.
Sect. 608. Special Requirements. — (a) Every gas service shall have
a shut-off easily accessible from the outside and conspicuously marked.
(b) Every boiler room or room containing heating apparatus shall be
separated from the rest of the building with a three-hour fire separation, as
specified in Part 13.
Sect. 609. Exceptions. — No requirement of this chapter shall be so
construed as to prohibit the construction of cells in jails or prevent the use
of locks or safety devices in buildings where it is necessary forcibly to restrain
the inmates.
(57)
Sec. 610
♦Sect. 610. Emergency Lights. — There shall be emergency lights and
they 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 per cent 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 per
cent of the nominal lamp voltage. The emergency source of current shall be
either: —
(1) A separate feeder of the service company other than that from
which the normal service is taken, or
(2) A separate feeder from a reliable generating plant independent of
that from which the normal service is taken, or
(3) An approved storage battery, or
(4) Illuminating gas.
[ *As amended by Ord. 1943, ch. 8 and 9 ]
(58)
Sec. 701
PART 7.
SPECIAL REQUIREMENTS FOR GROUP E OCCUPANCY;
COMMERCIAL BUILDINGS OF HAZARDOUS OC-
CUPANCY.
Section
701 — Group E Occupancy: Type, Height, Area.
702 — Separation of Occupancies.
703 — Exterior Walls.
704 — Enclosure of Vertical Openings.
705 — Exits.
706 — Light and Ventilation.
707 — Fire-Extinguishing Apparatus.
708 — Special Hazards.
♦Section 701. Group E Occupancy: Type, Height, Area. — (a) Group
E shall include such occupancies as —
Division 1. Planing mills, box factories, wood working plants, mattress
factories, paint shops and dry cleaning plants.
Division 2. Buildings for the storage of hazardous, highly flammable or
explosive material.
(b) Buildings or parts of buildings classified for occupancy in Group
E shall be limited as to type of construction, height and area of units, as
follows : —
Type of
Construction.
Height
Stories.
Maximum Area of Unit in Square Feet.
Accessibility from Outside Walls.
25%
or less.
More than
25% to 50%.
More than
50% to 75%.
More than
75%.
I..
II.
Ill
IV.
v..
VI.
15
10,000
4
8,000
4
8,000
3
1
4,000
6,000
1
6,000
1
3,000
15,000
10,000
10,000
6,000
8,000
8,000
4,000
20,000
12,000
12,000
8,000
10,000
10,000
5,000
25,000
14,000
14,000
10,000
12,000
12,000
6,000
The maximum area of Type IV units may be increased proportionately
within the limits given as the number of stories is decreased from the maximum.
(c) The limitations upon area of the foregoing table shall not apply to
buildings one story high of Division 1, of Type I construction, the units of
which may have areas not in excess of fifteen thousand, twenty thousand and
twenty-five thousand square feet, if accessible from one, two or three sides,
respectively.
[ *As amended by Ord. 1943, ch. S ]
(59)
Sees. 702-706
Sect. 702. Separation of Occupancies. — Group E occupancies shall
be separated from other occupancies, and fire divisions of Group E occupancy-
shall be separated from adjoining fire divisions as specified in Part 13. Two
tenants shall be separated by partitions of at least one-hour and, in a basement,
at least two-hour fire-resistive rating.
Sect. 703. Exterior Walls. — (a) Exterior walls or parts of walls,
except where fronting on a street, which are less than five feet from a property
line, shall be of four-hour fire-resistive construction without openings, except
that openings in such walls at the ends of courts shall be allowed when pro-
tected by Class B fire doors or fire windows. Such walls or parts of walls
which are five feet or more, but less than ten feet from a property line, shall
be of at least two-hour fire-resistive construction and all openings therein
shall be protected by Class B fire doors or fire windows.
(b) Every portion of an exterior wall which faces, at a distance of less than
twenty feet, the further side of a street, or a combustible wall or roof, or an
unprotected opening in a wall or roof of another building on the same lot,
shall be of at least two-hour fire-resistive construction, and all openings in
such portions shall be protected by Class B fire doors or fire windows.
(c) The Commissioner may waive the requirements of this section, for
protection or prohibition of openings in walls, temporarily pending construc-
tion on an adjoining lot or across a street, provided the owner agrees in a
writing recorded in the registry of deeds for Suffolk county to comply with
the said requirements on demand of the commissioner.
(d) In buildings of Type V construction exterior walls of unprotected
metal may be considered to meet the requirements of this section for two-hour
walls.
*Sect. 704. Enclosure of Vertical Openings. — (a) Elevator shafts,
ventilating shafts and other vertical openings except stairways and ramps
shall be enclosed.
(b) Mezzanine floors shall be enclosed when otherwise the total floor area
in one story exposed to a single fire would exceed the maximum area of unit
specified in section seven hundred and one. Vertical openings in enclosed
mezzazine floors shall be enclosed as herein provided for other floors.
(c) Stairways and ramps which pierce only one floor, shall be enclosed in
the story above or below but such stairways or ramps, which serve as required
exits from one story, shall be enclosed in the other story. Other stairways
shall be enclosed in all stories in which they occur.
[ *As amended by Ord. 1943, ch. 8 ]
Sect. 705. Exits. — (a) Every portion of a building shall be provided
with exits as specified in Part 18.
(b) Exits from every story shall be so located that no point within the
story shall be further than one hundred feet from the nearest exit.
(c) Doorways serving as exits from rooms into a stair or ramp enclosures
shall have one-way swinging self-closing doors opening in the direction of
egress.
fSect. 706. Light and Ventilation. — Rooms used by human beings
shall be provided with light and ventilation by means of windows or skylights
or with artificial light and a ventilating system.
[ fils amended by Ord. 1943, ch. 8 ]
(60)
Sees. 707-708
*Sect. 707. Fire-Extinguishing Apparatus. — (a) Automatic sprin-
klers or other adequate fire-extinguishing apparatus as approved by the com-
missioner shall be installed in the following locations: —
(1) Throughout every unit of occupancy higher than two stories or
having an aggregate floor area greater than ten thousand square feet.
(2) In cellars and basements of which the floor area is more than fifteen
hundred square feet.
(3) Throughout a building which is occupied wholly or in part as a
planing mill, box factory, or other wood working establishment, in which
more than two power-operated wood working machines, other than saws,
are used.
(4) Throughout a building which is occupied wholly or in part as a
mattress factory or used to manufacture, assemble or renovate mattresses
or stuffed furniture using cotton, silk floss, mohair or other like material
for packing or stuffing.
(5) In a building used as a film exchange, or for the manufacture or
storage of nitro-cellulose pyroxylin products.
(b) Portable fire-extinguishers, not less than one for every two thousand
square feet of floor area and at least one in each story, or first aid standpipes
shall be provided, except as required by chapter one hundred and forty-eight
of the General Laws and regulations issued thereunder.
(c) Fire department standpipes and first aid standpipes shall be provided
in every building more than seventy feet high.
[ *As amended by Ord. 1943, ch. 3 ]
fSect. 708. Special Hazards. — (a) Neither apparatus having an
open flame nor a heater with an enclosed flame shall be installed or operated
in a dry cleaning establishment or place where volatile flammable liquids
are used or stored, unless approved by the state fire marshal.
(b) Rooms in which volatile flammable liquids are used or stored shall be
enclosed with partitions of not less than one-hour fire-resistive construction
as specified in Part 22. Doorways in such partitions shall have Class C fire
doors so equipped as to close automatically in case of fire.
(c) In a dry cleaning establishment each machine which uses a volatile
flammable liquid shall have an adequate steam line directly connected to it,
so arranged as automatically to fill the machine with steam in case of fire
or explosion therein.
(d) In dry cleaning establishments and other buildings in which volatile
flammable liquids are used, sold or stored;
(1) Type VI construction shall not be used;
(2) Type IV construction shall not be used more than two stories in
height or over six hundred square feet in area.
(e) Rooms in which paint, petroleum or other flammable liquids are used
or stored otherwise than in unopened containers shall have non-absorbent,
iucombustible floor finish.
[ ^As amended by Ord. 1943, ch. 3 ]
(61)
Sec. 801
PART 8.
SPECIAL REQUIREMENTS FOR GROUP F OCCUPANCY;
OFFICES AND COMMERCIAL BUILDINGS.
Section
801 — Group F Occupancy: Type, Height, Area.
802 — Separation of Occupancies.
803 — Exterior Walls.
804 — Enclosure of Vertical Openings.
805 — Exits.
806 — Light and Ventilation.
807 — Fire=Extinguishing Apparatus.
♦Section 801. Group F Occupancy: Type, Height, Area. — (a)
Group F shall include such occupancies as —
Division 1 . Office buildings, restaurants, police and fire stations, museums
and libraries.
Division 2. Wholesale and retail stores, printing plants, factories and
work shops using materials not highly flammable.
Division 3. Buildings for the storage or sale of goods not highly flam-
mable, stables and buildings not on wharves for the storing or handling of
transient freight.
Division 4. Wharf buildings for the storage or handling of transient
freight.
Division 5. Garages of more than six cars capacity and hangars.
(b) Buildings or parts of buildings classified for occupancy in Group F
except those in Division 4 thereof, shall be limited as to type of construction,
height and area of units, as follows : —
Type of
Construction
Height in
Stories.
Maximum Area of Unit in Square Feet Accessible From
Minimum within
block Less than 30%.
30% and less than
50% of perimeter.
More than 50%
of perimeter.
I..
II.
Ill
IV.
V..
VI.
10,000
15,000
10,000
15,000
10,000
15,000
6,000
6,000
3,000
Not hereby limited.
15,000
15,000
15,000
15,000
15,000
15,000
8,000
8,000
5,000
40,000
Not hereby limited.
20,000
Not hereby limited.
20,000
Not hereby limited.
10,000
20,000
10,000
Note. — Where areas in 1 story buildings are not hereby limited, the maximum distance
from any point to an exit from the building shall be 175 lineal feet.
In garages over six cars Type VI shall not be allowed.
(62)
Sees. 801-803
The maximum area of Type IV units may be increased proportionately
within the limits given as the number of stories is decreased from the
maximum.
(c) The portions of police stations in which not more than ten persons
may be detained shall be constructed of incombustible materials and shall
be separated from the remainder of the building, if of combustible materials,
by a two-hour fire-resistive separation.
(d) Buildings on wharves, used for storage other than that which is
incidental to handling water-borne freight, or used for manufacturing or any
purpose other than such handling, shall be classified in an occupancy group
according to such use, disregarding their location on wharves. Buildings
on wharves of pile or other open construction over water, or of filled construc-
tion behind retaining walls or bulkheads, beside docks wherein vessels may
be moored, used for handling, namely for assembling, loading, discharging
and sorting water-borne freight, or for passengers, and of the several types
of construction shall not exceed in height and area of units of occupancy the
following limits: —
Type of Construction.
Stories.
Maximum Area of Unit (Square Feet).
I
Not hereby limited.
3 to 7
2
3 to 4
2
3
2
2
Not hereby limited.
15,000
II
Ill
120,000
12,000
IV
60,000
10,000
V
60,000
60 000
(e) In buildings on wooden wharves, such units of occupancy shall not
exceed twenty thousand square feet in area.
(f) The maximum areas provided in this section for buildings of Division 1,
and for buildings of Divisions 2 and 3 less than six stories in height, may be
increased fifty per cent if the entire floor area is protected with automatic
sprinklers.
[ *As amended by Ord. 1943, ch. 8 ]
Sect. 802. Separation of Occupancies. — Group F occupancies shall be
separated from other occupancies, and fire divisions of Group F occupancy
shall be separated from adjoining fire divisions as specified in Part 13. Two
tenants shall be separated by partitions of at least one-hour and, in a base-
ment, at least two-hour fire-resistive rating.
Sect. 803. Exterior Walls. — (a) Exterior walls or parts of walls,
except where fronting on a street, which are less than ten feet from a property
line, shall be of at least two-hour fire-resistive construction and all openings
therein shall be protected by Class B fire doors or fire windows.
(63)
Sees. 803-805
(b) Every portion of an exterior wall which faces, at a distance of less than
twenty feet, the further side of a street, or a combustible wall or roof, or an
unprotected opening in a wall or roof of another building on the same lot, shall
be of at least two-hour fire-resistive construction, and all openings in such
portions, except doorways and windows in the first story fronting on a public
way, shall be protected by Class B fire doors or fire windows.
(c) The commissioner may waive the requirements of this section, for pro-
tection of openings in walls, temporarily pending construction on an adjoining
lot or across a street, provided the owner agrees in a writing recorded in the
registry of deeds for Suffolk county to comply with the said requirements od
demand of the commissioner.
(d) In buildings of Type V construction exterior walls of unprotected
metal may be considered to meet the requirements of this section for two-hour
walls.
♦Sect. 804. Enclosure of Vertical Openings. — (a) Elevator shafts,
ventilating shafts and other vertical openings except stairways and ramps,
shall be enclosed.
(b) Ramps for the movement of freight shall be enclosed as specified in
Part 15 or shall be provided with automatic-closing Class A fire doors which
will serve as a fire stop between stories. A ramp with such doors shall not be
counted as a required exit.
(c) In buildings of Division 1 and in retail stores, stairways and ramps
other than for freight, serving only basements, first and second stories, need
not be enclosed. Exit stairways and ramps which pierce only one floor,
except as provided in the preceding sentence, shall be enclosed in the story
above or below. Other exit stairways and ramps shall be enclosed in all
stories in which they occur.
(d) This section shall not be held to require enclosure of mezzanine floors
nor of vertical openings in such floors. The provisions of this section shall not
apply to book stacks of incombustible material in libraries of Type I or Type
II construction.
(e) Ramps which are used for the movement of automobiles from one
story to another, or for a similar purpose, shall be enclosed or shall be provided
with automatic-closing, Class A fire doors which will serve as a fire stop
between stories. A ramp with such doors shall not be counted as a required
exit.
(f) Doors which are part of an automobile ramp enclosure may be kept
normally open but shall be so equipped as to close automatically in case of
fire.
(g) Mechanical stairways or mechanical conveyors and ramps may be
installed with manually operated closing devices satisfactory to the com--
missioner.
[ *As amended by Ord. 1948, ch. 3 ]
Sect. 805. Exits. — Every portion of a Group F building except library
book stacks three levels or less in height shall be provided with exits as
specified in Part 18.
(64)
Sees. 806-807
♦Sect. 806. Light and Ventilation. — Rooms used by human beings shall
be provided with light and ventilation by means of windows or skylights or
with artificial light and a ventilating system.
[ *As amended by Ord. 1948, ch. 8 ]
fSect. 807. Fire=Extinguishing Apparatus. — (a) Automatic sprin-
klers shall be installed in cellars and basements of which the floor area is more
than fifteen hundred square feet.
(b) Buildings of Divisions 2 and 3, six or more stories in height shall be
equipped throughout with automatic sprinklers.
(c) Buildings of Division 4 of Type III, Type IV or Type VI construction
or on wooden wharves, more than five thousand square feet in area of units,
and buildings of Type I, Type II or Type V construction on incombustible
wharves, more than twenty thousand square feet in area, shall be protected
by automatic sprinklers.
(d) In buildings more than two stories high either portable fire-extinguish-
ers, not less than one for every twenty-five hundred square feet of floor area
and at least one in each story, or first aid standpipes, shall be provided.
(e) Fire department standpipes and first aid standpipes shall be provided
in buildings more than seventy feet high.
(f) Garages shall have automatic sprinklers and other suitable fire-fighting
apparatus when floor area exceeds ten thousand square feet on any one floor
or if the height is five stories or more. Hangars shall have approved fire-
extinguishing apparatus.
[ fil* amended by Ord. 1948, ch. 8 ]
(65)
Sec. 901
PART 9.
SPECIAL REQUIREMENTS FOR GROUP Q OCCUPANCY:
COMMERCIAL BUILDINGS OF NON-HAZARDOUS
OCCUPANCY.
Section
901 — Group Q Occupancy: Type, Height, Area.
902 — Separation of Occupancies.
903 — Exterior Walls.
904 — Enclosure of Vertical Openings.
905 — Exits.
906 — Light and Ventilation.
907 — Fire-Extinguishing Apparatus.
♦Section 901. Group G Occupancy: Type, Height, Area. — (a)
Group G shall include such occupancies as —
Division 1. Ice, power and pumping plants, cold storage rooms and
plants, creameries, breweries and other similar buildings.
Division 2. Factories and workshops using incombustible and non-
explosive materials.
Division 3. Buildings for the storage or sale of incombustible and non-
explosive materials.
(b) Buildings or parts of buildings classified for occupancy in Group G
shall be limited as to type of construction, height and area of units, as follows: —
Height in
Stories.
Maximum Area of Unit in Square Feet Accessible From
Type of
Construction.
Minimum within
block Les8than30%.
30% and less than
50% of perimeter.
More than 50%
of perimeter.
I
8
2
1
4
2
1
3
2
1
2
1
2
Not herebv limited.
II
10,000
15,000
15,000
10,000
15,000
15,000
10,000
15,000
15,000
6,000
6,000
3,000
15,000
15,000
15,000
15,000
15,000
15,000
15,000
15,000
15,000
8,000
8,000
5,000
40,000
Ill
80,000
Not hereby limited.
20,000
IV
40,000
Not hereby limited.
20,000
V
30,000
Not hereby limited.
10,000
VI
20,000
10,000
Note. — Where areas in 1 story buildings are not hereby limited, the maximum distance
from any point to an exit from the building shall be 175 lineal feet.
The maximum area of Type IV units may be increased proportionately
within the limits given as the number of stories is decreased from the maximum.
[ *As amended by Ord. 1943, ch. S ]
(66)
Sees. 902-906
Sect. 902. Separation of Occupancies. — Group G occupancies shall
be separated from other occupancies, and fire divisions of Group G occupancy
shall be separated from adjoining fire divisions as specified in Part 13.
Sect. 903. Exterior Walls. — (a) Exterior walls or parts of walls,
except where fronting on a street, which are less than ten feet from a property
line, shall be of at least two-hour fire-resistive construction and all openings
therein shall be protected by Class B fire doors or fire windows.
(b) Every portion of an exterior wall which faces, at a distance of less
than twenty feet, the further side of a street, or a combustible wall or roof,
or an unprotected opening in a wall or roof of another building on the same
lot, shall be of at least two-hour fire-resistive construction, and all openings in
such portions shall be protected by Class B fire doors or fire windows.
(c) The commissioner may waive the requirements of this section, for
protection of openings in walls, temporarily pending construction on an
adjoining lot or across a street, provided the owner agrees in a writing recorded
in the registry of deeds for Suffolk county to comply with the said require-
ments on demand of the commissioner.
(d) In buildings of Type V construction exterior walls of unprotected
metal may be considered to meet the requirements of this section for two-
hour walls.
*Sect. 904. Enclosure of Vertical Openings. — (a) Elevator shafts,
ventilating shafts, and other vertical openings, except stairways and ramps
shall be enclosed.
(b) Ramps for the movement of freight shall be enclosed as specified
in Part 15 or shall be provided with automatic-closing Class A fire doors
which will serve as a fire stop between stories. A ramp with such doors
shall not be counted as a required exit.
(c) Stairways and ramps other than for freight which pierce only one
floor shall be enclosed in the story above or below but such stairways or
ramps which serve as required exits from one story shall be enclosed in the
other story. Other stairways and ramps shall be enclosed in all stories in
which they occur.
(d) This section shall not be held to require enclosure of mezzanine
floors nor of vertical openings in such floors.
(e) Doors which are part of an automobile ramp enclosure may be kept
normally open but shall be so equipped as to close automatically in case of fire.
(f) Mechanical stairways or mechanical conveyors and ramps may be
installed with manually operated closing devices satisfactory to the com-
missioner.
[ *As amended by Ord. 1948, ch. 3 ]
Sect. 905. Exits. — Every portion of a building shall be provided with
exits as specified in Part 18.
jSect. 906. Light and Ventilation. — Rooms used by human beings
shall be provided with light and ventilation by means of windows or skylights
or with artificial light and a ventilating system.
[ ]As amended by Ord. 1943. ch. 3 ]
(67)
Sec. 907
♦Sect. 907. Fire-Extinguishing Apparatus. — (a) Automatic sprin-
klers shall be installed in all cellars and basements, of Division 2 and 3, of
which the floor area is more than fifteen hundred square feet.
(b) Automatic sprinklers shall be installed throughout buildings of
Division 2 or 3, of Type IV construction more than seventy-five hundred
square feet in area.
(c) In buildings more than two stories high either portable fire-extin-
guishers not less than one for every thirty-five hundred square feet of floor
area and at least one in each story, or first aid standpipes shall be provided.
(d) Fire department standpipes and first aid standpipes shall be provided
in buildings more than seventy feet high.
[ *As amended by Ord. 1943, ch. 8 ]
(68)
Sec. 1001
PART 10.
SPECIAL REQUIREMENTS FOR GROUP H OCCUPANCY:
UNLIMITED HABITATIONS AND LARGE DWELL-
INGS.*
[ *As amended by Ord. 1943, ch. 3 ]
Section
1001 — Group H Occupancy: Type, Height, Area.
1002 — Separation of Occupancies.
1003 — Exterior Walls.
1004 — Enclosure of Vertical Openings.
1005 — Exits.
1006 — Light and Ventilation.
1007 — Rooms.
1008 — Fire-Extinguishing Apparatus.
1009 — Plumbing and Heating.
fSection 1001. Group H Occupancy: Type, Height, Area. — (a)
Group H shall include such occupancies as —
Division 1. Hotels, apartment hotels, dormitories, lodging houses,
convents, monasteries, and club houses, with sleeping accommodations for
ten or more persons, or for more than three families, or for more than two
families above the first story, and without kitchens in the individual apart-
ments.
Division 2. Apartment houses accommodating more than three families,
or more than two families above the first story, and with kitchens in the
individual apartments.
(b) Buildings or parts of buildings classified for occupancy in Group H
and of the several types of construction shall not exceed in height and area
of units of occupancy the following limits: —
Type of Construction.
Stories.
Maximum Area of Unit (Square Feet.)
I
Not hereby limited.
10
3
3
3
II
12,000
Ill
8,000
IV
6,000
VI
2,400
Type V construction shall not be used in buildings of Group H.
(c) Assembly halls in Group H buildings shall be classified in Group A
or Group B as the case may be, and shall conform to the requirements of this
code for the group in which they are so classified.
(69)
Sees. 1001-1005
(d) The first floor of buildings more than two thousand square feet in
area and more than three stories in height shall be of Type I or Type II
construction. The basement ceilings of other buildings shall be of at least
one-hour fire-resistive construction. All ceilings of buildings more than two
thousand square feet in area and three stories or more in height shall be of
at least one-hour fire-resistive construction.
(e) Partitions forming separations between adjoining apartments shall
be of not less than one-hour fire-resistive construction.
(f) Buildings of Type VI shall not be used for more than four families,
nor more than two families above the first story.
[ fAs amended by Ord. 1943, ch. 3 ]
Sect. 1002. Separation of Occupancies. — Group H occupancies shall
be separated from other occupancies, and fire divisions of Group H occupancy
shall be separated from adjoining fire divisions as specified in Part 13. A
garage of not more than six cars capacity shall be separated from a Group H
occupancy as specified in Part 12.
Sect. 1003. Exterior Walls. — (a) Exterior walls or parts of walls,
except where fronting on a street, which are less than ten feet from a property
line, shall be of at least two-hour fire-resistive construction and all openings
in such walls which are less than seven feet six inches from a property line
shall be protected by Class B fire doors or fire windows.
(b) Every portion of an exterior wall which faces, at a distance of less
than fifteen feet, the further side of a street, or a combustible wall or roof,
or an unprotected opening in a wall or roof of another building on the same
lot, shall be of at least two-hour fire-resistive construction, and all openings
in such portions shall be protected by Class B fire doors or fire windows.
(c) The commissioner may waive the requirements of this section, for
protection of openings in walls, temporarily pending construction on an
adjoining lot or across a street, provided the owner agrees in a writing recorded
in the registry of deeds for Suffolk county to comply with the said require-
ments on demand of the commissioner.
JSect. 1004. Enclosure of Vertical Openings. — (a) Vertical shafts
and floor openings, except as hereinafter mentioned, shall be enclosed.
(b) Except as otherwise noted herein, stairways and ramps shall be
enclosed in all stories in which they occur as specified in Part 15. Stairways
serving as exits from sleeping rooms shall be enclosed in all stories. Stairways
serving only basement rooms for the use of the public need not be enclosed.
Stairways serving only rooms for use of public in the basement, first and
second story need not be enclosed. Auxiliary stairway within an apartment
serving only two floors need not be enclosed.
(c) This section and Part 15 shall not be held to require enclosure of
mezzanine floors in Group H buildings nor of vertical openings in such floors.
[ %As amended by Ord. 1943, ch. 3 ]
*Sect. 1005. Exits. — (a) Every portion of a Group H building shall
be provided with exits as specified in Part 18.
(b) Every apartment of less than four rooms shall have at least one
exit opening upon a corridor which has at least two remote exits, or such
(70)
Sees. 1005-1006
apartment shall have two remote exits. Every apartment of four or more
rooms shall have at least two remote exits. Such exits may open into a
common corridor which has at least two remote exits.
(c) Every exit from an apartment shall not be more than fifty feet from
the nearest exit from the story.
(d) Corridors which serve as common exits from two or more apartments
shall have walls of at least one-hour fire-resistive construction. Corridors,
including their changes in directions and extensions beyond separations serv-
ing as required egress, shall be at least thirty-six inches wide. If more than
fifty feet and less than seventy-five feet in length they shall be at least forty-
eight inches wide. If seventy-five or more feet in length they shall be at
least sixty inches wide.
(e) Doors affording access from a stairway to a roof shall not be so locked
as to prevent egress to the roof in emergency.
(f) Every stairway and corridor common to two or more apartments
shall be adequately lighted at all times as determined by the building
commissioner.
[ *As amended by Ord. 1948, ch. 8 ]
fSect. 1006. Light and Ventilation. — (a) Kitchens having a floor
area more than seventy square feet and dining rooms, within apartments,
all sleeping rooms and living rooms shall be provided with light and venti-
lation by means of windows in the exterior walls. The area of windows in
kitchens shall not be less than one eighth of the floor area thereof, nor less
than eleven square feet. Windows in toilets or bathrooms shall not be less
than one eighth of the floor area thereof nor less than six square feet. Win-
dows shall be arranged to open for ventilation on not less than one half the
required area.
(b) Every window required by paragraph Ca) of this section shall front
upon a street, alley or open passageway not less than fifteen feet wide, or upon
a public park, cemetery, railroad right of way or other similar approved
open space, or upon a yard or court of the dimensions herein specified. A
court upon which such a window fronts shall be open to the sky and no cornice,
balcony, stairway, fire escape or other construction shall encroach upon
the required open area thereof herein specified. The height of a court shall
be measured from the sill of the lowest window required to front upon it.
The width and the horizontal area of such court shall not be less than as
provided in the following numbered paragraphs (1) to (5), inclusive.
(1) If the court is open at both opposite ends for its full width and full
height to a street, alley, park, or other permanently open space, not less
than fifteen feet wide, or to a yard, it shall be a through court. The least
width of such court shall be not less than six feet nor less than one tenth its
length from open end to open end measured along the center line and not
necessarily in a straight line. The width of such court at any level more
than fifty feet above the sill of the lowest window required to front upon
it shall be not less than six feet plus one eighth the excess of such height over
fifty feet, except a court the length of which is less than five times its least
width. If windows required by this section face a wall on the opposite
eide of a through court in which windows also required by this section
(71)
Sec. 1006
occur, the width of the court as determined by the foregoing requirements-
shall be increased by fifty per cent. The width of a through court need
not, however, exceed the width required in this section for an inner court
of the same height.
(2) If the court is open at one end for its full width and full height to a
street, alley, park, or other permanently open space not less than fifteen
feet wide, or to a yard, it shall be an outer court. The least width of such
court shall be not less than eight feet nor less than one fourth its horizontal
length measured along the center line, and not necessarily in a straight line.
The width of such court at any level more than fifty feet above the sill of the
lowest window required to front upon it shall be not less than eight feet
plus one eighth the excess of such height over fifty feet, except a court the
length of which is less than twice its least width. If windows required by
this section face a wall on the opposite side of an outer court in which
windows also required by this section occur, the width of the court as
determined by the foregoing requirements in this paragraph shall be in-
creased by fifty per cent. The width of an outer court need not, however,
exceed the width required in this section for an inner court of the same
height.
(3) Every court which is not open at one or both ends as provided for
an outer court or a through court shall be an inner court. The least width
of an inner court shall be not less than ten feet. The width of such court at
any level more than fifty feet above the sill of the lowest window required
to front upon it shall be not less than ten feet plus one eighth the excess of
such height over fifty feet. If windows required by this section face a wall
on the opposite side of an inner court in which windows also required by this
section occur, the width of the court as determined by the foregoing require-
ments in this paragraph shall be increased by fifty per cent. The horizontal
area of an inner court shall be not less than three hundred square feet nor less
above any floor level than sixty square feet for each story below said level
served by such court. Every inner court shall be provided with an intake
for fresh air, consisting of a court, corridor, passageway or ventilating
duct, of which the area of cross-section below the level of the top of the
lowest required window shall be not less than one fifteenth the maximum
required area of the court. Such intake or the required area thereof shall
be permanently open and unobstructed except for a grille or screen at least
eighty per cent open at one or both ends and shall extend from the court
to a street, alley, park, or other permanently open space, not less than
fifteen feet wide, or to a yard, above the level of the ground thereof.
(4) Windows required by paragraph (a) of this section may front Upon
an open recess from the street, alley, park, court; yard or other open space
from which they derive light and ventilation, provided the width of the
recess is not less than four feet nor less than its horizontal depth, and its
depth is not more than six feet. A recess from an inner court of width
less than the required width of the court of which it is a part shall be dis-
regarded in computing, for the purpose of this section, the area of the court.
(5) The length of outer courts T-shaped in plan shall be measured
from the open end to the end of each branch independently. A branch,
(72)
Sec. 1006
■open at only one end, of a through court, shall be considered to be a par
of an outer court of length measured from the nearest open end to the
.closed end of the branch, in determining the width of such branch. Where
a recess occurs at the closed end of an outer court the length of the court
shall include the depth of the recess. Adjoining courts which conform
independently to this section may be combined by omission of dividing
walls. An inner court between two sections of a through court may be
-disregarded in computing the length of the through court. Other arrange-
ments of courts shall be measured for the purposes of this section as deter-
mined by the commissioner with a view to providing for every required
window light and ventilation substantially as herein specified.
(6) Courts of exceptional form may be approved by the building
commissioner if in volume, lighting and ventilating properties they are in
his opinion the equivalent of the courts above described.
(c) Every kitchen having a floor area not more than seventy square feet
within an apartment and every room containing a water closet, shall be
provided with light and ventilation by means of a window, except as specified
in paragraph (d) of this section, in an exterior wall or in a ventilating shaft
or, if such room is immediately under a roof, by a skylight in the roof.
Such window or skylight shall have an area not less than three square feet
nor less than one tenth of the floor area of the room, and shall be arranged
to open for ventilation not less than three square feet nor less than one
twentieth the floor area of the room. Such windows shall front upon an
open space or a ventilating shaft of which the width shall be not less than
three feet and of which the horizontal area shall be not less than fifteen
square feet. If the height of such space or shaft above the sill of the lowest
window served is in excess of fifty feet, the width thereof shall be increased
one half foot and the area eight square feet for every ten feet or fraction of
such excess. If such ventilating shaft is covered, the covering shall be a
skylight with openings under the edges thereof on at least three sides equal
in the aggregate to at least twice the required area of the ventilating shaft.
(d) Rooms containing water closets need not have windows as specified
in paragraph (c) of this section if they are provided with adequate artificial
light and an approved system of mechanical ventilation which will com-
pletely exhaust the air in the room at least four times per hour. A kitchen
having a floor area not more than seventy square feet within an apartment
need not have windows if it is so provided with artificial light, and such
mechanical ventilation or ventilation by means of a ventilating exhaust
duct with at least one square foot net area of cross-section independent of
ducts from other rooms to a point above the roof. A kitchen ventilated as
provided in this paragraph or by a ventilating shaft shall have a permanent
opening of adequate size for fresh air which may, however, be drawn from
other rooms in the apartment.
(e) Dining rooms in hotels, dining rooms common to more than one
family, kitchens serving such dining rooms and other kitchens and rooms
for eating purposes except those within apartments, shall be provided with
light and ventilation as specified for kitchens and dining rooms respectively
(73)
Sees. 1006-1007
In paragraphs (a) and (b) of this section or shall have artificial light and an
approved system of mechanical ventilation providing not less than four
complete changes of air per hour.
(f) The boundary line of a lot on which a building is to be erected subject
to the provisions of this section, unless it is a common boundary between
such lot and a street, alley, public park, cemetery, railroad right of way or
other similar, permanently open space, not less than fifteen feet wide shall
be a boundary to an adjacent court or ventilating shaft required by this
section as though a wall without windows were erected on such line. If
there is, appurtenant to such lot, an easement for light and air over a portion
of an adjoining lot, in terms which assure that the easement will remain in
force and effect so long as any windows require it for light and ventilation
under the provisions of this code, and duly recorded in the registry of deeds
for Suffolk county, the portion subject to such easement may be considered
to be part of such lot for the purposes of this section. No building or
structure shall be erected in such manner as to reduce the light and ventila-
tion in a building on the same lot subject to the provisions of this section
below the requirements thereof, nor shall a lot line be moved by sale of
land or otherwise so as to permit such reduction by a building on an adjoining
lot.
(g) In a residence district, as defined in chapter four hundred and eighty-
eight of the acts of nineteen hundred and twenty-four, a building of Divi-
sion 2 upon a lot which abuts on only one street shall have a yard at the
rear. Such yard shall be open and unobstructed above the level of the sills
of windows opening thereon required by this section, shall extend the full
width of the lot, and shall have a depth, measured from the rear of the build-
ing to the rear line of the lot or, if an alley or open passageway lies at the
rear of the lot, to the middle line of such alley or passageway, not less than
twelve feet nor less than one fourth the height of the building above the
sill of the lowest window required to front upon such yard. If the rear line
of such lot is other than a straight line the required yard shall have an area
not less than twelve feet times the width of the lot at the rear of the building
and the building shall be so disposed at the rear as to leave a yard having
approved continuity with the yards of adjoining lots. The provisions of
this paragraph shall not apply to a lot which abuts at the rear upon a rail-
road right of way, cemetery, park or other permanently open space, not
less than fifteen feet wide. The Boston zoning law (chapter four hundred
and eighty-eight of the acts of nineteen hundred and twenty-four) also
contains provisions relative to yards.
(h) Every room containing a water closet compartment shall have
adequate means for lighting at all times.
[ fAs amended by Ord. 1948, ch. S ]
JSect. 1007. Rooms. — (a) In every apartment of an apartment
house or apartment hotel, at least one room shall have a floor area not less
than one hundred and twenty square feet. However, every kitchen in such
apartment shall be not less than six feet wide nor less than forty-eight square
feet in area. Every room containing a water closet shall be not less than
thirty-three inches wide and shall have a floor area not less than fifteen square
(74)
Sees. 1007-1009
feet. Every other room in such apartment, except closets and vestibules,
shall have not less than seventy square feet of floor area.
(b) Rooms in apartments, except closets, shall be at least eight feet high
in half their required area, an average of at least six feet high in the remainder
of the required area, and not less than four feet high at any point within
the required area.
(c) If the walls or floor of a sleeping room or living room are in contact
with the ground, the portions thereof in such contact shall be waterproofed
as specified in Part 29 or damp proofed in an approved manner, and the
interior finish of such portions of the walls of such rooms shall be furred
with impervious material. Not more than thirty per cent of the area of the
walls enclosing such a room shall be in contact with the ground
(d) The floor of every room containing a water closet shall be of tile,
terrazzo, linoleum or other impervious material with a base of similar ma-
terial around the walls at least four inches high. No water closet shall be
enclosed in woodwork placed close about the fixture. The walls of every
room containing a water closet shall extend to the ceiling.
[ %As amended by Ord. 1943, ch. 8 ]
♦Sect. 1008. Fire Extinguishing Apparatus. — (a) Automatic
sprinklers shall be installed in cellars, basements, workrooms, shops, store
rooms and kitchens, in buildings of Type I and Type II construction more
than six stories high, and in other buildings more than three stories high.
(b) First aid standpipes, as specified in Part 30, or portable extinguishers,
at least one for every twenty-five hundred square feet of floor area and at
least one in each story, shall be provided in buildings more than five thousand
square feet in area or more than six stories high.
(c) Fire department standpipes and first aid standpipes shall be installed
in buildings more than seventy feet high.
[ *As amended by Ord. 1948, ch. 8]
Sect. 1009. Plumbing and Heating. — (a) Every apartment in an
apartment house and every apartment of two or more rooms in an apartment
hotel shall have within it at least one room containing a water closet and
devoted exclusively to use as a bathroom or toilet room. One such room
shall be accessible from every sleeping room without passing through another
sleeping room. In every such apartment there shall be a lavatory or sink
with running water.
(b) Every apartment in a hotel and every apartment in an apartment
hotel not included in paragraph (a) of this section shall have within it at
least one room containing a water closet, as specified in paragraph (a) of this
section, or shall have access in common with other apartments to such a room
in the same story or in the next story above or below, by means of a common
corridor. Where the number of sleeping rooms without a water closet within
the apartment exceeds six in a story, separate toilet rooms for men and for
women shall be provided in the same story, plainly marked, and shall con-
tain one water closet for every nine sleeping rooms or fraction of nine. Com-
(75)
Sec. 1009
mon bathrooms shall have means for securely locking the door on the inside*
Every such room shall contain at least one lavatory or sink with running
water.
(c) In every apartment of an apartment house or apartment hotel which
is not adequately heated from a central heating plant, at least one room
with a floor area not less than one hundred and twenty square feet shall have
a chimney, as specified in Part 21, with a separate flue not less than eight
inches in diameter, or a common flue not less than twelve inches in diameter,
with a thimble at least six inches in diameter about six feet above the floor.
(d) In buildings more than three stories high, every boiler room or room
containing a central heating plant shall be separated from the rest of the
building by at least a two-hour separation as specified in Part 13.
(76)
Sees. 1101-1102
PART 11.
SPECIAL REQUIREMENTS FOR GROUP I OCCUPANCY t
LIMITED HABITATIONS AND SMALL DWELLINGS,*
[ *As amended by Ord. 1943, ch. 8 ]
Section
1101 — Group I Occupancy: Type, Height, Area.
1 102 — Separation of Occupancies.
1103 — Exterior Walls.
1104 — Enclosure of Vertical Openings,
1105 — Exits.
1 106 — Light and Ventilation.
1 107 — Fire-Extinguishing Apparatus.
fSection 1101. Group I Occupancy: Type, Height, Area. — (a)
Group I shall include such occupancies as —
Division I. Dwellings accommodating not more than three families, nor
more than two families above the first story.
Division 2. Dormitories, lodging houses, clubs, convents and monasteries,
with sleeping accommodations for less than ten persons.
(b) Buildings or parts of buildings classified for occupancy m Group I
shall be limited as to type of construction, height and area of units, as
follows: —
Type of Construction.
Stories.
Maximum Area of Unit (Square Feet).
I
Not hereby limited.
5
3
3
3
II
12,000
Ill
8,000
IV
6,000
VI
5,000
(c) The basement or cellar ceiling of all Group I buildings, more than
three stories in height, shall be of not less than one-hour fire-resistive con-
struction. Boiler rooms in Type IV and Type VI construction with more
than one family above the first story shall be separated by walls and ceilings
of not less than one-hour separation with any openings in the separation to be
Class B fire doors and windows.
[ ]As amended by Ord. 1943, ch. 3 ]
Sect. 1102. Separation of Occupancies. — Group I occupancies shall
be separated from other occupancies, and fire divisions of Group I occupancy
shall be separated from adjoining fire divisions as specified in Part 13. A
garage of not more than six cars capacity may be constructed as part of a
Group I building as specified in Part 12.
(77)
Sees. 1103-1107
Sect. 1103. Exterior Walls. — (a) Exterior walls or parts of walls,
except where fronting on a street, which are less than five feet from a property
line shall be of at least two-hour fire-resistive construction and all openings
therein shall be protected by Class B fire doors or fire windows.
I *As amended by Ord. 1943, ch. 3 ]
fSect. 1104. Enclosure of Vertical Openings. — (a) Elevator shafts,
ventilating shafts and other vertical openings, including stairways, except
stairway in a single family occupancy, shall be enclosed.
(b) Where two or more stairways are required as exits at least one shall
be^enclosed in all stories in which it occurs. Stairways which pierce more than
three floors shall be enclosed.
(c) In stairway enclosures not more than three stories high, the doors in
stories other than the basement or cellar need not be fire doors if they are of
wood not less than one and one half inches thick.
[ f As amended by Ord. 1943. ch. 3 ]
JSect. 1105. Exits. — Group I buildings more than three stories in height,
and Group I buildings in which the area of any floor, except the first floor,
exceeds fifteen hundred square feet, shall have at least two stairways or
ramps, one of which shall be interior and enclosed, and every Group I build-
ing where each dwelling does not have its own stairway within its own apart-
ment shall have two stairways, one of which shall be enclosed. A single
family house may have one stairway if it is less than three stories in height.
[ %As amended by Ord. 1943, ch. 3 and Ord. 1954, ch. 7 ]
§Sect. 1106. Light and Ventilation. — (a) Rooms of Group I build-
ings used for eating, living or sleeping purposes, shall be provided with light
and ventilation by means of windows. The space on which such windows
shall open shall not be less than as specified in Part 10 for similar windows in
Group H buildings.
(b) Kitchens and rooms containing water closets shall be lighted and
ventilated as provided for similar rooms of Group H buildings in Part 10.
[ §As amended by Ord. 1943, ch. 3 ]
||Sect. 1107. Fire-Extinguishing Apparatus. — (a) Automatic sprin-
klers shall be installed in cellars, basements, workrooms, shops, storerooms and
kitchens other than in apartments, in buildings more than six stories high.
(b) First aid standpipes, as specified in Part 30, or portable fire-extin-
guishers, at least one for every twenty-five hundred square feet of floor area,
and at least one in each story shall be provided in Group I buildings more than
five thousand square feet in area or more than six stories high.
(c) Fire department standpipes and first aid standpipes shall be installed
in buildings more than seventy feet high.
(d) This section shall not apply to buildings of Division 1, referred to in
section eleven hundred and one.
[ || As amended by Ord. 1943, ch. 3 ]
(78)
Sec. 1201
PART 12.
SPECIAL REQUIREMENTS FOR GROUP J OCCUPANCY t
MISCELLANEOUS STRUCTURES.
Section
1201 — Group J Occupancies: Type, Height, Area.
1202 — Separation of Occupancies.
1203 — Exterior Walls.
1204 — Exits.
1205 — Aisles and Seating.
1206 — Light and Ventilation.
1207 — Fire-Extinguishing Apparatus.
1208 — Floor Finish.
♦Section 1201. Group J Occupancies: Type, Height, Area. — (a)
Group J shall include such occupancies as —
Division 1. Garages for six cars or less.
Division 2. Tanks, towers, advertising signs and similar structures.
Division 3. Amusement park structures, reviewing stands, grand stands
and similar structures.
(b) Garages for six cars or less, not exceeding two stories in height nor
thirteen hundred square feet in floor area, may be of any type of construction
except Type VI. Garages, for three cars or less, one story in height and not
exceeding six hundred and fifty square feet in area, may be of Type VI
construction.
(c) Structures of Division 2, erected on the roof or on the facade of a
building in the first or second fire zone, shall be constructed with incom-
bustible materials, except water tanks, flag poles, isolated signs flat against
an exterior wall not more than twenty square feet in area, and isolated signs
projecting from an exterior wall; provided, that such projecting signs have a
frame of incombustible material, that the combustible material in such pro-
jecting signs is no more combustible than wood, that no part of such combus-
tible material is nearer an exterior wall than fifteen inches, and that the surface
area of such combustible material is not more than thirty-five square feet on
any face and not more than seventy square feet in the aggregate, except that
the surface area of such combustible material, if the nearest point thereof is
eighteen or more inches from all exterior walls, may be more than thirty-five
square feet on a face and more than seventy square feet in the aggregate if
the building commissioner certifies on the application for the permit to erect
such sign that in his opinion the spread of fire therefrom is no more likely
than from a projecting sign having an incombustible frame and two wooden
faces each thirty-five square feet in area the nearest point of which wood is
fifteen inches from the nearest exterior wall.
(d) Reviewing stands and grand stands may be constructed of masonry,
reinforced concrete, steel or wood or any combination thereof. When con-
structed, except for the seats, of incombustible materials, the size shall not
(79)
Sees. 1201=1202
hereby be limited. When the structure below the deck is constructed of
incombustible material, and the decking is of wood or other combustible
material, the horizontal distance from front to back shall not exceed one
hundred feet. When the entire structure is constructed of wood or other
combustible material, the horizontal distance from front to back shall not
exceed fifty feet.
(e) Amusement park structures of the open or skeleton framed type
may be constructed of any type of construction and are not hereby limited in
height and area.
(f) Amusement park structures of the enclosed type, shall be limited as
to type of construction, height and area of units, as follows: —
Type of Conbtbttction
(g) Amusement park structures of enclosed type used as places of assembly
shall be classified in Group A or Group B in accordance with the definitions
thereof.
(h) The maximum areas provided in this section may be increased fifty
per cent if the entire floor area is protected by automatic sprinklers.
[ *As amended by Ord. 1948, ch. 3 and Ord. 1950, ch. 6 J
Sect. 1202. Separation of Occupancies. — (a) When a garage of
size and arrangement to accommodate not more than two cars is constructed
as part of a Group H or Group I building, the walls and ceilings of the garage
shall be of not less than one-hour fire-resistive construction. When a garage
to accommodate more than two but not more than six cars is constructed as
part of a Group H or Group I building, the walls and ceiling of the garage
shall be of not less than three-hour fire-resistive construction. Openings in
such walls shall bo protected by Class B fire doors or by fire windows. A
garage to accommodate not more than six cars shall be separated from other
occupancies and from adjoining fire divisions as specified in Part 13.
(b) In a separation between a garage of Group J occupancy and another
occupancy there shall not be more than one opening, and the sill thereof
shall be raised one foot above the garage floor. There shall be no opening
from a garage directly into a living room, sleeping room or kitchen.
(80)
Sees. 1203-1208
Sect. 1203. Exterior Walls. — Exterior walls or parts of walls, of Group J
structures, except where fronting on a street, which are less than five feet
from a property line or less than ten feet from another building on the same
lot, shall be of not less than one-hour fire-resistive construction and all open-
ings therein shall be protected by Class B fire doors or fire windows, and such
walls which are less than three feet from a property line or less than six feet
from another building on the same lot, shall be of at least two-hour fire-resistive
construction and all openings therein shall be protected by Class B fire doors
or fire windows, except that in garages for three cars or less of Type V con-
struction, such walls may be of unprotected metal.
Sect. 1204. Exits. — (a) Reviewing stands, grand stands and similar
structures shall be provided with exits not less than four feet wide nor less
than one foot in width for each three hundred persons or fraction thereof
served. Exits shall have not less than seven feet in clear height nor be more
than sixty feet apart.
(b) Where the space under a grand stand, reviewing stand or similar
structure is used for any purpose other than ingress and egress, the required
exits through this space shall be enclosed by walls, floors, and ceilings of
not less than one-hour fire-resistive construction.
(c) Amusement park structures, other than grand stands or similar
structures, of either open or enclosed type shall be provided with exits as
required for Group B occupancy in Part 4.
Sect. 1205. Aisles and Seating. — Reviewing stands, grand stands
and similar structures having more than twenty rows of seats shall have
transverse aisles not over sixty feet apart leading to exits. Transverse
aisles shall have a clear width not less than thirty inches nor less than one
foot for every three hundred persons or fraction thereof served. Where
separate seats are not provided or marked off, a width of eighteen inches
shall be considered one seat in computing the required width of aisles and
exits.
♦Sect. 1206. Light and Ventilation. — Amusement park structures
shall be provided with light and ventilation sufficient to avoid dangerous or
unhealthful conditions as may be required by the commissioner. They shall
be lighted by artificial light sufficiently for safe egress.
[ *As amended by Ord. 1943, ch. 3 ]
Sect. 1207. Fire-Extinguishing Apparatus. — Fire-extinguishing ap-
paratus shall be provided in buildings and structures of Group J where
the fire hazard, in the judgment of the commissioner, is commensurate with
that for which such apparatus is specified in buildings of other groups.
Sect. 1208. Floor Finish. — Garages shall have non-absorbent incom-
bustible floor finish.
(81)
Sec. 1301
PART 13.
SEPARATION OF OCCUPANCIES.
Section
1301 — Multiple Occupancies.
1302 — Separations.
♦Section 1301. Multiple Occupancies. — (a) A [fire division, whether
occupying the whole or a part of a building, shall be limited as to type of
construction, height and area as provided in Parts 3 to 12, inclusive, according
to its principal occupancy.
(b) Adjoining fire divisions in a building shall be separated by a separation
at least as fire-resistive as required by Table A, section thirteen hundred and
two.
(c) A fire division may contain two or more units of different occupancies,
and every such unit shall be limited as to height above the ground and as to
area as provided in Parts 3 to 12, inclusive, according to its occupancy and
the type of construction of the building.
(d) Adjoining units of different occupancy in a fire division shall be
separated by a separation at least as fire-resistive as specified in Table A,
section thirteen hundred and two. Space within a unit of occupancy used
for a purpose or process customarily incidental to that occupancy and under
the same management and control shall not be considered a separate unit
of occupancy unless the floor area of such space exceeds one tenth the area
of the fire division in which it is located; but garage use shall not so be con-
sidered incidental.
(e) Every unit of occupancy shall conform to the provisions of Parts 3
to 12 of this code for the group and division in which it is classified.
(f) Two adjoining fire divisions may be of different types of construction
subject to the following limitations:
(1) Construction required to be of Type I shall not be supported
wholly or in part by construction of any other type.
(2) Construction required to be of Type II shall not be supported by
construction other than of Type I or Type II.
(3) Construction required to be of Type III shall not be supported by
construction other than of Type I, Type II or Type III.
(4) Construction required to be of Type IV shall not be supported by
construction other than of Type I, Type II, Type III or Type IV.
(5) Construction required to be of Type V shall not be supported by
construction other than of Type I, Type II or Type V.
(82)
Sees. 1301=1302
(6) Construction required to be of Type VI shall not be supported by
construction other than of Type I, Type II, Type III, Type IV or Type VI.
(g) Separations, as specified in this code, may be vertical, horizontal,
or inclined, depending upon the relative position of the portions of the building
to be separated, and shall consist of a system of walls, partitions, floors or
other construction of such materials and construction and so arranged as to
provide a complete, secure and continuous fire-break of the required fire-
resistive rating between the portions of the building separated.
(h) A building more than three stories high used on first floor or basement,
for commercial use and adapted for more than two families above the first
floor shall be equipped with automatic sprinklers throughout that portion
used for commercial use when, in the judgment of the commissioner, public
safety demands such protection.
[ *As amended by Ord. 1943, ch. 4 ]
fSect. 1302. Separations. — (a) Separations between units of occu-
pancy within a fire division and between fire divisions of a building shall be
classified, each classification being designated in Table A of this section by
the letter or figure symbol set against it, having the following significance:
A — means absolute separation.
4 — means four-hour separation.
3 — means three-hour separation.
2 — means two-hour separation.
1 — means one-hour separation.
N — means no separation required.
(b) An absolute separation shall provide in all its parts effective fire-
resistance of not less than four-hour rating as specified in Part 22 and shall
have no openings.
(c) A four-hour separation shall provide effective fire-resistance of not
less than four-hour rating as specified in Part 22. Openings in the walls
of such separations shall be protected on each side thereof by automatic-
closing Class A fire doors as specified in Part 22. The sum of the areas of
such openings in one story shall not exceed one third the area of the separating
wall and no single opening shall have a greater area than one hundred square
feet.
(d) A three-hour separation shall provide effective fire-resistance of not
less than three-hour rating as specified in Part 22. Openings in the walls
of such separations shall be protected on each side thereof by automatic-
closing Class B fire doors as specified in Part 22. The sum of the areas of
such openings in one story shall not exceed one third the area of the separsaing
wall and no single opening shall have a greater area than two hundred square
feet.
(e) A two-hour separation shall provide effective fire-resistance of not
less than two-hour rating as specified in Part 22. Openings in the walls of
such separations shall be protected on one side thereof by automatic-closing
Class A fire doors as specified in Part 22. The sum of the areas of such
(83)
Sec. 1302
openings in one story shall not exceed one third the area of the separating
wall and no single opening shall have a greater area than two hundred square
feet.
(f) A one-hour separation shall provide effective fire-resistance of not
less than one-hour rating as specified in Part 22. Openings in the walls of
such separations shall be protected on one side thereof by automatic-closing
Class B fire doors as specified in Part 22.
(g) Walls which form separations between fire divisions shall be fire
walls as specified in Part 14. Such walls, whether bearing or non-bearing,
shall be solid masonry not less than eight inches thick or reinforced concrete
not less than six inches thick. Openings in fire walls shall have fire doors on
both sides.
(h) The commissioner may waive in part the requirements of this section
for the protection of openings less than two square feet in area subject to
such conditions as he shall in each case specify.
(i) A fixed fire window, as specified in Part 22, may be considered equiva-
lent to one Class B fire door in the walls of separations, but two such windows
shall not be substituted as equivalent to two doors in an opening where two
fire doors are required.
(j) Table A.
(1) For required separations between different unit occupancies in on
fire division read above the zigzag line. Exception: For separation re
quirements between units of occupancy of Group J, Division 1 Occupancy,
and units in the same fire division of Group H or Group I Occupancy see
Section 1202, Part 12.
(2) For required separations between fire divisions read below the zigzag
line.
Separations between adjoining fire divisions of Type I, Type II, and
Type V construction shall be as listed. If either of two contiguous fire
divisions is of Type III, Type IV, or Type VI construction the provisions
of the Table shall be modified in accordance with the following:
The symbol of four hour separation shall be construed to require
absolute separation, and the other separation symbols shall be con-
strued to require one hour more than that indicated in the Table.
In the following table ordinates and coordinates are designated by the
letters and numbers used in this Code indicating various occupancies. The
requirements for separation between fire divisions and unit occupancies are
indicated by the number or letter which appears at the intersection of the
ordinate and coordinate representing any two contiguous fire divisions or
unit occupancies. See paragraph (a) for significance of said numbers and
letters.
(84)
Sec. 1302
Table A, (1)— Required Separations Between Different
Occupancies in One Fire Division.
(Above Zigzag Line.)
Group.
A
B
C
Dl
D2
El
E2
Fl
F2
F3
F4
Fo
Gl
G2
G3
HI
H2
11
12
N
2
2
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
4
3
1
3
2
4
4
2
2
3
3
4
3
2
2
1
1
1
1
4
2
2
3
9
-
4
4
1
2
2
2
4
3
2
2
1
1
N
N
4
4
4
2
3
4
4
3
3
3
3
4
3
3
3
3
3
3
3
4
4
4
4
2
4
4
1
2
2
3
4
3
2
2
1
1
1
1
A
A
4
4
A
3
2
3
3
3
3
3
3
3
3
3
3
3
3
A
A
4
4
A
3
3
2
2
2
2
3
3
2
2
3
3
3
3
4
3
3
4
3
3
3
3
N
N*
N
3
3
N
N
N
N
N
N
4
3
3
4
4
3
3
3
3
N
N
3
3
N
N
1
1
1
1
4
4
3
4
4
3
3
3
3
3
N
3
3
1
1
1
1
1
1
4
4
4
4
3
4
4
4
A
A
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
1
3
1
3
1
4
1
4
1
4
1
4
3
4
4
4
4
A
3
3
3
3
3
3
3
3
3
3
3
3
3
3
4
4
3
4
3
3
3
3
3
3
3
3
3
2
N
1
1
1
1
4
4
3
4
3
3
3
3
3
3
3
3
3
2
2
1
1
1
1
4
3
3
4
3
4
4
3
3
3
3
4
3
3
3
3
N
N
N
4
3
3
4
3
4
4
3
3
3
3
4
3
3
3
3
3
N
N
4
3
3
4
3
4
4
3
3
3
3
4
3
3
3
3
3
2
N
4
3
3
4
3
4
4
3
3
3
3
4
3
3
3
3
3
2
2
4
4
4
4
4
3
3
3
3
3
3
3
3
3
3
3
3
2
2
Jl
A
B
C
Dl...
D2...
El ....
E2
Fl.. ..
F2
F3 ... .
F4
F5
Gl
G2. ...
G3 . ...
Hi ...
H2
II....
12
Jl
3
Table A, (2) — Required Separations Between Fire Divisions.
(Below Zigzag Line.)
[ t-4s amended by Ord. 1943, ch, 4 )
(85)
Sec. 1401
PART 14.
WALLS AND PARTITIONS.
Section
1401 — Definition of Walls for Use or Function.
1402 — General Requirements for Walls.
1403 — Lateral Support of Walls.
1404 — Classification of Walls for Type of Construction.
1405 — Reinforced Concrete Walls.
1406 — Masonry Walls.
1407 — Bond in Masonry.
1408 — Lateral Support of Masonry.
1409 — Masonry Piers.
1410 — Beam Supports on Masonry Walls.
1411 — Masonry Chases, Recesses, Corbels and Lintels.
1412 — Masonry Foundation Walls.
1413 — Parapet Walls.
1414 — Use of Existing Masonry Walls.
1415 — Masonry Veneer.
1416 — Steel Frame Walls.
1417 — Wooden Frame Walls.
*Section 1401. Definition of Walls for Use or Function. — (a) Walls
and partitions shall be classified for use or function as follows: —
(1) A bearing wall is a wall which supports a floor, roof or other load
in addition to its own weight.
(2) A non-bearing wall is a wall which supports no load other than its
own weight.
(3) An exterior wall is a wall separating the interior from the exterior
of a building, marking the boundary or extent thereof which may be and
usually is exposed to the weather on one side.
(4) An interior wall is a wall wholly within a building and protected
from the weather.
(5) A party wall is a wall used or adapted for use in common as a
part of two buildings. A party wall may be either bearing or non-bearing
(6) A fire wall is an interior wall, bearing or non-bearing, forming
part of a separation between two fire divisions of a building, as provided
in Part 13.
(7) A partition is an interior wall, bearing or non-bearing, not over
one story in height, the chief function of which is to separate two rooms
of a story. A partition in one story may be supported by a bearing
partition in the story below.
(8) A foundation wall is a foundation in the form of a wall, either
exterior or interior; that portion of the exterior bearing wall of a building
which is below the grade of adjoining ground.
(86)
Sees. 1401-1402
(9) A retaining wall is a wall of which the chief function is to resist
ttie lateral displacement of liquid, granular or other materials. It may
be either bearing or non-bearing, exterior or interior.
(10) A curtain wall is an exterior, non-bearing wall more than one
story high and not supported at each floor level, which is laterally stayed
either by masonry piers or by the structural frame of the building.
(11) A panel wall is an exterior, non-bearing wall not over one story
high, or supported at each floor level.
(12) An enclosure wall is an interior wall, bearing or non-bearing,
which encloses a stairway, elevator shaft or other vertical opening.
[ *As amended by Ord. 1948, ch. 4 ]
fSect. 1402. General Requirements for Walls. — (a) Walls shall
have the resistance to fire and to the spread of fire required of them in Parts 3
to 13, inclusive, and Part 15 of this code, but may be finished, except on the
outside of exterior walls and within enclosures of vertical openings, with
wooden or other combustible wainscoating, insulating or acoustical material.
In Type III buildings, there shall be no concealed air spaces between such
finish and the wall. In Type V buildings such material shall be protected
from fire on both sides by sheet metal or its equivalent. In Type IV or
Type VI buildings every hollow space in walls shall be firestopped at floor
and ceiling.
(b) Bearing walls shall be so supported and constructed as to be stable
and to support their weight and the loads which may be placed upon them
without exceeding the stresses allowed for the materials of which they are
constructed as provided in Parts 23 to 29, inclusive. Exterior walls, party
walls, bearing walls and fire walls and their vertical or lateral supports shall
be capable of resisting the pressure of the wind applied to either side.
(c) Court walls shall be of such fire-resistive construction and shall have
such limitations as to openings and the protection of openings as are specified
for exterior walls in Parts 3 to 12, inclusive.
(d) Exterior bearing walls of buildings of Type I, Type II, Type III and
Type IV shall be of four-hour fire-resistive construction as provided in sec-
tions one hundred and twenty-six to one hundred and twenty-nine, inclusive,
of Part I. Where such exterior walls are required, in Parts 3 to 12, inclusive,
to be without openings the panels or non-bearing portions of the walls shall
afford resistance of four-hour rating to the spread of fire. Where openings
in such exterior walls are required, in Parts 3 to 12, inclusive, to be protected
with fire doors or fire windows, the panels or non-bearing portions of the walls
shall afford resistance of two-hour rating to the spread of fire. Where the
openings in such exterior walls are unrestricted, panels or non-bearing portions
of such walls shall be of incombustible construction, excepting, that sash,
window frames, blinds, shutters, screens, doors, door frames, door and window
trims, their architraves, pilasters and entablatures may be of wood or other
not easily inflammable material; and in buildings outside the fire limits isolated
pilasters and building cornices may be of wood or some other not easily
inflammable material. Furthermore, architectural surfaces, trimmings,
plaques, panels or the like of wood covered with metal or other incombustible
(87)
.Sees. 1402=1405
material may be applied to the exterior of buildings, and there may be in-
corporated in the masonry backing the necessary wooden grounds for their
attachment, or wooden grounds may be applied to masonry wall if embedded
in mortar. Metal cornices and the like may be applied to wooden outriggers
-and suitable grounds.
(e) In buildings with combustible floors, doorways required to have fire
doors shall have incombustible thresholds the full thickness of the wall and
cdoors in their closed positions, and the space thereunder shall be filled solid
with masonry. Thresholds may be flush with the floor.
[ fAs amended by Ord. 1948, ch. 4 ]
Sect. 1403. Lateral Support of Walls. — (a) Walls of any type or
.construction may be considered to have lateral support where anchored or
..secured : —
(1) To intersecting walls of equal or better fire-resistance.
(2) To buttresses or piers.
(3) To the floors, roof and framing.
Sect. 1404. Classification of Walls for Type of Construction. — (a)
Walls, including partitions, shall be classified for type of construction as
follows : —
(1) Reinforced concrete.
(2) Masonry.
(3) Steel frame.
(4) Wooden frame.
(b) Any wall which does not fall readily into one of the classifications of
this section shall be assigned thereto by the commissioner according to its
^pertinent characteristics.
Sect. 1405. Reinforced Concrete Walls. — (a) Reinforced concrete
walls may be used for any use or function described in section fourteen
ihundred and one.
(b) Reinforced concrete walls other than foundation walls shall be sup-
ported upon foundations of concrete or masonry or upon construction of
masonry, reinforced concrete or structural steel the metal of which, except
as otherwise provided in section fourteen hundred and eleven, shall have pro-
tection against fire of at least the rating required for the wall itself, and not
less than two-hour fire-resistive protection. Reinforced concrete walls shall
not be supported upon wood except wooden piles or other approved under-
water construction of wood.
(c) The pertinent provisions of Part 26 shall apply to walls of reinforced
concrete.
(d) Reinforced concrete bearing walls shall have a thickness of at least
one twenty-fifth the height or length between supports, whichever is the lesser
dimension.
(e) Foundation walls of reinforced concrete shall be not less than eight
inches thick.
(88)
Sees. 1405-1406
(f) Non-bearing walls of reinforced concrete shall have a thickness of at
least one sixtieth of the height or length between lateral supports, whichever
is the lesser dimension, and shall not be thinner than three inches. Reinforced
concrete beams which serve in part as walls shall conform to the requirements
for non-bearing walls.
(g) Party and fire walls of reinforced concrete shall be at least six inches
thick.
(h) Walls of reinforced concrete may be covered with a veneer of masonry
or other material adequately supported but such veneer shall not be con-
sidered to be a part of the wall for the purposes of this section.
(i) No chase or recess shall be cut or formed in a reinforced concrete wall
so as to impair its stability, or to reduce the minimum thickness to less than
four inches.
(j) 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. Where wooden
joists, beams or other combustible members frame into such walls, the ends
shall be separated from the opposite side of the wall and from such members
framing into the opposite side of the wall by not less than four inches of con-
crete. In buildings of Type III, Type IV or Type VI construction party
walls and fire walls shall extend through the roof as provided in section
fourteen hundred and thirteen.
(k) Exterior and bearing walls of reinforced concrete shall be anchored
to the floor and roof construction as specified in Parts 16 and 17.
♦Sect. 1406. Masonry Walls. — (a) Masonry may be used for walls of
any use or function described in section fourteen hundred and one. Specifica-
tions for masonry in this chapter shall also apply to plain concrete.
(b) Masonry walls and piers, other than foundation walls, shall be sup-
ported upon foundations of concrete or masonry, or upon construction of
masonry, reinforced concrete or structural steel the metal of which, except as
otherwise provided in section fourteen hundred and eleven, shall have pro-
tection against fire of at least the rating required for the wall itself, and not
less than two-hour fire-resistive protection. Masonry walls and piers shall
not be supported upon wood except wooden piles or other approved under-
water construction of wood, but this provision shall not apply to fire stopping
and nogging.
(c) Exterior bearing walls of masonry shall have a thickness of at least
one sixteenth the height or length between lateral supports in the top story
of a building and at least one twentieth such height or length in stories other
than the top, whichever is the lesser dimension. Masonry exterior bearing-
walls supporting the walls of Type V or Type VI buildings shall be not less
fchan eight inches thick.
(89)
Sec. 1406
(d) Exterior bearing walls of masonry shall have at least the thickness
given in the following tables:
Table A: Exterior Bearing Walls of Masonry for Group A, B, C, E, F,
G, J Occupancy.
Note. — Hollow masonry units may be used in walls of the thickness given only on the top
four stories. Minimum thickness of walls is given in inches.
Story.
Height
op Wall in Stories
8.
7.
6.
5.
4.
3.
2.
1.
Eighth
12
12
12
16
16
16
20
20
20
12
12
12
16
16
16
20
20
12
12
12
16
16
16
20
12
12
12
16
16
16
12
12
12
16
16
12
12
12
16
12
12
12
Sixth
Fifth
Third
First
12
12
Table B: Exterior Bearing Walls of Masonry for Group D, H, I
Occupancy.
Note. — For special provisions with respect to single-family, Group I occupancy, see the
following Table C.
Height
op Wall in Stories,
Story.
8.
7.
6.
5.
4.
3.
2.
1.
Eighth
12
12
12
12
12
16
16
16
16
12
12
12
12
12
16
16
16
12
12
12
12
12
16
16
12
12
12
12
12
16
12
12
12
12
12
12
12
12
12
8
12
12
Sixth
Fifth
_
Fourth
_
Third
_
First
8
12
(90)
Sees. 1406-1407
Table C: Exterior Bearing Walls of Masonry for Group I Occupancy,
Single-Family Dwellings Not Over Three Stories High, Supporting
Floors Not Over Twenty Feet in Span.
Stoby.
Height of Wall in Stobies.
3
2,
Third....
Second . . .
First
Basement
8
-
8
8
12
8
12
12
(e) Interior bearing partitions of masonry, supporting not more than one
floor and a roof shall have a thickness of at least one twentieth the height or
length between lateral supports, whichever is the lesser dimension, and at
least six inches. Such partitions, not over one story high, supporting stairs,
stair landings, platforms, a mezzanine floor, or the like, shall have a thickness
of at least one twentieth the height or length between lateral supports, which-
ever is the lesser dimension, and at least three and one half inches. Other
interior bearing walls of masonry shall have at least the thickness required
in this section for masonry exterior bearing walls.
(f) Bearing party walls of masonry shall be solid not less than twelve
inches thick. Non-bearing party walls and bearing or non-bearing fire walls,
of masonry shall be solid not less than eight inches thick.
(g) Exterior masonry panel walls shall be not less than three and one half
inches thick. Panel walls more than four feet high, and curtain walls, of
masonry shall be not less than eight inches thick. Panel or curtain walls of
metal or fire-resisting, impervious material may be backed up with masonry
at least two inches in thickness.
(h) Non-bearing masonry partitions and enclosure walls shall have a
thickness of at least one forty-fifth the height or length between lateral
supports, whichever is the lesser, and at least three inches.
(i) The minimum thickness specified in this section for masonry walls,
except as otherwise provided in this paragraph, shall be exclusive of unbonded
veneer, plaster or other covering on either face of the wall. The minimum
thickness specified in this section for non-bearing partitions and enclosure
walls shall be inclusive of plaster which is at least one half inch thick on either
or both sides, and when the masonry beneath the plaster is at least three
inches thick.
[ *As amended by Ord. 1943, ch. 4 ]
fSect. 1407. Bond in Masonry. — (a) Brick walls shall be bonded
with at least one full header, every other brick in every sixth course, on both
faces and the interior of the walls.
(91)
Sees. 1407-1408
(b) In homogeneous masonry walls of stone, bond stones shall be uni-
formly distributed and shall have a cross-section not less than ten per cent
of the area of the wall.
(c) In homogeneous masonry ivalls of structural clay tile or of solid or
hollow concrete or gypsum blocks or of similar masonry units, unless all the
units are the full thickness of the wall, the two faces of the wall shall be
bonded together through the wall, by varying the thickness of units in alter-
nate courses so that the blocks will overlap across the wall not less than three
and one half inches.
(d) Walls of structural clay tile, concrete blocks or similar masonry
units, faced with brick, in which the backing is bonded as required for the
material of which it is built and the brick facing is bonded to the backing as
required in a brick wall, shall be considered to have the strength and stability
of a homogeneous wall of the same total thickness of the weaker material.
(e) A wall of stone, brick, structural clay tile, concrete blocks or other
masonry units faced with stone ashlar bonded to the wall as herein provided,
shall be considered to have the strength and stability of a homogeneous wall
of the same total thickness of the weaker material. In order so to be con-
sidered a part of the wall, the ashlar facing shall be laid in a full bed of mortar,
shall be not less than three and one half inches thick and bond stones shall be
uniformly distributed in all or at least in alternate courses, not less than
seven and one half inches thick, nor less than four inches thicker than the
remainder of the facing, and constituting not less than twenty per cent of the
area of the wall.
(f ) Brick, stone or block facing may be considered to be bonded to back-
ing of plain or reinforced concrete when the facing, with all the provisions
for bond required for a facing backed with masonry, is laid in advance of the
pouring of concrete, and the concrete is poured in direct contact with the
facing, embedding the header brick or bonding units.
(g) Masonry walls covered with a veneer not bonded to the wall as pro-
vided for a facing in this section shall be considered to have a thickness equal
to that of the wall exclusive of the veneer.
(h) Hollow walls of brick, laid with every alternate brick in every other
course on each side of the wall a full header, or any equivalent bond, may be
used where walls of structural clay tile may be used.
[ iAs amended by Ord. 1943, ch. 4 ]
JSect. 1408. Lateral Support of Masonry. — (a) Masonry bearing
walls, exterior walls, and other masonry walls, which depend upon inter-
secting walls for lateral support shall be bonded to such walls at intersections
and corners by having each unit if other than brick alternately overlap by at
least one half the thickness of the wall at the intersection, and if of brick
have each alternate brick overlap by half the length of the brick, or a group
of not over six bricks overlap in alternating groups at least half the thickness
of the wall.
(b) Masonry walls which depend upon anchorage to the frame of a build
ing for lateral support shall be tied to the frame by suitable anchorage ap-
proved by the commissioner.
(92)
Sees. 1408=1411
(c) Exterior and bearing walls of masonry shall be anchored to the floor
and roof construction as specified in Part 16.
[ %As amended by Ord. 1943, ch. 4 ]
Sect. 1409. Masonry Piers. — (a) In walls with openings such that
the portion of wall between openings constitutes a pier, such portion of wall
shall be computed and constructed as required for piers. The height of
such a pier, with a continuous wall above and below the openings shall be
taken as the height of the openings.
(b) When the clear horizontal distance between piers in masonry walls
exceeds ten feet they shall be considered isolated piers.
(c) Isolated piers shall be built of solid units, for which hollow units
filled with concrete shall not be substituted. The unsupported height of
isolated piers shall not exceed twelve times their least dimension.
Sect. 1410. Beam Supports on Masonry Walls. — (a) Joists, beams
and other structural members shall not bear directly on hollow walls or walls
of hollow units, but shall be supported on a sufficient number of courses of
solid units or equivalent concrete or a metal plate or grillage sufficient to
distribute the load to the webs and shells in such manner as not to exceed
the allowable unit stress.
(b) Where structural steel beams or other metal members frame into
exterior, party, fire or enclosure walls of masonry, the ends shall have pro-
tection against fire of the rating specified for the wall. Where wooden joists,
beams or other combustible members frame into such walls the ends shall be
separated from the other side of the wall and from members framing into the
other side of the wall by not less than four inches of masonry.
*Sect. 1411. Masonry Chases, Recesses, Corbels and Lintels. —
(a) There shall be no chases in masonry bearing or exterior walls eight
inches or less in thickness or within the required area of a pier, and no chase
in a bearing, exterior or fire wall or pier shall reduce the thickness thereof
to less than eight inches. No horizontal or diagonal chase shall be allowed
except subject to the limitations and conditions provided in this section for
recesses.
(b) Recesses for stairways, elevators or other purposes may be made in
masonry bearing, or exterior walls, but in no case shall the walls at such
points be reduced to less than the thickness required in the fourth story.
Such walls of reduced thickness shall have such additional lateral support
as may be necessary. Recesses in masonry bearing or exterior walls for
radiators and similar purposes, shall have not less than eight inches of masonry
at the back. Such recesses shall be not more than eight feet in length unless
the wall at the back may be considered a curtain or panel wall, and they
shall then be arched over or spanned with lintels.
(c) No chases or recesses shall be permitted in fire or party walls that will
reduce the thickness below the minimum specified in this code.
(d) Chases and recesses may be built as provided in this section, but
shall not be cut in masonry walls of hollow masonry units or in hollow walls
of brick.
(93)
Sees. 1411-1412
(e) Chases shall be fire-stopped at floor and ceiling levels.
(f) Corbels may be built in masonry walls to furnish bearing for floors
or roof but such corbels shall not project from the face of the wall more than
one fourth the thickness of the wall nor more than one fourth the height of the
corbel. Corbels shall be built with solid masonry units and thoroughly
bonded to the wall. No corbel in a masonry wall less than twelve inches
thick shall be used for the support of a floor or roof.
(g) Chimneys constructed of the same material as that of the wall, and
lined as provided in Part 21, may be supported by corbels of which the
projection is not more than one fourth the height nor more than the thickness
of the wall, but no chimney shall be supported on a corbel from a wall less than
twelve inches thick.
(h) Openings in masonry walls for doorways and windows shall have
well buttressed arches or lintels of incombustible material. Structural or
reinforcing steel in such lintels shall have protection against fire of the rating
required for the wall, but not less than two-hour fire-resistive protection;
except that the masonry over an opening may be supported by a steel plate,
angle or similar member not fireproofed on the under side, if the width of the
opening does not exceed six feet in bearing walls and ten feet in non-bearing
walls, or if the member so unprotected is itself supported, at intervals not
exceeding six feet in bearing walls and ten feet in non-bearing walls, from a
beam or other adequate structure which has the required protection.
[ *As amended by Ord. 1948, ch. 4 ]
fSect. 1412. Masonry Foundation Walls. — (a) Masonry foundation
walls shall conform to the requirements for foundations of Part 29.
(b) Sand lime brick, gypsum tile and cinder concrete poured in place
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 provided in Part 29.
(c) Rough or random rubble stone masonry without level beds shall not
be used for foundation walls more than ten feet high or supporting buildings
more than forty-five feet high.
(d) Masonry foundation walls shall be at least as thick as the wall sup-
ported, and not less than the following thickness: —
Minimum Thickness (Inches) of Masonry Foundation Walls.
Concrete 8
Solid masonry (except rubble) . . . . . . .8
Hollow masonry 12
Rubble masonry 20
(e) Foundation walls and retaining walls, which depend upon a floor or
superimposed structure for resistance to overturning shall not be back-filled
until so supported or properly shored to the satisfaction of the commissioner
Walls damaged by premature back-filling shall be removed and replaced
if so required by the commissioner.
(94)
Sees. 1412-1415
(f) Masonry foundation walls supporting wood shall be carried at least
eight inches above adjoining ground and shall be effectually sealed to prevent
moisture from reaching the wood through capillary action.
(g) Masonry in foundation walls shall be laid in cement mortar or cement-
lime mortar.
[ 1[As amended by Ord. 1948, ch. 4 ]
Sect. 1413. Parapet Walls.— (a) In buildings of Type III, Type IV
or Type VI construction not more than forty-five feet in height, party walls
and fire walls shall extend through the roof not less than twelve inches, and in
such buildings more than forty-five feet in height, not less than thirty inches.
Masonry walls extending above the roof shall have a coping of incombustible
material.
(b) In such buildings, exterior walls required by Parts 3 to 12, inclusive,
to be of four-hour fire-resistive construction without openings, shall extend
above the roof, as provided in this section for party walls.
JSect. 1414. Use of Existing Masonry Walls. — An existing masonry
wall may be used in the construction of a post-code building and in the repair,
alteration or enlargement of a building providing it meets the requirements of
this code, and is structurally sound or can be made so by reasonable repairs.
Existing masonry walls which are structurally sound but which are of insuffi-
cient thickness for their proposed use shall be strengthened by an addition of
similar material not less than eight inches in thickness laid in mortar of re-
quired proportions. Foundations and lateral supports shall be provided as
required for newly constructed walls under similar conditions. Such addi-
tions or linings shall be thoroughly bonded to the existing masonry by toothings
bonded with the new masonry and built solidly into openings cut in the old
masonry at least four inches deep. Such toothings shall be distributed uni-
formly throughout the wall and shall aggregate in vertical cross-sectional area
not less than fifteen per cent of the total vertical area of the wall or lining. If
the existing wall is covered with plaster or other covering that might impair
the bond of the lining, such covering shall be stripped off and the masonry
cleaned. The repair, lining, or other strengthening of an existing masonry
wall to be used in the construction of a post-code building and in the repair,
alteration or enlargement of a building shall be in every respect satisfactory to
the commissioner and subject to such conditions as he may in any case pre-
scribe.
[ %As amended by Ord. 1948, ch. 4 ]
Sect. 1415. Masonry Veneer. — (a) Unbonded masonry veneer may
be used as a covering for a wall of any type of construction with or without air
space. It shall not be regarded as a structural part of the wall or as contribut-
ing to its strength or stability, but it may serve as protection from the weather
and where built without hollows or air spaces it may serve as protection for
metal against fire. Gypsum shall not be used in veneer exposed to the
weather.
(b) Masonry veneer shall be anchored to the backing, if of masonry, by
headers or bond units, built at least three and one half inches into the back-
(95)
Sees. 1415-1417
ing, uniformly distributed, and having an area at least one fortieth the area
of the wall, or by approved non-corrodible metal ties spaced not further apart
than one foot, or three times the thickness of the veneer except that masonry
veneer of thin flat stones on edge shall be anchored every twelve inches in all
horizontal joints by non-corrodible anchors not less than one quarter inch in
least dimension dowelled at least one inch into the top of veneer stones and
well secured to the backing.
Sect. 1416. Steel Frame Walls. — (a) Walls framed with structural
steel may be used for any of the functions described in section fourteen
hundred and one.
(b) The frames of exterior steel frame bearing walls shall have fire pro-
tection of the rating specified for the exterior bearing walls of the building,
according to its type of construction in sections one hundred and twenty-six
to one hundred and thirty, inclusive, of Part 1 and in Parts 3 to 12, inclusive.
(c) The frames of interior steel frame bearing walls shall have fire protec-
tion as required for structural steel columns in Parts 16 and 17.
(d) The frames of steel frame party walls shall have four-hour fire-resistive
protection.
(e) The frames of steel frame curtain and panel walls shall have fire pro-
tection of the rating specified for such walls in section fourteen hundred and
two and in Parts 3 to 12, inclusive.
(f) The frames of steel frame enclosure and fire walls shall have fire
protection of the rating specified for the walls in Parts 3 to 13 inclusive and
In Part 15.
(g) The steel frames of walls required by this section to be protected
against fire shall not be supported upon wood or other combustible material
nor upon metal with less protection than is required for such frames.
(h) The frames of steel frame exterior walls and other walls exposed to
moisture shall be protected from rusting.
(i) Solid or hollow non-bearing partitions of steel frame and plaster shall
have a total thickness not less than one sixtieth the height between lateral
supports, nor less than two inches. The plaster of hollow partitions shall be
not less than three quarters inch thick. Vertical steel frame members shall be
at least equivalent to twenty-four gage steel channels of a depth not less than
half the thickness of the partition spaced not over twenty-four inches on
centers.
(j) Except as otherwise specified in this section steel frame bearing or
non-bearing walls may have frames of unprotected steel and panels of incom-
bustible materials. Steel frame walls, bearing or non-bearing, with panels of
combustible materials, may be used only where wooden frame walls are
allowed by this code, except that in buildings of Type V, unprotected steel
frame walls may have panels containing a layer of combustible insulating
material between sheets of steel or equally protective covering.
*Sect. 1417. Wooden Frame Walls. — (a) Wooden frame walls shall
not be used for exterior walls except in buildings of Type VI construction nor
for interior bearing walls except in buildings of Type IV or Type VI con-
(96)
Sec. 1417
struction. Wooden frame walls shall not be used for party walls, fire walls,
enclosure walls required to have greater than one-hour fire resistance, nor
for walls where incombustible materials are specified. Wooden frame walla
shall not be used for foundation walls, nor for bearing partitions in basements
or cellars.
(b) Non-bearing wooden frame partitions may be used in buildings of
Type I, Type II, and Type V, in occupancy of Group F and Group G only,
solely for the purpose of sub-dividing space occupied by one tenant, provided
that the space so divided shall be separated from any other tenant in the
same story by partitions of fire-resistive quality as required by the particular
conditions.
Non-bearing wooden stud partitions covered on both sides with three
quarter inch thick plaster on incombustible lath may be used in buildings of
Type I and Type II for Groups H and J occupancy, solely for the purpose of
sub-dividing apartments or similar space occupied by one tenant, provided
that such partitions shall not exceed five hundred lineal feet within a single
floor area, separated from the rest of the story by partitions of fire-resistive
quality as required for the particular conditions.
Nothing in this paragraph shall be construed to allow wooden frame
partitions in Type I, Type II, and Type V buildings where fire-resistive
partitions of other materials for egress, enclosures or vertical openings, or
separations are required elsewhere in this code.
(c) Wooden frame exterior walls shall have posts, sills, and girts not
smaller than three and five eighths by five and five eighths inches. When the
studs are continuous throughout two stories they shall be of one piece, the girts
shall be replaced by a ledger board not less than fifteen sixteenths by five and
five eighths inches housed into the studs. Studs shall be no smaller than one
and five eighths by three and five eighths inches. Dimensions of members in
this paragraph are actual net dimensions.
Posts shall be well braced the full story height, and walls shall be framed to
them by a stud-sized brace attached to the post just below the girt and running
in the wall at an angle not more than sixty degrees from the vertical, attached
at the other end to the girt or sill. These braces shall be horizontally braced
at the corner post at least once in each story, and the studs which they inter-
sect shall be well fastened above and below the brace. Posts and girts
shall be mortised, tenoned, and pinned at each floor level or connected by
approved metal fasteners which provide equal rigidity. The tenons shall be
not less than one inch in thickness and the full height of the girt.
Where a ledger board replaced a full girt the space behind the ledger board
shall be fire stopped with at least one and five eighths inch lumber cut between
the studs. In wooden stud exterior bearing walls more than one story highi
the studs shall be not over sixteen inches apart on centers, and shall be bridged
at least once at mid-height. In one story walls studs shall be spaced not over
twenty inches apart on centers, and need not be bridged. At intersections,
between such walls and interior partitions, studs shall be well blocked, making
what is commonly known as solid corners. Wall plates shall consist, either
(97)
Sec. 1417
of two layers of wood not less than one and five eighths by three and five eighths
inches, each, or of one layer of wood not less than three and five eighths by
three and five eighths inches. At openings in bearing walls, studs shall be
doubled or have a minimum section of three and five eighths by three and
five eighths inches and the heads of openings shall be trussed.
Posts in one and two story walls shall be in one piece — in three stories they
may be spliced once in their length, just above the second or third floor girt.
Girts and caps may be spliced not oftener than once in twelve feet. Such
splices shall be made by halving the piece of wood with a lap of at least eight
inches. The lap shall be securely pinned or spiked. In two-piece caps the
minimum length of pieces shall be the full length of the wall or twelve feet.
Joints shall be broken with at least twelve inches overlap. If studs are
spaced farther apart than indicated in this paragraph they shall be classed as
wooden columns, girts and caps framing on them shall be classed as wooden
beams, and they shall all meet the requirements of section twenty-five hundred
and five and twenty-five hundred and six.
(d) Wooden stud bearing partitions shall have studs not less than one and
five eighths by three and five eighths inches supported upon a girder or upon a
sole plate not less than one and five eighths inches thick. The partition plate
shall be not less than one and one half inches thick. Studs of a partition
in an upper story over a partition below shall rest upon the plate of the lower
partition and not upon the ends of the floor beams. Studs of wooden frame
bearing partitions shall be bridged at least once at mid-height and studs
supporting a floor shall be not more than sixteen inches apart on centers.
Studs shall be doubled beside openings in partitions, and the heads of such
openings shall be trussed or framed sufficiently heavy to carry the load.
Wooden stud bearing partitions shall not be used to support more than a roof
and three floors and in buildings three stories or more in height shall have
one-hour fire-resistive rating. If studs are spaced farther apart than indicated
in this paragraph, they shall be classed as wooden columns and the caps over
them shall be classed as wooden beams and they shall both meet the require-
ments of sections twenty-five hundred and five and twenty-five hundred and
six unless in the category of the following: In one story habitations, where
height from sill to plate does not exceed nine feet, the studs may be one and
five eighths by two and five eighths inches, plate may be two pieces of one and
five eighths by two and five eighths inches or one piece of two and five eighths
by three and five eighths inches, sills may be two and five eighths by five and
five eighths inches and corner posts may be blocked studs.
(e) Hollow wooden frame walls and partitions shall be firestopped at
floor and ceiling levels. Bearing partitions shall be firestopped the full height
between ceiling and floor above. Firestopping shall consist of incombustible
materials or of wood not less than one and one half inches thick.
(f) Exterior wooden frame bearing walls shall be covered on the outside
with wood boarding nailed to the studs or with other approved material
equally effective in stiffening the frame of the building. Boards shall be not
less than three quarters inch thick unless a weather boarding is used, in which
case it shall have an average thickness of at least five eighths inch. Each
(98)
Sec. 1417
board shall have at least two nails to each stud. Stucco, masonry veneer
and any material composed principally of gypsum shall not be considered a
satisfactory substitute for boarding on exterior wooden frame walls.
(g) Any other style of wall construction which provides stability, rigidity
and fire-resistance equal to that of the walla specified in this section, as dis-
closed in tests prescribed by the commissioner and satisfactorily passed, may
be used where wooden frame walls are allowed.
i *As amended by Ord. 1948, ch. 4, Ord. 1953, ch. 7, and Ord. 1955, ch. 2 \
(99)
Sees. 1501-1502
PART 15.
PROTECTION OF VERTICAL OPENINGS.
Section
1501 — Protection of Vertical Openings.
1502 — Trap Doors.
1503 — Enclosure of Vertical Openings.
1504 — Floor Construction within Enclosures.
1505 — Openings for Ventilation in Ventilating Shafts.
1506 — Ventilating Ducts.
1507 — Use of Enclosures.
*Section 1501. Protection of Vertical Openings. — (a) Where
an opening in only one floor is required to be enclosed by provisions of Parts 3
to 12, inclusive, or by Part 18, it shall be enclosed either in the story above
or in the story below, or protected by a trap door in such manner as to resist
the spread of fire from one story to the other. Where a series of openings in
two or more floors, required to be enclosed, are enclosed in one shaft, they
shall be enclosed in all stories. A required exit shall not be closed by a trap
door, except as otherwise provided in Part 18. The exterior walls of buildings
are excluded from the provisions of this part, except as specifically provided
in section fifteen hundred and three.
(b) Openings in floors which are not provided with trap doors and are
not enclosed in the story above, shall be protected by an adequate railing
at least thirty inches high. Openings in roofs, unless covered by trap doors
or skylights, shall be protected by an adequate railing or parapet at least
thirty inches high.
[ *As amended by Ord. 1943, ch. 4 ]
*Sect. 1502. Trap Doors. — (a) A trap door in a floor or roof shall
be able to support its own weight and a concentrated load of two hundred
pounds; and unless protected by a curb not less than six inches high or by a
railing, shall be able to support a live load equal to that of the floor or roof
in which it is placed. The requirements of this section shall not apply to
stage construction in a theatre. A trap door in a floor shall be arranged to
close automatically in case of fire in a manner satisfactory to the commissioner.
(b) In buildings of Type I and Type II construction a trap door shall
not exceed six feet in either dimension, and shall have fire resistance equiva-
lent to that of a Class A fire door as specified in Part 22.
(c) In buildings of a type of construction other than Type I or Type II,
trap doors shall be of the construction required for the floor or roof, except
that a trap door in a ceiling required to have fire resistance shall be equivalent
in fire resistance to a Class A fire door as specified in Part 22 and shall not
exceed six feet in either dimension.
(d) The commissioner may waive in part or modify the requirements of
this section for protection of openings less than four square feet in area subject
to such conditions as he shall in each case specify.
(100)
Sec. 1503
*Sect. 1503. Enclosure of Vertical Openings. — (a) In buildings
of Type I, Type II or Type III construction, the required enclosure of a
floor opening shall have two-hour fire-resistive rating.
(b) In buildings of Type IV construction, except as otherwise provided
in this section, the required enclosure of a floor opening shall have not less
than one-hour fire-resistive rating. In such buildings four stories or more
in height and in such buildings three stories in height other than of Group H
or Group I occupancy, such enclosures shall also be of incombustible ma-
terials. In buildings of Type IV construction more than three stories high
an enclosure about both stairs and elevator shall have not less than two-hour
fire-resistive rating.
(c) In buildings of Type V construction floor openings, if enclosed, shall
be enclosed with incombustible materials.
(d) In buildings of Type VI construction, except as otherwise provided
in this section, the enclosure of a floor opening where required, shall have
not less than one-hour fire-resistive rating, and this provision shall apply
to the inside face of that portion of an exterior wall which forms part of such
an enclosure as well as to an interior wall.
(e) Combustible wainscoting, insulating or acoustical material may be
attached to the walls of enclosures provided for in this section, but not within
the enclosure, as specified in Part 14.
(f) Doorways in enclosures only about passenger elevators shall be pro-
tected by Class C fire doors or doors of incombustible materials in which
glass shall be wire glass. Doorways in other enclosures of vertical openings
shall be protected, in enclosures required to have two-hour fire-resistive rating
by Class B fire doors and in enclosures required to have one-hour rating by
Class C fire doors, except as otherwise provided in Parts 3 to 12, inclusive.
Window openings in required enclosures shall be protected by fire windows.
Openings for ventilation in required enclosures shall be protected as pro-
vided in section fifteen hundred and five. Other openings in required en-
closures shall be protected as the commissioner shall in each case specify.
(g) In required enclosures of floor openings, fire windows shall be fixed or
automatic-closing; doors shall be self-closing or automatic-closing, except
access doors for repairs which shall be kept closed and locked, and except
doors in enclosures only about passenger elevators.
(h) The enclosure of chutes and dumb-waiters not exceeding four square
feet in area need not have fire-resistive protection if constructed of metal
not thinner than sixteen gauge if in Type I, Type II, or Type V construction.
If in Type III, Type IV, or Type VI construction they shall be protected by
not less than one-hour fire-resistive enclosure and Class B automatic-clos-
ing doors.
(i) Every elevator shaft and stairway enclosure, except dumb-waiter
enclosures and enclosures in the interior of a building which do not serve the
top story, shall be ventilated at the top by an opening to the outside air
not less in area than one per cent of the area of the shaft. In addition, each
such shaft shall have at the top means for emergency ventilation in the form
(101)
Sees. 1503-1506
of windows or skylights with thin plain glass, with metal screen beneath,
or wire glass, or in other approved form, not less in area than one quarter the
area of the shaft.
[ *As amended by Ord. 1943, ch. 4 ]
Sect. 1504. Floor Construction within Enclosures. — Where the
enclosure of floor openings is required by the provisions of Parts 3 to 12, inclu-
sive, or of this part to be of a construction more fire-resistive than the floors
of the buildings or where such enclosure is required to be of incombustible
materials, any portion of a floor of the building which shall form part of the
enclosure, as when the walls thereof are offset, in successive stories, shall be
of materials and construction equivalent in fire resistance to that required
for the walls.
fSect. 1505. Openings for Ventilation in Ventilating Shafts. —
(a) Openings for ventilating purposes in enclosures, larger than one square
foot in area, except as otherwise provided in this section shall be protected
in one of the six following methods: —
(1) Louvres or dampers, which shall close by gravity or be held open
by a fusible link so placed as to permit them to close in the case of fire.
(2) Openings into a shaft or duct used exclusively to exhaust the air
from two or more stories may be protected by louvres of incombustible
material which close by gravity, like a check valve, to prevent reversal
of the air current.
(3) Openings into a shaft or duct used exclusively to supply air to two
or more stories of a building may be protected by louvres which close by
gravity, like a check valve, to prevent reversal of the air current.
(4) Openings in a ventilating shaft, connected with branch ducts at
least as long as twelve times the larger transverse dimension of the duct
need not have additional protection.
(5) An opening for ventilating exhaust in a shaft enclosure when
connected to a duct without openings in other stories, leading to a point
above the roof level, need not have the protection of automatic-closing
louvres or dampers.
(6) An opening for the supply of air to a ventilated space which is
connected by means of a duct without openings in other stories to a fan,
plenum chamber or other source of air supply, need not have the protection
of automatically closing louvres or dampers.
[ fAs amended by Ord. 1943. ch. 4 ]
Sect. 1506. Ventilating Ducts. — (a) Ventilating ducts in all buildings
shall be of incombustible materials, but may be lined with fibrous insulating
or sound deadening material which has been chemically treated, if necessary,
ao that it will not by itself support combustion. Horizontal offsets of vertical
ducts shall be protected in Type I and Type II buildings by at least one-hour
fire-resistive construction of incombustible materials.
(b) The combustible material of partitions and floors through which sheet
metal ventilating ducts pass shall be kept at least one inch from the metal or be
(102)
Sees. 1506-1507
protected by not less than one half inch of plaster or one quarter inch of
asbestos board or other incombustible material of equal insulating value.
Openings between sheet metal ventilating ducts and combustible floor con-
struction through which they pass shall be fire stopped with incombustible
material.
Sect. 1507. Use of Enclosures. Except as otherwise specifically pro-
vided, no limitation is imposed in this chapter upon the shape or size of the
enclosure in any story of a vertical opening, but the area within a stairway
shall not be used for storage or manufacturing, or within any enclosure for
other than the purpose or purposes for which the vertical opening was con-
structed, hut this provision shall not be held to prevent the placing of electrical
cabinets, piping, fire extinguishing apparatus and the like, in vertical enclosures
in such manner as shall not interfere with its required use. A corridor serving
as a passageway to two remote exits from a story shall be separated from such
exits, if enclosed, by the enclosure thereof.
(103)
Sees. 1601=1602
PART 16.
FLOOR CONSTRUCTION.
Section
1601 — Floor Construction.
1602 — Type I: Fireproof Floor Construction.
1603 — Type II: Semi-Fireproof Floor Construction.
1604 — Type III: Heavy Timber Floor Construction.
1605 — Type IV: Light Wooden Floor Construction.
1606 — Type V: Metal Frame Floor Construction.
1607 — Type VI: Wooden Frame Floor Construction.
1608 — Ratproofing.
Section 1601. Floor Construction. — The floor construction in all
buildings shall conform to the requirements of other chapters of this code as
to structural design, quality and strength of materials. Floors shall be so
constructed as to afford to walls, columns, piers, beams and other supporting
members the lateral support which is required for their stability.
*Sect. 1602. Type I: Fireproof Floor Construction. — (a) In
buildings of Type I construction the floors shall be of steel, reinforced concrete,
brick or structural clay tile arches, reinforced gypsum, or of combinations of
these materials or other approved system of floor construction, and shall be
of not less than three-hour fire-resistive construction as provided in Part 22.
Floor beams which are spaced not further apart than half the spacing of
columns, including in this case those connected to columns, may be considered
as a part of the floor and not of the building frame for purposes of this section.
(b) In buildings of Type I construction columns and framing supporting
floors, where they are not supported on masonry walls or piers, and such mem-
bers of the floor framing as are connected to columns or necessary for the
stability of columns, except as otherwise provided in this section, shall be of
structural steel protected by not less than four-hour fire-resistive protection
or of reinforced concrete the reinforcement of which is so protected, except
that fire protection need not be provided on steel or iron forms, on lintels not
more than six feet in span in bearing masonry walls and not more than ten feet
in span in non-bearing masonry walls, on supports for elevator guides and
elevator machines except where they support other loads or brace the floor
framing, on the metal framing of mezzanine floors which may be of wood as
specified in this section, or on the landings of enclosed stairways.
(c) Floors in Type I buildings may be covered with wood or other com-
bustible flooring. Where wooden sleepers are used for laying wooden floors the
space between the structural floor and the flooring shall be filled solidly with
incombustible material under corridor and permanent partitions and else-
where on continuous lines for at least a foot in width in such manner that there
will be no hollow spaces under the flooring exceeding one thousand square feet
(104)
Sees. 1602-1603
in area. Wooden flooring shall not underlie enclosure or toilet room parti-
tions, nor masonry partitions.
(d) Mezzanine floors in Type I buildings may be of wood or unprotected
metal provided there are not more than two such mezzanines in any one room,
the total area of the mezzanines does not exceed one third the area of the room
or five hundred square feet, and one is not above the other.
(e) The fire protective material required for structural steel shall prefer-
ably be applied directly to the metal but structural steel members enclosed in
spaces not over five thousand square feet in horizontal area, which are pro-
tected above, below and on all sides by ceilings, floors and walls of four-hour
fire-resistive construction and are unoccupied and inaccessible except in
emergency, need not have other fire protection.
(f) Ceilings in Type I buildings may be finished in wood or other combus-
tible but not highly flammable material for ornamental, insulating, acoustical
or similar purposes. Such material, with similar materials on walls and
partitions, shall not exceed ten pounds per square foot of floor area enclosed
by exterior walls and partitions of two-hour fire-resistive construction, nor a
total of five thousand pounds if said floor space is enclosed in exterior walls
and partitions of one-hour fire-resistive construction. Such materials shall
be backed up by three-quarter inch plaster or equivalent fire-resistive material.
[ *As amended by Ord. 1943, ch. 4 ]
fSect. 1603. Type II: Semi-Fireproof Floor Construction. — (a) In
buildings of Type II construction the floors shall be of incombustible materials
and structural metal shall have one-hour fire-resistive protection. Floor
beams which are spaced not further apart than half the spacing of columns,
including in this case those connected to columns, may be considered as a
part of the floor and not of the building frame for purposes of this section.
(b) In buildings of Type II construction columns and framing supporting
floors, where they are not supported on masonry walls or piers, and such
members of the floor frame as are connected to columns or necessary for
the stability of columns, except as otherwise provided in this section, shall
be of structural steel protected by not less than two-hour fire-resistive pro-
tection or of reinforced concrete the reinforcement of which is so protected,
except that fire protection need not be provided on steel or iron forms, on
lintels not more than six feet in span in masonry bearing walls and not more
than ten feet in span in non-bearing masonry walls, on supports for elevator
guides or elevator machines except where they support other loads or brace
the floor framing, or on the landings of enclosed stairways.
(c) Floors in Type II buildings may be covered with wood or other com-
bustible flooring as provided in section sixteen hundred and two for Type I
buildings.
(d) The fire protective material required for structural steel shall prefer-
ably be applied directly to the metal but structural steel members enclosed
in spaces not over three thousand square feet in horizontal area, which are
protected above, below and on all sides by ceilings, floors and walls of two-
hour fire-resistive construction, and are unoccupied and inaccessible except
Je emergency, need not have other fire protection.
(105)
Sees. 1603-1604
(e) Floor construction which consists of steel or other incombustible
beams or joists, spaced not more than the thirty-six inches on centers, sup-
porting a floor of reinforced concrete, steel plate or other incombustible
materials, and protected on the under side by an incombustible ceiling of one-
hour fire-resistive construction shall be considered as meeting the require-
ments of this section. Enclosed spaces formed by such a ceiling shall not
exceed five hundred square feet in horizontal area within incombustible fire
stops of one-hour fire-resistive construction.
(f) Ceilings in Type II buildings may be finished in wood or other com-
bustible but not highly flammable material for ornamental, insulating,
acoustical or similar purposes. Such material, with similar materials on walls
and partitions, shall not exceed ten pounds per square foot of floor space
enclosed with exterior walls, ceilings of three-hour fire-resistive incombustible
construction, and partitions of two-hour fire-resistive construction, nor six
pounds per square foot of floor space enclosed by exterior walls and par-
titions of one-hour fire-resistive incombustible construction or a total of
three thousand pounds. Such material shall be backed up by three quarters
inch plaster or equivalent fire-resistive material.
[ fAs amended by Ord. 1948, ch. 4 ]
Sect. 1604. Type III: Heavy Timber Floor Construction. — (a)
In buildings of Type III construction the floor planking, if of wood, shall
be not less than one and five eighths inches thick, tongued and grooved or
splined, and fire-stopped by a continuous layer of asbestos fabric or other
approved fire-resistive material, covered with wooden flooring not less than
three quarters inch thick, or equivalent protective flooring. Enclosed or
concealed spaces shall be avoided.
(b) Laminated floor construction consisting of lumber not less than one
and one half inches nor more than three inches thick placed on edge, and
securely spiked together, making a floor not less than three and one half
inches thick, may be used in place of planking.
(c) Floor beams in buildings of Type III construction, except as otherwise
provided in this section, shall be of structural timber not less than five
inches in least dimension nor less than forty square inches in cross-sectional
area, but this limitation shall not apply to nailing strips supported on masonry,
structural steel or the like.
(d) Columns supporting floors in buildings of Type III construction shall
be of structural timber not less than seven inches in least dimensions or of
steel protected as specified in this section. Column caps for the support of
beams and girders shall be of cast iron, steel or reinforced concrete, except
that wooden bolsters may be used on columns supporting not more than a
roof and one floor. Columns shall not rest upon the ends of wooden beams.
Wood shall not be used for columns in basements or cellars.
(e) The metal of steel column caps or of stirrups supporting beams or
girders shall not be thinner than three sixteenths inch nor shall that of cast
iron caps be thinner than one half inch.
(f) Timbers supported on masonry walls shall be bevelled so that they
may fall free of the wall in case of fire.
(106)
Sees. 1604-1607
(g) Structural steel I-beams or columns of H section may be used instead
of timber provided they are fireproofed by filling the space between flanges
solidly with concrete or masonry held in place by ties through or secured to
the web, or by enclosing the exposed faces in one-hour fire-resistive protection.
Other structural steel shapes may be used for beams or columns, protected
by one-hour fire-resistive protection. Standard weight steel pipe filled with
concrete may be used for columns in buildings of Type III construction.
(h) Floors shall be anchored to exterior and bearing walls and the beams
thereof shall be connected to form continuous ties from wall to wall sufficient
to resist the wind pressure specified in Part 23 applied outwardly to the walls.
(i) Structural masonry and reinforced concrete shall not be supported
upon wooden floor constructions, but this restriction shall not apply to fire-
stopping, the protective foundations under heat-producing apparatus or to
tile or concrete flooring with its base not more than four inches in total thick-
ness, laid upon the planking.
*Sect. 1605. Type IV: Light Wooden Floor Construction.— (a) In
buildings of Type IV construction the floors may be of wood unprotected
against fire. Floor beams and joists of wood shall not be less than one and
five eighths inches thick. Where joists frame on a girder or bearing partition
on both sides thereof, the spaces between the joists shall be fire-stopped
with incombustible materials or with wood not less than one and one half
inches thick.
(b) Floors may be supported upon the masonry walls of the building or
upon wooden columns or bearing partitions. Structural steel beams, steel or
iron columns without protection against fire, reinforced concrete or other
approved materials may be used in the floor framing or for its support. Wood
shall not be used for columns or bearing partitions in basements or cellars.
(c) Timbers supported on masonry walls shall be bevelled so that they
may fall free of the wall in case of fire.
(d) Floors shall be anchored to exterior and bearing walls and the beams
thereof shall be connected to form continuous ties from wall to wall sufficient
to resist the wind pressure specified in Part 23 applied outwardly to the walls.
(e) Structural masonry and reinforced concrete shall not be supported
upon wooden floor construction, but this restriction shall not apply to fire-
stopping, the protective foundations under heat-producing apparatus or to
tile or concrete flooring with its base not more than four inches in total thick-
ness, laid upon the boarding.
[ *As amended by Ord. 1948, ch. 4 ]
Sect. 1606. Type V: Metal Frame Floor Construction. — In buildings
of Type V construction the floors shall be constructed of incombustible '
materials. Structural steel or iron floor plates, structural steel beams, or
steel or iron columns supporting floors need not be protected against fire.
Sect. 1607. Type VI: Wooden Frame Floor Construction. — fa) In
buildings of Type VI construction the floors may be of wood unprotected
against fire. Floor beams and joists of wood shall be not less than one and
M07)
Sees. 1607-1608
five eighths inches thick. Where joists frame on a girder or bearing partition
on both sides thereof, the spaces between the joists shall be fire-stopped with
incombustible materials or with wood not less than one and one half inches
thick.
(b) Floors may be supported upon the walls of the building or upon
wooden columns or bearing partitions. Structural steel beams or steel or
iron columns without protection against fire, reinforced concrete or other
approved materials may be used in the floor framing or for its support. Wood
shall not be used for columns or bearing partitions in a basement or cellar.
(c) Structural masonry and reinforced concrete shall not be supported
upon wooden floor construction, but this restriction shall not apply to fire-
itopping, the protective foundations under heat-producing apparatus or to
tile or concrete flooring with its base not more than four inches in total thick-
ness, laid upon the under boarding.
Sect. 1608. Ratproofing. — (a) Every basement or cellar in buildings
hereafter erected shall be completely covered with a ratproof floor of con-
crete, or solid masonry laid in cement mortar, not less than two inches thick,
or other approved flooring. Pits or openings in such floors shall be lined on
all sides and the bottom with similar material.
(b) Recesses and inaccessible spaces where rats might find refuge and
breed shall be avoided if possible, and otherwise shall be sealed with masonry
or with substantial wire mesh of incorrodible metal.
(108)
Sec. 1701
PART 17.
ROOF CONSTRUCTION AND COVERING.
Section
1701 — Roof Construction.
1702 — Roof Covering.
1703 — Roof Drainage.
♦Section 1701. Roof Construction. — (a) Except as otherwise pro-
vided in this part, in so far as they are pertinent, the provisions of Part 16
for the construction of floors and their supports shall also apply to the con-
struction of roofs of buildings of the respective types of construction.
(b) Members of structural steel frames of roofs and other incombustible
roof construction covered with fire-retardant roofing, on Type I and Type II
buildings, over rooms of Group B occupancy and over approved rooms of
Group G occupancy shall be deemed to be sufficiently protected against fire
if they are not less than twenty-five feet distant from the floor, and from a
mezzanine floor or balcony below; or if they are not less than eighteen feet so
distant and are protected by an incombustible ceiling of one-hour fire-re-
sistive construction suspended at least one inch below the steel. Proximity
within these limiting distances of an inclined or stepped balcony with fixed
seats, of a mezzanine floor or level balcony not more than five feet wide,
shall not be grounds for requiring greater fire protection than is required
in this paragraph. The ceilings of such rooms and the walls more than five
feet above the floor shall not be covered or finished with combustible material.
(c) Filling for drainage on the roof of a building of Type I, Type II and
Type V construction shall be of incombustible material except that wood, in
amount not more than two board feet per square foot, may be used on a roof
of Type I or Type II construction designed for a future floor. Filling for
thermal insulation may be of combustible but not highly flammable material
laid without air space.
(d) In buildings of Type III the roof planking, if of wood, shall be not
less than one and one half inches thick. Wooden columns supporting a roof
in a building of Type III construction shall be not less than five inches in
least dimension.
(e) In buildings of Type III, Type IV and Type VI construction where
the exterior wall is required by Parts 3 to 12, inclusive, to be of fire-resistive
construction without unprotected openings, wooden joists, rafters and other
combustible roof construction shall not extend through or across the exterior
wall, except the roof boarding, planking or a nailing piece, which shall then
be covered with metal. Such walls shall extend up to the under side of the
roof boarding or planking and where required by Parts 3 to 12, inclusive, to
be of four-hour fire-resistive construction without openings, shall have para-
pots above the roof as specified in Part 14. Where such walls may have
(109)
Sees. 1701-1703
unprotected openings combustible roof construction may project not more
than one foot to form eaves except in the first and second fire zones.
[ *As amended by Ord. 1948, ch. 5 ]
Sect. 1702. Roof Covering. — Roof covering on buildings of Type I,
Type II or Type V shall be either fire-retardant or ordinary roofings as
specified in Part 22. Roof covering on buildings of Type III, Type IV or
Type VI shall be fire-retardant.
Sect. 1703. Roof Drainage. — (a) Roofs of buildings and of all parts
thereof shall be sloped to drain at a pitch of not less than one inch in ten feet.
Gutters and conductors or leaders shall be provided at the low points to
which water will flow, except on one story or two story buildings not over
six hundred and fifty square feet in area, with drains to lead away and satis-
factorily to dispose of rain water. Means shall be provided to prevent rain
water from any part of a building except window sills, copings and cornices
not more than one foot wide and awnings or marquises discharging off the
outer edge, from filling or flowing upon a public way.
(b) Where a roof is finished with a smooth surface of tile, terrazzo or
similar material and under other favorable circumstances, the commissioner
may waive the requirement of a slope and permit construction of a level roof
subject to such conditions as he shall in any case specify.
(c) No part of any roof shall be so constructed as to discharge snow or
ice upon a public way.
(d) Rain water leaders shall not be discharged upon a public way nor
upon land of another owner, nor so as to flow upon such public way or land.
(e) This section shall not be held to prevent the construction of a spray
pond on a roof or the use of a roof to contain water for industrial or other
approved purposes provided it is not allowed to become stagnant.
(110)
Sees. 1801-1802
PART 18.
EXITS.
Section
1801 — General Requirements for Exits.
1802 — Kinds of Exits.
1803 — Number of Occupancies.
1804 — Number and Location of Exits.
1805 — Corridors and Passageways.
1806 — Doorways as Exits.
1807 — Windows as Exits.
1808 — Interior Stairways.
1809 — Interior Ramps.
1810 — Smokeproof Towers.
1811 — Exterior Stairways or Ramps.
1812 — Fire Escapes.
1813 — Ladders as Exits.
1814 — Elevators as Exits.
1815 — Horizontal Exits.
1816 — Other Exits.
1817 — Exit Enclosures.
1818 — Exit Signs.
1819 — Exit Maintenance and Lighting.
Section 1801. General Requirements for Exits. — Every new building
and every portion thereof shall have exits in conformity with this part and
Parts 3 to 12, inclusive. No building shall be enlarged, altered or repaired
in such manner as to reduce the number or capacity of exits to less than
required nor shall the occupancy be changed unless the exits conform or are
made to conform to the requirements for the new occupancy.
Sect. 1802. Kinds of Exits. — (a) An exit from a room may be either —
1) A doorway.
2) A window.
3) An exit from a story.
(b) An exit from a story may be either —
1) An interior stairway.
2) An interior ramp.
3) A smokeproof tower.
4) An exterior stairway or ramp.
5) A fire escape.
6) A ladder.
7) Elevators.
8) An exit from the building or from the fire division.
(c) An exit from a building or from the fire division may be either —
(111)
Sees. 1802-1804
(1) A doorway in the exterior wall of the building opening upou a
street or an open space with access to a street.
(2) A horizontal exit.
(d) All exits shall be of the kinds listed in the preceding paragraphs
of this section subject to the limitations and requirements of this part, except
that where two exits are required the commissioner may permit the substi-
tution for one of them of sliding poles, chutes or other means of egress when
all the persons who may in emergency need to use such means of egress are
trained to their use in their daily occupations and when all other relevant
conditions are satisfactory to the commissioner.
(e) No exit of any kind may serve as a required exit unless it is or forms
part of a continuous path of exit from the floor space served to the street.
(f ) At least one exit from every story of a building, except a basement,
cellar, first or second story from which there is a doorway exit to a street or to
an open space accessible to a street, shall be an interior stairway, an interior
ramp or a smokeproof tower.
♦Sect. 1803. Number of Occupancies. — (a) The number of persons
to be served by an exit shall be stated in the application for permit and shall
be computed from the floor area on the following basis:
(1) One person for every six square feet in auditoriums, assembly halls,
dance halls, gymnasiums, armories, lodge rooms.
(2) One person for every fifteen square feet in court rooms, restaurants,
retail stores, class rooms in schools.
(3) One person for every twenty-five square feet in lodging houses,
reading rooms.
(4) One person for every thirty-five square feet in factories and work
rooms.
(5) One person for every fifty square feet in offices and show rooms.
(6) One person for every one hundred square feet in Group D buildings,
hotels, apartments and other dwellings, police and fire stations.
(7) One person for every two hundred square feet in automobile repair
shops and service rooms, museums, libraries, wholesale stores, and club-
houses, except in assembly halls thereof.
(8) One person for every thousand square feet in storage garages and
warehouses.
(b) For other occupancies the commissioner shall determine the ratio of
occupants to floor area in each case.
(c) Where the kind or width of an exit depends upon the number of per-
sons served by it, such number shall be determined by dividing the maximum
number of persons in any room or group of rooms, or in any story and within
a fire division, by the number of alternative exits to which they all have access
less one (assuming that one such exit may be blocked) except where only one
exit is required.
[ *As amended by Ord. 1943, ch. 5 ]
fSect. 1804. Number and Location of Exits. — (a) Except as other-
wise specified in Parts 3 to 12, inclusive, buildings and parts thereof shall have
at least the number of exits required in this section. The kinds of exits pro-
012)
Sec. 1804
vided, as required in this part, shall be subject to the limitations imposed by
sections eighteen hundred and five to eighteen hundred and sixteen inclusive.
(b) Every room and group of less than four rooms shall have at least one
exit conforming to the requirements of this chapter. The exit from an attic or
similar enclosed space, accessible but normally unoccupied, may be a scuttle
not less than two feet by three feet in the ceiling of the story below. Such
scuttle shall, if required by the commissioner, be provided with a paermanent
ladder. The flat roof of a building, if occupied by persons, shall be considered
a room and a story for the purposes of this section.
(c) Every room or group of rooms containing in the aggregate more than
twenty-five hundred square feet of floor area or seventy-five occupants and
every group of our or more rooms, except an attic or similar enclosed space
accessible but normally unoccupied, shall have at least two remote exits.
Such exits may open into a common corridor which has at least two remote
exits. Closets, vestibules, toilet rooms and the like shall not be counted as
rooms of a group for the purpose of this paragraph.
(d) When a story of a building is occupied by two or more tenants, each
tenant shall have access to at least two remote exits from the story.
(e) Every story in a building shall have at least two remote exits except:
(1) Stories above the first story in single family dwellings less than three
stories in height.
(2) A basement or cellar constructed large enough for low pressure
heating apparatus and its fuel storage only, requiring attendance of not
more than two persons.
(f) Every room or story required to have two remote exists shall have two
remote and independent paths of exit of the required width at all points.
(g) A single exit from a room or group of rooms which has no other exit
shall not be further than sixty feet from any point within the room or roomB
measured along the path of exit.
(h) Where two or more exits from a room are required they shall be
remote or distant from one another in such manner that persons in any place
may choose either of two directions in a path toward an exit, and in such a
manner that a single fire in its early stages cannot block both paths toward an
exit. The distance from any point in a room to the nearest exit, except as
specifically indicated in special group requirements, shall not exceed one
hundred and fifty feet in buildings of Type I, Type II and Type V nor seventy-
five feet in buildings of Type III, Type IV and Type VI.
(i) The exits from astory in a fire division shall be of such number and
so located that at least one such exit is within one hundred and fifty feet in
buildings of Type I, Type II and Type V, and within severy-five feet in
buildings of Type III, Type IV and Type VI, from every exit from a room or
group of rooms into a corridor or, in a story without a corridor, from every
point within the story and fire division, except as specifically indicated in
special group requirements. The distance to an exit, if a doorway, shall be
(113)
Sees. 1804-1806
measured to the nearer jamb thereof; if an enclosed stairway or ramp, to
the doorway in the enclosure; and if a stairway or ramp not enclosed, to the
nearest point of the top riser or commencement of slope.
[ 1[As amended by Ord. 1943, ch. 5 ]
*Sect. 1805. Corridors and Passageways. — (a) A passageway shall
be provided and maintained in every story of a building from all parts of
the floor to the required exits, of width not less than the required width of
the exit to which each leads, nor less than twelve inches for every one hun-
dred persons served.
(b) Corridors may serve as exits from the doorways from rooms to exits
from the story. The clear exit width of corridors shall be not less than the
required width of any doorway from which it leads, nor of the exit to which
it leads, nor less than thirty-six inches nor less than twelve inches for every
one hundred persons served.
(c) Neither radiators nor pipes, doors in an open position nor any other
equipment or construction shall be allowed to reduce or encroach upon the
required width of a corridor. If lockers are placed along one or both sides
of a corridor its clear width between lockers shall be increased over its required
exit width by eighteen inches for each side on which lockers are placed and
if other use than egress and lockers is made of corridors, the clear width
shall similarly be increased over its required exit width as the commissioner
shall in each case determine.
(d) Passageways which serve as exits from enclosed stairways or ramps
to exits from the building shall be enclosed corridors except where they may
occur in a building which is not over forty feet wide and of a total area not
exceeding two thousand square feet. In such a building one of the enclosed
corridors in the first floor only may be omitted provided the basement and
first story are equipped with automatic sprinklers and the class of construc-
tion is Type IV or more fire-resistant.
(e) The clear width of such passageways shall be not less than required
for the stairway or ramp nor less than twelve inches for every one hundred
persons in any story of the building served. The clear height shall be not less
than seventy-eight inches.
(f ) The floor and walls of a corridor serving as an exit from an enclosed
stairway or ramp shall have fire-resistance of the rating required for the
enclosure and the ceiling shall be of one-hour fire-resistive construction.
(g) The floor of such a corridor shall be level or shall slope not over one
vertical in ten horizontal, but such floor shall be level for a distance of forty-
four inches from a stairway and at all doorways or connecting corridors for
the full width thereof and one foot additional on each side.
(h) An outside passageway leading from an exit from a building to a
street shall have the clear width required for an interior passageway, and if
covered shall be covered by incombustible construction. Such passageway
shall be subject to all pertinent requirements for exits.
[ *As amended by Ord. 1948, ch. 5 ]
fSect. 1806. Doorways as Exits. — (a) Doorways which serve as
required exits shall be not less than twenty-four inches wide. Doorways
which serve as exits for more than ten persons shall be not less than seventy-
eight inches high nor less than thirty inches wide nor less than twelve inches
in width for every hundred persons so served.
(b) The floor both sides of a doorway exit shall be at the same level for
(114)
Sees. 1806-1808
a distance of three feet in either direction from the doorway, except that in
doorway exits from a building to the outside there may be a single step-down
not over six inches to a level landing not less than three feet wide.
(c) Thresholds in exit doorways shall not be over one inch high.
(d) In enclosures of stairways or ramps which serve as required exits,
doors shall swing in the direction of egress.
(e) Except in buildings of Group I, swinging doors in doorways which
serve as required exits from the building shall swing in the direction of egress.
(f) Revolving doors shall be of an approved type, without cable or bar
braces, designed and constructed to release when simultaneous outward
forces are exerted by persons of ordinary strength on both sides of the pivot
so that the wings will fold back on themselves like the leaves of a book in
the direction of egress. The use of revolving doors shall be limited as follows:
(1) They shall not be used in occupancies of Group A, Group B, Group
C, and Group D.
(2) They may be used in other group occupancies only if swinging doors
immediately adjacent to them provide seventy-five per cent of the required
egress.
(3) They shall not be used in any exit from premises where alcoholic
beverages are sold for consumption on the premises.
(g) Except in detention buildings, doors in required exits shall not be so
locked or fastened that they cannot be opened from the inside without use
of a key.
[ fAs amended by Ord. 1943, ch. 5 ]
Sect. 1807. Windows as Exits. — A window shall not serve as an exit
except in an existing building and in such case only as the second of two re-
quired exits serving not more than ten persons and subject to the approval of
the commissioner and to such conditions as he may in each case prescribe.
This provision shall not be held to limit the use of glass in a door.
JSect. 1808. Interior Stairway. — (a) Interior stairways may serve as
exits from any story of a building. Except as otherwise provided in this
section, every interior stairway required to be enclosed shall have a direct
doorway exit from the building or shall have an enclosed corridor leading to
such exit, except as provided in paragraph (d) of Section 1805.
(b) In buildings more than three stories high with flat roofs at least one
interior stairway or ramp shall extend to the roof; and where more than two
stairways or ramps serve as required exits, at least two shall be interior stair-
ways or ramps which shall extend to the roof. In such buildings more than
three hundred feet long there shall be at least two remote stairways or ramps
extending to the roof In a two-story or three-story building with flat roof,
unless a stairway extends to the roof, there shall be a scuttle in the roof, not
less than two feet by three feet, with a ladder, near a stairway.
(c) An interior stairway shall be located entirely within the exterior walls
of a building, but this requirement shall not be held to constrain the shape
or plan of the exterior walls or the construction of the enclosure wall.
(d) No interior stairway serving as a required exit shall be less than
thirty inches wide except a single flight stairway to a balcony serving not more
(115)
Sec. 1808
than ten persons which may be not less than twenty-four inches wide. No
stairway serving as a required exit for ten or more persons shall be less than
thirty-six inches wide nor less than twelve inches additional for every one
hundred persons so served in excess of three hundred. The clear vertical
headroom over each riser shall be not less than six feet six inches.
(e) Interior stairways shall be enclosed where so required in Parts 3 to 12,
inclusive, and in Part 15 of this code.
(f ) In buildings of Type I, Type II or Type V interior stairs, including
landings, which serve required exits shall be constructed of incombustible
materials, except that stairs with solid treads, risers and landings of incom-
bustible materials may have top surfaces of wood, linoleum or other similarly
combustible material. Treads, risers or landings of marble, slate or similarly
brittle material shall be backed with sheet steel, for stairs three feet or less in
width of at least number twelve gage, and for wider stairs at least number ten
gage. Cast iron shall have a thickness of at least three sixteenths inch in
treads and risers and three eighths inch in landings. Cast iron landings shall
not have greater area than nine square feet between steel or other supports.
Enclosed metal stairs and landings need not be protected against fire. Stairs
which are not enclosed as provided in Part 15, in buildings of Type I or Type
II shall have protection against fire as specified for floors.
(g) In buildings of Type III, Type IV or Type VI not over three stories
high, stairs, including landings, may be of wood. In buildings of Type III
wooden stairs which are not enclosed as provided in Part 15 shall have treads
at least one and one half inches thick; the risers, if any, shall be one and one
half inches thick; stringers shall be not less than three and one half inches in
least dimension; and the stairs shall be constructed without concealed spaces.
Wooden stairs with soffits enclosed by plaster, sheathing or otherwise, shall be
fire-stopped at floors and landings and not further apart than at every eighth
riser with incombustible material or with wood not less than one and one half
inches thick.
(h) Treads and risers of stairs serving as required exits, except in schools,
shall be so proportioned that the product of the tread and the rise in inches
shall be not less than seventy nor more than seventy-seven; and the treads
shall not be less than nine and one half inches nor the rise more than seven and
three quarters inches. In schools, the treads and risers may be proportioned,
with the approval of the commissioner, to suit the age of the pupils. Treads
and risers shall be uniform throughout any one flight.
(i) No flight of stairs shall have more than fifteen nor less than two risers
between landings. A landing between two flights of stairs in the same
direction shall be at least as wide as the stairs and at least three feet long in
the direction of travel. Stairs turning at a right angle shall have a square
or rectangular landing the full width of the respective stairways. Where
stairs return directly on themselves, a landing without steps shall be provided
at least as wide as the stairs.
(j) Spiral stairs shall not be used in a stairway serving as a required exit
for ten persons or more nor in stairways more than one story in height, except
in a single family dwelling; and in pre-code buildings with the approval of
(116)
Sees. 1808-1809>
the commissioner. Stairs may be curved if the tread and rise one foot from
the inner rail are as specified in this section.
(k) Where stairs and landings are not guarded at the side by a wall or
partition, they shall have a railing, balustrade, grille or similar guard at least
thirty-three inches high at the face of the riser. In case a stairway more than
two stories high has recurring flights and landings, about an interior well1
more than twelve inches wide in horizontal projection, the guard next the
well shall be not less than three feet high at the face of the riser, and shall con-
sist, if a railing, of at least two rails, if a balustrade, of balusters not over
six inches apart, and if a grille or other form of guard, of meshes not more
than six inches in least dimension, and the edge of the stairs and of the land-
ings shall have a curb at least three inches high.
(1) Stairs less than forty-four inches wide shall have a handrail on one
side; stairs forty-four inches wide or more and curved stairs shall have hand-
rails on both sides. Where the width of a stairway is required, as an exit,
to exceed eighty-eight inches one or more intermediate handrails shall be
provided not over eighty-eight inches apart. Handrails shall be about three
feet high above the center of the treads, shall be continuous between landings
and in stairways which serve as required exits, handrails which are not con-
tinuous shall be returned at the upper end to the wall or terminate at a post
in such manner as not to leave a free or projecting end. Handrails may be
of wood.
(m) No pipe, radiator or other equipment shall obstruct or encroach upon
the required width of a stairway or landing. No stairway which serves as a
required exit shall be obstructed while the building is occupied, within the
enclosure thereof, on the steps or landings or on the floors within the area
required for exit or for approach to the stairway, by materials, equipment
or by any use of such space except for passage.
(n) There shall be no closet within the required enclosure of a stairway.
There shall be no closet for storage under a stairway of combustible material
which is a required exit except a coat closet in dwellings or a toilet or similarly
non-hazardous use, and in such case the soffit of the stairway shall be pro-
tected by a ceiling of one-hour fire-resistive construction.
[ %As amended by Ord. 1943. ch. 5 ]
*Sect. 1809. Interior Ramps. — (a) Interior ramps may serve as
exits from any story of a building.
(b) An interior ramp shall be located entirely within the exterior walls of
a building.
(c) The width, enclosure, guarding and construction of ramps shall be
the same as provided for interior stairways. All requirements for interior
stairways which are pertinent shall also apply to interior ramps except the
requirement for handrails.
(d) Ramps which serve as required exits shall not have a slope greater
than one vertical in ten horizontal.
[ *As amended by Ord. 1948, ch. 5 ]
(117)
Sees. 1810-1811
*Sect. 1810. Smokeproof Towers. — Smokeproof towers, if built, may
serve as required exits from any story of a building. Interior stairways con-
structed and arranged as follows shall be known as smokeproof or fire towers,
(a) The enclosed walls of fire towers shall be of incombustible materials
or assemblies having a fire-resistive rating of at least four hours. Such walls
shall be without openings, except for doors serving as means of egress.
(b) At each story served by a fire tower access to the stairways of such
fire tower shall be provided through outside balconies or fire-proof vestibules.
Such balconies or vestibules shall be at least three feet eight inches in width
and shall have unpierced floors of incombustible materials and shall be pro-
vided with substantial guard rails at least four feet high, without any open-
ings greater than eight inches in width.
(c) Such balconies or vestibules of fire towers shall be level with the floors
of the structure and the platforms of the stairs connected by such balconies.
Such balconies or vestibules shall be separated from the structure and the
stairs by self-closing fire doors capable of being opened from both sides
without the use of a key, except the final balcony or vestibule as described
in paragraph (d) which may open only from one side without the use of a key.
(d) Balconies or vestibules of fire towers shall open on a street or yard
or on a court open vertically to the sky for its full height, having a minimum
net area of one hundred and five square feet and a minimum dimension of
seven feet. The opening from the vestibule to the street, yard or court shall
have a minimum area of eighteen square feet and a minimum dimension of
two feet six inches. It shall be unlawful to leave openings in the court walls
surrounding an interior fire tower other than the openings from the vestibules,
within fifteen feet of the balcony, except that self-closing fire windows may be
used if such windows are at least ten feet from the balcony, provided that the
area of the court is at least twelve feet by twenty-four feet.
(e) Fire towers shall terminate at the grade level and shall exit directly
to the street independently of corridors serving other stairways except when
the fire tower terminates in the ground floor corridor outside of the inner
vestibule and within ten feet of the building line.
(f) Doors opening into fire towers may be constructed with observation
panels made of polished wire glass, one-quarter of an inch thick, if such glass
is set with a three-quarter inch rabbet. Such glass shall have a maximum
area of sixteen square inches. Doors shall be capable of being opened from
both sides without the use of a key. A handrail shall be provided on both
sides.
[ *As amended by Ord. 1943, ch. 5 ]
Sect. 1811. Exterior Stairways or Ramps. — (a) Exterior stairways
or ramps may serve as required exits from any story or stories of a building.
Except as to enclosure and location within the exterior walls of a building,
an exterior stairway or ramp shall conform to the requirements for interior
stairways or ramps, respectively. Exterior stairways or ramps shall be
located outside the exterior walls of a building, but not nearer than five
feet from a lot line other than a street line.
(b) Exterior stairways or ramps serving as required exits, and their land
(118)
Sees. 1811-1812
Inge, railings and enclosures, if any, shall be of incombustible materials except
on buildings of Type VI construction and except that handrails may be of wood.
(c) A doorway serving as an exit from a story to an exterior stairway or
ramp shall open upon a landing level with or not more than one six-inch step
below the floor, and shall be protected except in buildings of Type VI con-
struction by a self-closing Class B fire. door. Openings for doorways or win-
dows under or within five feet from an exterior stairway or ramp, except in
buildings of Type VI construction, shall be protected by automatic-closing
Class B fire doors or fire windows, unless the exterior stairway or ramp is
enclosed in one-hour fire-resistive construction.
(d) Except where guarded on the side by the exterior wall of the building,
or by an enclosing wall, an exterior stairway or ramp more than three stories
or thirty feet above the ground shall be guarded by a railing, balustrade or
grille not less than six feet high with openings not more than six inches wide.
*Sect. 1812. Fire Escapes. — (a) Fire escapes shall not be erected to
serve as required exits except as follows: —
(1) From pre-code buildings where ordered by the commissioner under
the provisions of Section 16 of Part I.
(2) From post-code buildings four stories or less in height and five
thousand square feet or less in area.
(3) Where ladders may serve as exits.
(4) As emergency exits from buildings of Group A or Group B occu-
pancy as provided in Parts 3 and 4, and
(5) Where ordered by the commissioner under the provisions of section
sixteen of Part 1.
(b) Fire escape landings and stairs shall have a clear exit width of not
less than twenty-four inches where the maximum number of persons to be
served does not exceed one hundred and forty-four, and an additional one
inch in width shall be added for each additional six persons served, excepting
therefrom emergency exits as required in Group A and Group B.
(c) Fire escapes shall be of incombustible materials.
(d) The floors of fire escape balconies or landings, if of steel, shall be of
open construction with steel bars not over one half inch nor less than one
quarter inch wide and spaces not over one and one quarter inches each nor
less in the aggregate than two thirds the floor area. The bars shall be rigidly
spaced near their ends and at intervals not exceeding two feet. Floors shall
be securely attached to supports.
(e) Fire escape stairs, if steeper than is allowed for interior stairs, shall
not be steeper than necessary, nor in any event steeper than sixty degrees
with the horizontal. Stairs steeper than sixty degrees shall be deemed
ladders and shall not be used for exits except where ladders are allowed.
The product of the tread and rise in inches shall be not greater than seventy-
seven and the rise shall not exceed nine inches. The construction of the
tread shall be as required for landing floors, if of steel, and not less than seven
and one-half inches wide. Treads shall be securely attached to stringers.
There shall not be less than three nor more than fifteen risers between
landings.
(119)
Sees. 1812-1813
(f) The sides and ends of fire escape landings and the sides of stairs, where
not guarded by a wall, shall have a railing at least three feet high, consisting
of a bar not less than one and one half by three eighths inch and a balustrade
of half -inch round bars or equivalent with a lower rail. The railing shall be
supported by posts and shall be sufficient to withstand safely a lateral force
of twenty pounds per foot of rail, and in Group H and Group I shall have
one-half inch round bar palings not over six inches from center to center.
(g) Openings for doorways or windows under or within five feet from a
fire escape, except in buildings of Type VI construction, shall be protected
by automatic-closing Class B fire doors or fire windows, unless in the case of
show windows or other windows the commissioner modifies this requirement
in consideration of other specific provisions contributing to safe egress over
the fire escape in question.
(h) Fire escapes shall not be bracketed from masonry walls more than five
times the thickness of the wall. Bracketed cantilevers shall be bolted through
the wall with plate washers set in mortar on the inside.
(i) Except in the webs of structural channels and I-beams, and in the
recticular or cross bars of factory-assembled floor gratings approved as
flooring for fire escapes, the steel in fire escapes shall not be thinner than
one quarter inch nor shall bolts be less than three eighths inch. Stove bolts
shall not be used. If stringers of stairs are spliced, the splice shall be made
by riveting or welding, and not by bolting.
(j) The lowest run of fire escape stairs may be hinged near the top to
swing up into a horizontal position when not in use. Such runs shall be
counter-balanced but not so heavily that they will fail to lower by gravity
when released. The hinge shall consist of a single round bar, not less than
seven eighths inch diameter, with approved bearings on both stringers of the
lower run and properly supported. The hinge bar shall be not less than two
inches horizontally back from the nosing of the stair tread under which it is
placed. The hinged run shall be held in horizontal position by a bent bar
at least seven eighths inch in diameter, rigidly held in bearings and bent
across the stairway above the hinged run in such manner that a person using
the fire escape for egress must release the hinged run before reaching it, or
by other approved device.
[ *As amended by Ord. 1943, ch. 5 ]
fSect. 1813. Ladders as Exits. — (a) Ladders shall not serve as
exits except where specifically allowed in this part and in Parts 3 to 12, in-
clusive. A ladder not more than one story high may serve as exit where a
scuttle is allowed.
(b) Ladders serving as exits shall be permanently fixed in place and shall
be not over fifteen feet in length. In buildings of Type I, Type II and Type V,
ladder exits shall be incombustible. Rungs shall be uniformly spaced, not
over twelve inches top to top, and shall be supported by two rails not less
than twelve inches apart.
[ \As amended by Ord. 1943, ch. 5
(120)
Sees. 1814-1815
*Sect. 1814. Elevators as Exits. — (a) Elevators may serve as
exits from stories of buildings where all the following requirements are com-
plied with, namely: —
(1) There are at least two other remote exits from the stories conform-
ing with the provisions of Section 1804 and not less than three feet six
inches wide.
(2) The elevators shall be passenger elevators, not less than two in
number enclosed in a single shaft or in adjoining shafts. The elevators
shall have capacity to evacuate the occupants of any floor in five trips each
(3) The elevators shall be in operation and in charge of licensed opera-
tors during usual business hours and when the building is occupied.
(4) The elevators shall have a lobby outside their enclosure in each
story served by the elevators with a floor area of at least two square feet
for every occupant in the story, separated from the occupied area of the
story by partitions of not less than one-hour fire-resistive construction.
Vertical openings within such lobbies shall be enclosed in all stories in
which they occur. Corridor space contiguous to the lobby shall be con-
sidered a part of the lobby.
(5) In buildings of Type III or Type IV construction, the enclosure
of lobbies in successive stories shall be continuous, forming a complete
one-hour separation as specified in Part 13, through all stories.
(b) Elevators serving as exits shall have sufficient speed to make a round
trip from first story to top and back without intermediate stops in two minutes
[ *As amended by Ord. 1943, ch. 5 ]
Sect. 1815. Horizontal Exits. — (a) A horizontal exit shall consist
of a doorway in an exterior or party wall of a building or in a fire wall separat-
ing two fire divisions of a building, which leads to a story, in another building
or fire division, at the same or approximately the same level, from which
egress may be made.
(b) A horizontal exit may serve as an exit from a room, from a story or
from a building, but not from the interior stairway or ramp required in
paragraph (f) of section eighteen hundred and two.
(c) The clear floor area in the story in the building or fire division to which
a horizontal exit leads shall be sufficient to contain the occupants of the story
in both buildings or fire-divisions allowing three square feet for each person.
(d) A horizontal exit shall have at least the width required for it as an
exit, or for the exits which it serves as outlet.
(e) Where the floors connected by a horizontal exit are at different levels
a ramp shall be provided the full width of the exit sloping not over one vertical
In ten horizontal, with guard railing on the open sides.
(f) The doorway of a horizontal exit in an exterior wall of a building may
lead to an adjoining or nearby building by means of a connecting balcony
or bridge or by a tunnel, at least as wide as the doorway. The floor of such
balcony or bridge, except as provided in paragraph (g) of this section, shall be
solid of Type I construction, and shall be level with, or not more than one
six-inch step down from, the floors with which it connects. The floor of such
a balcony, bridge or tunnel shall be horizontal or have a slope not exceeding
(121)
Sees. 1815-1819
one vertical in ten horizontal, and shall not contain steps or stairs except with
the approval of the commissioner. Unless the balcony or bridge is enclosed
in one-hour fire-resistive incombustible construction, doorways or windows
opening on or under, or within five feet from such balcony or bridge, shall
have automatic-closing Class B fire doors or fire windows. The open sides
of such balcony or bridge shall be guarded as required for the landings of
exterior stairways.
(g) Connecting balconies of fire escape construction may be used for
horizontal exits only where fire escapes are permitted.
Sect. 1816. Other Exits. — Sliding poles, chutes or other devices pro-
vided as means of egress shall conform in all respects to such requirements
as the commissioner shall in any case prescribe.
Sect. 1817. Exit Enclosures. — (a) Interior stairways and ramps shall
be enclosed as specified in Parts 3 to 12, inclusive, and in Part 15.
(b) Interior stairways and ramps which serve as required exits from
stories above the second story shall be enclosed, except as otherwise provided
in Parts 3 to 12, inclusive, in all stories in which they occur.
(c) Doors in a stair enclosure shall be automatic or self-closing and shall
never be locked against egress except in detention buildings. Such doors
shall swing in the direction of egress and shall not in any position reduce the
width of the stairway or its landings below that which is required.
Sect. 1818. Exit Signs. — Required exits, except in buildings of Group I,
Division 1, shall be marked by suitable signs sufficiently illuminated to be
easily read when the building is occupied. If exits are located where they
would not be expected to be found, directing signs shall be provided as they
may be required by the commissioner.
Sect. 1819. Exit Maintenance and Lighting. — (a) Required stair-
ways, passageways, corridors and other exits shall be at all times maintained
in safe condition, and when the building is occupied, shall be kept clear of
obstructions and ready for use.
(b) Outside stairs and fire escapes and the vestibules of smokeproof
towers shall be cleared promptly of ice or snow. Awnings shall not be per-
mitted to interfere with fire escapes.
(c) Required stairways, passageways, corridors and other exits, interior
or exterior, except in single-family dwellings and within apartments or suites
of buildings of Group H and Group I, shall be kept adequately lighted when
the building is occupied, or shall be provided with approved means for light-
ing which can be turned on by an occupant at a convenient point or points.
(122)
Sec. 1901
PART 19.
DOORS, WINDOWS AND SKYLIGHTS.
Section
1901 — Doors.
1902 — Windows.
1903 — Skylights.
1904 — Sidewalk Lights.
*Section 1901. Doors. — (a) Doors in doorways which serve as re-
quired exits shall conform to the requirements of Part 18.
(b) Doorways in enclosures of vertical openings shall have doors which
conform to the requirements of Part 15.
(c) Doorways in required separations between two units of occupancy or
between two fire divisions of a building shall have doors which conform to the
requirements of Part 13.
(1) Except where otherwise specified in this code, doorways in walls
required to have one-hour resistance to the spread of fire shall have doors
which, if of wood, shall be not less than one and one half inches thick in
any part. Such doors, if not of wood, or if larger than twenty-five square
feet in area, shall be Class C fire doors.
(2) Except where otherwise specified in this code, doorways in walls
required to have two-hour resistance to the spread of fire shall be automatic-
closing Class B fire doors.
(3) Except where otherwise specified in this code, doorways and other
openings in walls required to have three-hour resistance to the spread of fire
shall have automatic-closing Class B fire doors on both sides of the wall.
The sum of the areas of such openings in one story shall not exceed one-half
the area of the sum of said walls and no single opening shall be greater in
area than two hundred square feet.
(4) Doorways and other openings in party walls and, except where
otherwise specified in this code, in walls required to have four-hour re-
sistance to the spread of fire, shall have automatic-closing Class A fire
doors on both sides of the wall. The sum of the areas of such openings
in one story shall not exceed one-half of the sum of the areas of said party
walls and no single opening shall be greater in area than one hundred
square feet.
(5) In the protection of openings less than two square feet in area in
fire-resistive walls, the commissioner may waive in part or modify the
requirements of this section subject to such conditions as he shall in each
case specify.
(6) In doorways required to have specified width and height a stop
moulding forming a rabbet of the frame may project on each side and at
the top not more than three-quarters of an inch inside the required dimen-
(123)
Sees. 1901-1903
sions. The door, in open position, shall clear the required width of the
doorway completely and the door and frame shall have additional width
if necessary for this purpose.
(7) Doors required to be automatic-closing shall be self-closing and
normally closed, or equipped to close automatically by the action of heat
in the event of fire.
[ *As amended by Ord. 1943, ch. 5 ]
fSect. 1902. Windows. — (a) Fire windows shall conform to the
requirements of Part 22.
(b) Windows in exterior walls of buildings shall conform to the require-
ments of Parts 3 to 12, inclusive, and Parts 14 and 20.
(c) Wiadows in enclosures of vertical openings shall conform to the
requirements of Part 15.
(d) Windows in required separations between two units of occupancy or
between two fire divisions of a building shall conform to the requirements
of Part 13.
(e) Windows in other walls and partitions required to have resistance to
the spread of fire shall be fire windows.
(f) In walls and partitions the openings of which are required to have
the protection of fire doors, a fixed fire window may be considered equivalent
to one Class B fire door, but two such windows shall not be substituted as
equivalent to two doors in an opening where two fire doors are required.
(g) In the exterior walls of buildings of approved occupancy and con-
struction the commissioner may allow the substitution of an approved system
of open sprinklers and ordinary windows for the fire windows specified in
this section.
(h) Windows in exterior walls of elevator shafts shall be protected by
vertical metal bars not less than five eighths inch in diameter, outside the
sash, forming spaces not more than ten inches wide, firmly secured in the
opening.
(i) Openings in cellar and basement walls shall have effective protection
against the passage of rats.
(j) In display windows fronting on a public way, in the first story of a
building, a bulkhead may be constructed which shall be of the same type
of construction as the first floor. Where the first floor is continuous to the
exterior wall without opening, a platform of wood or other combustible
material may be built to form the raised floor of the display space. In dis-
play windows, fronting on a public way, not more than two stories high,
the back, sides and ceiling of the display space, shelves, partitions and the
like, and entrance vestibules and doorways in connection with such display
windows, may be of wood or other combustible but not highly flammable
material; provided, that this paragraph shall not be construed to allow a
vertical opening in any floor without the enclosure specified in Part 15.
[ fAs amended by Ord. 1943, ch. 5 ]
JSect. 1903. Skylights. — (a) Except on greenhouses skylights shall
be of incombustible materials.
(124)
Sees. 1903=1904
(b) Except on greenhouses, and except over photographic studios with
the approval of the commissioner, skylights shall be glazed with wire glass
or shall be protected by wire screens. Such screens shall be of at least No. 12
gage wire with not larger than one-inch mesh, on substantial metal supports,
at least six inches but not more than twelve inches above the glass and parallel
thereto, and projecting at least six inches beyond the edge of the skylight.
(c) Skylights over stairways and corridors, except in buildings of Group I,
and skylights over restaurants, halls and other public rooms, shall be glazed
with wire glass or protected by a wire screen or a ceiling light of wire glass
below.
(d) Skylights, except the glass thereof, shall be designed to support the
loads provided in Part 23 for roofs of corresponding slope.
(e) The parts of skylights exposed to the weather, gutters for leakage
or condensation, outside screens and their supports if of metal, shall be of
metal protected against corrosion.
[ {As amended by Ord. 1943, ch. 5 ]
Sect. 1904. Sidewalk Lights. — Glass units of approved shape, size
and thickness may be set in reinforced concrete roofs, floors or sidewalks,
with or without metal shields, in a manner approved by the commissioner.
Screen protection shall not be required above or below such construction
except where specifically required by the commissioner.
(125)
Sees. 2001-2002
PART 20.
PENTHOUSES AND ROOF STRUCTURES.
Section
2001 — Height of Buildings.
2002 — Penthouses.
2003 — Roof Structures.
♦Section 2001. Height of Buildings. — (a) Limitation, wherever it
occurs in this code, upon the height of buildings measured to the highest
point of the roof thereof shall not be held to limit the height of the steeples
of churches, towers, domes, cupolas, belfries, parapets, or other walls, cor-
nices, statuary, balustrades, railings, flag poles, weather-vanes, chimneys,
vent pipes, skylights, ventilators, steam exhausts, tanks, signs and pent-
houses for the enclosure of tanks, stairways, elevator machinery, ventilating
fans and the like, erected upon or above the roof of a building, provided
such structures shall not be occupied by persons nor be used for storage or
for a manufacturing process requiring constant or frequent attendance.
(b) The provisions of this part shall not be held to authorize construc-
tion of any kind above the limit of height specified for every part of a build-
ing in section one hundred and thirty-six of Part 1 of this code.
(c) The limitation of height of buildings contained in Parts 3 to 12, in-
clusive, of this code and the provisions of this part shall not be held to pro-
hibit the use of the open roof of a building, nor the laying of suitable flooring
over the roof covering, which conforms with the provisions of this code for
the type of construction of the building.
[ *As amended by Ord. 1943, ch. 5 ]
Sect. 2002. Penthouses. — (a) Penthouses enclosing elevator machin-
ery, ventilating fans, tanks, elevators, stairways and the like shall not be
larger than reasonably necessary for their purpose, including the storage of
tools, spare parts, appliances and materials necessary for the maintenance
and repair of such equipment.
(b) Penthouses on buildings of Type I or Type II construction shall be of
incombustible materials and the walls and roofs thereof shall afford protection
against fire outside of one-hour fire-resistive construction. Doors and win-
dows in such walls shall be Class C fire doors or fire windows.
(c) Penthouses on buildings of Type V construction shall be of incom-
bustible materials including the doors and windows thereof.
(d) Penthouses on buildings of Type III, Type IV or Type VI shall be
of the same type of construction as the building and the walls thereof may
be constructed as provided in this code for partitions, covered on the outside
by metal, cement plaster on metal lath or equally fire-retardant covering.
(e) The wall of a penthouse which rests upon the exterior wall of a build-
ing shall conform to the requirements of this code for an exterior wall.
(126)
Sees. 2002-2003
(f) Except where used as provided for in paragraph (a) of this section, a
penthouse upon the roof of a building shall be considered an additional story
or additional stories of the building and shall conform to the requirements
therefor. The provisions of this section shall not be held to limit the con-
struction of such additional stories.
Sect. 2003. Roof Structures. — (a) The walls of dormers shall be
constructed as specified in this code either for the exterior walls or for the
roof of the building on which they are built.
(b) Where persons occupy or use the open roof of a building, such roof
or the portion so occupied shall be guarded by a parapet wall or approved
fence or railing not less than forty-two inches high.
(c) Except as otherwise provided in this part, and except flag poles and
water tanks, all structures erected on the roof of a building shall be of incom-
bustible materials.
(127)
Sees. 2101-2102
PART 21.
CHIMNEYS AND HEATING APPARATUS.
Section
2101 — Support of Chimneys.
2102 — Chimney Construction.
2103 — Chimney Height.
2104 — Wood near a Chimney.
2105 — Smokestacks.
2106 — Smoke Pipes.
2107 — Fireplaces.
2108 — High Pressure Boilers.
2109 — Low Pressure Boilers.
2110 — Hot Air Furnaces.
2111 — Hot Air Pipes and Registers.
2112 — Electric Ranges, Water Heaters and Hot Plates.
2113 — Domestic Stoves and Ranges.
2114 — Commercial Stoves and Ranges.
2115 — Oil Burners.
2116 — Incinerators.
2117 — Support of Heat Producing Apparatus.
2118 — Smoke Connection.
2119 — Other Heat Producing Apparatus.
♦Section 2101. Support of Chimneys. — (a) A chimney shall support
no vertical load except its own weight, but this provision shall not apply to
masonry bonded to a chimney outside the required thickness thereof, nor shall
It be held to forbid a suspended staging for erection or maintenance. An
independent or free-standing chimney shall be stable and shall support its
weight and resist the force of the wind without exceeding the stresses allowed
by this code for the materials of which it is constructed.
(b) Unless corbelled from a masonry wall, a chimney shall be supported
upon a foundation of masonry or reinforced concrete conforming to the pro-
visions of Part 29, upon the furnace which it serves, if of masonry and capable
of supporting the chimney, or upon primary framing of Type I or Type II
construction.
(c) No chimney shall be corbelled from a masonry wall more than the
thickness of the wall nor from a wall less than twelve inches thick.
[ *As amended by Ord. 1943, ch. 5 ]
Sect. 2102. Chimney Construction. — (a) The walls of chimneys
shall be of brick, stone, cast stone, concrete blocks, structural clay tile or plain
or reinforced concrete, with such lining as is specified in this section.
(b) For the purposes of this part the lining of a chimney flue shall mean
the material forming the inner surface of the flue, whether the remainder of
the chimney wall is (1) integral with the lining, (2) additional thickness of
similar material or (3) of different materials. Except as otherwise specified
in paragraph (i) of this section, the lining of every flue in a chimney shall be
of burned clay or shale brick not less than three and one half inches thick of
(128)
Sec. 2102
A or B quality as specified in Part 24, or of refractory material as specified
in this section. The lining of every chimney flue more than two hundred
and fifty-six square inches in area of cross-section shall be of refractory
material from a point not less than twice the inside diameter of the chimney
(the larger diameter if rectangular) below the bottom of the smoke pipe
entrance, or from the bottom of the flue, to a point not less than six times such
inside diameter above the top of the smoke pipe entrance. Refractory
material shall consist of burned fire clay flue lining not less than five eighths
inch thick, fire brick not less than three and one half inches thick, or radial
hollow clay chimney tile, made of suitable refractory clay capable of with-
standing the heat and corrosive effect of flue gases and having a softening point
not lower than nineteen hundred degrees Fahrenheit. In such a chimney
mounted upon a masonry furnace the required refractory flue lining shall be
continuous with the lining of the furnace and shall extend not less than six
times the inside diameter of the flue above the top of the furnace.
(c) Burned fire clay flue linings shall be built in as the masonry of the
chimney is laid. All joints and spaces between the masonry and lining shall
be thoroughly filled with mortar as each course of the masonry is laid.
Cracked, broken or otherwise defective flue lining shall not be used in a
chimney. Fire brick or radial tile lining shall be laid in fire clay or with
narrow beds and joints of mortar. Burned clay or shale brick lining shall be
laid in mortar or fire clay. Brick or radial tile lining may be separated from
the chimney wall provided the wall outside the lining is not less than eight
inches thick, and both wall and lining are independently stable.
(d) Not more than three flues of burned fire clay flue lining may be laid
contiguous in a chimney nor shall the aggregate width of such contiguous
flues exceed thirty-seven inches without separating masonry withes at least
four inches thick bonded to the walls of the chimney. Walls of brick between
two flues in a chimney shall be not less than three and one half inches thick.
(e) The masonry wall of a chimney outside the flue lining shall be not less
than four inches thick. In chimneys of radial hollow clay chimney tile in
which wall and lining are integral the total wall thickness shall not be less than
six inches.
(f) Stone masonry of sawed or dressed stone in courses, well bonded at
corners and tied with anchors of non-corrodible metal shall be not less than
four inches thick outside the flue lining. Chimney walls of other stone
masonry shall be not less than twelve inches thick outside the flue lining.
(g) Concrete block masonry shall not be used in an independent or free-
standing chimney nor in chimneys bonded to walls more than three stories
in height.
(h) Structural clay load-bearing tile of A grade, as specified in Part 24,
may be used in the walls of chimneys, or radial hollow clay chimney tile of
equivalent quality. Other hollow clay tile shall not be used. Units shall
be so laid that the ends of cells are not exposed.
(i) Chimneys of concrete cast in place shall be reinforced for shrinkage
and temperature stresses. Concrete integral with the chimney wall shall be
considered satisfactory flue lining in such chimneys above a point thirty feet
above the smoke entrance, and in flues less than one hundred and forty-four
(129)
Sees. 2102-2105
square inches in area in buildings of Group I, Division 1, provided the con-
crete walls are not less than six inches thick and the concrete is proportioned
for a strength of two thousand pounds per square inch as specified in Part 26.
(j) Chimneys shall have a coping at the top for protection of the masonry
from the weather.
Sect. 2103. Chimney Height. — (a) Chimneys shall be carried to a
height sufficient to protect adjoining buildings from fire and smoke and unless
the roof is covered with incombustible material, shall extend at least thirty
inches above the highest point of intersection with the roof.
(b) Chimney flues shall have a well below the entrance of the lowest
smoke pipe and shall be provided with a metal cleanout door with built-in
frame.
*Sect. 2104. Wood near a Chimney. — (a) No chimney shall
be built nearer than one inch from wooden floor or roof joists or nearer than
one inch from wooden studding, furring or other woodwork. The space
about a chimney shall be fire-stopped at each floor and ceiling level with
incombustible material, unless such space is treated as a vertical opening
and is enclosed as provided in Part 15.
(b) In case wooden beams or other woodwork are supported on a masonry
wall or pier bonded to a chimney, such woodwork shall not be nearer than
four inches from the chimney. For the purposes of this section a chimney
shall consist of the flue or flues, the lining, if any, and the walls to the
required thickness.
[ *As amended by Ord. 1943, ch. 5 ]
fSect. 2105. Smokestacks. — (a) A smokestack shall support no
vertical load other than its own weight, but this shall not be held to forbid
a suspended staging for erection or maintenance. A smokestack exposed to
the force of the wind shall be capable of resisting such force and support its
own weight without exceeding the stresses allowed by this code for the
materials of which it is constructed.
(b) A smokestack shall be supported by incombustible construction or
by the construction supporting the furnace which it serves, but in buildings of
wooder construction a stack may be stayed laterally by incombustible stays
to the wooden construction. A smokestack may be mounted directly upon
and supported by the boiler or furnace which it serves if such boiler or furnace
is designed and constructed to support safely the weight thereof.
(c) The metal of a circular steel or sheet iron smokestack shall have not
less than the following thickness: —
Diameter
of Stack.
Thickness.
No. 10 Gage
No. 8 Gage
3/16 inch
1/4 inch
5/16 inch
(130)
Sees. 2105-2107
(d) A smokestack may be mounted on the outside of a building sup-
ported by and secured to the exterior wall thereof. If the wall is of com-
bustible materials the stack shall be not less than four inches and not less
than one third the stack diameter away and the wall for a width not less than
twice the diameter of the stack shall be covered by one quarter inch of asbestos
and sheet metal, or approved equivalent.
(e) A smokestack inside a building shall be protected from contact with
goods or persons by a substantial shield of incombustible materials, with
provision for ventilating the space between stack and shield. If a smoke
stack is within a ventilating shaft or other enclosure of a vertical opening,
provision shall be made for ventilating the shaft or enclosure at the bottom
and above the roof. Such enclosure shall be of incombustible materials and
the stack shall stand clear of the enclosing walls on all sides.
(f) A smokestack shall have at least four inches clearance from com-
bustible material; such material within twelve inches of the stack shall be
covered by one quarter inch asbestos and sheet metal or its approved equiva-
lent and the space about the stack shall be ventilated.
(g) Pertinent provisions for chimneys shall apply also to smokestacks.
[ \As amended by Ord. 1943, ch. 5 ]
JSect. 2106. Smoke Pipes. — (a) Smoke pipes of metal shall be not
less than number twenty-four gage copper-bearing, black or galvanized sheet
iron, except that where gas is used for fuel, sheet copper weighing not less than
sixteen ounces per square foot, or other approved material may be used.
(b) Smoke pipes, where they connect with a chimney, shall be tightly
fitted in a burned fire clay, cast iron or other substantial thimble built into the
masonry, or a smooth-sided opening of brick or other masonry.
(c) Smoke pipes of unprotected metal shall not be nearer than eighteen
inches below exposed combustible construction unless the combustible
material is protected by an incombustible shield having a width equal to twice
the diameter of the pipe, suspended at least three inches below such combus-
tible material and three inches above the pipe and ventilated on both sides.
The space between a metal smoke pipe covered with not less than one and one
half inches of asbestos or other approved insulation and combustible material
above, or between a smoke pipe of unprotected metal and woodwork above
protected by a ceiling of one-hour fire-resistive rating shall be not less than
three inches.
(d) Metal smoke pipes shall be at least twelve inches horizontally from
combustible material unless protection and clearance are provided as speci-
fied in paragraph (c) of this section.
(e) If a masonry flue connects a furnace with a chimney or a stack, it shall
be lined and otherwise constructed as specified for a chimney.
[ tAs amended by Ord. 1943, ch. 5 ]
*Sect. 2107. Fireplaces. — (a) Fireplace walls shall be not less than
eight inches thick and if built of stone or hollow units shall be not less than
twelve inches thick. The faces of such walls exposed to fire shall be lined
with fire brick or other suitable fire-resistive material. When lined with four
(131)
Sees. 2107-2110
inches of fire brick such lining may be included in the required minimum
thickness. Every fireplace shall be connected to a chimney flue built as
specified in section twenty-one hundred and two.
(b) Fireplaces shall have hearths supported by trimmer arches or other
approved fire-resistive construction. Trimmer arches and hearths shall be
not less than twenty inches wide measured from the face of the chimney
breast and shall extend not less than twelve inches beyond the fireplace open-
ing on each side. Trimmer arches shall be of brick, stone or hollow tile not
less than four inches thick, shall spring from the masonry supporting the
fireplace and may thrust against the floor frame whether of wood or other
material. A flat stone or reinforced concrete slab may be used to support a
hearth instead of an arch if it is properly supported and a suitable fill provided
between it and the hearth. Hearths shall be of brick, stone, tile or concrete.
Wood centering under a trimmer arch shall be removed after the masonry
has thoroughly set. No combustible materials shall be placed within three
inches from the jambs or from the top or arch of a fireplace opening.
(c) No heater burning solid or liquid fuel shall be placed in a fireplace
which does not conform with the requirements of this section. The provi-
sions of this section shall not be held to prevent construction without flue
of a suitable foundation and wall protection, resembling a fire place for a gas-
burning space heater; but if such construction has a flue, it shall conform in
all respects to the provisions of this section for a fireplace.
(d) Each fireplace shall have a separate and independent flue throughout
its length to the open air.
[ *As amended by Ord. 1943, ch. 5 ]
Sect. 2108. High Pressure Boilers. — (a) Boilers generating steam
at a pressure in excess of fifteen pounds per square inch shall be so located
that no combustible material shall be less than two feet from the top or sides
or ten feet from the front; and all combustible material less than four feet from
the top or sides shall be protected by incombustible construction of at least
one-hour fire-resistive rating and shall be well ventilated to prevent the
temperature from rising above two hundred and fifty degrees Fahrenheit.
(b) Steel, cast iron or reinforced concrete columns adjacent to such boilers,
except columns which support only the boilers, shall not be in direct contact
with boiler settings but there shall be an open and unobstructed space at
east four inches wide for ventilation.
Sect. 2109. Low Pressure Boilers. — Boilers generating steam at a
pressure not over fifteen pounds per square inch, and hot water heaters not
including domestic water supply heaters, shall have clearance from wooden
partitions, ceiling and other combustible material, the same as specified for
hot air furnaces in section twenty-one hundred and ten.
fSect. 2110. Hot Air Furnaces. — (a) Hot air furnaces shall be en-
cased in a metal or masonry shield with an air space between shield and fire
box. Unless the shield over the top is double with an air space, the top of
the furnace shall be covered with approved insulating material one inch thick.
(132)
Sees. 2110-2111
(b) Combustible material placed within seven feet from a hot air furnace
at the front or within two feet at the sides or rear shall be protected by sheet
metal, or asbestos board, and if such material is within one foot from such
furnace at the sides or rear, it shall be protected in the manner required in
section twenty-one hundred and six for woodwork near a metal smoke pipe.
The distance from the top of a hot air furnace to exposed combustible ma-
terial above, within two feet laterally from such furnace and four feet in front,
shall be not less than eighteen inches unless such woodwork is protected as
provided in section twenty-one hundred and six for combustible material
above a metal smoke pipe.
[ ^As amended by Ord. 194-3, ch. 5 ]
JSect. 2111. Hot Air Pipes and Registers. — (a) Horizontal hot
air furnace pipes shall be placed at least six inches below combustible material
except that if such material is protected by metal lath and plaster or a loose-
fitting metal shield or if the hot air pipe is covered with one half inch of corru-
gated asbestos insulation, the clear distance may be reduced to three inches
for portions of pipes within five feet from the furnace and to one inch for
more distant pipes.
(b) Hot air pipes passing through combustible partitions or floors either
shall be double sheet metal pipes with at least one half inch air space or be
covered with asbestos paper weighing not less than sixteen pounds per one
hundred square feet.
(c) No hot air pipes shall be placed in a wooden stud partition or wooden
enclosure unless it is at least five feet horizontally from its outlet on the
furnace. Hot air pipes in combustible partitions either shall be double with
one half inch air space, or the space shall be lined with sheet metal or other
incombustible material, or the pipe shall be covered securely with asbestos
paper weighing not less than sixteen pounds per one hundred square feet.
Hot air pipes in closets shall be not less than one inch away from woodwork
or be double pipe with one half inch air space or be covered with asbestos
paper weighing not less than sixteen pounds per one hundred square feet.
(d) Every hot air furnace shall have at least one hot air pipe and register
without damper, valve or louvres.
(e) Where a register in the floor directly over a furnace is connected by
a pipe from the top thereof, such pipe shall be double with not less than one
inch ventilated air space and no combustible material shall be within three
inches from the inner pipe.
(f) Hot air registers placed in woodwork shall be surrounded with borders
of incombustible material which shall prevent the register from coming in
contact therewith.
(g) Register boxes for warm air in wooden floors or partitions shall be made
of sheet metal, double, with at least one half inch air space or shall be kept
at least one half inch from woodwork and covered with asbestos paper weigh-
ing not less than sixteen pounds per one hundred square feet.
(h) The provisions of this section shall not apply to hot air pipes and
registers from indirect low pressure steam or hot water radiators.
[ %As amended by Ord. 1943, ch. 5 ]
(133)
Sees. 2112-2114
*Sect. 2112. Water Heaters and Hot Plates. — (a) Gas or electric
domestic water supply heaters and gas or electric hot plates shall not be
nearer than seven inches from a combustible wall unless the combustible
material in the wall is protected by two inches clearance and sheet metal or
its approved equivalent extending at least nine inches beyond each side and
two feet above the apparatus. Wooden ceiling or shelving shall not be less
than three feet above such apparatus.
(b) Gas hot plates and electric hot plates or appliances of more than
eighteen hundred watts capacity shall not be placed upon a wooden shelf
or counter unless the appliance has a solid metal floor under the burners or
heating elements, raised not less than two inches above the shelf, and the
shelf is protected with sheet metal; or unless equivalent approved protection
is provided.
[ *As amended by Ord. 1943, ch. 5 ]
fSect. 2113. Domestic Stoves and Ranges. — (a) Insulated or un-
insulated stoves and ranges not of the flushback type used for heating rooms,
water, or for the cooking or laundry of a family, whether burning solid, liquid,
gaseous fuel or electricity shall not be placed within seven inches from a
combustible wall. No wood or other combustible materials forming shelves,
ceiling, cabinets or fixed furnishings shall be installed less than three feet
above the top of stove or range or the uppermost oven of either, or within
seven inches of the sides of ranges or stoves. Where incombustible materials
are used for shelving — ceiling, cabinets or fixed furnishings — the minimum
clearance above the top of range, stove or uppermost oven of either shall be
eighteen inches and from the sides of range or stove, four inches.
(b) Insulated Flushback Type Ranges or stoves may be placed directly
against existing or new partitions, walls or other structure providing the
entire wall, partition or structure is composed wholly of incombustible ma-
terials. Arrangement of shelving, cabinets, ceiling and fixed furnishings shall
be as mentioned in paragraph (a) of this section.
(c) Combustion chambers of stoves or ranges burning solid or liquid fuel
shall be connected to a chimney or a smokestack. Ovens and hoods of stoves
and ranges may be ventilated to a chimney, smokestack, or ventilating duct.
Such connections shall be of metal not less than number twenty-six gage
thickness and wherever they pass through construction of combustible
material they shall be encased in a sleeve of approved type which provides a
clearance of at least three-fourths of an inch from any combustible material.
[ fAs amended by Ord. 1943, ch. 5 ]
Sect. 21 14. Commercial Stoves and Ranges. — (a) Stoves and ranges
such as are used in kitchens of restaurants, hotels, clubs and similar estab-
lishments shall not be placed nearer than twenty-four inches from a com-
bustible wall unless the combustible material in the wall is protected by six
inches clearance, not less than one-hour fire-resistive construction and a shield
of metal or other approved incombustible material with free circulation of air
between it and the wall, extending at least twenty-four inches beyond each
side of the range and four feet above the top.
(134)
Sees. 2114-2117
(b) Such stoves and ranges shall be provided with hoods of incombustible
material connected by pipe or duct with an independent chimney flue or smoke
stack extending above the roof. The hood, if of sheet metal or other simi-
larly thin material, shall be separated from combustible material above by
at least nine inches clearance, or by a ceiling of one-hour fire-resistive con-
struction. The connecting pipe or duct shall be separated from combustible
material as specified for smoke pipes in section twenty-one hundred and six,
with one half the clearances there specified.
Sect. 2115. Oil Burners. — Oil burners shall be installed in accordance
with chapter one hundred and forty-eight of the General Laws and regulations
issued thereunder.
Sect. 2116. Incinerators. — (a) All incinerators, except those not
exceeding four square feet in grate area, shall be constructed of brick masonry
or reinforced concrete. The walls and roof shall be at least eight inches
thick; if the area of the combustion chamber is fifteen square feet or more,
the walls and roof shall be at least twelve inches thick.
(b) The combustion chamber above the grate, and both above and below
the grate in down-draft incinerators, shall be lined with fire brick laid in mor-
tar or fire clay or with equally fire-resistive material. Fire brick lining may be
included in the required wall and roof thickness.
(c) If the smoke flue is used as a refuse chute, it shall be a smooth-lined
chimney, vertical and directly over the combustion chamber. Charging
hoppers shall be of approved design and construction and shall not project
within the flue area. The area of charging opening shall not exceed one third
the flue area nor shall the least dimension of the flue be less than three times the
vertical dimension of the charging hopper. The top of the chimney shall be
covered with a cage or screen of non-corrodible metal of approved design, and
having an area not less than twice the flue area.
Sect. 2117. Support of Heat Producing Apparatus. — (a) Except
as otherwise provided in this section, heat producing apparatus whether
electrical or by the combustion of solid, liquid or gaseous fuel shall be sup-
ported upon a substantial foundation of incombustible and heat-resistive
materials laid on the ground, or upon a floor of Type I construction.
(b) Electrical appliances of less than eighteen hundred watts capacity
shall not be subject to the requirements of this section.
(c) Domestic stoves and ranges used for heating one room or for the
cooking or laundry of one family, gas or electric water supply heaters, and
heaters burning solid or liquid fuel for the domestic hot water supply of one
family, may be supported upon floors of Type II or Type V construction with
incombustible flooring. Such apparatus may be supported upon a wooden
floor or combustible flooring, either; —
(1) Where the apparatus has solid metal construction under the heating
elements, fire or burners and ovens, not less than six inches above the floor
and, except under gas or electric apparatus, with free circulation of air over
the floor; or
(135)
Sees. 2117-2119
(2) Where the floor is protected by sheet metal under and extending
at least six inches beyond the sides and rear and at least twelve inches
beyond the front of the apparatus and at least four inches of solid brick
masonry or concrete under the apparatus; or with equivalent approved
protection.
(d) Stoves, ranges and coal or oil burning water supply heaters, for
restaurants, hotels, clubs and similar establishments may be supported upon
Type II or Type V construction with incombustible flooring, when the appa-
ratus has solid metal construction under the fire, burners or other heating
elements and ovens, raised on metal legs not less than four inches above the
floor with free circulation of air between. Such apparatus may be supported
upon a wooden floor or combustible flooring, either; —
(1) Where the apparatus has solid metal construction under the fire,
burners, or other heating elements and ovens, raised on metal legs not less
than four inches above the floor with free circulation of air between, and
the floor is protected with non-corrodible sheet metal under and extending
at least six inches beyond the sides, rear and front of the apparatus and a
baffle sheet of one half inch asbestos secured between two sheets of non-
corrodible sheet metal under the entire apparatus suspended two inches
below the floor thereof; or
(2) Where the floor is protected by non-corrodible sheet metal under
and extending at least six inches beyond the sides, rear and front of the
apparatus, and hollow construction, under the apparatus, of brick on edge
not less than four nor more than twelve inches apart, topped by reinforced
concrete not less than three inches thick; or by equivalent approved pro-
tection.
(e) Heating apparatus such as down-draft and oil burning furnaces in
which the floor of the combustion chamber rests directly upon a reinforced
concrete or other structural floor, shall have a heat-resistive foundation, with
ventilation and insulation if necessary, to prevent injury to structural metal
or other materials in the floor.
(f) Under boilers, furnaces and other heat-producing apparatus sup-
ported upon a floor required by the provisions of Part 29 to be waterproofed,
shall be installed insulation equivalent to that required for a wooden floor,
to protect the waterproofing against damage from heat.
Sect. 2118. Smoke Connection. — Every apparatus for the generation
of heat by the combustion of fuel shall have suitable connection to an ade-
quate chimney or smokestack except gas appliances exempted by the regu-
lations for gas fitting issued under section one hundred and sixteen of Part 1
of this code and other small apparatus of similarly intermittent use burning
oil and generating not over twenty thousand British thermal units per hour,
and except such apparatus in foundries, forge shops and similar establish-
ments as shall be exempted with the approval of the commissioner.
♦Sect. 2119. Other Heat Producing Apparatus. — Other heat pro-
ducing apparatus such as bake ovens, coffee roasting ovens, core ovens,
japanning ovens, rendering furnaces, stereotype furnaces, wood-drying kilns,
(136)
Sec. 2119
annealing furnaces, charcoal furnaces, galvanizing furnaces, gas producers,
smoke houses, forges and the like, shall be supported, and nearby woodwork
and other combustible material shall be protected from such apparatus in the
manner specified in this chapter for apparatus of similar size, temperature,
and character of heat exposure. These and other special or uncommon
sources of heat and flame shall be so constructed and protected as to prevent
heating any wood or other combustible material used in the construction of
floors, ceilings, partitions or other parts of a building, or required waterproof-
ing, to a temperature over two hundred and fifty degrees Fahrenheit, when in
full operation, and shall be so constructed as not to be liable to undue corro-
sion or deterioration or to accidental overturn or other disarrangement con-
ducive to danger.
Every application for such permit shall be in writing, shall be filed with the
commissioner and shall set forth the character of the building, the size,
power and purpose of the apparatus, and such other information as the com-
missioner may require. The commissioner may, after an examination of the
premises described in the application, and after hearing the applicant and
any objectors, issue a permit for placing this apparatus on such premises, upon
such conditions as he shall prescribe, or he may refuse such permit. If the
application is for anything other than a boiler or furnace the applicant shall
publish in at least two daily newspapers published in the city of Boston, and
on at least three days in each, and if so directed by the commissioner, shall
also post conspicuously on the premises a copy of the application, and shall
deliver copies thereof to such persons as the commissioner may designate.
If no objection is filed with the commissioner before the expiration of ten
days after the time of the first publication of notice, or within ten days of the
delivery and first posting of the notice, if such delivery or posting is required
the commissioner shall if the arrangement, location and construction of the
proposed apparatus is proper and in accordance with the provisions of this
act, issue a permit for the same. If objection is filed the application shall
be referred to the board of appeal which may in its discretion require the
deposit by the objector of a reasonable sum as security for the payment of
the costs.
After such notice as the board shall order it shall hear the same and shall
direct the commissioner to issue a permit under such conditions as it may
prescribe, or to withhold the same. If the permit is refused, the applicant
and if it is granted the objectors shall pay such cost as the board may order.
The commissioner may, from time to time, after public notice and hearing,
prescribe the conditions on which furnaces, boilers, or other steam generator
and hot water heaters may be maintained in buildings, and, if any person
interested objects to such conditions and appeals from his decision establishing
the same, the appeal shall be referred to the board of appeal, and thereupon
said board shall prescribe the conditions.
[ *As amended by Ord. 1943, ch. 5 ]
(137)
Sec. 2201
Section
2201 —
2202 —
2203 —
2204 —
2205 —
2206 —
2207 —
2208 —
2209 —
2210 —
2211 —
2212 —
2213 —
2214 —
2215 —
2216 —
2217 —
PART 22.
FIRE=RESISTIVE CONSTRUCTION.
Determination of Fire- Resistance.
re=Resistive Materials and Construction.
re=Protection of Steel Columns.
re-Protection of Cast Iron Columns.
re-Protection of Steel in Reinforced Concrete Columns.
re-Protection of Steel Beams, Girders and Trusses.
re-Protection of Steel in Reinforced Concrete Beams.
re=Protection of Steel Reinforcing in Floors and Roofs.
re-Resistive Floor and Roof Construction.
re-Resistive Ceiling Construction.
re-Resistive Bearing Walls and Partitions.
re-Resistive Non-Bearing Walls and Partitions.
re-Resistive Doors,
re Door Construction.
re-Resistive Shutters.
re-Resistive Windows.
re-Resistive Roof Covering.
♦Section 2201. Determination of Fire-Resistance. — (a) Materials
of construction and fire-protective materials, and assemblies or combinations
thereof, shall be classified for fire-protective and fire-resistive purposes in
terms of their performance in authoritative tests made in accordance with
Standard Specifications for Fire Tests of Building Construction and Materials
of the American Society for Testing Materials, hereinafter called the Standard
Fire Test.
(b) The materials, assemblies and combinations of materials specified and
listed in this chapter shall be assumed to have the fire-resistive rating here
given. Other materials, assemblies and combinations shall be given fire-
resistive ratings by the commissioner. Such ratings shall be determined by
reasonable interpolation among the materials, assemblies and combinations
listed and rated in this chapter, and by authenticated evidence of performance
in standard fire tests, with such margin of safety as he shall consider necessary
to provide for the exigencies of commercial production and field construction.
(c) Where the interior of a building of Type III construction is of incom-
bustible construction protected to provide one-hour fire-resistive rating, the
exterior walls may be of two-hour fire-resistive construction.
(d) Where the interior of a building of Type IV construction is of incom-
bustible construction, the exterior walls may be of two-hour fire-resistive
construction.
(138)
Sees. 2201-2203
(e) In such group occupancies and where Type VI is allowed, but in no
case over two stories in height, Type IV buildings may be constructed with
their frames and exterior walls of incombustible construction.
(f) All construction referred to in paragraphs (c), (d), and (e) shall be
subject to the structural requirements of other parts of this code.
[ *As amended by Ord. 1943, ch. 6 ]
fSect. 2202. — Fire-Resistive Materials and Construction. — (a)
Materials, to be given the fire-resistive ratings specified in this part, shall
have the following minimum qualities: —
(1) Concrete of Class 1 shall be so proportioned, in accordance with
Part 26, as to have a strength of at least fifteen hundred pounds per square
inch and the coarse aggregate shall consist of limestone, trap rock, blast
furnace slag, cinders containing not more than twenty per cent of combus-
tible material, burned clay or shale.
(2) Concrete of Class 2 shall be so proportioned, in accordance with
Part 26, as to have a strength of at least fifteen hundred pounds per square
inch, the coarse aggregate consisting of sandstone, granite, quartzite,
siliceous gravel or other similar material not over one inch in size.
(3) Masonry shall consist of the materials specified in Part 24 laid in
lime-cement or cement mortar, or approved masonry cement mortar,
except that masonry of gypsum tile shall, and masonry of structural clay
tile may, be laid in gypsum mortar. Masonry shall be thoroughly bonded
by breaking joints in successive courses or by the use of metal ties.
(4) Brick shall be burned clay or shale, concrete or sand-lime brick
of Grade C or better as specified in Part 24.
(5) Stone shall be limestone, marble, slate or equally fire-resistive natural
stone. Sandstone, granite or other stone which, because of its crystalline
structure or for other reason, is less fire-resistive, shall not be considered
fire-protection for structural metal, but may be used in a masonry wall
not less than twelve inches thick required to have fire-resistance. Stone
masonry shall have the same fire-resistive rating as brick masonry.
(6) Cast stone shall conform to the requirements of Part 24. Cast
stone masonry shall have the same fire-resistive rating as brick masonry.
(7) Concrete blocks, whether solid or hollow, shall have as coarse
aggregate limestone, trap rock, blast furnace slag, cinders containing not
more than twenty per cent of combustible material, burned clay or shale,
and shall otherwise conform to the requirements of Part 24.
(8) Structural clay tile shall conform to the specifications for load-
bearing tile, floor tile or partition tile of Part 24. Where partition tile is
specified, load-bearing tile may be used.
(9) Gypsum tile or pre-cast gypsum concrete, whether solid or hollow,
shall conform to Standard Specifications for Gypsum Partition Tile or
Block of the American Society for Testing Materials and shall not contain
more than three per cent by weight of wood or other combustible binder
or filler.
(139)
Sec. 2202
(10) Gypsum concrete shall not contain more than twelve and one-half
per cent by weight of wood or other combustible binder or filler, and shall
have a compressive strength of at least five hundred pounds per square
inch as provided in Part 27. It shall not be used where exposed to the
elements.
(11) Expanded metal or wire lath as a base or reinforcement for plaster-
ing shall weigh not less than two and two tenths pounds per square yard
and shall have not less than two and one half meshes per inch.
(12) Metal mesh reinforcement specified for masonry fire protection
of structural metal shall consist of wire lath strips the full thickness of
the masonry, laid in the beds thereof, or its approved equivalent.
(13) Metal mesh reinforcement specified for concrete fire protection
of structural metal shall consist of wire mesh weighing not less than one
and one half pounds per square yard with wire spaced not over four inches,
or not less than number eleven gage steel wire spaced not over four inches
apart, or its approved equivalent.
(14) Cement plaster shall be proportioned of one part Portland cement,
and not more thaD two parts of sand measured by volume dry and loose
to which may be added lime putty or hydrated lime not exceeding fifteen
per cent of the cement.
(15) Gypsum plaster, except where otherwise specified, may contain
sand not in excess of three times the weight of the gypsum.
(16) Lime plaster shall consist of a mixture of one part lime, not over
three parts sand, and water.
(17) Pneumatically projected mortar made of Portland cement, sand
and water shall be rated for fire-protection the same as Class 1 concrete.
(18) Concrete fill, where specified in this chapter in connection with
hollow masonry units, shall consist of Class 1 or Class 2 concrete poured
in the hollow spaces of the units as they are laid.
(b) Portland cement concrete or gypsum concrete poured in place as
fire-protection for beams, trusses and other horizontal or inclined members of
structural steel and pneumatically projected mortar applied to structural
steel as fire-protection shall be reinforced with metal mesh reinforcement.
Concrete protection for vertical columns of structural metal shall have rein-
forcing consisting of number five wire spaced not over eight inches apart or
its equivalent. Reinforcement shall be wrapped around the structural
member and so arranged as to be completely embedded in the fire-protective
material and to ensure its integrity.
(c) Plaster used as fire-protection or to resist the spread of fire shall be
reinforced with metal lath, except plaster less than one inch thick on masonry
or concrete.
(d) In the protection of structural metal including reinforcement, one
half inch of cement or gypsum plaster may replace an equal thickness of
poured concrete or pneumatically projected mortar as protective material;
and one inch of cement or gypsum plaster reinforced with metal lath may
replace an equal thickness of poured concrete, pneumatically projected mortar
or masonry protection.
(140)
Sees. 2202-2205
(e) Where plaster is required without other specification, it shall consist
of one half inch of cement or gypsum plaster, except that only gypsum plaster
shall be used on gypsum masonry.
(f) In this chapter, except where otherwise specifically stated, the thick-
ness given in a list of materials applies to the next following item only, and not
to the total thickness where additional materials are specified.
(g) Pipes, wires, conduits and ducts shall not be embedded in or placed
behind the fire-protective materials required for the protection of structural
steel or iron except as otherwise provided in this paragraph. Above fire-
protective hung ceilings and within the enclosed spaces in buildings of Type
I and Type II construction, within which, other than the enclosure, fire pro-
tection of steel is not required, as specified in Part 16, pipes, wires, conduits
and ducts may be placed, provided they are so arranged and so secured that
they will not, either by expanding in the event of fire, or otherwise impair the
effectiveness of the enclosing protective materials. Electric conduits and
wires and gas pipes may be embedded in concrete or masonry fire protection of
structural steel where the protective material is reinforced with wire mesh,
provided they shall have protective covering except over the tops of beams
and girders, at least as thick as required for the steel.
(h) In factories, garages, warehouses and other buildings in which the
fire-protective covering required for steel or iron columns may be injured by
the movement of vehicles, materials or equipment, the commissioner shall
require such covering to be protected by metal or other material in a manner
satisfactory to him.
(i) Fire-stopping, for the purposes of this chapter, shall mean the stop-
ping-off or enclosure at the ends and wherever else specified of the spaces
between studs of partitions, joists of floors and roofs and other similar spaces
to prevent drafts of air and the communication of fire from one such space to
another. Fire-stopping shall consist of wood not less than one and one half
inches thick, of sheet metal not less than twenty-four gage or of masonry, or a
combination of such materials. Fire-stopping shall be tightly fitted in the
space to be filled, about pipes, wires and ducts and if cut or disturbed in the
placement of pipes, wires and ducts shall be repaired.
[ fAs amended by Ord. 1943, ch. 6 ]
JSect. 2203. Fire=Protection of Steel Columns.— (a) Structural
steel columns required to have fire-protection of a given rating shall be
covered on all sides with protective material having not less than the thickness
necessary for the required rating. Except where "no fill" is specified, re-
entrant and other accessible spaces behind the specified outer protection
shall be filled with concrete or brick masonry or the material of the outer
protection.
(b) The following materials shall be assumed to afford to steel columns
fire-protection of the rating indicated:
Four-hour rating:
(1) Two inches Class 1 concrete.
(2) Three inches Class 2 concrete, metal mesh reinforcement.
(3) Three and one half inches brick masonry.
(141)
Sees. 2203-2204
(4) Two layers two-inch structural clay partition tile masonry, metal
mesh in beds.
(5) Two inches structural clay partition tile masonry, concrete fill,
metal mesh in beds, three fourths inch gypsum plaster.
(6) Four inches structural clay partition tile masonry, concrete fill,
metal mesh in beds, five eighths inch lime plaster.
(7) Four inches structural clay partition tile or concrete block mason-
ry, concrete fill, plaster.
(8) Three inches hollow gypsum tile masonry and plaster.
(9) Two inches gypsum concrete, metal mesh reinforcement.
(10) Two inches solid gypsum tile masonry and plaster.
(11) Three inches solid cinder concrete block masonry and plaster.
(12) Four inches hollow cinder concrete block masonry and plaster.
Three-hour rating:
(13) One and three fourths inches Class 1 concrete.
(14) Two inches Class 2 concrete, metal mesh reinforcement.
(15) Two inches gypsum concrete.
(16) Two inches solid cinder concrete block masonry and plaster.
(17) Two inches structural clay partition tile masonry, concrete fill.
Two-hour rating:
(18) One and one half inches Class 1 concrete.
(19) Two inches Class 2 concrete, metal mesh reinforcement.
(20) One inch Class 1 or Class 2 concrete encased in standard weight
steel or wrought iron pipe.
(21) Two inches structural clay partition tile masonry and plaster.
(22) Two layers plaster, each on metal lath, with three fourths inch air
space between, two inches total thickness.
(23) Two inch gypsum concrete.
(24) Two inches solid or three inches hollow gypsum tile masonry.
One-hour rating:
(25) One inch Class 1 concrete.
(26) One and one half inches Class 2 concrete with metal mesh rein-
forcement.
(27) Two and one fourth inches brick masonry.
(28) Two inches structural clay partition tile or concrete block masonry.
(29) One inch cement or gypsum plaster on metal lath.
(c) The thickness of protection on the outer edges of lugs or brackets
need not exceed one inch.
[ %As amended by Ord. 191,8, ch. 6 ]
*Sect. 2204. Fire-Protection of Cast Iron Columns. — (a) Cast
iron columns required to have fire-protection of a given rating shall be covered
on all sides with protective materials having not less than the thickness
necessary for the required rating. Re-entrant spaces, if any, on the exterior
of cast iron columns, and other accessible spaces behind the specified protec-
tion, shall be filled with Class 1 concrete or brick masonry or the material
of the outer protection.
(142)
Sees. 2204-2206
(b) The following materials shall be assumed to afford to cast iron columns
fire-protection of the rating indicated: —
Four-hour rating: —
Cast iron columns shall not be used where protect on of four-hour rating is
required.
Three-hour rating: —
(1) Two inches Class 1 concrete.
(2) Three inches Class 2 concrete, metal mesh reinforcement.
(3) Two inches structural clay partition tile or concrete block masonry
concrete fill.
(4) One and one half inches cement or gypsum plaster on metal lath
and metal furring to form one half inch air space.
Two-hour rating: —
(5) One and one half inches Class 1 concrete.
(6) Two inches Class 2 concrete with metal mesh reinforcement.
One-hour rating: —
(7) One inch Class 1 concrete.
(8) One and one half inches Class 2 concrete with metal mesh rein-
forcement.
(9) One inch cement or gypsum plaster on metal lath.
[ *As amended by Ord. 1943, ch. 6 ]
fSect. 2205. Fire-Protection of Steel in Reinforced Concrete
Columns. — (a) The main steel reinforcement, including spiral reinforce-
ment and ties larger than one half inch, in reinforced concrete columns re-
quired to have fire-protection of a given rating shall be covered with concrete
having not less than the thickness listed in this section for the rating indi-
cated:—
Four-hour rating: —
(1) One and one half inches Class 1 concrete.
(2) Two inches Class 2 concrete.
Three-hour rating: —
(3) One and one half inches Class 1 or Class 2 concrete.
Two-hour rating: —
(4) One inch Class 1 concrete.
(5) One and one half inches Class 2 concrete.
One-hour rating: —
(6) One inch Class 1 or Class 2 concrete.
(b) The thickness of protection on column ties not larger than one half
inch may be one half inch thinner than that listed above.
[ -\As amended by Ord. 1943, ch. 6 ]
JSect. 2206. Fire-Protection of Steel Beams, Girders and Trusses. —
(a) Steel beams, girders and trusses or the members of trusses, required to
have fire-protection of a given rating, shall be covered on all sides with ma-
terial having not less than the thickness necessary for the required rating.
(b) The following materials shall be assumed to afford steel beams, girders
and trusses, or the members thereof, fire-protection of the rating indicated:
(143)
Sees. 2206-2207
Four-hour rating:
(1) Two inches Class 1 concrete.
(2) Three inches Class 2 concrete.
(3) Three inches structural clay partition tile or concrete block masonry
and plaster.
(4) Three inches hollow gypsum tile masonry and plaster.
(5) Two inches gypsum concrete.
(6) Two inches solid gypsum tile masonry and plaster.
Three-hour rating:
(7) One and three quarters inches Class 1 concrete.
(8) Two and one half inches Class 2 concrete.
(9) Two inches gypsum concrete.
(10) Two inches structural clay partition tile, or concrete block masonry
and plaster.
(11) Two inches solid, or three inches hollow gypsum tile masonry.
Two-hour rating:
(12) One and one half inches Class 1 concrete.
(13) Two inches Class 2 concrete.
(14) Two inches gypsum concrete.
One-hour rating:
(15) One inch Class 1 concrete.
(16) One and one half inches Class 2 concrete.
(17) Seven eighths inch cement or gypsum plaster on metal lath.
[ tAs amended by Ord. 1948, ch. 6 J
*Sect. 2207. Fire=Protection of Steel in Reinforced Concrete
Beams. (a) The main steel reinforcement, including stirrups larger than
one half inch, in reinforced concrete beams, girders and trusses, including
the ribs of reinforced concrete ribbed floors or roofs where one or both sides
of the ribs, in addition to the soffit, are exposed to fire, required to have fire-
protection of a given rating, shall be covered on all sides with concrete having
not less than the thickness listed in this section for the required rating. Where
a reinforced concrete floor or roof has a flush ceiling formed with approved
permanent masonry fillers between ribs, the reinforcement shall have the
protection required for reinforcing steel of floors and roofs in section twenty ■
two hundred and eight.
Four-hour rating: —
(1) One and one half inches Class 1 concrete.
(2) Two inches Class 2 concrete.
Three-hour rating: —
(3) One and one half inches Class 1 or Class 2 concrete.
Two-hour rating: —
(4) One inch Class 1 concrete.
(5) One and one half inches Class 2 concrete.
One-hour rating: —
(6) One inch Class 1 or Class 2 concrete.
(144)
Sees. 2207-2209
(b) The thickness of protection on stirrups not larger than one half inch
may be less than that listed by not more than one half inch.
[ *As amended by Ord. 1948, ch. 6 ]
fSect. 2208. Fire-Protection of Steel Reinforcing in Floors and
Roofs. — (a) The steel reinforcement in reinforced concrete floors and roofs
with flush or plane ceilings, such that the exposure to fire is on the soffit only,
required to have fire-protection of a given rating, shall be covered with con-
crete having not less than the thickness listed in this section for the required
rating. In floors or roofs having reinforced concrete ribs where the concrete
surrounding the steel reinforcement is exposed to fire on one or both sides in
addition to the soffit, such reinforcement shall have the protection specified
in section twenty-two hundred and seven for steel in reinforced concrete
beams.
Four-hour rating: —
(1) One inch Class 1 concrete.
(2) One and one fourth inches Class 2 concrete.
Three-hour rating:
(3) One inch Class 1 or Class 2 concrete.
Two-hour rating: —
(4) Three fourths inch Class 1 concrete.
(5) One inch Class 2 concrete.
One-hour rating: —
(6) Three fourths inch Class 1 or Class 2 concrete.
[ fAs amended by Ord. 1943, ch. 6 ]
JSect. 2209. Fire-Resistive Floor and Roof Construction. — (a)
Floors and roofs required to have resistance of a given rating to the spread of
fire shall have such thickness of the materials of which it is constructed, as
shall be necessary for the required rating, and structural metal forming a
part of such floors or roofs shall have protection against fire of such required
rating. Floors and roofs required to have two-hour or longer resistance to
fire shall be constructed of incombustible materials. Granolithic, burned
clay tile, ceramic tile or other similar incombustible floor finish of a given
thickness may be substituted for an equal thickness, and sand, cinder or
other incombustible filling material, with or without embedded wooden
screeds, may be substituted for two thirds its thickness, of the floor or roof
construction material specified in this section; provided, that such floors and
roofs shall have adequate thickness for structural purposes.
(b) The following floor or roof construction shall be assumed to afford
resistance to the spread of fire of the rating indicated:
Four-hour rating:
(1) Four inches solid slab of reinforced Portland cement concrete or
reinforced precast gypsum concrete.
(2) Four inches solid masonry arches or slabs.
(3) Four inches structural clay floor tile masonry arches or slabs with
top covering of not less than two inches of solid masonry or reinforced
concrete.
(145)
Sees. 2209-2210
(4) Five inches combination reinforced Portland cement concrete slab
consisting of permanent fillers of concrete block, gypsum or structural
clay tile and one and one half inches of concrete topping; but if structural
clay partition tiles are used for fillers they shall be plastered on the soffit.
Three-hour rating:
(5) Three inches solid slab of reinforced Portland cement concrete or
reinforced precast gypsum concrete.
(6) Three inches solid masonry arches or slabs.
(7) Four inches structural clay floor tile masonry, arches or slabs with
top covering of not less than one and one half inches of solid masonry or
reinforced concrete.
(8) Four inches combination reinforced Portland cement concrete slab
consisting of permanent fillers of concrete block, gypsum or structural clay
tile and one-inch concrete topping; but if structural clay partition tiles
are used for fillers, they shall be plastered on the soffit.
Two-hour rating:
(9) Two and one half inches solid slab of reinforced Portland cement
concrete or reinforced precast gypsum concrete.
(10) Two and one half inches solid masonry arches or slabs.
(11) Three inches structural clay floor tile masonry, arches or slabs
with top covering of not less than one inch of solid masonry or reinforced
concrete.
One-hour rating:
(12) Three inches structural clay floor tile masonry, arches or slabs
with all joints thoroughly filled with cement or gypsum mortar.
(13) Wood floor or roof construction with joists not less than one and
five-eighths inches in least dimension, fire-stopped, double board floor,
approved asbestos felt between layers of boards, and with a ceiling of at
least three quarters inch cement or gypsum plaster on metal lath.
(14) Steel beams or steel joists not more than thirty-six inches apart
on centers with incombustible floor and a ceiling of at least three fourths
inch cement or gypsum plaster on metal lath metal furring.
[ JAs amended by Ord. 1943. ch. 6 ]
♦Sect. 2210. Fire=Resistive Ceiling Construction. — (a) Ceilings
required to afford fire-protection of a given rating to the floor or roof framing
under which it is supported shall be of fire-resistive materials of at least the
thickness necessary for the given rating. A fire-resistive ceiling and all
hangers and fastenings necessary for its support to the protected framing
shall be of incombustible materials. It shall be capable of sustaining its
own weight without exceeding allowable stresses. Metal reinforcement in
such a ceiling shall be protected from fire as specified in section twenty-two
hundred and eight for reinforcing in a floor.
(b) The following ceiling construction shall be assumed to afford to floor
or roof framing fire-protection of the rating indicated: —
Four-hour rating: —
(1) Two and one half inches solid slab of reinforced Portland cement
concrete or reinforced precast gypsum concrete.
(146)
Sees. 2210=2211
(2) Two inches precast reinforced gypsum concrete, plastered.
Three-hour rating: —
(3) Two inches solid slab of reinforced Portland cement concrete or
reinforced precast gypsum concrete.
(4) Two inches precast reinforced gypsum concrete, lapped or rabbeted
joints.
Two-hour rating: —
(5) One and one half inches solid slab of reinforced Portland cement
concrete or reinforced precast gypsum concrete.
One-hour rating: —
(6) Three fourths inch cement or gypsum plaster on metal lath.
[ *As amended by Ord. 194-3, ch. 6 ]
fSect. 2211. Fire-Resistive Bearing Walls and Partitions. — (a)
Bearing walls and partitions required to have resistance to fire or the spread
of fire of a given rating shall be constructed of fire-resistive materials and
shall have at least the thickness necessary for the required rating. Walls
required to have two-hour or longer rating shall be of incombustible materials.
Steel reinforcement in reinforced concrete walls shall have the same protection
for the given rating as is required in section twenty-two hundred and eight
for steel in floors.
(b) Bearing walls and partitions of the following construction and thick-
ness shall be assumed to have resistance to fire and the spread of fire of the
rating indicated:
Four-hour rating:
(1) Eight inches solid brick masonry.
(2) Twelve inches hollow wall of brick masonry, minimum eight inch
masonry thickness.
(3) Twelve inches structural clay load-bearing tile masonry with two
units and not less than three cells in the thickness of the wall.
(4) Eight inches structural clay load-bearing tile masonry with one unit
and not less than two cells in the thickness of the wall, plastered both sides.
(5) Twelve inches concrete block masonry with one unit and not less
than two cells in the thickness of the wall.
(6) Eight inches one-piece concrete block masonry with shells and
webs at least one and one half inches thick, plastered both sides.
(7) Twelve inches total thickness of brick masonry facing bonded to
structural clay load-bearing tile masonry backing.
(8) Eight inches solid concrete.
(9) Six inches solid reinforced concrete.
(10) A steel or reinforced concrete frame bearing wall in which the
steel has fire-protection of four-hour rating, with panel filling as specified
in section twenty-two hundred and twelve for a non-bearing wall of four-
hour rating.
Three-hour rating:
(1L) Eight inches structural clay load-bearing tile masonry with two
units and not less than four cells in the thickness of the wall.
(147)
2>ecs. 2211-2212
(12) Twelve inches structural clay load-bearing tile masonry with one
unit and not less than three cells in the thickness of the wall.
(13) Eight inches one-piece concrete block masonry with shells and,
webs not less than one and one half inches thick, plastered both sides.
(14) Eight inches one-piece concrete block masonry with shells and
webs not less than two inches thick.
(15) Five inches solid reinforced concrete.
(16) A steel or reinforced concrete frame bearing wall in which the
steel has fire-protection of three-hour rating, with panel filling as specified
in section twenty-two hundred and twelve for a non-bearing wall of three-
hour rating.
Two-hour rating:
(17) Eight inches structural clay load-bearing tile masonry with not
less than three cells in the thickness of the wall.
(18) Eight inches concrete block masonry with shells and webs not less
than one and one half inches thick.
(19) A steel or reinforced concrete frame bearing wall in which the
steel has fire-protection of two-hour rating, with panel filling as specified
in section twenty-two hundred and twelve for a non-bearing wall of two-hour
rating.
One-hour rating:
(20) A steel or wooden stud bearing wall covered on both sides with
one-inch cement or gypsum plaster on metal lath, fire-stopped, if of wood.
(21) A steel or reinforced concrete frame bearing wall in which the
steel has fire-protection of one-hour rating, with panel filling as specified
in section twenty-two hundred and twelve for a non-bearing wall of one-,
hour rating.
[ fAs amended by Ord. 194$, ch. 6 ]
{Sect. 2212. Fire=Resistive Non=Bearing Walls and Partitions. —
(a) Non-bearing walls and partitions required to have resistance to fire and
the spread of fire of a given rating shall be constructed of fire-resistive ma-
terials and shall have at least the thickness necessary for the required rating.
Walls required to have two-hour or longer rating shall be of incombustible
materials. Steel reinforcement in reinforced concrete walls shall have the
same protection for the given rating as is required in section twenty-two
hundred and eight for steel in floors.
(b) Non-bearing walls and partitions of the following construction and
thickness shall be assumed to have resistance to fire and the spread of fire
of the rating indicated:
Four-hour rating:
(1) Eight inches solid brick masonry.
(2) Three and one half inches solid brick masonry, plastered both sides .
(3) Six inches structural clay load-bearing tile, plastered both sides.
(4) Six inches solid concrete.
(5) Four inches solid reinforced concrete.
(148)
Sees. 2212-2213
(6) Any wall which, as a bearing wall, has a three-hour or four-hour
rating in section twenty-two hundred and eleven, except the steel or re--
inforced concrete frame bearing wall.
Three-hour rating:
(7) Three and one half inches solid brick masonry.
(8) Four inches structural clay load-bearing tile, plastered both sides.
(9) Four inches solid concrete.
(10) Three inches reinforced concrete.
(11) Any wall which, as a bearing wall, has a two-hour rating in section
twenty-two hundred and eleven, except the steel or reinforced concrete
frame bearing wall.
Two-hour rating:
(12) Three inches gypsum tile masonry, plastered both sides except in
exterior walls.
(13) Eight inches structural clay partition tile masonry, plastered both
sides.
(14) Eight inches structural clay load-bearing tile, with three cells in
the thickness of the wall.
(15) Four inches concrete block plastered both sides.
(16) Two inches solid neat, fibered, gypsum plaster on metal lath and
incombustible studding.
One-hour rating:
(17) Three inches gypsum tile masonry.
(18) Two inches solid gypsum tile masonry plastered both sides.
(19) Three inches structural clay partition tile plastered both sides.
(20) Two and one half inches solid cement or sanded gypsum plaster
on metal lath and incombustible studding.
(21) Three inches total thickness of hollow wall, three fourths inch
cement or gypsum plaster on metal lath and incombustible studding.
(22) Three inches total thickness of hollow wall, three fourths inch
cement or gypsum plaster on metal lath and wooden studding, fire-stopped.
[ %As amended by Ord. 1943, ch. 6 ]
*Sect. 2213. Fire-Resistive Doors. — (a) Doors which are required
to be fire doors, fire-resistive doors, or of fire-resistive construction shall
conform to the requirements of this section and section twenty-two hundred
and fourteen.
(b) Fire doors shall be classified for the purposes of this code as Class A,
Class B, and Class C.
(c) Class A fire doors shall be doors of the following construction as
specified in Section twenty-two hundred and fourteen.
(1) Tin-clad, three-ply wood core, sliding.
(2) Tin-clad, three-ply wood core, swinging single leaf, doorway not
over six feet wide.
(3) Tin-clad, three-ply wood core, swinging in pairs, doorway not over
ten feet wide.
(149)
Sec. 2213
(4) Hollow metal, swinging single leaf, doorway not over four feet wide.
(5) Hollow metal, swinging in pairs, doorway not over eight feet wide.
(6) Sheet metal, sliding, single, doorway not over ten feet wide.
(7) Sheet metal, sliding in pairs, doorway not over twelve feet wide.
(8) Sheet metal, swinging single leaf, doorway not over six feet wide.
(9) Sheet metal, swinging in pairs, doorway not over ten feet wide.
(10) Steel rolling, doorway not over twelve feet wide.
(11) Steel plate, doorway not over four feet wide.
(12) Any other construction equal or superior to a tin-clad three-ply
wood core door in a standard fire test, for resistance to fire, the spread of fire
and smoke, and transmission of heat.
(d) Class B fire doors shall be doors of the following construction as
specified in section twenty-two hundred and fourteen.
(13) Tin-clad, three-ply wood core.
(14) Tin-clad, two-ply wood core, sliding, doorway not over ten feet
wide.
(15) Tin-clad, two-ply wood core, swinging single leaf, doorway not
over six feet wide.
(16) Tin-clad, two-ply wood core, swinging in pairs, doorway not over
ten feet wide.
(17) Hollow metal, sliding, doorway not over eight feet wide.
(18) Metal-clad, paneled, swinging single leaf, doorway not over three
feet wide.
(19) Metal-clad, paneled, swinging in pairs, doorway not over six feet
wide.
(20) Any other construction equal or superior to a tin-clad two-ply
wood core door in a standard fire test, for resistance to fire, the spread of
fire and smoke, and transmission of heat.
(e) Class C fire doors shall be doors of the following construction as
specified in section twenty-two hundred and fourteen.
(21) Metal-clad, paneled, swinging single leaf, doorway not over four
feet wide.
(22) Metal-clad, paneled, swinging in pairs, doorway not over eight
feet wide.
(f) A Class A door may be used where Class B or Class C is specified;
a Class B door may be used where Class C is specified. Two Class B or
Class C doors on opposite sides of the wall may be used where a single Class A
or Class B door is specified.
^g) Fire-resistive doors, when closed, shall completely cover the doorways
in the walls and partitions or the openings in the floors or roofs to which they
are fitted. A swinging fire door shall either overlap both jambs and the head
of the opening not less than four inches or be fitted to a fire-resistive frame
with a rabbet the full thickness of the door and with not less than one half
inch overlap on the door. A sliding fire door, except in enclosures about
passenger elevators, shall overlap both jambs and the head of the opening
not less than four inches. A sliding fire door in an enclosure about a passenger
elevator shall overlap jambs, head and adjoining panels not less than one
(150)
Sec. 2213
half inch. Fire doors shall fit closely at the floor with clearance of not over
one quarter inch.
(h) In buildings with combustible floors, doorways required to have fire
doors shall have incombustible thresholds the full thickness of the wall, extend -
ing at least four inches from the face of the wall where a door is hung and
extending laterally at least six inches beyond each jamb of the doorway.
Thresholds may be flush with the floor.
(i) The rabbeted frame of a swinging fire door shall be constructed of
structural steel built into the concrete, masonry or other fire-resistive material
of the wall about the opening and secured thereto, except that the rabbeted
frame of a Class B or Class C door may be of wood, covered with sheet metal
not less than twenty-six gage in thickness, secured to the wall in the opening.
(j) Fire doors when closed shall fit tightly against the wall or frame so
as to provide an effective stop for fire and smoke. Except for the metal -
covered wooden frame specified in this section, combustible material shall
not intervene between the door and the fire-resistive material of the wall,
floor or roof to which it is fitted.
(k) Hinge hardware for fire doors shall be of malleable iron or rolled struc-
tural steel not less than one fourth inch thick except that tubular steel track for
sliding doors may be not less than one eighth inch thick. Equivalent thickness
of solid bronze or brass may be used. Fire doors shall not depend upon cords,
cables or chains to support them in closed position except in elevator shafts.
(1) Tracks for sliding fire doors shall be so supported that a track hanger
comes at each door hanger when the door is closed. Track hangers shall be
secured to wood stud walls by screws or bolts, to steel stud walls by bolts or
rivets, to masonry walls by through bolts and to concrete walls by through
bolts or approved built-in inserts. Expansion shields shall not be used to
support fire doors.
(m) Hinges for swinging fire doors, except in wooden stud walls, shall be
riveted or through-bolted to the structural steel frame of the opening, through-
bolted to the wall if of masonry or concrete or secured by approved inserts
in the concrete or built into masonry in approved manner.
(n) Strap hinges and sliding door hangers shall be secured to fire doors by
through-bolting, riveting or welding. Swinging fire doors in rabbeted frames,
except tin-clad, wood core doors, may be hung on butts. Other swinging
fire doors shall have strap hinges.
(o) Sliding fire doors shall have adequate stops for the closed position.
Swinging Class A fire doors shall have surface latches or unit locks. Class B
and Class C doors shall have surface latches, unit or mortise locks. The
latch bolts of unit or mortise locks on fire doors shall have a throw of three
fourths inch. When mounted in pairs fire doors shall be rabbeted by means of
an astragal or otherwise where they come together. One of a pair of swinging
fire doors shall have push bolts at top and bottom with a throw of three
fourths inch and the other shall be held by latch to the first.
(p) Except in detention buildings, fire doors hung in required exits shall
be so fitted with hardware that they can be opened from inside without use
of a key when the building is occupied.
[ *As amended by Ord. 1943, ch. 6 ]
(151)
Sec. 2214
♦Sect. 2214. Fire Door Construction. — (a) In the construction
of fire doors solder shall not be used, except for filling joints. Sheet metal
shall be fastened to wood by nailing and to metal frame by bolting, riveting
or welding.
(b) Class A doors shall not have glass panels. Class B doors may have
glass panels not larger than one hundred square inches in exposed area nor
more than twelve inches in width or height. Class C doors may have glass
panels not larger than two thousand and sixteen square inches in total ex-
posed area, and no single light shall have an exposed area exceeding twelve
Tiundred and ninety-six square inches. Glass in fire doors shall be wire
glass not less than one quarter inch thick and shall be set five eighths inch in
grooves three quarters of an inch deep.
(c) Fire doors shall be constructed as follows: —
(1) Tin-clad, three-ply wood core doors shall be constructed in ac-
cordance with the specifications of the National Board of Fire Under-
writers for such doors in Class A openings, and shall bear the label of
the Underwriters Laboratories to this effect.
(2) Tin-clad, two-ply wood core doors shall be constructed in accord-
ance with the specifications of the National Board of Fire Underwriters
for such doors in Class B openings and shall bear the label of the Under-
writers Laboratories to this effect.
(3) Hollow metal doors shall have substantial stiles and rails of heavy
pressed steel, reinforced for hinges and other hardware. Panels shall be
of sheet steel filled with asbestos board or other approved insulating
materials. The door shall be assembled by welding or riveting.
(4) Sheet metal doors shall be constructed with a rolled steel rigid
frame covered both sides with one sixteenth inch asbestos board and
twenty-six gage corrugated sheet metal, with corrugations vertical on one
side and horizontal on the other, bound on the edges with rolled steel or
pressed steel shapes.
(5) A steel rolling fire door shall be constructed of sheet steel inter-
locking slats, sliding in grooves, counterweighted by springs, the roller and
mechanism enclosed in heavy sheet metal.
(6) A steel plate fire door shall be constructed of not less than twelve
gage steel plate mounted on a rolled steel frame, assembled by welding or
riveting.
(7) A metal clad, paneled fire door shall have a wood core with stiles
and rails not less than one and three fourths inches thick covered with
twenty-six gage sheet steel; panels three fourths inch thick covered with
twenty-six gage sheet steel, set three fourths inch in grooves; joints of
metal lapped and well nailed.
(d) A door properly bearing the Underwriters' Label certifying that it is
suitable for the protection of a Class A opening shall be acceptable as a
Class A door
(e) A door properly bearing the Underwriters' Label certifying that it is
suitable for the protection of a Class B opening shall be acceptable as a Class
B door, except that metal clad doors wider than three feet shall not be
accepted as Class B doors.
(152)
Sees. 2214-2216
(f) A door properly bearing the Underwriters' Label certifying that it is
suitable for the protection of a Class C opening shall be acceptable as a Class
C door.
[ *As amended by Ord. 1948, ch. 6 ]
Sect. 2215. Fire-Resistive Shutters. — Shutters required to be fire
shutters or fire-resistive shutters shall be constructed and hung as specified
for Class B fire-resistive doors in sections twenty-two hundred and thirteen
and twenty-two hundred and fourteen.
fSect. 2216. Fire-Resistive Windows. — (a) Windows which are re-
quired to be fire windows, fire-resistive windows, or of fire-resistive construc-
tion shall conform to the requirements of this section.
(b) Fire-resistive windows may be fixed or arranged to open and close.
Fixed fire-resistive windows shall be so secured in the walls in which they
are placed that they may expand in case of fire without buckling. Movable
fire-resistive windows shall be opened or closed in one of the following:
manners : —
(1) One or more sashes may slide horizontally in a fire-resistive frame.
(2) One or more sashes may slide vertically with counterweights or
with two sashes counterbalanced and hung on chains. If a sash is closed
in raised position it shall have a fastening.
(3) A sash may be hinged at top, bottom, or either side.
(4) A sash may be pivoted at top and bottom or at the sides.
(5) A sash may be arranged to open and close in any other approved
manner, with approved hardware.
(c) Movable sashes in fire-resistive windows shall be fitted to fire-resistive
frames of the same or similar construction. Both sashes and frames, and
metal mullions between window units, shall be so fitted in the walls in which
they are placed as to be continuous with the fire-resistive material of the wall
and so secured that they may expand in case of fire without buckling.
(d) Glass in fire-resistive windows shall be wire glass not less than one
fourth inch thick and the area of a single light shall not exceed seven hundred
and twenty square inches. Glass shall be set three eighths inch in grooves
at least one half inch deep. Glass shall be secured by glazing angles or mold-
ings screwed to the sash and forming continuous grooves for the glass.
(e) Fire-resistive windows shall be of the following construction: —
(6) Hollow sheet metal sashes and frames fabricated by pressing,
welding, riveting or crimping without the use of solder or other fusible
alloy, except for filling joints, and bearing the label of the Underwriters'
Laboratories.
(7) Rolled steel or pressed steel sashes fabricated by pressing, welding,
riveting or crimping, of a make and style approved by the commissioner.
(8) Any other approved constructions as fire-resistive as that specified in
paragraph (6).
(f) Fixed fire-resistive windows of hollow sheet metal construction shall
not exceed seven feet in width nor ten feet in height. Fire-resistive windows
of hollow sheet metal construction with movable sashes shall not exceed six
feet in width nor ten feet in height.
(153)
Sees. 2216-2217
(g) Fire-resistive windows of rolled steel construction shall not exceed
eighty-four square feet in area nor twelve feet in either height or width.
(h) Fire-resistive windows and their fastenings shall be capable of resist-
ing the wind pressure on the wall of the building applied either on the inside or
the outside of the window without exceeding allowable stresses.
(i) Where fire-resistive windows are required, wooden windows and plain
glass may be substituted provided the openings are protected by fire-resistive
doors or shutters, or, in buildings of approved occupancy and construction,
by an approved system of open sprinklers.
[ jAs amended by Ord. 1943, ch. 6 ]
{Sect. 2217. Fire= Resistive Roof Covering. — (a) Roof covering
allowed under this code shall be classified as fire-retardant or ordinary, accord-
ing to their resistance to fire outside, as provided in this section. Fire-
retardant roof covering is the more fire-resistive and may be used on any
building. Ordinary roof covering shall not be used where fire-retardant roof-
ing is specified. Roof covering less fire-resistive than ordinary roof covering
shall not be used on any building.
(b) Fire-retardant roofing shall be any roof covering which meets the
requirements of Class A or Class B roofing under the specifications of the
Underwriters' Laboratories, Inc. The following roof covering shall be as-
sumed to meet the requirements for fire-retardant roofing: —
(1) Built up roofing consisting of successive layers of roofing felt im-
pregnated with asphalt; a final layer of asphalt in which, while molten, is
embedded a continuous layer of roofing gravel or slag.
(2) Built up roofing consisting of successive layers of roofing felt im-
pregnated with coal tar; a final layer of tar in which, while molten, is
embedded a continuous layer of roofing gravel or slag.
(3) Built up roofing consisting of successive layers of roofing felt impreg-
nated with asphalt; a final layer of asbestos roofing felt impregnated with
asphalt weighing not less than fourteen pounds per hundred square feet,
or a final layer of asphalt-saturated prepared roofing coated with granu-
lated slate or other similar material.
(4) Built up roofing consisting of successive layers of roofing felt im-
pregnated with tar or asphalt and a finish of burned clay floor tile, stone
flagging, cement concrete or other similar material.
(5) Sheet metal with locked and soldered joints not less than number
twenty-six gage in thickness.
(6) Shingles of natural slate .
(7) Shingles of burned clay tile.
(8) Shingles of sheet metal not less than number twenty -six gage in
thickness.
(9) Shingles of asbestos board not less than one eighth inch thick.
(10) Shingles of asphalt saturated felt surfaced with granulated slate
or other similar material and carrying the Underwriters Class "C" label.
(11) Corrugated sheet metal with lapped joints not less than number
twenty-six gage in thickness.
(12) Corrugated asbestos board not less than three sixteenths inch
thick.
(154)
Sec. 2217
(c) Ordinary roofing shall be any roof covering which meets the require-
ments of class C roofing under the specifications of the Underwriters' Labora-
tories, Inc. The following roof covering shall be assumed to meet the require-
ments for ordinary roofing: —
(13) Built up roofing consisting of successive layers of roofing felt
impregnated with asphalt, coal tar or other approved material, not equal
in fire-resistance to a fire-retardant roofing.
(14) Prepared roofing consisting of felt or fabric impregnated or coated,
or both, with asphalt, tar or other approved material or shingles of such
prepared roofing, not equal in fire-resistance to fire-retardant roofing.
(15) Canvas stretched tightly and coated with paint.
(d) Built-up roofing shall be secured to the roof deck in the following
manner:
1 Over masonry slab. The first layer shall be laid in molten asphalt
or tar mopped on the roof deck, after the deck is properly primed, or by
nailing a layer of building paper to nailing inserts other than wood placed
in the deck.
2 Over wood decks the built-up roofing shall be secured by nailing a
layer of building paper to the roof deck over which the prepared roofing
is to be laid with the first layer laid in molten asphalt or tar.
3 Roofings other than built-up roofings, such as shingles, slates, tile
roll roofing shall be well secured to the deck by nailing, bolting, wiring,
or other approved methods.
[ £4s amended by Ord. 1943, ch. 6 and 9 }
(155)
Sees. 2301-2303.
PART 23.
DEAD AND LIVE LOADS.
Section
2301 — Design for Loads.
2302 — Dead and Live Loads.
2303 — Weights of Materials.
2304 — Loads from Partitions.
2305 — Live Loads on Floors.
2306 — Special Concentrations.
2307 — Partial Loadings.
2308— Impact.
2309 — Lateral and Uplift Forces.
2310 — Reduction of Live Loads.
2311 — Roof Loads.
2312 — Wind Loads.
2313 — Load Tests of Structure.
Section 2301. Design for Loads. — All buildings and other structures
and parts thereof shall be designed to support the loads and to withstand the
forces to which they are to be subjected during construction as well as after
completion. The design shall allow for dead and live loads including wind
and snow loads as required in this part without exceeding the allowable
stresses prescribed for supporting members elsewhere in this code.
Sect. 2302. Dead and Live Loads. — (a) The dead loads acting upon
a building or structure shall include all the forces due to weight of walls,
permanent partitions, floors, roofs, framing and all other permanent stationary
construction and fixed service equipment entering into and becoming part
of the structure.
(b) The live loads acting upon a building or structure shall include all
loads other than dead loads.
Sect. 2303. Weights of Materials. — (a) The actual weights of the
constituent parts of a structure and of materials to be supported shall be
Used in calculation of loads. The materials listed in the following table shall
be taken to weigh not less than there indicated:
Pounds Per
Cubic Foot
Masonry:
Brick (face, clay, shale, or concrete) 140
Brick (sand-lime) 113
Brick (common) 120
Cast stone 1 44
Clay tile 60
Concrete (Portland cement, sand and stone aggregates):
Unreinforced 1 44
Reinforced 1 50
(156)
Sees. 2303-2304.
Pounds Per
Cubic Foot
Concrete (Portland cement, sand cinder aggregates) :
Fill 100
Class block 54
•Granite 165
Limestone 160
Marble 160
Sandstone 144
Metals:
Cast iron 450
Steel 490
Soils:
Earth, common, dry and compacted 100
Sand and gravel, compacted 120
Timber, structural 40
Plaster:
Gypsum, on tile or concrete 5
Gypsum, and wood lath (excluding furring) 8
Gypsum, and suspended metal lath 10
Cement, and suspended metaJ lath 15
Roofing, tar and gravel 6
Water (fresh) 62.4
Sect. 2304. Loads from Partitions. — (a) 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 pre-
scribed live load does not exceed fifty pounds per square foot, allowance for
partition weight shall always be made whether or not partitions are shown
on plans.
(b) If a layout of partitions is included in the building plans, the weights
of the partitions and their locations shall be determined in accordance there-
with, or such layout shall be used to determine an equivalent load per square
foot of floor to be applied uniformly as a super-imposed dead load for purposes
of design. But the aPowance for partition weight in portions 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 pounds for each foot of story
height for each square foot of floor.
(c) In estimating loading from actual weights of partitions it may be
assumed that the partition occupies a space one foot wide, and a deduction
may be made of the live load displaced on this width.
(d) Arch action of partitions sha'l not be assumed to relieve the supporting
members.
(157)
Sec. 2305.
Sect. 2305. Live Loads on Floors. — The live loads taken on floors for
purposes of design shall be the greatest loads that will probacy be produced
by the intended occupancies but the following distributed live loads shall be
taken as the minimum for the occupancies named. For occupancies not listed,
the design engineer shall submit the proposed design live load to the Com-
missioner for approval. All plans filed for permit shall include a list or
notation of tne live loads used in design. In buildings, structures or portion
thereof used for industrial, mercantile or storage occupancies the live load
for which each floor or part of a floor is designed and approved shall be con-
spicuously posted in that part of the story to which it, applies. See also
Section 114.
Pounds per
Square Foot
Domestic Occupancy: All parts of private dwellings, rooms and
suites in apartment houses, lodging houses and clubs, private, ward or
dormitory rooms in hospitals, asylums, educational and religious in-
stitutions, including corridors giving access thereto, and bedrooms
of hotels 40
Office Buildings:
Basement 100
First Floor 80
Upper Floors 50*
Church Auditoriums: With fixed seats, including aisles, sanctuary
or chancel, sacristies, choirs and chapels 60
Classrooms: Not exceeding nine hundred square feet in area, or
larger size rooms where fixed seats are used 50
Kitchen: Other than domestic, and school laboratories 100
Theatre Auditorium and Assembly Halls: With fixed seats, in-
cluding aisles and passageways 75f
Theatre Stages: Gridirons and fly galleries 150
Public Occupancy: Lobbies, foyers, vestibules and similar public
spaces of hote^, theatres, churches, clubs, and public buildings;
assembly haPs, including class and lecture rooms exceeding nine
hundred square feet in area, without fixed seats; dance halls, public
dining rooms and restaurants, public rooms for social purposes,
skating rinks, gymnasiums 100
Bleachers: Grandstands and temporary grandstands 150
Corridors r
In theatres and those serving assembly halls 100
In school buildings 75
Other corridors same loading as heaviest occupancy to which they
provide access
♦See Section 2304
(158)
Sees. 2305-2306.
Pounds per
S quare Foot.
Fire Escapes and Exterior Balconies:
Serving theatres or assembly halls 100
In other buildings 75
Stairs:
Same loading as heaviest occupancy to which they give access, but
maximum required 100f
Stores:
For light merchandise, first and basement floors 100
For light merchandise, above first floor, including mezzanine 75
For heavy merchandise, all floors 125
Storage:
Light storage 125
Heavy storage 250
Manufacturing :
Light manufacturing 75
Intermediate manufacturing 1 50
Heavy manufacturing 250
Locker Rooms , 75
Garages: Including Apparatus Rooms of Fire Stations:
Class A — Floors used for vehicles exceeding 20,000 lbs. in weight,
including loads; and first or street floors of garages except those
limited exclusively to passenger vehicles of not more than 9
persons capacity 250f
Class B — Floors not included in Class A and first or street floors of
garages limited to passenger vehicles exclusively weighing not
more than 9,000 lbs 150f
Class C — Floors above the first or street floors for passenger vehicles
weighing less than 6,000 lbs 100f
A floor connected directly with the street or by a ramp or driveway
not more than eight feet high shall be regarded as a first or street floor
Sidewalks 250f
Driveways 250f
Sect. 2306. Special Concentrations. — In the design of floors and struc-
tural systems, consideration shall be given to the effects of known or prob-
able concentrations of load to which they may be subjected; and in structures
designed for the occupancies listed herein, floors shall be made capable of
carrying the prescribed distributed loads or the following minimum concen-
trations, whichever may result in the greater stresses. Unless otherwise noted
the following concentrated loads indicated, in pounds shall be taken to occupy
a space two and one-half feet square, and so placed as to produce maximum
stresses in the members affected:
tFor special floor concentrations and lateral thrusts on stair and balcony rails, see Sections
2306 and 2309.
(159)
Sees. 2306-2308.
Pounds per
Square Foot.
(1) For office floors including corridors, theatre stages, grid-
irons and fly galleries and corridors serving them 2,000 lbs.
(2) For portions of garages subject to:
Class A loading 20,000 lbs.
Class B loading 10,000 lbs,
(3) For sidewalks 12,000 lbs,
(4) For driveways, and for trucking spaces within the limits
of a structure 20,000 lbs,
(5) For structural supports of ceilings under accessible
spaces, and for trap doors and skylights 200 lbs,,
(6) That portion of hangars subject to concentrated loads
shall be designed to accommodate the heaviest vehicle housed
therein
(7) For elevator machine room grating (on an area of four
square inches) 300 lbs,
(8) For stair treads (on an area of four square inches) 300 lbs.
(9) For exposed metal light floor plate construction (on
an area of one square inch) 200 lbs.
Sect. 2307. Partial Loadings. — (a) The effect of a partial live load on
a structure — taking into account its construction connections and rigidity —
which will produce maximum stress in any member shall be provided for in
the design as well as the full live load.
(b) The partial loading shall a^o conform to the design requirements of
other sections of this code.
(c) For snow and wind load requirements, see Sections 2311 and 2312.
Sect. 2308. Impact. — (a) The live loads prescribed herein include a suffi-
cient allowance to cover the effects of ordinary impact.
(b) For structures carrying live loads which induce unusual vibration or
impact forces, the live load shall be increased sufficiently to provide for same.
For machinery and other vibratory loads care shall be taken to avoid near
resonant conditions.
(c) The increase shall be:
For supports of elevators 100 Percent
For traveling crane support girders and their connections 25 Percent
For supports of light machinery, shaft or motor driven,
not less than 20 Percent
For supports of reciprocating machinery or power driven
units not less than 50 Percent
For hangers supporting floors and balconies 33 Percent
(160)
Sees. 2308-2311
(d; The lateral force on crane runways to provide for the effect of moving
crane trolleys shall, if not otherwise specified, be 20 percent of the sum of the
weights of the lifted load and of the crane trolley (but exclusive of other
parts of the crane), applied at the top of rail, one half on each side of the
runway; and shall be considered as acting in either direction normal to the
runway rail.
(e) The longitudinal force shall, if not otherwise specified, be taken as 10
percent of the maximum wheel loads of the crane applied at the top of rail.
Sect. 2309. Lateral and Uplift Forces. — (a) In the design of basement
walls and similar approximately vertical structures below grade, the forces
due to lateral pressure of adjacent soil shall be calculated. Due allowance
shall be made for possible surcharge from fixed or moving loads. When a
portion or the whole of the adjacent soil is below a free water surface, calcula-
tions shall be based on the weight of the soil as diminished by buoyancy, plus
full hydrostatic pressure.
(b) In the design of structures below ground grade, the upward pressure of
water, if any, in the supporting soil, shall be taken as the fu1! hydrostatic
pressure applied over the entire area.
(c) Balcony and stairway railings, exterior and interior, shall be designed
to resist a horizontal thrust of twenty pounds per linear foot applied at the
top of the rail.
Sect. 2310. Reduction of Live Loads. — (a) Roof Live Loads — No reduc-
tion shall be made in the roof live load. No reduction shall be made in wind
loads.
(b) Live Loads 100 Pounds per Square Foot or Less — For uniformly
distributed live loads of 100 pounds or less per square foot the design live
load on any member (except one-way slabs) supporting 150 square feet or
more may be reduced at the rate of 0.06 percent per square foot of area
supported by the member, except that no reduction shall be made for areas
to be occupied as places of public assembly. The reduction shall exceed
neither R as determined by the following formula, nor 50 per cent:
D plus L
R = 100 x — £-
5L
in which
R = reduction in percent
D = dead load per square foot of area supported by the member
L = design live load per square foot of area supported by the member
(c) Live Loads Exceeding 100 Pounds per Square Foot — For live loads
exceeding 100 pounds per square foot, no reduction shall be made, except that
the design live loads on columns may be reduced by | the percentage
specified in (b).
Sect. 2311. Roof and Snow Loads. — (a) Flat roofs and roofs having a
rise of two inches or less per foot of run shall be designed to support a vertical
(161)
Sees. 2311-2312.
snow load of thirty pounds per square foot of horizontal projection. Roofs
used as roof gardens, or for other such purposes shall be designed as floors to
support the Joad prescribed for corresponding occupancies.
(b) Roofs having a rise of more than two and less than twelve inches per
foot of run shall be designed for a vertical snow load of (34-2r) pounds per
square foot of horizontal projection in which r is the rise in inches per foot
of run.
(c) Roofs having a rise of twelve inches or more per foot of run shall be
designed for a vertical snow load of ten pounds per square foot of horizontal
projection.
(d) Roof structures or portions thereof shall be designed for stresses
produced by partial snow loading whenever such stresses exceed those pro-
duced by full snow loading. In such cases the partial snow load per square
foot shall be taken as two thuds of the load required by paragraph a, b, or c
of this section.
(e) All roofs shall be designed for the wind loads specified in Section
2312 in addition to the live loads presented in this section. Two thirds of
the wind load required by Section 2312 shall be combined with two thirds
of the snow load required by paragraph a, b, c, or d of this section, whenever
such a combination produces higher stresses than those existing with wind
or snow load acting separately.
Section 2312. Wind Loads. — (a) All structures shall be designed to
resist wind forces applied to both walls and roofs without exceeding the
stresses allowed elsewhere in this code.
(b) The design wind pressure P in pounds per square foot shall vary
with the height above the average ground elevation adjacent to the base of
the structure in accordance with the following table: For a sloping roof the
heights of the structure shall be measured to the average height of the roof.
P in Lbs.
Height in Feet Per Sq. Foot
0 to less than 25 20
25 to Jess than 50 25
50 to less than 100 30
100 to less than 150 35
150 to less than 400 45
400 to less than 700 55
700 to less than 1,500 65
(c) Wind pressure on the elements of a structure shall not be less than
the following values:
Total horizontal pressure on the walls of rectangular buildings
(combining the effect of pressure on the windward wall and suction
on the leeward wall) 1.0 P
Total horizontal pressure acting simultaneously on each of any two
perpendicuW walls of a rectangular building (combining the effect of
pressure on the windward walls and suction on the leeward walls) 7 P
(162)
Sees. 2312-2313.
Pressure in or out on an exterior wall 1.0 P
Total suction on the entire surface of all roofs 1.2 P
Pressure normal to windward surface only of roofs with slopes equal
to or greater than 30 degrees (to be combined with zero pressure on
leeward slope) 9 P
Uplift on eaves, cornices or other local projections, and fastenings
of roof coverings 1.5 P
Total pressure on gross area of signs with less than 25% openings. . 1 .2 P
Total pressure on net area of signs with more than 25% openings ... 1 . 6 P
Total pressure on projected area of round chimneys or tanks 7 P
(d) As an alternative to the provisions of Section 2312 (c) and with the
approval of the Building Commissioner, 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 .77P where P is given by the table
in paragraph 2312 (b).
(e) The overturning moment due to wind pressure shall not exceed
66 2/3 percent of the moment of stability due to the dead load only, unless
the building or structure is securely anchored to the foundation to resist
this force.
Section 23 13. Load Tests of Structures. — (a) The Commissioner may
order tests under load or other tests of any portion of a structure (whenever
the Commissioner doubts the adequacy of a structure to serve the purpose
for which it was intended). Such tests shall not be required to be made on
any concrete or masonry construction until it is at least sixty days old.
(b) In such tests the member or portion of the structure under test shall
be subject to a total load including its own weight which shall equal the total
dead load plus twice the live load for which it is required to be designed.
This load shall be left in position for a period of twenty-four hours before
removal. The structure, if a floor or portion thereof, shall be considered to
have passed the test if within twenty-four hours after the removal of the load
such floor or roof recovers three quarters of the maximum deflection under
the test load. If the member or portion of the structure shows evident failure
or fails to meet the recovery requirement, it sha1! be rebuilt or may be modified
as is necessary to make the structure adequate for the rated capacity, except
that, where lawful, and where the structure is undamaged a lower rating may
be established.
(163)
Sees. 2401-2402
PART 24.
MASONRY.
Section
2401 — Design of Masonry.
2402 — Materials of Masonry.
2403 — Brick.
2404 — Stone.
2405 — Cast Stone.
2406 — Concrete Blocks.
2407 — Structural Clay Tile.
2408 — Gypsum Tile.
2409 — Plain Concrete.
2410 — Plain Gypsum Concrete.
2411 — Mortar.
2412 — Bond in Masonry.
2413 — Allowable Unit Stresses in Masonry.
2414 — Masonry Arches.
2415 — Reinforced Masonry.
2416 — Second=Hand Materials for Masonry.
Section 2401. Design of Masonry. — Masonry shall be designed by a
method admitting of rational analysis according to established principles of
mechanics, supplemented by the assumptions herein specified, to support
the loads and withstand the forces to which it is subject without exceeding
the stresses allowed in this chapter for the various materials thereof.
Sect. 2402. Materials of Masonry. — (a) 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
this chapter.
(b) The materials entering into masonry shall be classified for the pur-
poses of this code as follows: —
Brick.
Stone.
Cast Stone.
Concrete Blocks.
Structural Clay Tile.
Gypsum Tile.
Plain Concrete.
Plain Gypsum Concrete.
Mortar.
(c) A material of masonry other than those classified in this chapter,
which is incombustible and otherwise sufficiently embodies the characteristics
of one of the materials here classified, and which satisfies the requirements of
(164)
Sees. 2402-2405
this chapter for that material may be included by the commissioner in the
classification of that material which it most closely resembles.
(d) The commissioner may require reasonable tests from time to time of
masonry to determine their quality and whether they conform to the require-
ments of this chapter.
(e) Tests of masonry or of the materials thereof shall be made in accord-
ance with the standard specifications of the American Society for Testing
Materials for testing the material in question and if for any material such
standard specification is not available the commissioner shall specify the
method and manner of making the test.
*Sect. 2403. Brick. — (a) Brick, as classified in this code, shall include
masonry units usually about two and one quarter inches thick, three and
three quarters inches wide and eight inches long. Brick shall be made of
burned clay or shale, concrete, or a mixture of sand and lime.
(b) Burned clay brick shall be either solid or hollow, but if hollow shall
be at least three quarters solid.
(c) Concrete brick shall be made of Portland cement, aggregates and
water as specified for concrete in Part 26.
(d) Sand-lime brick shall be made of sand, lime, and water well mixed,
pressed and cured in a carefully controlled process to a uniformly hard and
durable product.
(e) Brick, whether of burned clay, concrete, or sand and lime, shall be
classified for strength when tested flatwise according to the following table: —
Classification of Brick by Strength.
Grade.
Compressive Strength
(Pounds per Square
Inch).
Modulus of Rupture
(Pounds per Square
Inch).
Average of
Five Tests.
Individual
Minimum.
Average of
Five Tests.
Individual
Minimum.
A
4,500 or more
2,500 to 4,500
3,500
2,000
600 or more
450 or more
400
B
300
(f) Brick for load-bearing masonry or masonry exposed to the weather
shall be of Grade A or B.
(g) Brick for fire protection, fire-resistive walls, or fire-stopping shall be
of Grade B or better.
[ *As amended by Ord. 1948, ch, 6 ]
Sect. 2404. Stone. — Stone for masonry shall be hard and durable.
Sandstone in masonry exposed to the weather shall be laid with its natural
bed horizontal.
tSect. 2405. Cast Stone. — (a) Cast stone shall be made of Portland
cement, aggregates and water with or without admixtures. Cast stone for
load-bearing masonry or exposed to the weather shall have an average com-
(165)
Sees. 2405-2407
pressive strength at an age of twenty-eight days of at least five thousand
pounds per square inch and shall have not more than seven nor less than three
per cent water absorption by weight.
(b) Cast stone shall not project more than six inches beyond the support-
ing material. Cast stone shall have reinforcing as required for reinforced
concrete in Part 26 of this code together with three inch damp-proofing
protection of the reinforcing.
[ 1[As amended by Ord. 1943, ch. 6 ]
Sect. 2406. Concrete Blocks. — (a) Concrete blocks, as classified in
this Code, shall include hollow masonry wall units of concrete made from
Portland cement, water and suitable aggregates, such as sand, gravel, crushed
stone, bituminous or anthracite cinders, burned clay or shale and blast-furnace
slag. The materials shall conform to the requirements for the materials of
concrete specified in Part 26 except that cinder aggregate for concrete blocks
shall contain not more than twenty per cent of combustible matter.
(b) Concrete blocks shall have outer shells at least five eighths inch thick
and shall have strength in compression not less than two hundred and fifty
pounds per square inch of gross area for an average of five blocks tested.
Concrete blocks in load-bearing masonry or in masonry exposed to weather
or soil shall have a strength in compression not less than one thousand pounds
per square inch of gross area for an average of five blocks tested, and a mini-
mum of seven hundred pounds per square inch for any block.
(c) Concrete blocks exposed to weather or soil in masonry shall have not
more than twelve per cent water absorption by weight.
Sect. 2407. Structural Clay Tile. — (a) Structural clay tile shall con-
sist of well burned hollow units of clay or shale.
(b) Structural clay tile shall be classified for use as follows : —
(1) Partition Tile.
(2) Floor Tile.
(3) Load-Bearing Tile.
(c) Structural clay partition tile shall be classified for physical quality as
Grade A or Grade B according to the following table: —
Structural Clay Partition Tile.
Water Absorption by Weight (per cent).
Grade.
Average of
Five Blocks.
Individual
Maximum.
Individual
Minimum.
A
5 to 16
16 to 25
19
28
4
B
4
(166)
Sec. 2407
(d) Structural clay partition tiles of the dimensions indicated shall have
-the construction and dry weights given in the following table: —
Structural Clay Partition Tile.
Dimensions (Inches).
Minimum Number
of Cells.
Minimum Weight
(Pounds).
2x 12 x 12
3
3
3
3
4
4
4
4
14
3 x 12 x 12
15
4x12x12
16
6x 12 x 12
22
6 x 12 x 12
25
8x 12 x 12
30
10 x 12 x 12
35
12 x 12 x 12
40
(e) Structural clay partition tile shall not be used in load-bearing masonry.
Partition tile exposed to the weather shall be Grade A. Partition tile in fire-
resistive construction shall be Grade B or better. The exterior shells shall be
at least five eighths inch and the interior webs at least one half inch thick.
(f) Structural clay floor tile shall be classified for physical quality as
Grade A or Grade B according to the absorption table of paragraph (c) of this
section for Structural Clay Partition Tile. Structural clay floor tile used in
floor and roof arches shall have at least the physical qualities of the tile here
classified as Grade B, as provided in Specifications for Structural Clay Floor
Tile of the American Society for Testing Materials.
(g) Structural clay load-bearing tile shall be classified for physical quality
as Grade A or Grade B according to the absorption table of paragraph (c)
of this section, and the tile of each grade shall satisfy also the requirements
for strength of the following table: —
Structural Clay Load=Bearing Tile.
Compressive Strength
(Pounds per Square Inch op Gross Area).
Grade.
END CONSTRUCTION.
SIDE CONSTRUCTION.
Average of
Five Blocks.
Individual
Minimum.
Average of
Five Blocks.
Individual
Minimum.
A
1,400 or more
1,000 or more
1,000
700
700 or more
700 or more
500
B
500
(h) Tests to establish the grade of structural clay load-bearing tile shall
be made as provided in Specifications for Structural Clay Load-Bearing Wall
Tile of the American Society for Testing Materials.
(167)
Sees, 2407-2411
(i) Structural clay load-bearing tile shall have the cellular construction
and minimum weights given in the following table: —
Structural Clay Load-Bearing Tile.
Thickness in Wall (Inches).
Minimum Cells in
Thickness of Wall.
Minimum Tile
Weight per Square
Foot (Pounds).
1
2
2
2
3
20
30
8
36
10
42
12
52
(j) Structural clay tile used in load-bearing masonry shall be load-bearing
tile having at least the physical qualities of Grade B, and such tile in masonry
exposed to weather or soil shall be of Grade A. Load-bearing tile shall have
shells at least seven eighths inch and webs at least five eighths inch thick and
shall otherwise conform to Specifications for Structural Clay Load-Bearing
Wall Tile of the American Society for Testing Materials.
♦Sect. 2408. Gypsum Tile. — (a) Gypsum tile used for fire-resistive
purposes shall conform to the provisions of Specifications for Gypsum Parti-
tion Tile or Block and Specifications for Gypsum of the American Society for
Testing Materials.
(b) Gypsum tile shall not be used in load-bearing masonry or in masonry
exposed to weather or soil.
♦Sect. 2409. Plain Concrete. — (a) Plain concrete is concrete cast
in place and not reinforced, or reinforced only for shrinkage or changes of
temperature. Plain concrete shall be mixed, placed and cured as specified
for concrete in Part 26.
(b) Plain concrete in load-bearing 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 pounds per square inch and where ex-
posed to wetting or freezing at least two thousand pounds per square inch as
provided in Part 26.
[*As amended by Ord. 1943, ch. 6 and Ord. 1955, ch. 2]
fSect. 2410. Plain Gypsum Concrete. — (a) Plain gypsum concrete
may be used for fire protection and non-structural purposes and shall contain
not over fifteen per cent by weight of wood or other combustible binder.
[ \As amended by Ord. 1943, ch. 6 ]
JSect. 2411. Mortar. — (a) Masonry, other than plain concrete and
plain gypsum concrete, shall be laid in mortar except stone masonry in under-
water masonry, in retaining walls not in buildings which may be laid without
mortar. Load-bearing masonry laid in mortar shall have full beds and full
builds of mortar in which the units are placed.
(168)
Sec. 2411
(b) Mortar shall consist of a mixture of suitable proportions of Portland
ement, lime, sand and water; but approved special masonry cement may be
<ubstituted for the Portland cement or lime, or both.
(c) Portland cement and sand shall conform to the requirements for these
materials in Part 26 of this code. Lime shall conform to Specifications for
Quicklime for Structural Purposes or Specifications for Hydrated Lime for
Structural Purposes of the American Society for Testing Materials.
(d) Lime putty shall be made by slaking to a smooth paste fresh and
properly burned quicklime. The resultant paste shall be stored in a suitable
box or other receptable for not less than forty-eight hours before being mixed
with sand. Hydrated lime may be substituted in equivalent amount for
lime putty.
(e) Lime mortar shall be composed of one part of lime putty and not
over three parts of sand by volume. Portland cement may be added to
lime mortar, replacing an equal volume of lime putty, and when the cement
is not less than one half the lime by volume, the working stress allowed in
the masonry may be increased proportionally up to the stress specified for
lime-cement mortar.
(f) Lime-cement mortar Class A shall be composed of one part of lime
putty, one part of Portland cement and not more than six parts of sand by
volume. Portland cement may be added to lime-cement mortar replacing
an equal volume of lime putty, and when such addition is made, the working
stress allowed in the masonry may be increased proportionally up to the
stress specified for cement mortar.
(g) Lime-cement mortar Class B shall be composed of two parts lime
putty, one part of Portland cement and not more than eight parts of sand by
volume. Portland cement may be added to lime-cement mortar replacing
an equal volume of lime putty, and when such addition is made, the working
stress allowed in the masonry may be increased proportionally up to the
stress specified for cement mortar.
(h) Cement mortar shall be composed of one part of Portland cement
and not more than three parts of sand by volume with an allowable addition
of lime putty or hydrated lime not to exceed fifteen per cent by volume of the
cement content.
(i) Mortar made of so-called "Masonry Cement" may be used. The
unit stress allowed in masonry laid with such mortar shall be determined by
the commissioner after tests or other satisfactory evidence have been sub-
mitted to him, but the unit stress shall not be greater than that given in
section twenty-four hundred and thirteen for masonry laid in lime-cement
mortar.
(j) In proportioning mortar a sack of Portland cement weighing about
ninety-four pounds shall be taken as one cubic foot and the volume of the
sand shall be based on dry and loose measurement.
(k) Except as otherwise provided in paragraph (a) of this section load-
bearing masonry, party walls, fire walls and masonry exposed to weather, or
soil shall be laid in lime mortar, lime-cement mortar, cement mortar or
(169)
Sees. 2411-2413
approved masonry cement mortar. Hollow masonry walls and masonry of
hollow units shall be laid in lime-cement mortar, cement mortar or approved
masonry cement mortar. Masonry likely to be under water or in contact
with wet soil, if laid in mortar, shall be laid in cement mortar. Mortar or
grout under metal bases of columns or beams resting upon concrete shall be
made without lime.
(1) Gypsum tile walls and other non-bearing masonry walls may be laid
in gypsum mortar.
[ %As amended by Ord. 1948, ch. 6]
Sect. 2412. Bond in Masonry. — Masonry walls and piers shall be
bonded as provided in Part 14.
*Sect. 2413. Allowable Unit Stresses in Masonry. — (a) In ma-
sonry walls and piers subject to axial loads the average unit compressive
stress shall not exceed the values given in the following table: —
Average Unit Compressive Stress in Masonry.
(Pounds Per Square Inch, Gross Area.)
Lime
Mortar.
Lime-Cement Mortar.
Cement
Masonry.
Class A.
Class B.
Mortar.
Brick:
100
75
200
150
180
130
300
225
Cut Stone:
Granite 1
Limestone 1
300
450
400
600
Marble [ '
Sandstone J
Cast Stone \
Rubble Stone J*
100
200
180
300
__
100
90
150
Structural Clay Tile:
80
70
100
—
80
70
100
The compressive unit stress in plain concrete shall not exceed one fifth the
compressive strength at twenty-eight days when determined as specified
in Part 26.
(b) The unit shear in masonry shall not exceed one tenth the allowable
unit compressive stress.
(c) The maximum unit stress in bending in sound natural stones used in
lintels, foundations, retaining walls and elsewhere shall not exceed the values
given in the following table: —
(170)
Sees. 2413-2416
Maximum Unit Stress in Bending.
[Pounds Per Square Inch.]
Granite 180
Limestone 140
Marble 120
Sandstone . 100
The maximum unit stress in bending in plain concrete shall not exceed one
fiftieth the compressive strength at twenty-eight days when determined as
specified in Part 26.
(d) The unit bearing stress in masonry under supported beams, columns
and other concentrations, and the maximum unit stress in masonry walls and
piers including stress due to calculated bending and eccentric loading shall
not exceed by more than twenty-five per cent, the allowable average stresses
given in this section.
(e) In hollow walls or in masonry of hollow units, solid masonry shall be
provided under concentrations of load to transmit the load without excessive
stress.
(f) Masonry bearing walls shall have at least the thickness specified in
Part 14.
[ *As amended by Ord. 1948, ch. 6 ]
fSect. 2414. Plain Masonry Arches. — (a) Masonry arches shall be
so designed that the line of thrust under all loadings lies within the middle third
of the structural arch, or arch ring. Abutments shall be provided capable of
resisting the horizontal as well as the vertical component of the thrust without
settlement which would permit the line of thrust to depart from the middle
third of the arch ring.
(b) The horizontal component of the arch thrust may be resisted by
metal ties so placed that the horizontal component furnished by the ties com-
bined with the vertical supporting reaction shall be in line with the arch
thrust.
(c) In the design of tie rods and beams to resist the thrust of successive
masonry floor arches, the load producing the thrust shall be considered to be
the live load for interior panels and the total load for exterior panels.
[ fAs amended by Ord. 1943, ch. 6 ]
{Sect. 2415. Reinforced Masonry. — Lintels in masonry walls, and other
approved structures, may be constructed of reinforced masonry when designed
and constructed in a manner consistent with the provisions of Parts 26 and 28
of this code.
[ %As amended by Ord. 1943, ch. 6 )
Sect. 2416. Second-Hand Materials for Masonry. — Second-hand
brick, stone, blocks and other masonry units shall not be used in masonry
unless they conform to the requirements of this code and have been thoroughly
cleaned.
(171)
Sees. 2501-2502
PART 25.
WOOD.
Section
2501 — Design of Wood.
2502 — Quality of Lumber.
2503 — Lumber Sizes and Grades.
2504 — Allowable Unit Stresses in Wood.
2505 — Wooden Columns.
2506 — Wooden Beams.
2507 — Wooden Floors and Roofs.
2508 — Wooden Walls and Partitions.
2509 — Wood Framing.
Section 2501. Design of Wood. — (a) Structures of wood shall be
designed by methods admitting of rational analysis according to established
principles of mechanics, supplemented by the assumptions herein specified, to
support the loads and withstand the forces to which they are subject without
exceeding the stresses allowed in this part for the various grades and species
of wood.
(b) Wooden structural members shall be so framed, tied, braced and
anchored as to develop the strength and rigidity necessary for the purposes
for which they are used.
(c) Walls and partitions of wood shall conform to the provisions of Part 14.
Floor and roof construction shall conform to the provisions of Parts 16 and
17 respectively. Wood near chimneys and heating apparatus shall con-
form to the provisions of Part 21.
(d) Except as otherwise provided in Part 29, wood shall not be used in
the foundation of a structure. Except as otherwise provided in Parts 14, 16
and 17, wood shall not be used to support masonry.
Sect. 2502. Quality of Lumber. — Structural wood of the species
listed in the tables of allowable unit stresses in section twenty-five hundred
and four shall conform to the requirements for the several grades in specifica-
tions or grading rules of regional associations of lumber manufacturers which
are based upon the grading procedure of American Lumber Standards in
Simplified Practice of the United States Department of Commerce and the
Guide to the Grading of Structural Timbers and the Determination of Work-
ing Stresses (Miscellaneous Publication No. 185 of the United States De-
partment of Agriculture). The lumber of the several grades and species
shall be so specified as to justify the allowable stresses in accordance with
the said Guide to the Grading of Structural Timbers and the Determination
of Working Stresses.
(172)
Sees. 2503-2504
*Sect. 2503. Lumber Sizes and Grades. — (a) The minimum sizes
of structural members of wood specified in this part refer to net sizes,
for which American Lumber Standard dressed sizes shall be accepted as
minimum. For convenience nominal sizes may be shown on the plans sub-
mitted with applications to the commissioner for permit, provided that com-
putations of stresses in wood members used structurally shall be determined
by the net finished sizes of lumber and timber employed. The actual di-
mensions of greater rough and/or dressed sizes of lumber supplied may be
computed for strength provided such sizes are specified or shown on the
drawings.
(b) The species, classification and grade of all wood used structurally
shall be specified on the drawings filed with the commissioner.
[ *As amended by Ord. 1943, ch. 6 ]
fSect. 2504. Allowable Unit Stresses in Wood. — (a) The unit
stress in wooden structural members of the several species and grades shall
not exceed the allowable values specified in the following tables computed
on the net cross section, except stresses due to wind impact and temporary
loads and as otherwise provided in this section.
[The tables which in law follow here are, for typographical
reasons, reproduced on pages 178 to 181, inclusive .]
The working stresses listed in the tables are allowed for lumber in con-
tinuously dry locations, for pressure impregnated lumber and timber with
approved preservative toxics, and for wet timbers below mean low water
level. Compression across the grain in untreated lumber used in damp
locations, alternately wet and dry or wholly wet shall not exceed seventy
per cent of the values shown in Table I. In structures such as bridges in
the open, trestles, towers and reviewing stands, the allowable unit stresses,
except for shear and rigidity, in untreated lumber and timbers shall be re-
duced to eighty-five per cent of the unit stresses listed and in untreated
structures more or less continuously damp or wet such unit stresses shall
not exceed seventy-five per cent.
(b) Except for form-work, sewer and trench dynnage and other tem-
porary purposes, sheathing, inaccessible attic joists, lumber and timber
used structurally or for load bearing purposes shall be of the grades and
species listed in accompanying Tables I and II and their corresponding
allowable unit stresses, in pounds per square inch, computed on the basis
of actual dimensions, shall not be exceeded except as herein modified for
impact, wind, etc. Those species, grades and corresponding stresses not
included in Tables I and II shall be established by the commissioner on the
basis of miscellaneous publication now known as No. 185 "Guide to the
Grading of Structural Timbers and Determination of Working Stresses"
and supplement thereto of the United States Department of Agriculture.
(173)
Sec. 2504
(c) In wooden members subject to axial tension the tensile stress shall
not exceed the allowable stress in bending. Compression parallel to the
grain shall not exceed the stress allowed in short columns.
(d) The unit stress in wooden structural members due to wind alone or
in combination with static live and dead loads shall not exceed by more than
one half the allowable stresses specified in this section.
(e) When the unit stress in wooden structural members due to impact
does not exceed that due to static live load the members need not be increased
in size on account of impact. When the stress due to impact exceeds that
due to static live load, the unit stress in the member due to impact and dead
load combined shall not exceed the allowable stresses specified in this section .
(f) All structural lumber shall be grade marked or other evidence satis-
factory to the commissioner shall be submitted verifying its appropriate
grade. Salvaged lumber, if it meets grading requirements, may be used.
(g) Temporary Structures.
1. In temporary structures and structures subject to loading for short
periods allowable stresses may be exceeded by not more than fifty per
cent in the discretion of the commissioner.
2. In joists supported on a ribbon or ledger board and spiked to the
studs, the allowable unit stress in compression across the grain may exceed
the allowable stresses specified in this section by not more than one half.
3. The unit stress in compression across the grain in a limited area
not over six inches long along the grain nor less than three inches from the
ends of the timber may exceed the allowable stresses specified in this
section by not more than the following percentages:
Length of Bearing (Inches).
Percentage Excess.
1/2
1.......
1 1/2....
2
3
4
6 or more .
85
60
45
30
15
10
None
Intermediate values shall be determined by interpolation. The bearing
stress under a washer or small plate shall not exceed that provided in this
paragraph for a bearing the length of which equals the diameter of the
washer or plate.
A. Temporary structures as considered above shall be removed within
one year.
(174)
Sees. 2504-2505
(h) Unit compressive stress on a surface inclined to the grain shall not
exceed the following value: —
CQ
C Sin2 $ + Q cos2 Q
in which (C) is the allowable unit compression parallel to the grain.
(Q) is the allowable unit compression across the grain.
(0) is the angle between the direction of the pressure and the direc-
tion of the grain.
(i) The allowable unit shear specified in this section is based upon the
maximum amount of checking, due to shakes or seasoning, permitted by the
grading rules for each species. Lumber with greater checking than is per-
mitted in the grading rules may be used in structures with the approval of the
commissioner, provided the unit shear is proportionately less than the allow-
able values specified in this section.
(j) The unit shear in joint or connection details of wooden trusses or
framing may exceed the values specified in this section by not exceeding fifty
per cent.
[fAs amended by Ord. 1943, ch. 6 and Ord. 1955, ch. 2]
|Sect. 2505. Wooden Columns. — (a) The average unit compression
in wooden columns axially loaded shall not exceed the values specified in
section twenty-five hundred and four, depending upon the ratio of length to
least net dimension. Intermediate values shall be determined by inter-
polation. The ratio of length to least dimension shall not exceed fifty.
(b) The axial load on a wooden column of round cross-section shall not
exceed that allowed on a square column of the same cross-sectional area.
(c) The least lateral dimension of a tapered column for determining its
elenderness ratio shall be measured at a point one third the length from the
small end but shall not be taken as more than three halves the least dimension
at the small end. The average unit compression at the small end shall not
exceed the allowable stress for a short column.
(d) Built up wooden columns of several adequately seasoned pieces shall
have each well spiked, screwed, glued, or bolted together with approved
mechanical connectors. Solid laminated columns shall have boards or planks
coverplated securely to the edges of all laminations.
(e) In a built up wooden column subject to axial load the average unit
compression shall not exceed three quarters of the allowable stress specified
in section twenty-five hundred and four nor shall its load exceed the allowable
load of a solid rectangular wooden column of which the moment of inertia
about each principal axis is equal to the sum of the moments of inertia of the
several pieces of the built up column about corresponding axes.
(f ) Wooden columns and posts shall be squared at the ends at right angles
to their axes.
(g) Wooden columns resting upon concrete or masonry which is in contact
with the ground shall be separated from such concrete or masonry by an
effectual seal to prevent moisture from reaching the wood through capillary
action.
[ %As amended by Ord. 1943, ch. 6 ]
(175)
Sec. 2506
*Sect. 2506. Wooden Beams. — (a) In computing the maximum unit
shear in wooden beams the effect of loads not further from the center of the
support than the depth of the beam may be neglected.
(b) Wooden beams notched at the end supports shall not be so loaded
that the unit shear exceeds the allowable value specified in section twenty-five
hundred and four when computed by the following formula —
3 Vh
2bda
in which (V) is the shear.
(h) is the total depth of the beam,
(b) is the breadth of the beam.
(d) is the depth of the beam from the bottom of the notch to the
opposite face.
(c) Unless the local unit stress is calculated and found to be not in excess
of allowable stresses specified in section twenty-five hundred and four, wooden
beams shall not be cut, notched or bored to clear pipes, wires, conduits or
for other purposes except as follows : —
(1) Notches may be cut in the top or bottom not deeper than one
fifth the depth of the beam and not further from the support than one
fifth the span.
(2) Holes may be bored in the middle third of the depth and length
not larger in diameter than one quarter the depth.
(3) Holes may be bored elsewhere in the piece limited as to size and
placement the same as knots in the grade of lumber used, having due
regard to the existence of knots in the piece.
(d) Trimmers, tail joists and headers more than eight feet long or more
than four feet long where the live load exceeds fifty pounds per square foot
unless framed on top of supporting beams, shall be hung in approved stirrup
irons or joist hangers.
(e) In wooden floor and roof construction where the depth of joists is
more than three times the thickness, and where the span is greater than eight
feet, bridging shall be placed between joists not less than eight feet apart
nor less than eight feet from supports. Cross-bridging shall not be less than
two square inches in net cross-section; and where the live load is greater
than fifty pounds per square foot, not less than four square inches.
(f) Joists doubled under bearing partitions shall be well spiked together
or separated by solid bridging not more than sixteen inches apart.
(g) Beams built up of timbers shall be firmly bolted together. Bolts
shall be staggered and spaced longitudinally not further apart than four
times the depth of the beam.
(h) Where wooden girders or beams meet at columns they shall be fitted
around the columns or butted up close, and unless the post caps or bolsters
provide sufficient anchorage, shall be held in place and tied through to form
a continuous tie across the building sufficient to resist the wind pressure
(176)
Sees. 2506-2507
specified in Part 23 applied outwardly to the walls. Where wooden beams
are supported by girders they shall be tied to form a similar continuous tie
across the building.
(i) Wooden beams or girders resting upon masonry walls, or parallel to
masonry walls, and nailing pieces for planking or boarding supported by
masonry walls, shall be bolted or otherwise anchored to the walls in such a
manner as to resist the wind pressure specified in Part 23 applied outwardly
to the walls.
(j) Joists supporting a live floor or roof load not more than forty pounds
per square foot and supported at the ends by a wooden girder, may rest upon
a wooden strip or cleat, not less than one and one half by three and one half
inches, well spiked or otherwise secured to the girder. Such joists supporting
heavier loads shall rest on top of the girder or be hung in approved joist
hangers.
(k) Nailing strips for the support of wooden joists or planking on a steel
girder or beam shall be bolted to the web of the girder or beam. Where the
live load exceeds forty pounds per square foot the nailing strip shall be bolted
to the girder or beam and shall rest upon the flanges or upon shelf angles
attached to the web which provide a three-inch bearing or upon other approved
support.
(1) The ends of wooden beams or girders resting upon masonry or concrete
exterior, party or fire walls shall be separated from the opposite face of the
wall and from beams entering the opposite face of the wall by at least four
inches of solid masonry or concrete.
[ *As amended by Ord. 1943, ch. 6 ]
Sect. 2507. Wooden Floors and Roofs. — (a) Wood shall not be used
in the first floor of a building where there is not a basement or cellar below,
unless it has clearance above the ground of at least twenty-four inches, and the
space below is ventilated either to a heated basement or to the outside air.
Ventilation of such space to a heated basement shall consist of at least two
remote openings in the basement wall having a total area of at least two square
feet for each twenty-five linear feet of wall. Ventilation of such space to
outside air shall consist of one or more openings in each exterior wall thereof,
well distributed, except that openings need not be provided in the front wall
when the space is ventilated in the rear and both side walls. The aggregate
area of openings shall be not less than two square feet for each twenty-five
linear feet of wall. Openings in exterior walls shall be protected by non-
corrodible wire mesh with openings not greater than one half inch.
(b) Rough or sub-floor boards in buildings of Type IV or Type VI shall
be laid across the joists at an angle of not less than forty-five degrees. Each
board shall be nailed twice at each joist. The sub-flooring shall extend to
and be fitted to the rough walls and partitions.
(c) Floor boards and planking shall not penetrate a party or fire wail nor
extend through a doorway in a party or fire wall. Roof boarding and planking
shall not penetrate or extend over a party or fire wall.
(177)
Sees. 2508-2509
fSect. 2508. Wooden Walls and Partitions. — (a) Wooden stud
bearing walls shall be designed to support their vertical loads without assist-
ance from boarding or other wall covering. Bridging and other bracing shall
be provided as may be necessary for this purpose and otherwise as provided
in Part 14.
(b) Floor or roof girders, hip and valley rafters framing on exterior stud
walls shall be supported by adequate posts.
(c) Stud partitions containing plumbing, heating or other pipes shall be
so framed and the joists beneath so spaced as to provide proper clearance for
the piping. Where a partition containing such piping is parallel to supporting
floor joists, the joists shall be doubled under the partition, spaced to clear the
piping and bridged with solid bridging.
(d) All concealed openings through floors shall be fire-stopped as provided
in section 2202, paragraph (i) of this code.
[f As amended by Ord. 1943, ch. 6 ]
Sect. 2509. Wood Framing. — (a) In bolted connections of wooden
trusses or framing the center of a bolt shall not be less than twice its diameter
from the edge of the member. In the direction of the force transmitted the
distance from the edge shall be such that the unit shear shall not exceed
the allowable shear specified in section twenty-five hundred and four. The
bolt shall fill the hole completely without splitting the timber. Bolts with
rolled threads shall not be used in shear. Bolt threads shall be full and
clean and of sufficient length to allow the nut to be screwed up tight. Washers
shall be used under nuts and, except on carriage bolts, under heads. Nuts
shall be concentric.
(b) Timber joints in which other fastening devices and connectors are
used shall be designed and framed in accordance with good engineering
practice.
(178)
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(182)
PART 26.
REINFORCED CONCRETE.
Section
2601 — Design of Reinforced Concrete.
2602 — Definitions Pertaining to Reinforced Concrete.
2603 — Inspection of Concrete.
2604 — Tests of Materials of Reinforced Concrete.
2605 — Cement.
2606 — Concrete Aggregates.
2607 — Water in Concrete.
2608 — Metal Reinforcement.
2609 — Storage of Materials for Concrete.
2610 — Concrete Quality.
261 1 — Average Concrete.
2612 — Controlled Concrete.
2613 — Field Tests of Concrete.
2614 — Concrete Proportions and Consistencies.
2615 — Mixing Concrete.
2616 — Concrete Forms and Equipment.
2617 — Removal of Water from Excavations.
2618 — Transporting Concrete.
2619 — Placing Concrete.
2620 — Depositing Concrete in Cold Weather.
2621 — Curing Concrete.
2622 — Construction Joints in Concrete.
2623 — Bonding Fresh and Hardened Concrete.
2624 — Bending Reinforcement.
2625 — Placing Reinforcement.
2626 — Splices in Reinforcement.
2627 — Protective Covering of Reinforcement.
2628 — Pipes and Conduits Embedded in Concrete.
2629 — Allowable Unit Stresses in Concrete.
2630 — Allowable Unit Stresses in Steel.
2631 — Design of Reinforced Concrete for Wind Loads.
2632 — Design of Reinforced Concrete in Flexure.
(183)
Section
2633 — Span Length of Reinforced Concrete Members.
2634 — Depth of Reinforced Concrete Beams or Slabs.
2635 — Analysis of Bending in Reinforced Concrete.
2636 — Arbitrary Moment Coefficients for Reinforced Concrete.
2637 — Points of Inflection in Reinforced Concrete, and Shear.
2638 — Diagonal Tension in Reinforced Concrete Beams.
2639 — Types of Web Reinforcement.
2640 — Design of Web Reinforcement.
2641 — Shearing Stress in Concrete Flat Slabs.
2642 — Shear and Diagonal Tension in Footings.
2643 — Bond Stress in Reinforced Concrete.
2644 — Ordinary Anchorage of Reinforcement.
2645 — Special Anchorage of Reinforcement.
2646 — Anchorage of Web Reinforcement.
2647 — Slenderness of Reinforced Concrete Beams.
2648 — T-Beams of Reinforced Concrete.
2649 — Compression Reinforcement in Beams and Girders.
2650 — Structural Steel Beams Encased in Concrete.
2651 — Shrinkage and Temperature Reinforcement.
2652 — Concentrated Loads on Concrete Slabs.
2653 — Concrete Ribbed and Combination Slabs.
2654 — Two-way Slabs of Reinforced Concrete.
2655 — Limitations upon Reinforced Concrete Flat Slabs.
2656 — Assumptions in Concrete Flat Slab Design.
2657 — Bending in Interior Flat Slab Panels.
2658 — Spacing of Flat Slab Reinforcement.
2659 — Thickness of Concrete Flat Slabs.
2660 — Point of Inflection in Flat Slabs.
2661 — Arrangement of Flat Slab Reinforcement at Column Heads.
2662 — Arrangement of Flat Slab Reinforcement — Two-way System
2663 — Arrangement of Flat Slab Reinforcement — Four-way System
2664 — Flat Slab Reinforcement Other than Two-way or Four-way.
2665 — Discontinuous Flat Slab Panels.
2666 — Marginal Beams in Flat Slabs.
2667 — Openings in Flat Slabs.
2668 — Construction Joints in Flat Slabs.
2669 — Limiting Dimensions of Concrete Columns.
2670 — Unsupported Length of Concrete Columns.
084^
Sees. 2601-2602
2671 — Design of Spirally Reinforced Concrete Columns.
2672 — Design of Tied Reinforced Concrete Columns.
2673 — Long Columns.
2674 — Bending in Concrete Columns.
2675 — Combined Axial and Bending Stresses.
2676 — Allowable Combined Axial and Bending Stresses.
2677 — Combination Columns.
2678 — Concrete Walls.
2679 — Sloped or Stepped Concrete Footings.
2680 — Bending in Concrete Footings.
2681 — Plain Concrete Footings.
2682 — Bearing on Concrete Footings.
2683 — Pedestals — Plain Concrete.
Section 2601. Design of Reinforced Concrete. — Reinforced concrete
shall be designed by methods admitting of rational analysis according to
established principles of mechanics, supplemented by the assumptions herein
specified, to support the loads and withstand the forces to which it is subject
without exceeding the stresses allowed in this part for the various materials
thereof.
♦Sect. 2602. Definitions Pertaining to Reinforced Concrete. — (a)
The following terms are defined for use in this part of the code: —
Aggregate: Inert material used as a filler in concrete.
Blast-Furnace Slag: The non-metallic product, consisting essentially of
silicates and alumino-silicates of lime, which is developed simultaneously with
Iron in a blast furnace.
Column: An upright compression member the length of which exceeds
three times its least lateral dimension, excluding piles and caisson piers.
Column Capital : An enlargement of the upper end of a reinforced concrete
column designed and built to act as a unit with the column and flat slab. A
framework of metal for the same purpose.
Column Strip: A portion of a flat slab panel one half panel in width occupy-
ing the two quarter-panel areas outside of the middle strip. (See Middle
Strip.)
Combination Column: A column in which a structural steel section, de-
signed to carry the principal part of the load, is encased in concrete in such
a manner that some additional load may be allowed.
Composite Column: A column in which the structural steel or cast iron
column designed to carry the principal part of the load is encased in concrete
containing reinforcement of spiral and longitudinal steel.
Concrete: A mixture of Portland cement, fine aggregate, coarse aggregate
and water.
(185)
Sec. 2602
Diameter: The diameter of a square bar shall be the distance between
opposite sides. The diameter of a deformed bar shall be the diameter of a
plain bar having the same area of cross-section.
Dropped Panel: The structural portion of a flat slab which is thickened
throughout an area surrounding the column capital.
Effective Area of Concrete: Of a cross-section, the area which lies between
the centroid of the tensile reinforcement and the compression surface in a
beam or slab, and having a width equal to the width of the rectangular beam
or slab, or the effective width of the flange of a T-beam.
Effective Area of Reinforcement: The area obtained by multiplying the
right cross-sectional area of the metal reinforcement by the cosine of the angle
between its direction and that for which the effectiveness of the reinforcement
is to be determined.
Flat Slab: A concrete slab reinforced in two or more directions generally
without beams or girders to transfer the loads to columns.
Hook: A hook made by bending a length at the end of a bar one hundred
and eighty degrees about a pin of a diameter not less than five nor more than
eleven bar-diameters, with a straight extension of at least four bar-diameters
at the free end.
Laitance: Extremely fine material of little or no strength which may collect
on the surface of freshly deposited concrete or mortar, usually recognized by
its relatively light color.
Middle Strip: A portion of a flat slab panel one half panel in width, sym-
metrical with respect to the panel center line and extending through the panel
in the direction in which bending moments are being considered.
Paneled Ceiling: The ceiling of a flat slab in which approximately that
portion of the area enclosed within the intersection of the two middle strips is
reduced in thickness.
Panel Length: In a flat slab, the distance along a panel side from center to
center of columns.
Pedestal: An upright compression member whose height does not exceed
three times its least lateral dimension.
Pedestal Footing: A column footing projecting less than one half its depth
from the faces of the column on all sides and having a depth not more than
three times its least width.
Portland Cement: The product obtained by finely pulverizing clinker pro-
duced by calcining to incipient fusion an intimate and properly proportioned
mixture of argillaceous and calcareous materials, with no additions subse-
quent to calcination excepting water and calcined or uncalcined gypsum.
Ratio of Reinforcement: The ratio of the effective area of the reinforce-
ment cut by a section of a beam or slab to the effective area of the concrete
at that section.
Reinforced Concrete: Concrete in which metal other than that provided
for expansion and contraction, is embedded in such a manner that the two
materials act together in resisting forces.
(186)
Sec. 2602
Screen: A metal plate with closely spaced circular perforations.
Sieve: Woven wire cloth or a metal plate with square openings of uniform
size.
Strut: A compression member other than a column or pedestal.
Water-Cement Ratio: The total quantity of water entering the concrete
mixture, including the surface water carried by the aggregate, expressed in
terms of the quantity of cement. The water-cement ratio shall be expressed
in U. S. gallons per bag Cninety-four pounds) of cement.
(b) The symbols and notations used in this part are denned as follows:
a — Angle between inclined web bars and axis of beam.
A — Total area of pedestal, pier, or footing at the column base.
A' — Loaded area of pedestal, pier, or footing at the column base.
Ao — Total area of the concrete section = Ag-AP.
Ar — The cross-sectional area of the steel column.
Ag — Gross area of concrete column.
Ag — Effective cross-sectional area of steel in tension in beams and slabs, or
compression in columns.
Av — Total area of cross-section of one unit of web reinforcement.
b — Width of rectangular beam or width including flange of T-beam.
b' — Thickness of web in beams of I or T section.
c — Diameter of column capital of a flat slab.
c' — The distance from gravity axis to extreme fiber in compression.
C — The ratio of fa to the allowable fiber stress for members in flexure.
Co — In two-way slab design, coefficient dependent on position of panel
relative to adjacent continuous panels.
Ci — Coefficient for bending dependent upon continuity and restraint.
d — Depth of beam or slab from compression face to center of longitudinal
tensile reinforcement,
d' — Least lateral dimension of a column.
e — The eccentricity of resultant load, measured from the gravity axis.
Eo — Modulus of elasticity of concrete in compression.
EB — Modulus of elasticity of steel (thirty million pounds per square inch).
fa — Average allowable stress on an equivalent axially loaded concrete
column.
o — Compressive unit stress in concrete.
V, — Ultimate compressive strength of concrete at age of twenty-eight days.
'r — The allowable stress for unencased steel column.
, — Tensile unit stress in longitudinal reinforcement.
'B — The useful limit stress of spiral reinforcement. See Sec. 2671, par. (d).
r — Tensile unit stress in web reinforcement.
g — Sum of perimeters of bars in one set.
(187)
Sees. 2602-2603
h — Unsupported length of column.
I — Moment of inertia of a section about the neutral axis for bending.
j — Ratio of arm of resisting couple in bending to depth (d).
L — Span length of beam or slab; length or width of flat slab panel.
Li — Length of width of a two-way or flat slab panel at right angles to the
direction in which bending is considered.
M — Bending moment or moment of resistance in general.
Mo — Sum of positive and negative bending moments at the principal design
sections of a panel of a flat slab,
n — Ratio of modulus of elasticity of steel to that of concrete (E8/Ec).
p — Ratio of effective area of tensile reinforcement in bending.
p' — Ratio of volume of spiral reinforcement to the volume of the concrete
core (out to out of spirals).
pg — Ratio of the effective cross-sectional area of vertical reinforcement
to the gross area Ag.
P — Total safe axial load on a short column.
P' — Total safe axial load on a long column,
r — Ratio of breadth to span of panel of a two-way slab.
R — Least radius of gyration of a column section or equivalent concrete
section.
s — Spacing of web reinforcement measured along the axis of the beam.
s' — Distance from the center of a concentrated load to nearer support of a
slab,
t — Thickness of flange of T-beams.
t' — The overall depth of section.
ti — Thickness of flat slab near column (including dropped panel, if any);
t» — Thickness of flat slab outside the dropped panel,
u — Bond stress per unit of surface area of bar.
v — Shearing unit stress.
V — Total shear at a cross-section.
V — Excess of the total shear over the allowed resistance in shear of the
concrete unreinforced.
w — Uniformly distributed load per unit length of beam or slab or per unit
area.
w' — Actual width of a concentrated load upon a slab.
W — Total uniformly distributed load in a single panel area.
[ *As amended by Ord. 1948, ch. 8 ]
Sect. 2603. Inspection of Concrete. — The commissioner shall require
an applicant for a permit involving the structural use of concrete to have a
competent inspector at all times on the work while such concrete is being
proportioned, mixed and deposited.
(188)
Sees. 2604-2607
Sect. 2604. Tests of Materials of Reinforced Concrete. — The
commissioner shall have the right to require reasonable tests from time to
time to determine whether the materials and methods in use are such as to
produce reinforced concrete of the necessary quality. Copies of the reports
of such tests shall be kept readily available by the commissioner for a period
of two years after the completion of the structure.
Sect. 2605. Cement. — (a) Portland cement shall conform to the
Standard Specifications and Tests for Portland Cement of the American
Society for Testing Materials.
(b) Special cement may be used for Portland cement, subject to the ap-
proval of the commissioner, provided it meets the requirements for Portland
•cement in regard to strength, soundness and setting time.
Sect. 2606. Concrete Aggregates. — (a) Concrete aggregates shall
consist of graded natural sands and gravels, crushed rock, or other inert
materials having clean, uncoated grains of strong and durable minerals.
Aggregates containing soft, friable, thin, flaky, elongated or laminated par-
ticles totaling more than three per cent, or containing shale in excess of
one and one half per cent, or silt and crusher dust finer than the number
one hundred standard sieve in excess of two per cent, shall not be used.
These percentages shall be based on the weight of the combined aggregate
as used in the concrete. When all three groups of these deleterious materials
are present in the aggregates, the combined amounts shall not exceed five
per cent by weight of the combined aggregate.
(b) Burnt shale or clay, cinders, slag or other hard, clean, inert, artificial
materials may be used as concrete aggregates, subject to the approval of the
commissioner, provided they contain not more than one per cent by weight
of sulphur or similar compounds (free or combined), nor more than ten per
cent by weight of combustible matter, are properly prepared by crushing and
screening to give a graded coarse and fine aggregate, and come from a source
that is known to give uniform quality.
(c) Fine aggregate shall not contain organic material sufficient to give
a color darker than the standard color when tested in accordance with the
Standard Method of Test for Organic Impurities in Sands for Concrete of
the American Society for Testing Materials.
(d) Coarse aggregate shall not be larger than one fifth of the narrowest
dimension between forms of the member in which the concrete is to be used,
nor larger than three fourths of the minimum clear spacing between reinforcing
bars. By maximum size of aggregate is meant the smallest sieve size through
which eighty-five per cent by weight of the materials can be passed. Aggre-
gate larger than one inch of sandstone, granite, quartzite and siliceous gravel
shall not be used in fire-protective concrete.
(e) Fine aggregate shall consist of all particles passing a number four sieve.
Sect. 2607. Water in Concrete. — Water used in mixing concrete shall
be free from injurious amounts of acids, salts, alkalies or organic materials.
(189)
Sees. 2608=2610
Sect. 2608. Metal Reinforcement. — (a) Metal reinforcement shall
be steel bars conforming to the requirements of the Standard Specifications
for Billet-Steel Concrete Reinforcement Bars of Structural or Intermediate
Grade, or for Rail-Steel Concrete Reinforcement Bars of the American
Society for Testing Materials, or rerolled bars, whether from rails or from
other suitable approved sections, which otherwise meet the requirements of
one of the three specifications, or wire or expanded metal. The provision in
these specifications for machining deformed bars before testing shall be
disregarded. The tests called for in the said specifications shall always be
made when rerolled steel is used.
(b) Wire for concrete reinforcement shall conform to the requirements
of the Specifications for Cold-Drawn Steel Wire for Concrete Reinforcement
of the American Society for Testing Materials.
(c) Structural steel shall conform to the requirements of Part 28.
(d) Cast-iron sections for composite columns shall conform to the require-
ments of Part 28.
(e) Deformed bars shall have closely spaced shoulders, lugs or projections
formed integrally in rolling, of such nature as to produce a bond or resistance
to slipping when embedded in concrete, at least twenty-five per cent greater
than that of plain hot-rolled round bars. Wire mesh with welded intersections
not further apart than twelve inches (six inches in web reinforcement) in the
direction of the principal reinforcing, and with cross wires of at least number
ten gage, or expanded metal, may be rated for bond as deformed bars.
Sect. 2609. Storage of Materials for Concrete. — Cement and aggre-
gates shall be stored at the work in a manner to prevent deterioration or the
intrusion of foreign matter. Any material which has deteriorated or has
been damaged shall not be used in concrete.
Sect. 2610. Concrete Quality. — (a) The allowable unit stresses for
the design of reinforced concrete structures shall be based upon the twenty-
eight-day strength of the concrete to be used in the structure in accordance
with the values given in section twenty-six hundred and twenty-nine. Plans
submitted for approval or used on the work shall clearly show the strength
of concrete for which all parts of the structure were designed. The strength
of concrete shall be determined in accordance with one of the following
methods : —
(1) By established results for average materials as provided in section
twenty-six hundred and eleven (Average Concrete).
(2) By specific test of materials for the structure as provided in section
twenty-six hundred and twelve (Controlled Concrete).
(b) Structural concrete made with artificial aggregates, with special
cements, or with admixtures, shall always be made in accordance with
method (2) for controlled concrete. (The water-cement ratio strength
relation will generally be different than for natural aggregates, normal
cement, or usual mixtures.) The commissioner may waive the requirements
of this paragraph subject to such conditions as he may specify.
(190)
Sees. 2611=2612
Sect, 2611. Average Concrete. — (a) The following table gives the
compressive strength in pounds per square inch which shall be assumed aa
the basis for design where no preliminary concrete strength tests of the
materials to be used are made. A bag of cement weighing ninety-four pounds
shall be assumed to measure one cubic foot.
Assumed Strengths of Concrete Mixtures.
Minimum Proportions:
Volume of Portland Cement to
Sum of Separate Volumes of
Fine and Coarse Aggregates,
measured Dry and Loose.
Maximum Water-Cement
Ratio, United States
Gallons per Bag of
Cement, i
Assumed Compressive
Strength at 28 Days
(Pounds per Square Inch).
1:7^
1:6
1:5
1:4
1:3
8.00
7.25
6.50
6.00
5.00
1,500
2,000
2,500
3,000
3,750
1 Including the water content of the aggregate. Unless this content is determined by
tests, it shall be assumed to be one half gallon per cubic foot of fine aggregate.
(b) During the progress of the work, such reasonable number of com-
pression tests shall be made as may be required by the commissioner, but
at least one set of specimens shall be tested for each three hundred cubic
yards of each different mixture of concrete being placed. The tests shall
be made in accordance with provisions of section twenty-six hundred and
thirteen. If the average twenty-eight-day strength falls below the strength
called for on the plans, the commissioner shall have the right to require a
load test under the provisions of Part 23. The commissioner may waive
the requirement of tests on work involving in all less than two hundred cubic
yards of concrete.
(c) Average concrete exposed to the weather shall contain not less than
six bags of cement per cubic yard of concrete and the water-cement ratio
shall not exceed six gallons per bag of cement.
Sect. 2612. Controlled Concrete. — (a) When the proportions are to
be established by tests, the tests shall be made in advance of the beginning
of construction using the materials proposed and consistencies suitable for
the work and in accordance with the provisions of section twenty-six hundred
and thirteen. The relation between the average twenty-eight-day strength
of the concrete and the water-cement ratio shall be determined by such
tests for a range of values including all of the strengths called for on the
plans. The water-cement ratio determined for each quality of concrete to
be used shall allow sufficient margin of strength to provide for the exigencies
of field operations. In no case, however, shall concrete exposed to the
weather contain less than five bags of cement per cubic yard of concrete or
have a water-cement ratio in excess of six gallons per bag. No change or
substitution shall be made in the materials being used on the work without-
additional tests to determine the new water-cement ratios to be used.
(191)
Sees. 2612-2614
(b) During the progress of the work, a reasonable number of compression
tests may be required by the commissioner, but at least one set of specimens
shall be tested for each one hundred and fifty cubic yards of concrete of a
given strength, and not less than one set of specimens of each strength of
concrete for each day's operation. Such tests shall be made in accordance
with the provisions of section twenty-six hundred and thirteen. If the
average twenty-eight-day strength of the tested specimens for any portion
of the structure falls below the strength called for od the plans, the com-
missioner shall have the right to require load tests as specified in Part 23 on
the portions of the building affected, and to order a change in the mixture
for the remaining portion of the structure.
(c) Controlled concrete shall be proportioned, mixed and placed under
the supervision of an approved concrete control engineer.
Sect. 2613. Field Tests of Concrete. — (a) Specimens for compres-
sion tests of concrete, when required, shall be made and stored in accordance
with the Standard Method of Making and Storing Compression Test Speci-
mens of Concrete in the Field, and tested in accordance with the Standard
Method of Making Compression Tests of Concrete, of the American Society
for Testing Materials; provided, that each set shall consist of at least three
specimens which shall be stored under moist curing conditions at seventy
degrees Fahrenheit, and no specimens need be stored on the structure.
(b) If tests disclose a consistent relation between the seven-day and the
twenty-eight-day strength of the concrete, the tests required during the
progress of concrete work may be made at seven days and the strength at
twenty-eight days determined therefrom.
Sect. 2614. Concrete Proportions and Consistencies.— -(a) The
proportions of cement and aggregates for concrete shall be such as to produce
concrete that will work readily into the corners and angles of the forms and
around the reinforcement without excessive puddling or spading and without
permitting the materials to segregate or free water to collect on the surface.
The combined aggregate shall be of such composition of sizes that when sepa-
rated by a number four standard sieve, the weight retained on the sieve shall
not be less than one third nor more than two thirds of the total. The consist-
ency of the concrete shall be such that the slump as measured by the slump
test shall not exceed the values given in the following table: —
CLASS OF CONCRETE.
Maximum Allowable Slump.
4 inches
6 inches
(b) The methods of measuring concrete materials shall be such that the
proportion of all ingredients including water can be accurately controlled
during the progress of the work and easily checked at any time by the
commissioner
(192)
Sees. 2615-2620
Sect. 2615. Mixing Concrete. — Concrete shall be mixed until there is a
uniform distribution of the materials and the mass is homogeneous and
uniform in color. In machine mixing, only batch mixers shall be used.
Each batch shall be mixed not less than one minute after all the materials
are in the mixer and must be completely discharged before the mixer is
recharged.
Sect. 2616. Concrete Forms and Equipment. — (a) Forms shall be
substantial and sufficiently tight to prevent loss of mortar from the concrete.
(b) Before concrete is placed equipment for mixing and transporting the
concrete and forms shall be clean; the spaces to be occupied by the concrete
shall be free of snow, ice and debris.
Sect. 2617. Removal of Water from Excavations. — Water shall be
removed from excavations before concrete is deposited, unless otherwise
directed by the commissioner. Water flowing into an excavation shall be
diverted through proper side drains to a sump, or be removed by other ap-
proved methods which will avoid washing the freshly deposited concrete.
Sect. 2618. Transporting Concrete. — (a) Concrete shall be handled
from the mixer to the place of final deposit by methods which will prevent the
separation or loss of the ingredients. Under no circumstances shall concrete
that is partially hardened be deposited in the work.
(b) Concrete otherwise meeting the requirements of this code but mixed
at a distance from the structure in which it is to be deposited may be used pro-
vided the time elapsed between addition of the cement to the aggregate and its
deposit in the forms does not exceed one hour.
Sect. 2619. Placing Concrete. — (a) Concrete shall not be placed until
the forms and reinforcement have been inspected and approved by the in-
spector required by section twenty-six hundred and three.
(b) When concreting is once started, it shall be carried on as a continuous
operation until the placing of the section or panel is completed. The top
surface shall be kept generally level and accumulations of water on the surface
shall be promptly removed. Where construction joints are necessary, they
shall be made in accordance with section twenty-six hundred and twenty-two.
(c) Concrete shall be thoroughly compacted by puddling with suitable
tools during the operation of placing, and thoroughly worked around the
reinforcement.
Sect. 2620. Depositing Concrete in Cold Weather. — When deposit-
ing concrete at freezing or near freezing temperature, the concrete shall be
maintained at a temperature of not less than fifty degrees Fahrenheit, and not
more than one hundred and twenty degrees. The temperature of the concrete
shall be maintained at not less than fifty degrees for at least seventy-two hours
after placing. When necessary, concrete materials shall be heated before
mixing. Dependence shall not be placed on salt or other chemicals for the
prevention of freezing.
(193)
Sees. 2621-2625
Sect. 2621. Curing Concrete. — (a) Exposed surfaces of concrete shall
be kept moist for a period of at least seven days after being deposited.
(b) Forms shall be removed in such a manner and with such precautions
as to insure complete safety of the structure.
*Sect. 2622. Construction Joints in Concrete. — (a) Joints not
indicated on the plans shall be so made and located as least to impair the
strength of the structure. Such joints in floors shall be located near the
middle of spans of slabs, beams, or girders, unless a beam intersects a girder
at this point, in which case the joint in the girder shall be offset a distance
equal to twice the width of the beam. At least two hours must elapse after
depositing concrete in columns or walls before depositing in beams, girders, or
slabs supported thereon. Beams, girders, brackets, column capitals, and
haunches shall be considered part of the floor system and shall be placed
monolithically therewith. All joints shall be bonded in accordance with sec-
tion twenty-six hundred and twenty-three. (For construction joints in flat
slabs, see also section twenty-six hundred and sixty-eight.)
(b) Construction joints shall occur within the middle third of the span
and preferably where the shear is least. At each such joint, reinforcing steel
shall be provided perpendicular to the joint and near the top of the slab and
its amount shall be equal to .003 of cross-section area of the concrete. These
rods shall be spaced not over two times the thickness of the slab or within
the width of the beam or girder. Rods shall be fully anchored each side of the
joint.
[ *As amended by Ord. 1943, ch. 8 and Ord. 1955, ch. 2.\
fSect. 2623. Bonding Fresh and Hardened Concrete. — Before new
concrete is deposited on or against concrete which has set, the surface of the
set concrete shall be roughened, cleaned of foreign matter and laitance and
thoroughly wetted but not saturated. Such surfaces shall first be slushed
with a coating of neat cement grout, against which, before it has attained its
initial set, the new concrete shall be placed.
[ fAs amended by Ord. 1943, ch. 8 ]
Sect. 2624. Bending Reinforcement. — Metal reinforcement shall not
be bent, straightened or handled in any manner that will injure the material.
Reinforcement may be heated only when approved by the commissioner.
Cold bends shall be made around a pin having a diameter of not less than
four times the diameter of the bar. Bars with kinks or bends not shown on
the plans shall not be used.
Sect. 2625. Placing Reinforcement. — (a) Metal reinforcement shall
be clean and free of loose mill and rust scale and of other coatings that would
destroy or reduce the bond. It shall be accurately placed, supported and
secured.
(b) The minimum clear distance between parallel bars shall be one and
one half times the diameter for round bars and twice the diameter for square
bars. If the ends of bars are anchored as specified in section twenty-six
hundred and forty-five, the clear spacing may be made equal to the diameter
(194)
Sees. 2625=2628
of round bars or to one and one half times the diameter of square bars, but
in no case shall the spacing between bars be less than one inch, nor less than
one and one third times the maximum size of the coarse aggregate. The
minimum clear distance between bars and forms shall be the diameter of
round bars and one and one half times the diameter of square bars. Bars
shall be embedded a distance from the face of a member not less than the
distance required for fire and rust protection in this code. The main longi-
tudinal steel of a reinforced concrete slab shall be spaced not more than three
times the slab thickness.
Sect. 2626. Splices in Reinforcement. — (a) In slabs, beams and
girders, splices of reinforcement shall generally be avoided at points of maxi-
mum stress and, where made, shall provide sufficient lap to transfer the stress
by bond and shear.
(b) In columns longitudinal reinforcement may be spliced by lapping
the bars a length sufficient to develop the working stress in the reinforcement
by means of bond, but in no case shall the lap be less than twenty-four bar
diameters for deformed bars or thirty diameters for plain bars. Butt joints of
approved design are permitted at points where only compressive stress occurs.
Sect. 2627. Protective Covering of Reinforcement. — (a) At the
underside of footings and elsewhere in concrete poured in contact with the
ground, the main metal reinforcement shall have a minimum covering of
three inches except that in floor slabs poured on dry earth such covering
may be one and one half inches. In concrete poured in forms but exposed
to soil backfill, moisture or weather, such covering shall be two inches.
(b) In buildings of Type I and Type II construction, and in other rein-
forced concrete required to have specified fire resistance, main metal rein-
forcement shall be protected as required in sections one hundred and twenty-
four to one hundred and thirty-one, inclusive, of Part 1, in Parts 16, 17 and
22, respectively, and elsewhere in this code.
(c) Bars used for the support or spacing of reinforcement, shrinkage
reinforcement, column ties and stirrups not over one half inch in diameter,
shall not be considered main reinforcement. Such bars shall have minimum
protective covering one half inch less than specified in this section for main
reinforcement.
Sect. 2628. Pipes and Conduits Embedded in Concrete. — Pipes
which will contain liquid, gas or vapor at other than room temperature shall
not be embedded in concrete necessary for structural stability or fire pro-
tection. Drain pipes and pipes whose contents will be under pressure greater
than atmospheric pressure by more than one pound per square inch shall not
be embedded in structural concrete except in passing through from one side
to the other of a floor, wall or beam. Electric conduits and other pipes
embedment of which is allowed shall not, with their fittings, displace that
concrete of a column on which stress is calculated or which is required for
fire protection, to greater extent than four per cent of the area of cross-section.
Sleeves or other pipes passing through floors, walls or beams shall not be of
(195)
Sees. 2628-2629
such size or in such location as unduly to impair the strength of the construc-
tion; such sleeves or pipes may be considered as replacing structurally the dis-
placed concrete, provided they are not exposed to rusting or other deterioration,
are of galvanized or uncoated iron or steel not thinner than standard wrought
iron pipe, have a nominal inside diameter not over two inches, and are spaced
not less than three diameters on centers. Embedded pipes or conduits other
than those merely passing through shall not be larger in outside diameter than
one third the thickness of the slab, wall or beam in which they are embedded,
shall not be spaced closer than three diameters on centers, nor so located as
unduly to impair the strength of the construction. Circular uncoated or
galvanized electric conduit of iron or steel may be considered as replacing the
displaced concrete.
*Sect. 2629. Allowable Unit Stresses in Concrete. — (a) Rein-
forced concrete members shall be designed with reference to safe loads and
working stresses. The unit stresses in pounds per square inch in concrete of
the strength indicated shall not exceed the following allowable values, where
(f'o) is the strength at twenty-eight days: —
Allowable Unit Stresses.
Kind of Stress.
Expressed
as a
Proportion
of the
Strength.
Specific Values for
Common Strengths
(Pounds per Square Inch).
Strength.
2,000.
2,500.
3,000.
Flexure:
0.40 f'o
0.02 f'o
0.03 f'o
0.06 f'o
0.09 f'o
0.025 f'o
0.02 f'o
0.04 f'o
0.05 f'o
0.25 f'o
0.375 f'o
0.18 f'o
0.225 f'o
n - 15
n =» 12
n = 10
Extreme fiber stress in compression
800
40
60
120
180
50
40
80
100
500
750
360
450
1,000
50
75
150
225
62
50
100
125
625
937
450
562
1,200
Shear:
Beams with no web reinforcement and without
Beams with no web reinforcement, but with spe-
cial anchorage of longitudinal steel
60
90
Beams with web reinforcement, but without spe-
cial anchorage of longitudinal steel
180
Beams with web reinforcement and with special
anchorage of longitudinal steel
270
Flat slabs at distance (d) from edge of column
Footings (see also section 2642)
75
60
Bond:
Plain bars not to exceed 160 # □"
120
Bearing:
On full area
150
750
Axial Compression:
In columns with lateral ties
1,125
540
In columns with continuous spirals enclosing a
circular core
675
(b) The bond stress computed in accordance with section twenty-six
hundred and forty-three may be allowed to reach double these values where
special anchorage is provided as specified in section twenty-six hundred
and forty-five.
(c) The allowed bearing stress on an area greater than one third but less
than the full area shall be interpolated between the values given in the table.
(196)
Sees. 2629-2632
(d) The ratio of the moduli of elasticity of steel and concrete shall be
30,000.
ssumed as (n) =
1 0
[ *As amended by Ord. 191+3, ch. 8 ]
fSect. 2630. Allowable Unit Stresses in Steel. — (a) The following
allowable unit stresses shall not be exceeded in reinforcing steel.
Allowable Unit Stress (Pounds per Square Inch).
Tension :
Structural grade billet steel bars 18,000
Rerolled steel bars 18,000
Intermediate grade billet steel bars 20,000
"Cold drawn steel wire or cold stretched expanded metal fabric 20,000
Rerolled rail steel reinforcing bars 20,000
Web reinforcement (steel) 16,000
Other steel reinforcement fifty per cent of the yield point, but
not to exceed 18,000
(b) Compression in reinforcing steel except in columns, shall not exceed
(n) times the compressive stress in the concrete at a line in the cross-section
through the center of the bars.
(c) Compression in structural steel and cast iron in composite and com-
bination columns shall not exceed the stress specified in sections twenty-six
hundred and seventy-five and twenty-six hundred and seventy-six.
(d) The modulus of elasticity shall be assumed as thirty million pounds
per square inch.
[ ]As amended by Ord. 1943, ch. 8 and Ord. 1949, ch. 8 ]
Sect. 2631. Design of Reinforced Concrete for Wind Loads. — In
■designing the members of reinforced concrete structures to resist wind loads,
the allowable unit stresses for dead and live load and wind loads may be
increased to four thirds of the allowable values specified in sections twenty-six
hundred and twenty-nine and twenty-six hundred and thirty, but no member
shall be less than that required if the wind load be neglected.
Sect. 2632. Design of Reinforced Concrete in Flexure. — (a) The
accepted theory of flexure as applied to reinforced concrete shall be applied
to all members resisting bending. The following assumptions shall be made: —
(1) The steel alone resists tensile stress and acts only in the direction
of its length.
(2) The ratio (n) of the modulus of elasticity of the steel either in
tension or compression to that of any given concrete is constant.
(3) Plane sections before bending remain plane after bending.
(197)
Sees. 2632-2635
(b) Beams and slabs shall be designed to resist safely the actual bending
and shear produced by the loads and supporting forces under the existing
conditions of end restraint or continuity. It is the intent of this part to
require that the bending moments throughout the spans be determined so
far as possible consistently with the elastic deformation of the structure,
being in general calculated according to the provisions of section twenty-six
hundred and thirty-five by methods of elastic analysis; but they may in the
special cases and with the limitations described in section twenty-six hundred
and thirty-six be approximated by the use of arbitrary moment coefficients
as provided therein. Wherever negative bending may occur, the full amount
thereof shall be provided for, except in slabs thirty inches or less in span.
Sect. 2633. Span Length of Reinforced Concrete Members. — (a)
The span length of freely supported beams and slabs shall be the distance
between centers of bearings, but need not exceed the clear span plus the
depth of beam or slab.
(b) The span length for continuous or restrained beams and slabs built
to act integrally with supports shall be the clear distance between faces of
supports, the spaces occupied by supports where restraint or continuity
occurs being suppressed in the force and moment diagrams.
(c) For continuous beams having brackets built to act integrally with
both beam and support and of a width not less than the width of the beam
and making an angle of forty-five degrees or more with the beam, the span
shall be measured from the section where the combined depth of the beam
and bracket is at least one third more than the depth of the beam. Biackets
making an angle of less than forty-five degrees with the beam may be con-
sidered as increasing the effective depth of the beam, but not as decreasing
the span length. Beams shall be designed to resist at each section the bending
there occurring.
(d) Maximum negative moments are to be considered as existing at the
ends of the span, as defined above.
*Sect. 2634. Depth of Reinforced Concrete Beam and Slabs. — (a)
The effective depth of beams and slabs shall be taken as the distance from
the center of gravity of the tensile reinforcement to the compressive surface
of the structural member; except for monolithic beams and slabs where the
top is a wearing surface, then the effective depth shall be taken to a plane
one-half inch below the finished surface.
(b) For beam and slab construction the total thickness for slabs shall
not be less than three and one-half inches except as provided in sections
twenty-six hundred fifty-three and twenty-six hundred fifty-nine.
[ *As amended by Ord. 1943, ch. 8 ]
Sect. 2635. Analysis of Bending in Reinforced Concrete. — (a)
The determination of bending moments to be provided for at various points
in the span of a member restrained at supports, or a series of continuous
spans, in accordance with section twenty-six hundred and thirty-two, shall
be made by application of the theorem of three moments, principle of least
work, or equivalent method based on elastic deformation, and shall be subject
to the following qualifications: —
(198)
Sees. 2635=2636
(1) Supports afforded by beams, girders and columns of usual arrange-
ment shall be assumed to be and remain in alignment conforming to the
position of the unloaded beam or slab.
(2) The effect on bending moments in the spans produced by the
torsional resistance of interior supporting beams and by the bending
resistance of ordinary interior supporting columns may be neglected,
and shall be neglected unless the restraint is computed and provided for
in the supports. Restraint at exterior supports shall be provided for both
in the spans and in the supports.
(3) The difference in moment of inertia of beams of approximately
the same depth in different spans and of the same beam acting to resist
positive and negative bending, may be considered negligible so far as
regards its effect on distribution of moment throughout the spans. The
moment of inertia may be calculated from the gross section of the concrete
neglecting reinforcement and the flanges of T-beams may be neglected.
(4) Design for bending, both positive and negative, that may occur
within a span shall include consideration of the effects of a partial distribu-
tion of load on the span itself and either or both adjacent spans, but not
on spans more remote than these. Maximum negative moment at a
support may be assumed to result from full loading on adjacent spans only,
(b) The commissioner may approve analyses conforming to the intent
of this part, based on accepted theory, and incorporating refinements other
than these provided herein; and he may require special analysis for extraor-
dinary conditions of support, restraint, span lengths and distribution of load.
Sect. 2636. Arbitrary Moment Coefficients for Reinforced Con-
crete.— (a) In the case of a beam or a slab, or a series of continuous beams
or slabs with spans differing not more than twenty-five per cent of the longer
span, uniformly loaded, and falling within one of the specified cases of restraint
at the supports, designs may be made to resist bending moments computed
by the arbitrary coefficients presented in this section, instead of by elastic
analysis.
(b) The coefficients of (wL2) set forth in the following table may be used
to compute the positive bending at mid-span and the negative bending at
supports in the locations and under the conditions indicated.
Table of Arbitrary Coefficients for Bending.
Number
of
Spans.
End Span.
First
Interior
Support.
Interior Spans.
Conditions of Restraint.
End
Support.
Mid-
Span.
Mid-
Span.
Other
Interior
Supports.
Case 1: Slabs or beams with
negligible restraint at end
supports.
Case 2: Slabs or beams with
moderate restraint at end
supports.
Case 3: Slabs or beams with
full restraint at end sup-
ports.
f 1
2
, Mult.
{ *
I Mult.
{ •
{ Mult.
1/24
1/24
1/24
1/16
1/16
1/16
1/12
1/12
1/12
1/8
1/10
1/12
1/10
1/12
1/14
1/12
1/16
1/16
l/8~
l/9i
1/9
1/10
1/10
1/11
1/16
1/16
1/16
1/12
1/12
1/12
1 One tenth for slabs.
(199)
Sees. 2636-2638
(c) In the use of this table negligible restraint shall be assumed for slabs
supported on walls of masonry units, or on the upper flanges of steel beams
not encased in concrete; and for beams supported on steel or cast iron columns
not encased in concrete, or on combination columns, or on masonry piers or
walls of any type other than reinforced concrete columns acting integrally
therewith, or by other beams or girders; or on any supports which do not
assure as great restraint as that described as "moderate."
(d) Moderate restraint may be assumed for slabs supported by rein-
forced concrete beams, or by steel beams encased in concrete, or by reinforced
concrete walls; and for beams or girders supported on composite columns
or on reinforced concrete columns, provided the slabs or beams act integrally
with the support.
(e) Full restraint may be assumed only for slabs acting integrally with
supporting reinforced concrete walls and for beams or girders acting integrally
with reinforced concrete columns, when (I/L) for the slab, beam or girder
is less than the sum of the values of (I/h) for the walls or columns, respec-
tively, above and below. In this section (I) represents the moment of
inertia, calculated for the gross section of the concrete, neglecting reinforce-
ment and the flanges of T-beams. (L) and (h) are span length and column
or wall height, respectively.
(f) In calculating negative bending at a support between two spans
of unequal load or length, the average unit load over the two spans shall be
used, and an assumed span which is two thirds the longer span plus one third
the shorter span.
(g) For continuous or restrained beams or girders subject to equal con-
centrated loads which occur at approximately regular intervals with a con-
centration at each support, the positive and negative bending may be deter-
mined as though the entire load were distributed uniformly on the beam
or girder.
♦Sect. 2637. Points of Inflection in Reinforced Concrete, and Shear.
— The location of points of inflection, reactions and shears, shall be assumed
consistently with the loading and the computed distribution of bending
moments. In the three cases of slabs and beams of two or more continuous
spans when the arbitrary coefficients for bending of section twenty-six hun-
dred and thirty-six may be applied, the reactions on end supports shall be
taken as forty per cent for Case 1, forty-five per cent for Case 2, and fifty
per cent for Case 3, of the load on the end span, and the reaction on the first
interior support shall be computed accordingly; the loads on interior spans
may be assumed as evenly divided between supports in determining shears
and reactions.
[ *As amended by Ord. 1943, ch. 8 ]
Sect. 2638. Diagonal Tension in Reinforced Concrete Beams. — (a)
Reinforced concrete beams (including ribs of ribbed and combination slabs,
and other members subject to bending) shall be designed to resist the diagonal
tension in their webs without exceeding the stresses prescribed in sections
twenty-six hundred and twenty-nine and twenty-six hundred and thirty.
(200)
Sees. 2638-2640
(b) For the purpose of design, the diagonal tension in the web of a beam
shall be assumed to be directed at an angle of forty-five degrees with the
axis of the beam, and its intensity to be equal to the unit shear, computed by
the formula:
V
v =
b'jd
In this formula (b') is to be taken as the width of the concrete section
between the tensile steel and the compressive flange, the average width
if the sides slope but not over twenty per cent more than the minimum.
(c) Beams in which the diagonal tension in any portion of the web exceeds
the stress allowed in beams without web reinforcement shall be reinforced
in that portion for the excess.
Sect. 2639. Types of Web Reinforcement. — (a) Web reinforcement
shall consist of vertical stirrups or of stirrups or bars inclined at an angle of
not less than fifteen degrees with the axis of the beam.
(b) Web reinforcement shall be considered effective only to the extent
that its stress can be developed by bond and anchorage as provided in section
twenty-six hundred and forty-six.
Sect. 2640. Design of Web Reinforcement. — (a) A web reinforcing
bar, whether vertical or inclined, shall be considered to afford for resistance
to diagonal tension the component of its tensile stress in the direction of the
diagonal tension. The spacing of stirrups (or the length of beam over which
the resistance of a stirrup or bar is effective) is therefore determined by the
following formula:
Av fv jd (cos a -f- sin a)
s =
V
For vertical stirrups this becomes —
Av fv jd
s =
V
and for stirrups or bars inclined at forty-five degrees —
Av fy jd
s =
0.7 V
(b) In the formulas of this section (V) is the shear in the beam at any
cross-section in excess of the allowed resistance of the unreinforced web, and
it shall be subject to the limitation imposed upon the unit shear by section
twenty-six hundred and twenty-nine. The spacing (s) of stirrups, vertical
or inclined, or of bars inclined at not less than forty-five degrees shall not
exceed three fourths the effective depth of the beam. In the case of bars
inclined at less than forty-five degrees, (s) shall not exceed three fourths the
axial projection of the inclined length.
(201)
Sees. 2640-2643
(c) In portions of beams where the unit shear exceeds (0.06 f'c) the
limits for (s) shall be reduced by changing the fraction three-fourths to one-
half in the preceding paragraph.
Sect. 2641. Shearing Stress in Concrete Flat Slabs. — (a) In flat
slabs, the shearing unit stress on a vertical section which lies at a distance
(d) from the edge of the column capital and parallel with it, shall not exceed
the following allowable values when computed by the formula given in section
twenty-six hundred and thirty-eight for shearing unit stress in beams.
(1) 0.03 f'c — when at least fifty per cent of the total negative rein-
forcement in each column strip passes directly over the column capital.
(2) 0.025 f^ — when twenty-five per cent of the total negative rein-
forcement in each column strip passes directly over the column capital
(which is the least that shall be permitted).
(3) For intermediate percentages, proportionate intermediate values of
the allowable shearing unit stress shall be used.
(b) In flat slabs, the shearing unit stress on a vertical section which lies
at a distance (d) from the edge of the dropped panel and parallel with it shall
not exceed (0.03 f'0).
(c) For the purposes of this section (d) shall be the average depth at the
section in question from the compressive surface of the concrete to the center
of the tensile reinforcement for negative bending.
Sect. 2642. Shear and Diagonal Tension in Footings, —(a) The
shearing unit stress computed by the formula given in section twenty-six
hundred and thirty-eight on any vertical peripheral or plane section of a
footing at a distance (d) from the face of the supported column or pier and
parallel with it, shall not exceed (0.02 f '0) for footings with straight bars, nor
(0.03 f'c) for footings in which the bars have special anchorage as specified in
section twenty-six hundred and forty-five.
(b) In footings supported on piles, the critical section for diagonal tension
shall be considered at a distance (d/2) from the face of the supported col-
umn or pedestal and any piles whose centers are at this section or nearer the
supported column or pedestal shall be excluded in computing the shear.
Sect. 2643. Bond Stress in Reinforced Concrete. — (a) Members
subject to bending shall be so proportioned that the increments of stress in the
tensile steel are transmitted to it from the concrete in which it is embedded,
without producing bond stress exceeding that specified in section twenty-six
hundred and twenty-nine.
(b) In beams in which the tensile reinforcement is parallel to the com-
pressive face, and is not specially anchored, the bond stress (u) shall be
assumed to be determined by the following formula: —
V
gjd
(c) In non-prismatic or wedge-shaped beams, as represented by a canti-
lever bracket, a sloped top footing, or a beam with cambered compressive
face in which the depth of the beam is increased in the direction of increasing
(202)
Sees. 2643-2644
bending moment, the bond stress is not proportional to the shear, being at all
sections smaller than indicated by the formula of paragraph (b) for a pris-
matic beam of depth equal to the depth at the section considered. For such
beams the bond stress shall be assumed to be determined by the following
formula: —
V M
u = X (1 - m )
gjd Vd
in which (m) is the tangent of the angle between the compressive face and
the tensile re-inforcement.
(d) Adequate end anchorage of bars in prismatic beams which are sub-
ject to excessive bond stress, as computed by the formula of paragraph (b),
may result in the relief of such excessive bond stress, by inducing in the beam
an arch action, with distribution of bending stresses analogous to that in a
cambered beam. About bars so anchored the computed bond stress may be
double that allowed for unanchored reinforcement.
(e) Special anchorage adequate to justify increased bond stress shall be
capable of developing the maximum tension in the bars in excess of that
developed by bond at its allowable value. The excess tension (T') shall be
determined by the formula: —
u'
T' = T (1 )
u
in which (T) is the maximum tensile stress.
(u') is the allowable stress in bond for unanchored reinforcement,
(u) is the maximum bond stress computed by one of the formulas of
paragraphs (b) and (c).
(f) In simply supported beams the required special anchorage shall be pro-
vided beyond the face of the support. In continuous beams sufficient special
anchorage of the positive reinforcement beyond the point of inflection may be
considered to be provided by the extension of such bars to the ends of the
span. For the negative reinforcement of restrained or continuous beams,
and for the tensile reinforcement of cantilevers, brackets and footings, the
required special anchorage shall be provided by extending or hooking the bars
beyond the point at which tension begins.
(g) In applying the formulas of paragraphs (b) and (c) to any section of
a beam in which the tensile reinforcement is varied by bending or discon-
tinuing a portion of the bars, there shall be counted as contributing their
perimeters to bond resistance only those bars at that section and in the plane
of the main longitudinal tensile steel, in which tensile stress is increasing
consistently with the assumptions under which the beam is designed.
Sect. 2644. Ordinary Anchorage of Reinforcement. — (a) Rein-
forcement acting in tension at a restrained end of a beam or in a cantilever
shall have anchorage on both sides of the face of the support and beyond the
point where any portion of the reinforcement is discontinued sufficient to
develop the tension in each of the bars.
(203)
Sees. 2644-2646
(b) In a restrained beam at least one third of the tensile reinforcement
for negative bending shall be extended at least to the point of inflection of the
beam.
(c) At least one fourth of the tensile reinforcement for positive bending
in a beam shall be extended at least to the end of the span. Bars not so
extended may be bent across the web, becoming continuous with the nega-
tive reinforcement, or otherwise anchored in a region of compression.
Sect. 2645. Special Anchorage of Reinforcement. — (a) Where, by-
reasons of special anchorage of reinforcement, increased shearing stresses are
allowed, reinforcement in the proportions specified in section twenty-six
hundred and forty-four shall be extended in beams as there specified, and
anchorage shall further be provided beyond the points of inflection for the
negative reinforcement of restrained beams, and beyond the end of the span
for positive reinforcement of freely supported beams, sufficient to develop
at least one half of their allowable tensile stress. In footings, special anchor-
age justifying increased shearing stress shall be considered as provided when
all bars are anchored by means of hooks at their ends. The outer face of
hooks shall be as close to the face of the footing as the requirements for rust
protection will allow.
(b) Where anchorage is furnished by extension of the bars, such exten-
sion may be assumed to provide an anchorage capacity equal to the embedded
surface multiplied by the allowable unit bond resistance specified in section
twenty-six hundred and twenty-nine. A hook, for the purpose of this section,
means a complete semicircular hook as defined in section twenty-six hundred
and two. Such a hook may be assumed to develop a stress of not more than
ten thousand pounds per square inch in the bar so anchored. A bend of
larger radius than allowed in a hook shall be considered as a mere extension
of the bar.
Sect. 2646. Anchorage of Web Reinforcement. — (a) The stress in a
stirrup or web reinforcement bar for resistance of diagonal tension in a beam
shall not exceed the capacity of its anchorage in the upper or lower one half
of the effective depth of the beam nor the allowable stress specified in section
twenty-six hundred and thirty.
(b) Web reinforcement which is provided by bending into an inclined
position one or more bars of the main tensile reinforcement where not required
for resistance to positive or negative bending shall be considered completely
anchored by continuity with the main tensile reinforcement or by embed-
ment of requisite length in the upper or lower half of the beam, provided at
least one half of such embedment is as close to the upper or lower surface
of the beam as the requirements of fire or rust protection allow. A hook
placed close to the upper or lower surface of the beam may be substituted
for a portion of such embedment.
(c) Stirrups shall be anchored at both ends by one of the following methods
or by a combination thereof: —
(1) Rigid attachment, as by welding, to the main longitudinal rein-
forcement. The capacity of this anchorage is limited to that of the attach-
ment.
(204)
Sees. 2646-2650
(2) Bending around and closely in contact with a bar of the main
longitudinal reinforcement in the form of a U-stirrup or a hook. The
capacity of this anchorage may be taken as sixteen thousand pounds per
square inch in the stirrup.
(3) A hook placed as close to the upper or lower surface of the beam
as the requirement for fire and rust protection will allow. The capacity
of this anchorage shall be ten thousand pounds per square inch in the
stirrup plus the stress developed by bond between mid-height of the effec-
tive depth of the beam and the beginning of bending of the hook.
(4) A length of embedment in the upper or lower half of the effective
depth of the beam, whether straight or curved. The capacity of this
anchorage shall be limited to the stress developed by bond on the embedded
length. Anchorage of this type shall not be used on stirrups where the
unit shear exceeds (0.06 f0).
Sect. 2647. Slenderness of Reinforced Concrete Beams. — The
clear distance between lateral supports of a beam shall not exceed thirty-two
times the width of the compression area of the cross-section.
Sect. 2648. T-Beams of Reinforced Concrete. — (a) In T-beam con-
struction the slab shall be built integrally with the beam. In the design
of symmetrical T-beams the overhanging flange width on either side of the
web shall not exceed one tenth the span, nor eight times the thickness of
the slab nor one half the clear distance to the next beam.
(b) For beams having a flange on one side only, the effective overhanging
flange width shall not exceed one twelfth of the span length nor six times
the thickness of the slab nor one half the clear distance to the next beam.
(c) Where the principal reinforcement in a slab which serves as the flange
of a T-beam (not a rib in ribbed floors) is parallel to the beam, transverse
reinforcement shall be provided in the top of the flange. The spacing of the
bars shall not exceed five times the thickness of the flange, or eighteen inches.
(d) Isolated beams in which the T-form is used only for the purpose of
providing additional compression area, shall have a flange thickness not less
than one half, and a total flange width not more than four times, the web
thickness.
Sect. 2649. Compression Reinforcement in Beams and Girders. —
Steel reinforcing bars in compression in girders and beams shall be thoroughly
anchored against buckling by ties or stirrups not less than one quarter inch
in diameter spaced not further apart in the region where compression steel is
required than twelve times the diameter of the bars, or by equivalent lateral
support.
*Sect. 2650. Structural Steel Beams Encased in Concrete. — (a)
Structural steel beams which are fireproofed by being wholly encased in the
concrete of a reinforced concrete floor or roof may be designed for bending
as composite beams, the two materials assumed to act elastically together,
the concrete not to act in tension, the stresses in the respective materials not
to exceed those allowed by this code.
(205)
Sees. 2650-2652
(b) Any steel beam or girder completely encased in concrete as described
in paragraph (a) having a compressive strength of at least two thousand
pounds per square inch and comprising an integral part of a complete floor
system such as concrete slabs and beams, in conformity with section twenty-
six hundred and forty-eight, may have its resistance to bending increased
fifteen per cent.
(c) Stresses allowed in paragraph (b) shall be allowed in tension members
of trusses, if the requirements of this section are fulfilled.
[ *As amended by Ord. 1943, ch. 8 ]
Sect. 2651. Shrinkage and Temperature Reinforcement. — (a)
Reinforcement for shrinkage and temperature stresses shall be provided in
floor and roof slabs perpendicular to the reinforcement for bending where
this runs in one direction only. Such reinforcement shall have an area of
cross-section not less than two one thousandths times the area of the concrete
and bars shall be spaced not more than five times the slab thickness nor more
than eighteen inches.
(b) In reinforced concrete spandrel beams and parapet walls shrinkage
reinforcement shall be provided, in amount not less than one half of one per
cent, in addition to the reinforcement for bending. Such reinforcement
shall be continuous and rods shall be spliced by lapping or otherwise, except
at expansion joints.
(c) Consideration shall be given to the stresses due to expansion and
shrinkage in buildings more than two hundred feet long and provision shall be
made satisfactory to the commissioner for avoiding excessive stress. In
buildings longer than four hundred feet expansion joints shall be provided not
more than three hundred feet apart. Such joints shall be constructed with
at least one inch opening and shall allow for expansion of each section of
building not less than one half inch for every one hundred feet of its length.
Sect. 2652. Concentrated Loads on Concrete Slabs. — (a) For
computation of stresses due to bending and shear, concentrated loads on
one-way slabs may be considered as evenly distributed over an effective
width at right angles to the direction of the span as follows: —
Solid concrete construction . . . w + 0.8 s
Combination floor construction . . w + 0.6 s
Ribbed floor construction . . . w + 0.4 s but not more than
w + twice the rib spacing
where (w) is the actual width of the concentration and (s) is the distance from
the nearer support to the center of the concentration. For concentrations
at mid-span or for loads such as partitions which are concentrated laterally
but distributed longitudinally to the span, (s) shall be taken as equal rto
half the span.
(b) If adequate bridging is provided to distribute concentrations among
adjacent ribs, the effective width for combination and ribbed slabs may be
(206)
Sees. 2652-2653
taken as for solid slabs, but in the case of ribbed slabs, unless the bridging
has approximately the same spacing as the ribs, not more than three adja-
cent ribs shall be assumed to share the load.
*Sect. 2653. Concrete Ribbed and Combination Slabs. — (a)
Ribbed floor construction consists of concrete ribs, running in one or two
directions and topping placed monolithically with the ribs, not over twenty
inches apart between faces. The ribs shall be straight and of a width not less
than four inches nor less than one third the depth. The topping shall be of
sufficient strength to transmit loads coming upon it to the adjacent ribs
and shall be not less than two inches thick. Ribbed slabs shall be reinforced
at right angles to the ribs with a minimum of forty-nine one thousandths
square inch of reinforcing steel per foot and in slabs on which the prescribed
live load does not exceed fifty pounds per square foot, no additional rein-
forcement shall be required.
(b) Combination floor construction consists of concrete ribs running in one
or two directions, with masonry fillers, filling the entire space between ribs,
and either with or without a monolithic concrete topping over the ribs. Each
masonry filler shall have contact with ribs on two opposite sides. Ribs shall
be not over twenty inches apart between faces, shall be straight and of a
width not less than four inches nor less than one third the depth. Either the
fillers or the topping over them, or the combination of the two shall be of
sufficient strength to transmit any load coming on them to the adjacent
ribs. If a monolithic topping is used, it shall be not less than one inch thick.
(c) If structural fillers as specified in paragraph (e) are used, then, and
not otherwise, certain portions of them may be included with the concrete in
calculations of resistance to shear and bending, but the amount included shall
nowhere exceed the actual thickness of the portion of the filler nor one and one
half inches. In one-way construction the webs of structural fillers which are
in contact with the concrete ribs and where there is a topping the web in
contact therewith may be included with the concrete in calculations of re-
sistance to shear and bending. In construction in which the ribs run in both
directions and at approximately the same distance on centers, and whether
designed as one-way or two-way slabs, the webs in contact with the concrete
ribs may be included in calculations of resistance to shear and bending and
the top and bottom webs may be included in calculations of resistance to
bending.
(d) The maximum stress in both the concrete and the filler shall not
exceed that allowed in the weaker of the two materials.
(e) A structural filler, for the purpose of this section, shall have an ultimate
strength in compression, on its net section, when tested on end at the age of
twenty-eight days, of two thousand pounds per square inch. If structural clay
tiles are used as fillers they shall at least equal those classified as Grade B in
Part 24 of this code. Gypsum tile shall not be used as a structural filler.
(f) The unit extreme compressive fibre stress in the filler tile shall not
exceed four tenths of its ultimate unit compressive strength, determined for
the net section from an average of three fillers tested on end at an age of
(207)
Sees. 2653-2654
twenty-eight days. The unit stress allowed in shear computations shall not
exceed one quarter of the average ultimate strength in shear of the joint
between the ribs and the filler blocks.
(g) Where the topping contains conduits or pipes, the thickness shall
not be less than one inch plus the total overall depth of such conduits or pipes
at any point. Such conduits or pipes shall be so located as not to impair the
strength of the construction.
(h) Shrinkage reinforcement shall be provided in the slab as required in
section twenty-six hundred and fifty-one.
(i) Neither paper, wood, nor roofing material shall be used between or at
the ends of structural hollow masonry fillers included in calculations of re-
sistance to shear or bending to prevent concrete from flowing into the inter-
stices thereof, nor any other material that would impair the bond between
the end of the filler and the concrete, but this shall not prevent the use of
such materials when inserted in but not projecting from the openings of the
fillers nor the use of the same material that is permitted for the fillers them-
selves. If concrete is allowed to penetrate the interstices of hollow masonry
fillers, the weight thereof shall be included in the dead load to be supported.
The webs of structural filler units whose ends are thus in contact with the
concrete may be included in calculations of resistance to bending.
[ *As amended by Ord. 1948, ch. 8 ]
fSect. 2654. Two=Way Slabs of Reinforced Concrete. — (a) Con-
crete slabs, either solid, ribbed or combination slabs, supported on four sides
by beams, girders or walls, and reinforced to span in two directions shall be
designed in accordance with the provisions of this section.
(b) The slab shall be regarded as consisting of a series of adjacent strips
of unit width spanning in each direction. In computations for shear and
diagonal tension, bond, and for the loading of supporting members, each strip,
spanning in either the longer or the shorter direction, shall be assumed to
carry and transmit to its supports a total load (W), represented by the expres-
sion:
W = 1/2 C0r w L = 1/2 C0w Li
in which (w) is the total load per unit area of the slab.
(L) is the span of the strip.
(Li) is the width of the panel transverse to the span.
(r) is the ratio of Li to L.
(Go) is a coefficient dependent on the position of the panel relative
to adjacent panels continuous with it at its ends and sides,
as indicated on the accompanying diagram. Full restraint
at end support, as defined in section twenty-six hundred and
thirty-six, shall be considered equivalent to continuity in
determining (C0).
(208)
Sees. 2654=2655
MARGINAL. BEAM OR WALL.
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I
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(c) The positive bending moment for a strip of unit width in the middle
half of the panel, spanning in either direction, shall be assumed as given by
the following formula: —
M = 0.33 CiC0r2wL2 = 0.33 CiC0wL?
in which (Ci) is a coefficient for bending determined in accordance with the
conditions of restraint at end supports of the strips as provided in section
twenty-six hundred and thirty-five|or section twenty-six hundred and thirty-six.
(d) Negative moments at and adjacent to supports between two panels
shall be determined by the formula given in paragraph (c) for positive moment
taking (Ci) as the coefficient for negative moment determined according
to section twenty-six hundred and thirty-five or section twenty-six hundred
and thirty-six, and in case the conditions of continuity in the two panels are
different, taking the mean value of (C0).
(e) The positive bending in strips of unit width in the outer quarters of
the panel may be assumed to be three quarters that of the strips of the middle
half
(f) Lines of inflection in a two-way panel shall be assumed at a distance
of one fourth of its shorter span from supports over which the slab is con-
tinuous.
[ ]As amended by Ord. 1943, ch. 8 ]
JSect. 2655. Limitations upon Reinforced Concrete Flat Slabs. —
(a) The term "flat slabs" as used herein refers to concrete slabs with rein-
forcing bars in two or more directions, whose interior supports are columns
or the like, generally without beams.
(209)
Sec. 2655
(b) The methods of stress computation herein specified apply to a series
of slabs of approximately uniform size extending at least three panels in each
direction and in which the length of panel does not exceed one and one half
times its width. Flat slabs of other arrangement shall be proportioned to
have at least equal carrying capacity and degree of safety according to estab-
lished principles of mechanics.
(c) Flat slabs with paneled ceiling or with dropped panels may be pro-
portioned by the methods herein specified provided the dropped panel shall
have a length or diameter in each rectangular direction not less than one third
the panel length in that direction, and the thickness of the thicker portion of
the slab shall not exceed one and one half times that of the remainder. In
the ceilings of flat slabs, concrete between rods in tensile regions and in com-
pressive regions where it can be spared may be displaced by permanent or
removable fillers, provided allowable stresses are not exceeded in the concrete
which remains and provided the tensile stress in the reinforcing rods in that
region shall not exceed eight ninths the stress allowed in the reinforcement of
solid concrete slabs. Compression concrete above such fillers shall have a
thickness not less than two inches, and the construction shall safely support
any concentration of load that may come upon it. The term "slab thickness"
used in connection with such construction shall refer to the total thickness of
the structural concrete.
(d) Column capitals, if of concrete, shall be of the mixture required for
the column up to a level where the area of a horizontal section is fifty per
cent more than the gross area of the shaft of the column. In dimensioning
the concrete capital for design purposes, no portion of the capital shall be
considered which lies outside the largest ninety-degree circular cone contained
within its outlines. The diameter of the capital shall be measured for design
purposes at the junction of the cone with the bottom of the slab or dropped
panel.
(e) Column capitals of structural metal may be substituted for concrete
capitals, whether contained within the thickness of the slab and dropped
panel, or not, provided they meet the following requirements: —
(1) they shall have the same protection against fire required for rein-
forcement in similar exposures;
(2) they shall safely support the slab on the periphery of the capital
without exceeding stresses allowed in this code for the kind of metal used;
(3) they shall provide support for the slab or dropped panel at a dis-
tance above the bottom thereof not substantially greater than the require-
ments for fire protection, and such support shall either be continuous along
the periphery of the capital or with intervals not greater than three times
the thickness of concrete slab, or slab and dropped panel;
(4) the capitals shall be so designed and arranged as to permit the proper
placement of concrete in and about them without pockets or voids, and to
provide for the transmission of load from columns above to columns below;
(5) the diameter of a structural metal column capital, for purposes of
slab design, shall be taken as twice the distance from the center of the
column to the center of bearing of slab or dropped panel on a continuous
(210)
Sees. 2655-2657
circumferential support, or twice the average distance to centers of bearing
on radial or non-continuous supports, the unit bearing assumed as uniform
and not in excess of the stress allowed by this code.
[ %As amended by Ord. 1943, ch. S ]
Sect. 2656. Assumptions in Concrete Flat Slab Design. — (a)
A flat slab panel shall be considered as consisting of strips, parallel to sides
of the panel, as follows: —
(1) A middle strip one half panel in width, symmetrical with respect
to the panel center line.
(2) A column strip one half panel in width made up of two quarter-
panel areas outside the middle strips.
(3) The strips shall be considered in each rectangular direction for the
computation of bending moments.
(b) The critical sections for bending are referred to as the principal
design sections and are located as follows: —
(1) Sections for negative bending shall be taken along the edges of the
panel at ends of the strips, on center lines of columns, and around the
periphery of the column capital.
(2) Sections for positive bending shall be taken at mid-length of the
strips, on the center line of the panel.
♦Sect. 2657. Bending in Interior Flat Slab Panels. — (a) The
numerical sum of the positive and negative bending moments in either
rectangular direction of an interior panel, for the design of tensile reinforce-
ment, shall be assumed as not less than —
(2c\2
1-3-l) -
Mo - 0.09 WL I 1 I = Mpo + Mpm + Mno + Mnm
where (Mpo) is the positive moment at mid-span of the column strip.
(Mpm) is the positive moment at mid-span of the middle strip.
(Mnm) is the negative moment at one end of a middle strip.
(Mno) is the negative moment at one end of the column strip.
(L) is the length of the strips between center lines of columns,
(c) is the diameter of the column capital, or top of column if
there is no capital.
(W) is the total live and dead load uniformly distributed over
a single panel area.
(b) The bending moments for the design of tensile reinforcement in the
principal design sections shall be assumed to be those given in the following
table, except that (Mno) may be (0.03 M0) greater or smaller, and each of
(Mpc), (Mpm) and (Mnm) may be (0.01 M0) greater or smaller provided that
the sum remains not less than the value specified for (M0).
(c) If a flat slab is supported at interior column points by supports less
rigid than the columns specified in section twenty-six hundred and sixty-nine,
paragraph (b), the positive bending in column and middle strips shall be
increased twenty per cent above the tabular values.
(211)
Sees. 2658-2660
Bending Moments in Flat Slabs for Tensile Reinforcement — Interior
Panels Fully Continuous.
Two-way Reinforcement.
Foxm-WAT Reinforcement.
Moment.
Without
Dropped Panel.
With
Dropped Panel.
Without
Dropped Panel.
With
Dropped Panel.
MPo
0.22Mo
0.20Mo
0.20M<>
0.19Mo
Mpm
O.I6M0
0.15Mo
0.20Mo
0.19Mo
Mno
0.46Mo
0.50Mo
0.50Mo
0.54Mo
Mum
O.I6M0
0.15Mo
O.lOMo
O.O8M0
[ *As amended by Ord. 1948, ch. 8 ]
Sect. 2658. Spacing of Flat Slab Reinforcement. — (a) Bands of
rods in two-way systems of reinforcement shall be spread evenly over the
width of the strips.
(b) Direct bands of rods in four-way systems shall have a width of about
(0.4) times the panel width, diagonal bands (0.4) times the average panel
widths, and the rods shall be spread evenly in the bands.
(c) The maximum spacing of rods shall not exceed three times the thick-
ness of the slab.
fSect. 2659. Thickness of Concrete Flat Slabs. — (a) The thickness
of a flat slab, and the size and thickness of the dropped panel shall be such
that the compressive stress due to bending will not exceed that allowed for
concrete on the principal design sections of any strip. The bending moments
for which the compressive stress shall be computed shall be assumed to be
four thirds those specified for the design of reinforcement.
(b) The width of section for computing compression in concrete due to
negative bending at the column head shall be taken as the width of the dropped
panel if any; otherwise, half the panel width. The width of other principal
sections shall be taken as half the panel width.
(c) The thickness of the slab and the size and thickness of the dropped
panel shall be such that shearing stresses computed as specified in section
twenty-six hundred and forty-one shall not exceed the stress allowed.
(d) In no case, however, shall the slab thickness be less than one fortieth
the length of the panel nor less than six inches.
[ -\As amended by Ord. 1943, ch. 8 ]
Sect. 2660. Point of Inflection in Flat Slabs. — (a) In a middle
strip the point of inflection for slabs without dropped panels shall be assumed
at a line (0.33L) distant from the center of the span and for slabs with dropped
panels (0.3L) distant from the center of the span.
(b) In a column strip, the point of inflection for slabs without dropped
panels shall be at a line 0.33 (L-c) distant from the center of the panel and 0.3
(L-c) for slabs with dropped panel.
(212)
Sees. 2661-2663
Sect. 2661. Arrangement of Flat Slab Reinforcement at Column
Heads. — Reinforcement shall be provided not only for the moments at
principal design sections but also for moments at intermediate sections.
Steel of the full area required for negative moment at the column head shall
be continued in the same plane close to the upper surface of the slab to the
edge of the dropped panel, and not less than a distance (0.2L) from the center
line of the column. Lapped splices shall not be permitted at or near regions
of maximum stress except as described in section twenty-six hundred and
twenty-six.
Sect. 2662. Arrangement of Flat Slab Reinforcement — Two-way
System. — (a) In column strips at least four tenths of the area of steel
required at the principal design section for positive moment in the strip
shall be in bars of such length and so placed as to reinforce the sections for
negative moment at the adjacent column heads. These bars, and other bars
for negative reinforcement shall extend into the adjacent panel to a point
at least (0.05L) beyond the point of inflection. Not less than one third of
the bars used for positive reinforcement in the column strip shall be straight
and extend into the dropped panel at least twenty diameters of the bar, but
not less than twelve inches; or if no dropped panel is used, shall extend to
within (0.125L) of the center line of the columns. The remainder of the
bars for positive reinforcement in the column strip shall extend at least
(0.33L) on either side of the center line of panel. Not less than one fourth
in area of the bars for negative reinforcement of each column strip shall lie
directly over the column capital and not less than one half within the width
of the dropped panel, if any.
(b) In the middle strip at least one half of the bars for positive moment
shall be bent up for negative moment and extend over the bands of the
column strips at both sides of the panel to a point at least (0.25L) beyond the
center line of columns. The location of the bends shall be such that for a
distance (0.15L) for slabs with dropped panels, and (0.125L) for slabs without
dropped panels, on each side of the center line of columns, the full reinforce-
ment required for negative moment will be provided in the top face of the
slab. The full reinforcement for positive moment in the middle strip shall
extend in the bottom face of the slab to a point at least (0.25L) on either
side of the panel center line, and at least one half of it shall extend to points
(0.325L) on either side of the panel center line for slabs with dropped panels,
and (0.35L) for slabs without dropped panels.
Sect. 2663. Arrangement of Flat Slab Reinforcement — Four-way
System. — (a) Provisions governing the placing of steel in column strips
in two-way systems apply as well to the direct bands in four-way systems.
(b) In diagonal bands, at least four tenths of the area of steel required
at the section for positive moment shall be in bars of such length and so
placed as to reinforce the negative moment section at the two diagonally
opposite column heads. These bars and other bars for negative reinforce-
ment, if any, shall extend into the adjoining panel to points at least (0.4L)
beyond a line drawn through the column center perpendicular to the direc-
(213)
Sec. 2663-2665
tion of the band. The straight bars for positive moment in the diagonal
bands shall not be shorter than the length of panel center to center of columns,
(c) For negative moment in the middle strip, the required steel shall
extend not less than (0.25L) on either side of the column center line.
♦Sect. 2664. Flat Slab Reinforcement Other than Two-way or
Four-way. — Arrangement of reinforcement other than two-way or four-
way shall provide reinforcing at the principal design sections and at inter-
mediate sections equivalent to that specified above. All such arrangements
shall be subject to the approval of the commissioner.
[ *As amended by Ord. 1948, ch. 8 ]
Sect. 2665. Discontinuous Flat Slab Panels. — (a) In panels ad-
jacent to an exterior wall and other panels where the slab is discontinuous
on one or two of its edges, the bending on principal design sections parallel
to a discontinuous edge shall be assumed at values not less than specified in
this section, depending upon the degree of restraint in bending furnished by
the support at such discontinuous edge.
(b) The numerical sum of the positive bending moment at mid-span and
the average of the negative bending moments at the discontinuous edge and
at the first interior supports for a full panel width, for the design of tensile
reinforcement, shall be assumed as not less than
Mo = 0.10 WL
V'-nr)
in which (L) is the span center to center of columns, walls or other supports;
(c) is the diameter of the interior column capital and (a) is the thickness of
the exterior support in the direction of the span. A bracket on the inner
face of an exterior column shall be ignored in determining the value of (a).
(c) The bending moments for the design of tensile reinforcement in the
principal design sections of the several strips shall be assumed, within the
range of allowable variation specified in paragraph (b) of section twenty-six
hundred and fifty-seven, as follows: —
Bending Moment for Tensile Reinforcement in Wall Panels of Flat
Slabs.
Moment.
Two-way Reinforcement.
Without
Dropped Panel.
With
Dropped Panel.
Four-way Reinforcement.
Without
Dropped Panel.
With
Dropped Panel.
Negligible Restraint at Discontinuous Edge.
MPc
0.32Mo
0.31Mo
0.30Mo
0.29Mo
Mpm
0.26Mo
0.25Mo
0.30Mo
0.29Mo
Mno (ext.)
0.05Mo
0.05Mo
0.05Mo
0.05Mo
Mnm (ext.)
0.05Mo
0.05Mo
0.05Mo
0.05Mo
Mno (int.)
0.55Mo
0.60Mo
O.6OM0
0.65Mo
Mnm (int.)
0.19Mo
O.I8M0
O.lOMo
0.09Mo
(214)
Sec. 2665
Bending Moment for Tensile Reinforcement in Wall Panels of Flat
Slabs. — Continued.
Moment.
Two-way Reinforcement.
Without
Dropped Panel.
With
Dropped Panel.
Four-way Reinforcement.
Without
Dropped Panel.
With
Dropped Panel.
Moderate Restraint at Discontinuous Edge.
Mpe
0.29Mo
0.27Mo
0.26Mo
0.25M0
Mpm
0.23Mo
0.22Mo
0.26Mo
0.25Mo
Mno (est.)
0.22Mo
0.23Mo
0.25Mo
0.26Mo
Mnm (ext.)
O.O8M0
O.O8M0
O.O6M0
0.06Mo
Mno (int.)
0.50Mo
0.55Mo
0.55Mo
O.6OM0
Mnm (int.)
O.I8M0
O.I6M0
O.lOMo
O.O8M0
Full Restraint at Discontinuous Edge.
Mp0
0.25Mo
0.22Mo
0.22Mo
0.21Mo
Mpm
0.20M<>
0.20Mo
0.22Mo
0.21Mo
Mno (ezt.)
0.38Mo
0.41Mo
0.46Mo
0.48Mo
Mnm (est.)
O.lOMo
O.lOMo
O.O6M0
O.O6M0
Mno (int.)
0.46Mo
0.50Mo
0.50Mo
0.54 Mo
Mnm (int.)
O.I6M0
0.15Mo
O.lOMo
O.O8M0
(d) If restraint at a discontinuous edge is furnished by a wall, the negative
bending at the exterior support may be more nearly evenly distributed
between column and middle strips. If the supports at interior column points
are less rigid than the column specified in section twenty-six hundred and
sixty-nine the positive bending in column and middle strips shall be increased
twenty per cent above the tabular values.
(e) Negligible restraint in bending at the discontinuous edge of a flat slab
panel shall be considered to be furnished by a supporting wall of masonry or
a row of masonry piers or by any support that does not assure as great
restraint as that specified as moderate.
(f) Moderate restraint shall be considered to be furnished by a wall of
reinforced concrete or by a row of reinforced concrete columns or of steel
columns encased in concrete when the slab acts integrally with the support
and when the support is not sufficiently rigid to afford full restraint.
(g) Full restraint shall be assumed where the discontinuous edge of a
flat slab is supported by a reinforced concrete wall or row of columns with
which it acts integrally and when the ratio ( — ) for the slab is less than the sum
L
I
of the ratios (-) for the walls or columns, respectively, above and below the
h
(215)
Sees. 2665=2666
slab. For the purpose of this section (I) is the moment of inertia of the slab,
wall or column calculated for the gross area of the concrete and neglecting
the reinforcement.
(h) Except in the case of negligible restraint where precautions are taken
to avoid restraint, the bending incidental to the restraint shall be trans-
mitted to the supports, with or without the aid of brackets, in such manner
that the stresses specified in this code for the materials used shall not be
exceeded. The supports shall be made capable of resisting the bending
bo transmitted in addition to their other loads and forces without excessive
stress. The bending moments transmitted shall be assumed to be four
thirds those specified in this section for design of the tensile reinforcement
;of the slab.
,(i) The reinforcement for positive bending perpendicular to the dis-
continuous edge shall extend to this edge and have an embedment of at
least six inches in spandrel beams, walls or columns. Reinforcement for
negative bending shall be bent or hooked at spandrel beams, walls or columns
to provide adequate anchorage. The length and placement of other rein-
forcement in wall panels shall be adapted from the requirements of sections
twenty-six hundred and sixty-one, twenty-six hundred and sixty-two and
twenty-six hundred and sixty-three having in view the changed location of
the points of inflection.
(j) The half column strip parallel and adjacent to a marginal beam
having a depth not greater than one and one half times the slab thickness,
or parallel and adjacent to a discontinuous edge without marginal beam, shall
be designed to resist at least one half the moments specified for a full interior
column strip. The half column strip parallel and adjacent to a marginal
beam having a depth greater than one and one half times the thickness of the
slab, shall be designed to resist at least one fourth the moments specified for
a full column strip.
(k) If a flat slab is supported at a discontinuous edge by a row of columns
having brackets extending from the side of the column in a direction parellel
to the discontinuous edge which are equivalent to column capitals, the value
of (c) parallel to the discontinuous edge shall be the total width of the capital
or brackets. If such columns are without brackets the value of (c) parallel
to the discontinuous edge shall be taken as the width of the column plus
twice the difference between the depth of the marginal beam, if any, and the
depth of the slab.
| (1) Dropped panels at wall columns may be omitted, provided the allowed
unit stresses are not exceeded.
(m) The provisions of section twenty-six hundred and fifty-nine shall
apply to wall panels.
Sect. 2666. Marginal Beams in Flat Slabs. — (a) In panels having
a marginal beam on one edge or on each of two adjacent edges, whether or
not the slab is there discontinuous, the beam shall be designed to carry at
least the load superimposed directly upon it, exclusive of the panel load.
A^ marginal beam which has a depth greater than one and one half times the
slab ^thickness, shall be designed to support, in addition to the load super-
(216)
Sees. 2666-2669'
imposed directly upon it, a uniformly distributed load equal to at least one
fourth the total live and dead load for which the adjacent panel or panels are
designed.
(b) Where there is a beam or a bearing wall at the center line of columns
in the interior portion of a continuous flat slab, the negative moment at the
beam or wall line in the middle strip perpendicular to the beam or wall shall
be taken as thirty per cent greater than the negative moment specified in
section twenty-six hundred and fifty-seven or section twenty-six hundred
and sixty-five for a middle strip. The half column strip adjacent and parallel
to and lying on either side of the beam or wall shall be designed to resist
moments, at least one fourth of those specified in section twenty-six hundred
and fifty-seven or section twenty-six hundred and sixty-five for a column
strip. The beam or wall in such cases shall be designed to carry a uniformly
distributed load equal to one fourth of the panel loads on both sides in addition
to the loads directly imposed upon it.
Sect. 2667. Openings in Flat Slabs. — (a) Openings of any size may
be formed in the area common to two intersecting middle strips, provided the
total positive and total negative moments as specified in section twenty-six
hundred and fifty-seven or section twenty-six hundred and sixty-five are
effectually resisted when these total positive and total negative moments are
redistributed between the remaining principal design sections to meet the
conditions.
(b) In an area common to two column strips, not more than one opening
shall be allowed and the greatest dimension of such an opening shall not
exceed (0.05L).
(c) In an area common to one column strip and one middle strip, openings
shall not interrupt more than one quarter of the bars in either strip when
evenly spaced and the equivalent of the bars so interrupted shall be provided
by extra reinforcement on both sides of the opening.
(d) An opening larger than allowed by this section shall be completely
framed with beams to carry the loads to the columns.
*Sect. 2668. Construction Joints in Flat Slabs. — Construction
joints in flat slabs shall occur preferably midway between columns. Where
such joints occur, steel reinforcing shall be provided perpendicular to the
joints in addition to the reinforcement required for bending of cross-sectional
area equal to one third that required for bending at the joint. Steel rods so
provided shall be spaced not over two times the slab thickness, shall be fully
anchored for the allowed tensile stress by embedment each side of the joint,
and shall be placed in the same plane with the reinforcement provided for
bending in each strip.
[ *As amended by Ord. 1943, ch. 8 ]
tSect. 2669. Limiting Dimensions of Concrete Columns. — (a)
Unless designed as long columns under the provision of section twenty-six
hundred and seventy-three, reinforced concrete columns shall not be longer
than ten times the least lateral dimension. Struts shall be designed as
columns.
(217)
Sees. 2669=2671
(b) In flat slab construction, except as otherwise provided in paragraph
(c) of section twenty-six hundred and fifty-seven and paragraph (d) of section
twenty-six hundred and sixty-five, the least dimension of a column supporting
a floor shall be not less than one fifteenth the average center to center spacing
nor less than sixteen inches; and that of a column supporting only a roof not
less than one twentieth the average spacing nor less than fourteen inches.
[ 1[As amended by Ord. 1948, ch. 8 ]
Sect. 2670. Unsupported Length of Concrete Columns. — (a) The
unsupported length of a column shall be taken as the clear distance between
lateral supports. When the lateral support consists of a floor or roof with
beams of different depths, the height of the column to the bottom of the
deepest beam in a given direction shall be used with the thickness of the
column in that direction in computing the slenderness ratio. When free-
standing ties or struts are provided for lateral support, they shall be adequate
to prevent the column from bending, and the clear distance between supports
in any direction shall be used with the thickness of the column in that direc-
tion in computing the slenderness ratio.
(b) Concrete column capitals in flat slab construction, and brackets the
full width of supported beams which are inclined at least forty-five degrees
to the column, may be considered lateral supports.
JSect. 2671. Design of Spirally Reinforced Concrete Columns. —
(a) The maximum allowable axial load, P, on columns reinforced with
longitudinal bars and closely spaced spirals enclosing a circular core shall not
exceed P = 0.225 f0 Ag + A8f8. See section 2602 for symbols.
(b) The normal working stress in the vertical column reinforcement, fB,
shall be taken at 40% of the minimum specification value of the yield point;
viz. 16,000 lbs. per sq. in. for intermediate grade steel and 20,000 per sq. in.
for hard grade or rail steel. This reinforcement shall consist of at least six
bars and the minimum diameter of the bars shall be five-eighths inch and
not less than one per cent nor more than eight per cent of the gross concrete
area.
(c) Where lapped splices are required in the longitudinal reinforcement,
the minimum amount of lap for deformed bars, where the strength of the
concrete is 3000 lbs. per square inch or above, shall be twenty-four diameters
of bar of intermediate grade steel and thirty diameters of bar of hard grade
steel. For bars of higher yield point, the amount of lap shall be increased
in proportion to the normal working stress. When the concrete strengths
are less than 3000 lbs. per square inch the amount of lap shall be one-third
greater than the values given in this paragraph.
The lapped splices of plain bars shall be at least 25% greater than that
given above for deformed bars.
Welded splices or other positive connections may be used instead of lapped
splices, if approved.
(218)
Sees. 2671-2672
(d) Spiral reinforcement shall consist of evenly spaced continuous spirals
held firmly in place and true to line by at least three vertical spacer bars.
The outside diameter of spirals shall be maintained constant and the ends of
the spiral wire shall be anchored. Spiral wire may be spliced by lapping one
third the circumference of the spiral and hooking the ends, or by welding.
The spacing of the spirals shall not exceed one sixth the diameter of the
core nor three inches. The ratio of spiral reinforcement, p', shall not be
less than
\AC / f's
p' = 0.45
\AC
where p' is the ratio of volume of spiral reinforcement to the volume of the
concrete core (out to out of spirals).
Ag
— is ratio of gross area to core area of column.
Ac
' s is useful limit stress of spiral reinforcement to be taken as 40,000 lbs.
per square inch for hot rolled of intermediate grade, 50,000 lbs. per square
inch for hard grade and 60,000 lbs. for cold drawn wire.
(e) Spiral and longitudinal reinforcement shall be protected by a covering
of concrete cast monolithic with the core not less than one and one half
inches thick.
(f) In columns supporting a beam-and-slab floor or roof, the spiral rein-
forcement shall extend from the floor below at least to one and one half inches
above the bottom of the lowest beam of the floor or roof above, which frames
into the column.
(g) In columns supporting a flat slab floor or roof the spiral reinforcement
shall extend from the floor at least to mid-height of the concrete column
capital above.
[ tAs amended by Ord. 1948, ch. 8 ]
*Sect. 2672. Design of Tied Reinforced Concrete Columns. — (a)
The maximum allowable axial load, P, on columns reinforced with longitu-
dinal bars and separate lateral ties shall not exceed
P = 0.18 f'0Ag -f- 0.8A8fB
See section 2671 (b) for value of f„.
(b) The minimum ratio of longitudinal reinforcement shall not be less
than one per cent nor more than four per cent of the gross concrete area,
also at least four bars shall be used, of minimum diameter of five eighths
inch. Clear distance of the face of each bar to the face of the column shall
be one and one-half inches plus the thickness of the column tie. Corner
rods in columns shall not be nearer to either adjacent surface than two inches
plus the thickness of the column tie.
(c) Lateral ties shall be at least one quarter inch in diameter. They
shall be spaced not more than twelve inches apart. In columns of rec-
tangular section, containing more than four longitudinal bars cross ties shall
be arranged to afford support to all bars.
[ *As amended by Ord. 1943, ch. 8 ]
(219)
Sees. 2673-2675
*Sect. 2673. Long Columns. — (a) The axial load on columns which
are longer than ten times the least dimension shall not be greater than —
h
P' = P (1.3-0.03 - )
d'
(b) The maximum allowable load P' on eccentrically loaded columns in
h
which - exceeds 10 is given by the formula in paragraph (a) in which P is
d'
the allowable eccentrically applied load on the short column. In long columns
subjected to definite bending stresses, as determined by Sections 2674, 2675,
2676, the ratio shall not exceed 20.
[ *As amended by Ord. 1943, ch. 8 ]
fSection 2674. Bending in Concrete Columns. — (a) The bending
moments in the columns of all reinforced concrete structures shall be deter-
mined on the basis of loading conditions and restraint and shall be provided
for in the design. When the stiffness and strength of the columns are utilized
to reduce the moments in beams, girders and slabs, as in the case of rigid
frames, or in other forms of continuous construction wherein column moments
are unavoidable, they shall be provided for in the design. In building frames,
particular attention shall be given to the effect of unbalanced floor loads on
both exterior and interior columns and of eccentric loading due to other cases.
Wall columns shall be designed to resist moments produced by
1. Loads on all floors of the building.
2. Loads on a single exterior bay at two adjacent floor levels, or
3. Loads on a single exterior bay at one floor level.
(b) Resistance to bending moments at any floor level shall be provided by
distributing the moment between the columns immediately above and below
the given floor in proportion to their relative stiffness and condition of restraint.
At the roof the moments shall be provided for in the section of the column
below.
[ ]As amended by Ord. 1948, ch. 8 ]
JSect. 2675. Combined Axial and Bending Stresses. — (a) In rein-
forced concrete columns subjected to bending stresses, recognized methods of
analysis shall be followed in calculating the stresses due to combined axial
load and bending. The maximum fiber stress in compression and in the case
of large eccentricities of loading the tensile stresses in the vertical bars, as given
in this Part will govern the design.
(b) For designs where the eccentricity is less than 1/2 the overall
column width, and the value of pgn is 0.3 or more, the following formula shall
be used to calculate the combined fiber stress in compression.
f =^
Kl
Ag 1 + (n-1) pg
(220)
Sees. 2675-2676
where e is the eccentricity of resultant load, measured from the gravity axis,
c' is the distance from the gravity axis to the extreme fiber in com-
pression.
R is the radius of gyration of the equivalent concrete section,
n is as given in section 2629.
t' is the overall depth of the section.
The other symbols are as given in section 2602, paragraph (b).
ec' 6e
The term — may be replaced by the value — for rectangular columns and
R2 t'
8e
— for round columns,
t'
(c) For other limitations than mentioned in paragraph (b) more accurate
methods of design shall be used to insure that the allowable stresses are not
[ tAs amended by Ord. 1948. ch. 8 ]
*Sect. 2676. Allowable Combined Axial and Bending Stresses. —
(a) For spiral and tied columns, eccentrically loaded or otherwise subjected
to combined axial compression and flexural stress, the maximum allowable
compressive fiber stress shall not exceed f0 in
f. -f.
1 + -
^ R2
1 + ciT°
where fa is the average allowable stress on an equivalent axially loaded con-
crete column.
C is the ratio of f« to the allowable fiber stress for members in flexure;
This
0.225 f'0 + f8pg
fm = for spiral columns.
1 + (n-1) pg
[0.225 f'. + f.p«1
1 + (n-1) pg J
fa = 0.8 I I for tied columns.
f«
C =
0.45 f '«
(b) The allowable tensile stress in the longitudinal reinforcement shall
equal that specified for flexural members, provided however that splices
in the tensile steel at or near the section of maximum column moment are
capable of developing fully the yield point strength of the reinforcement.
(c) When columns are subjected to wind stresses in addition to combined
axial loads and bending, the column section need not be increased unless the
allowable stress given in paragraph (a) of this section is exceeded by more than
one- third.
[ *As amended by Ord. 1948, ch. 8 )
(221)
Sees. 2677-2679
*Sect. 2677. Combination Columns. — (a) The axial load on combi-
nation columns, in which structural steel columns of rolled or built-up section
wrapped with No. 10 gage wire spaced four inches on centers or its equivalent
are encased in concrete not less than two inches thick over all of the metal,
except rivet heads and connections, shall not exceed
P = Arf'r[l + 1
L 100Ar J
where Ac is the total area of the concrete = Ag-Ar
A, is the cross-sectional area of the steel column
f 'r is the allowable stress for unencased steel column, as allowed in
Part 28.
(b) The concrete shall be at least equal in quality to two thousand pound
concrete as specified in section twenty-six hundred and ten.
(c) Stress allowed in paragraph (a) shall be allowed in compression
members of trusses, if the requirements of this section are fulfilled.
[ *As amended by Ord. 1943, ch. 8 ]
fSect. 2678. Concrete Walls. — (a) Reinforced concrete walls shall
have at least the thickness specified in Part 14. Reinforced concrete walls
shall be reinforced in two directions at right angles by steel reinforcement
having an effective area in each direction of not less than (0.0025) times the
cross-sectional area of the concrete. In walls less than six inches thick the
reinforcement may be placed at mid-thickness of the wall unless calculated
bending requires it to be placed near one face. In walls six inches or more in
thickness, not less than half the steel required by this paragraph shall be
placed as close to each face of the wall as requirements for fire and rust pro-
tection will allow. Such steel reinforcement shall be in the form of reinforcing
bars not less than three-eighths inch in diameter and spaced not over eighteen
inches apart or of approved wire mesh.
(b) Protective covering for reinforcing shall be as required in section
2627 and Part 22, except as provided in paragraph (a).
(c) Provide construction joints and expansion joints for walls, copings
and balustrades, together with drainage and weep holes as required by the
commissioner.
(d) The capacity of a reinforced concrete wall to support a vertical load
shall be computed in the same manner as specified in sections twenty-six
hundred and seventy-two, twenty-six hundred and seventy-three, and twenty-
six hundred and seventy-four for columns with lateral ties. The vertical
reinforcement shall not be assumed to contribute to the capacity of the wall
unless it conforms to the requirements for longitudinal reinforcement in
columns and is stayed by lateral ties perpendicular to the wall.
[ fAs amended by Ord. 1943, ch. 8 ]
JSect. 2679. Sloped or Stepped Concrete Footings. — (a) Footings
shall be designed to sustain the applied loads without exceeding the allowable
working stresses in this part. Allowable bond stress shall be reduced 25%
from the stresses allowed in section 2629 in all tension regions requiring
moment reinforcement in more than one direction.
(b) Footings may have sloped or stepped tops provided the thickness of
the footing above the reinforcement shall not be less than six inches for footings
(222)
Sees. 2679-2680
on soil, nor less than nine inches for footings on piles, also plain concrete
footings may have sloped or stepped tops provided the thickness is not less
than twelve inches.
(c) Concrete in reinforced footings shall be proportioned for a strength
of at least eighteen hundred pounds per square inch.
[ tAs amended by Ord. 1943, ch. 8 ]
*Sect. 2680. Bending in Concrete Footings. (Critical Sections.) —
(a) The critical section for bending in a concrete footing which supports a
concrete column or pedestal, shall be considered to be at the face of the column
or pedestal. Where a steel or cast iron column base rests on a concrete
footing, moments in the footing shall be considered at the middle and at the
edge of the base and the larger one shall be used in the design. Loads shall
be considered as uniformly distributed over the column. In the case of
columns other than square or rectangular the critical section shall be taken
at the side of a concentric square of equal area. For concrete footings under
masonry walls, moments in the footing shall be taken midway between the
middle and the edge of the wall.
(b) The bending moment at a critical section shall be computed from all
the forces acting on the footing on one side of the section (excluding the weight
of the footing). Critical sections for bond and shear shall be taken for the
same loading and same plane as for bending. Bonds shall also be investigated
at planes where changes in concrete section or reinforcement occur. The
critical section for diagonal tension in footings on soil shall be considered as the
concentric vertical section through the footing at a distance d from each face
of the column pedestal or wall. This depth d should be measured from the
top of the section to the plane of the centroid of longitudinal reinforcement.
The critical section for diagonal tension for footing supported on piles should
be considered as the concentric vertical section through the footing at a
d
distance — from each face of the column, pedestal or wall, and any piles
2
whose centers are at, or outside this section should be included in computing
the shear.
(c) Shear in footings shall be computed as specified in section 2642.
(d) For reinforced concrete columns, the critical section for transverse
bending should be taken at the faces of the columns or pedestals. For footings
under metallic column bases, the critical section should be assumed midway
between the face of the column and the edge of the metallic base. The trans-
verse reinforcement should be divided into groups proportionate in sectional
area to the column loads. The transverse reinforcement at each column
should be placed uniformly within a band having a width not greater than the
width of the column plus twice the effective depth of the footing. Longi-
tudinal reinforcement should be distributed over the whole width.
The critical sections for diagonal tension in combined footings should be
taken at the faces of the supported members for all beam elements and also
for all projecting cantilevers.
[ *As amended by Ord. 1943, ch. 8 ]
(223)
Sees. 2681-2683
♦Sect. 2681. Plain Concrete Footings. — (a) The critical section of
plain concrete footings shall be computed and cast as a monolithic section of the
entire width and depth measured from a plane two inches above the bottom
of the footing. The maximum tensile fiber stress in the concrete shall not
exceed 0.025 of the ultimate compression strength of the concrete. The
average shearing stress shall not exceed 0.02 of the ultimate compressive
strength of the concrete, computed on a concentric vertical section through the
footing at a distance (d'-2) inches from each face of the column, pedestal or
wall, excluding two inches of depth nearest the bottom.
(b) The area of the top of the footing shall not be less than the amount
given by formula section 2682.
[ *As amended by Ord. 1943, ch. 8 ]
fSect. 2682. Bearing on Concrete Footing. — (a) The compressive
stress in the longitudinal reinforcement at the base of a reinforced concrete
column shall be transferred to a pedestal or to a footing by extending the bars
into the pedestal or footing or by use of dowels. There shall be at least one
dowel for each column bar, and the total sectional area of the dowels shall be
not less than the sectional area of the longitudinal reinforcement in the column.
The dowels or column bars shall extend into the column and into the pedestal
or footing the distance required to transfer to the concrete, by allowable bond
stress, their full working strength. Hooks shall not be considered as adding
to bond resistance in compression. The unit compressive stress on the top
of the pedestal or footing directly under the column or base shall not be
greater than that determined by the formula
Kl
fc r
16
nor greater than (0.375 f0) unless the pier pedestal or footing is reinforced
laterally as provided in paragraph (b).
(b) When lateral reinforcement in the form of a spiral or hoops is provided
in the pedestal or footing the unit stress in bearing for the core area may be
increased to (1 + 2.5 np') times that allowed for plain concrete, but no area
outside the outer face of the spiral or hoops shall be considered.
[ fAs amended by Ord. 1943, ch. 8 ]
JSect. 2683. Pedestals — Plain Concrete. — (a) The compressive
unit stress on the gross area of a concentrically loaded pedestal or the upper
surface of a pedestal footing shall not exceed 0.25 f'0.
(b) The depth and width of a pedestal or pedestal footing shall be deter-
mined by consideration of shear and bending stresses as given in section
2681. However, in no case shall the depth be greater than three times its
least width.
(c) A pedestal or pedestal footing supported directly on piles shall have a
mat of reinforcing, of cross-sectional area not less than 0.20 square inch per
foot of width in each direction, placed three inches above the top of the piles.
[ %As amended by Ord. 1943, ch. 8 ]
(224)
Sec. 2701
PART 27.*
PRECAST GYPSUM CONCRETE.
Section
2701 — Precast Gypsum Concrete.
Section 2701. Precast Gypsum Concrete. — (a) 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. The span of precast gypsum con-
crete shall not exceed four feet in floors and six feet in roofs except in so-called
suspension construction in which the span for floors shall not exceed six
feet and in roofs shall not exceed eight feet. For the purpose of this section
any span over three feet shall be called long span.
(b) Except as otherwise provided in paragraph (c) of this section, precast
gypsum concrete units shall have not less than the following thicknesses: —
(1) Solid units in roofs shall be not less than two inches thick, nor if
long span, less than three inches thick.
(2) Solid units in floors shall be not less than two and one half inches
thick, nor, if long span, less than four inches thick.
(3) Hollow units in roofs shall be not less than three inches nor the shell
in compression less than three fourths inch thick; if long span, the units
shall be not less than five inches thick nor the shell in compression less
than one and three eighths inches thick.
(4) Recessed units in roofs shall be not less than five inches thick nor
the panel less than one and three eighths inches thick.
(c) Precast solid reinforced gypsum concrete units not more than fifteen
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 inches
thick. If the length of units is not less than one and one half 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 stag-
gered at random provided they are not less than two feet apart and the con-
struction may be designed as continuous.
(d) 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.
(e) Precast gypsum concrete units shall be designed in accordance with
conditions outlined in paragraph (g) below.
(f) 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 commissioner has given his approval. Approval
shall be conditioned upon such requirements as to design, materials, methods
of manufacture, erection and support as the commissioner shall determine.
(225)
Sec. 2701
(g) The basis of design and materials shall be consistent with the following
requirements to qualify for approval:
(1) Precast gypsum concrete shall contain not more than three per cent
wood chips, shavings or fibre by weight of dry materials before mixing.
(2) Precast gypsum concrete shall have a minimum strength of one
thousand pounds per square inch.
(3) In designing the precast gypsum concrete the modulus of elasticity
shall be considered as six hundred thousand pounds per square inch.
(4) In design of structural members of reinforced gypsum concrete
the unit stress in the concrete shall not exceed the following allowable
values :
Maximum unit compression in bending 0 . 25 f g
Axial compression or bearing 0 . 20 f g
Bond on plain bars or wires 0.02 fg
Bond on deformed bars or wire mesh . . . . . . 0 . 04 f g
Shear (straight rods or wires) 0.02 fg
Shear (reinforcement anchored) 0.03 fg
In this table (fg) indicates the ultimate compressive strength of the gypsum
concrete as approved by paragraph (f ) of this section.
Unit stress in steel reinforcement shall not exceed the values allowed in
Part 26.
(5) Fire protection coverage for steel reinforcement in gypsum shall be
limited to a minimum of one-half inch in thickness.
(6) In no case shall gypsum concrete be used for a wearing surface in
gypsum construction.
(7) 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.
[ *As amended by Ord. 1948, ch. 8 ]
(226)
PART 28
STEEL AND IRON
ACKNOWLEDGEMENTS
The revision of Part 28 of the Building Code was accomplished
by the Technical Committee, the membership of which is given
below. Much time and effort were expended by the Technical
Committee in specifying modern practice for steel and iron
construction. When the 1963 specifications of the American
Institute of Steel Construction became available, the Committee
decided to adapt those specifications, and in the same format,
to the requirements of the Boston Building Code, making changes
appropriate to Boston in the Institute text. Adaptations from
the 1962 publication of the American Iron and Steel Institute
covering Light Gage Cold-Formed Steel Structural Members
have also been included. Valuable suggestions and criticisms
were received from representatives of trades and professions
concerned with the building industry. The work was reviewed
and recommended for approval by an Advisory Committee
appointed by Mayor John F. Collins.
TECHNICAL STEEL AND IRON COMMITTEE
Prof. Albert G. H. Dietz, Chairman
Massachusetts Institute of Technology
Prof. J. Melvin Biggs
Massachusetts Institute of Technology
Mr. Harold S. Gillis, Jr.
American Institute of Steel Construction
Mr. Oliver G. Julian
Jackson & Moreland, Inc.
Mr. William J. LeMessurier
LeMessurier Associates, Inc.
Mr. Waldo F. Pike
Cleverdon, Varney & Pike
Mr. Julius Wolozin
Groisser & Shlager Iron Works
Mr. David Mathoff
Boston Building Department
ADVISORY COMMITTEE
Mr. Richard C. Tousley, Chairman
Shepley, Bulfinch, Richardson & Abbott,
vice
Mr. C. Clark Macomber, resigned
George B. H. Macomber Company
Mr. John C. Cronin, C. H. Cronin, Inc.
Mr. Edward C. Keane, Fay, Spofford & Thorndike, Inc.
Mr. Neil MacKenzie, Representative of Labor
Mr. Frank A. Marston, Metcalf & Eddy, Engineers
Mr. Lawrence Moore, Assistant Corporation Counsel, Boston
Mr. Frederick W. Westman, Whelan & Westman, Architects
Col. Robert E. York, Building Commissioner, Boston
(227)
PART 28
STEEL AND IRON
Okdinances of 1963, Chapter 8
Chapter 479 of the Acts of 1938 was amended, by striking out
Part 28 as amended by chapter 8 of the Ordinances of 1943, and
chapter 2 of the Ordinances of 1955, and inserting in place thereof
a new Part 28.
Passed by the City Council, October 7, 1963.
Approved by the Mayor, October 9, 1963.
Ordinances of 1964, Chapter 6
Section 28 — 1.6A of Part 28 of Chapter 479 of the Acts of
1938, as appearing in Chapter 8 of the Ordinances of 1963, is
hereby amended by striking out Subdivision 1.6.1 A and inserting
in place thereof a new subdivision; and Subsection 1.29.2.2 of
Section 28 — 1.29 of Part 28, as so appearing, is amended by
striking out Formula (27) and inserting in place thereof a new
Formula (27).
Passed by the City Council, August 3, 1964.
Approved by the Mayor, August 5, 1964.
October 1, 1964
(228)
PART 28
STEEL AND IRON
Note.— Sections 28-1.1A through Section 28-1.26.5 and Sections 28-2.0
through Section 28-2.9 of this Part are based on the Specification for
the Design, Fabrication and Erection of Structural Steel for Buildings
as adopted April 17, 1963 by the American Institute of Steel Construc-
tion. Sections 28-1.28 through 28-1.28.3.3 are based on the Specifica-
tion for the Design of Light Gage Cold-Formed Steel Structural Mem-
bers, 1962 Edition, of American Iron and Steel Institute. Where the
letter "A" appears as a part of the section numbering a change from
the original text of the reference specification applicable to Boston has
been made.
Section
28-1.0 — Design of Steel and Iron.
28-jl.lA — Plans and Drawings.
2&-1.2A — Classes of Construction.
28- 1 .3A — Loads and Forces.
28-1.4A —Materials.
28-1. 5A — Allowable Unit Stresses — Elastic Design.
28-1. 6A — Combined Stresses.
28-1.7 — Members and Connections Subject to Repeated Vari-
ation of Stress.
28-1.8A — Slenderness Ratios.
28-1.9 —Width Thickness Ratios.
28-1.10 —Plate Girders and Rolled Beams.
28-1.11 — Composite Construction.
28-1.12A — Simple and Continuous Spans.
28-1.13 —Deflections.
28-1.14 — Gross and Net Sections.
28-1. IS — Connections.
38-1. 16A— Rivets and Bolts.
218-1.17 —Welds.
38-1.18 —Built Up Members.
28-1.19 —Camber.
23-1.20 — Expansion.
28-1.21 — Column Bases.
28-1.22 —Anchor Bolts.
28-1.33 —Fabrication.
28-1. 24A — Protection and Painting.
28-1.25 — Erection.
28- 1.26 A — Inspection.
28- 1.27 A— Open Web Steel Joists.
(229)
Section
38-1. 28A— Light Gage Steel Construction.
28-1. 29 A— Concrete-Filled Pipe Columns.
28-1.30A — Cast Iron Columns.
28-^.0 —Plastic Design.
28-2.1 A —Scope.
28-2.2A —Structural Steel.
28-2.3 — Columns.
28-2.4 —Shear.
28-2.5 —Web Crippling.
28-2.6 — Minimum Thickness (Width Thickness Ratios),
28-2.7 — Connections.
38-2.8A —Lateral Bracing.
28-2.9 —Fabrication.
(230)
NOMENCLATURE
Ah Nominal body area of a bolt
Ae Actual area of effective concrete flange in composite design
Aic Planar area of web at beam-to-column connection
Af Area of compression flange
A a Area of steel beam in composite design
Att Cross-sectional area of stiff ener or pair of stiff eners
Aw Area of girder web
B Coefficient used in column formula for plastic design
Cb Bending coefficient dependent upon moment gradient; equal to
/MA /MA2
Ce Column slenderness ratio dividing elastic and inelastic buckling; equal to
Cm Coefficient applied to bending term in interaction formula and dependent
upon column curvature caused by applied moments
C* Ratio of "critical' ' web stress, according to the linear buckling theory,
to the shear yield point of web material; equal to
**EkVz
12(1 -v*)(h/t)*Ft
D Factor depending upon type of transverse stiffeners
E Modulus of elasticity of steel (29,000,000 pounds per square inch)
Ee Modulus of elasticity of concrete
Fa Axial compressive stress permitted in the absence of bending moment
Fa» Axial compressive stress, permitted in the absence of bending moment
for bracing and other secondary members
Fi Bending stress permitted in the absence of axial force
F'b Allowable bending stress in compression flange of plate girders as reduced
because of large web depth-to-thickness ratio
F\ Euler stress divided by factor of safety; equal to
149,000,000
m
Fp Allowable bearing stress
Ft Allowable tensile stress
F9 Allowable shear stress
Fy Specified minimum yield point of the type of steel being used (pounds per
square inch unless otherwise noted)
O Coefficient used in column formula in plastic design
H Coefficient used in column formula in plastic design
Itr Moment of inertia of transformed composite section
(231)
/ Coefficient used in column formula in plastic design
K Effective length factor
L Span length, in feet
Lu Maximum unbraced length of compression flange, in feet, for which full
bending stress is permitted by Formula (5B)
M Moment
Mi Smaller end moment on unbraced length of beam-column
M% Larger end moment on unbraced length of beam-column
Mb Moment produced by dead load
Mi, Moment produced by live load
M o Reduced plastic moment
Mp Plastic moment
N Length of bearing of applied load
P Applied load
Py Plastic axial load: equal to profile area times specified minimum yield
point
R Reaction or concentrated transverse load applied to beam or girder
S8 Section modulus of steel beam used in composite design, referred to the
tension flange
Str Section modulus of transformed composite cross-section, referred to the
tension flange
Tb Proof load of a high strength bolt
V Shear on beam
Vh Total horizontal shear to be resisted by connectors
Vu Shear produced by "ultimate" load in plastic design
Y Ratio of yield point of web steel to yield point of stiffener steel
a Clear distance between transverse stiffeners
a' Distance required at ends of welded partial length cover plate to develop
stress
6 Effective width of concrete slab
bf Flange width of rolled beam or plate girder
c Distance from neutral axis to top of concrete slab
d Depth of beam or girder. Also diameter of roller or rocker bearing
e Horizontal displacement, in the direction of the span between top and
bottom of simply supported beam at its ends
fa Computed axial stress
fb Computed bending stress
/ e Specified compression strength of concrete at 28 days
ft Computed tensile stress
/„ Computed shear stress, in pounds per square inch
fv9 Shear between girder web and transverse stiffeners, in pounds per linear
inch of single stiffener or pair of stiffeners
g Transverse spacing between fastener gage lines
h Clear distance between flanges of a beam or girder
k Coefficient relating linear buckling strength of a plate to its dimensions
and condition of edge support. Also distance from outer face of flange
to web toe of fillet
/ Actual unbraced length in inches
(232)
Sees. 2S-1.0.-1.1.2A
h Actual unbraced length in plane of bending, in inches
ler Critical unbraced length adjacent to plastic hinge, in inches
n Modular ratio; equal to E/Ee
q Allowable horizontal shear to be resisted by a connector
r Governing radius of gyration
rb Radius of gyration about axis of concurrent bending
ry Lesser radius of gyration
8 Spacing (pitch) between successive holes in line of stress
t Girder or beam web thickness
t/ Flange thickness
U Thickness of thinner part jointed by partial penetration groove weld
w Web thickness of plastically designed rolled beams. Also length of
channel shear connectors
v Poisson's ratio
> Is equal to or greater than
< Is equal to or less than
> Is greater than
< Is less than
Section 28-1.0. Design of Steel and Iron. — Structures of steel and iron
shall be designed by methods admitting of rational analysis according to
established principles of mechanics, supplemented by the assumptions herein
specified, to support the loads and withstand the forces to which they are
subject without exceeding the stresses allowed in this part for the various
members and the materials thereof.
Sect. 28- 1.1 A. Plans and Drawings.
1.1.1 A. Plans. — The plans (design drawings) shall show a complete de-
sign with sizes, sections, and the relative locations of the various members.
Floor levels, column centers, and offsets shall be dimensioned. Plans shall be
drawn to a scale large enough to convey the information adequately.
Plans shall indicate the class or classes of construction (as defined in Sect.
28-1. 2A) to be employed, and they shall be supplemented by such data con-
cerning the assumed loads, shears, moments and axial forces to be resisted by
all members and their connections, as may be required for the proper prepa-
ration of the shop drawings.
Where joints are to be assembled with high strength bolts and are required
to resist shear between the connected parts, the plans shall indicate the type
of connections to be provided, namely, friction or bearing.
Camber of trusses, beams and girders, if required, shall be called for on the
design drawings.
1.1. 2A. Shop Drawings. — Shop drawings, giving complete information
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.
(233)
Sees. 1. 1.2 A.- 1.2 A
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.
1.1.3. Notations for Welding. — Note shall be made on the plans and on
the shop drawings of those joints or groups of joints in which it is especially
important that the welding sequence and technique of welding be carefully
controlled to minimize locked-up stresses and distortion.
Weld lengths called for on the plans and on the shop drawings shall be the
net effective lengths.
1.1.4A. Standard Symbols and Nomenclature. — 'Welding symbols used
on plans and shop drawings shall preferably be the American Welding Society
symbols. Other adequate welding symbols may be used, provided a complete
explanation thereof is shown on the plans or drawings.
Sect. 28- 1.2 A. Classes of Construction. — Three basic classes of con-
struction and associated design assumptions are permissible under the re-
spective conditions stated hereinafter, and each will govern in a specific
manner the size of members and the types and strength of their connections.
Class A, commonly designated as "rigid-frame" (continuous frame), assumes
that beam-to-column connections have sufficient rigidity to hold virtually
unchanged the original angles between intersecting members.
Class B, commonly designated as "conventional" or "simple" framing
(unrestrained, free-ended), assumes that the ends of beams and girders are
connected for shear only, and are free to rotate under load.
Class C, commonly designated as "semi-rigid framing" (partially restrained),
assumes that the connections of beams and girders possess a dependable and
known moment capacity intermediate in degree between the complete rigidity
of Class A and the complete flexibility of Class B.
The design of all connections shall be consistent with the assumptions as to
class of construction called for on the design drawings.
Class A construction is unconditionally permitted under this Code. Two
different methods of design are recognized. Within the limitations laid down
in Sect. 28-2.1 A, members of continuous frames, or continuous portions of
frames, may be proportioned, on the basis of their maximum predictable
strength, to resist the specified design loads multiplied by the prescribed load
factors. Otherwise Class A construction shall be designed, within the limi-
tations of Sect. 28-1. 5 A, to resist the stresses produced by the specified design
loads, assuming moment distribution in accordance with the elastic theory.
Class B construction is permitted under this Code, subject to the stipu-
lations of the following paragraph wherever applicable. Beam-to-column
connections with seats for the reactions and with top clip angles for lateral
support only are classed under Class B.
In tier buildings, designed in general as Class B construction (that is, with
beam-to-column connections other than wind connections flexible) the distri-
bution of the wind moments between the several joints of the frame may be
made by a recognized empirical method provided that the wind connections.
(234)
Sees. 1.2A-1.4.2A
designed to resist the assumed moments, are adequate to resist the moments
induced by the gravity loading and the wind loading at the increased unit
stresses permitted therefor.
Class C (semi-rigid) construction will be permitted only upon evidence that
the connections to be used are capable of furnishing, as a minimum, a pre-
dictable proportion of full end restraint. The proportioning of main members
joined by such connections shall be predicated upon no greater degree of end
restraint than this minimum.
Classes B and C construction may necessitate some non-elastic but self-
limiting deformation of a structural steel part.
Sect. 28-1. 3A. Loads and Forces. — See Part No. 23, "Live and Dead
Loads."
Sect. 28-1.4A. Materials.
1.4.1 A. Structural Steel.
1 .4. 1 . 1 . — Structural steel shall conform to one of the following specifications:
Steel for Bridges and Buildings, ASTM A7-61T
Structural Steel for Welding, ASTM A373-58T
Structural Steel, ASTM A36-62T
High-Strength Structural Steel, ASTM A440-63T
High-Strength Low- Alloy Structural Manganese Vanadium Steel, ASTM
A441-63T
High-Strength Low-Alloy Structural Steel, ASTM A242-63T
1.4. 1.2 A. — Certified mill test reports or certified reports of tests, made by
the fabricator or a testing laboratory in accordance with ASTM A6-62T and
the governing specification, shall constitute evidence of conformity with one of
the above ASTM Specifications. Additionally, the fabricator shall, if request-
ed, provide an affidavit stating that the structural steel furnished meets
the requirements of the grade specified.
1.4.1.3. — Unidentified steel, if free from surface imperfections, may be used
for parts of minor importance, or for unimportant details, where the precise
physical properties of the steel and its weldability would not affect the strength
of the structure.
1 .4. 1.4. — Steels of higher strength than are covered by the above mentioned
ASTM Specifications may be used provided the design is based upon the
minimum properties of such higher strength steel as certified by the manu-
facturer's test reports and approved by the Building Commissioner.
1.4.2A. Other Metals. — Cast steel shall conform to one of the following
specifications:
Mild-to-Medium-Strength Carbon-Steel Castings for General Application,
ASTM A27-62, Grade 65-35
High-Strength Steel Castings for Structural Purposes, ASTM A 148-60,
Grade 80-50
Certified test reports shall constitute sufficient evidence of conformity with
the specifications.
(235)
Sees. 1.4.2.A-1.4.3A
Steel forgings shall conform to one of the following specifications:
Carbon Steel Forgings for General Industrial Use, ASTM A235-62T, Class
CI, F and G. (Class CI Forgings that are to be welded shall be ordered
in accordance with Supplemental Requirements S5 of A235.)
Alloy Steel Forgings for General Industrial Use, ASTM A237-62T, Class A
Certified test reports shall constitute sufficient evidence of conformity with
the specifications.
Steel for light gage structural members cold-formed to shape shall conform
to the following specifications:
(a) Flat-Rolled Carbon-Steel Sheets of Structural Quality, ASTM
A245-62aT
(b) Hot-Rolled Carbon-Steel Strip of Structural Quality, ASTM A303-62T
(c) High Strength Low Alloy Cold- Rolled Steel Sheets and Strip, ASTM
A374-62T
(d) High Strength Low Alloy Hot-Rolled Steel Sheets and Strip, ASTM
A375-62T
(e) Zinc-Coated (Galvanized) Steel Sheets of Structural Quality, Coils and
Cut Lengths, ASTM A446-60T
(f) Steel of higher strength than is covered by the above mentioned
ASTM Specifications may be used provided the design is based upon the
minimum properties of such higher strength steel as certified by the manu-
facturer's test reports.
Cast iron to Standard Specifications for Gray Iron Castings, ASTM A48-56,
Class 25.
Pipe for concrete-filled pipe columns to Tentative Specifications for Welded
and Seamless Steel Pipe, ASTM A-53-62T, Grade B.
Structural steel members installed in buildings built in the year 1924 or
earlier shall not be stressed in excess of 16000 psi. Similar members installed
after 1924 and prior to the year 1943, and after 1942 and prior to the adoption of
this Code shall not be stressed in excess of 18000 psi and 20000 psi respectively.
Structural steel which has previously been used in a building or other
structure or which has been fabricated for such use, shall not be used in another
building or structure except with the approval of the Commissioner and under
such conditions as he may in each case specify.
The Commissioner 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 part.
1.4.3 A. Rivet Steel. — Rivet steel shall conform to one of the following
specifications:
Structural Rivet Steel, ASTM A141-58
High-Strength Structural Rivet Steel, ASTM A195-59
High-Strength Structural Alloy Rivet Steel, ASTM A406-59
Certified mill test reports shall constitute sufficient evidence of conformity
with the specifications in accordance with Sect. 1.4. 1.2 A.
(236)
Sees. 1.4.4A-1.5.1.3.1
1.4.4A. Bolts. — High strength steel bolts shall conform to one of the
following specifications:
High-Strength Steel Bolts for Structural Joints, ASTM A325-61T
Quenched and Tempered Alloy Steel Bolts and Studs with Suitable Nuts,
ASTM A354-58T, Grade BC
Other bolts shall conform to the Specification for Low-Carbon Steel Externally
and Internally Threaded Standard Fasteners, ASTM A307-61T, hereinafter
designated as A307 bolts.
Manufacturer's certification shall constitute sufficient evidence of conformity
with the specifications.
1 .4.5 A. Filler Metal for Welding. — Welding electrodes for manual shielded
metal-arc welding shall conform to the E60 or E70 series of the Specification
for Mild Steel Arc-Welding Electrodes, ASTM A233-58T.
Bare electrodes and granular flux used in the submerged-arc process shall
conform to the provisions of Sect. 28-1.17.3.
Manufacturer's certification shall constitute sufficient evidence of conformity
with the specifications.
Sect. 28- 1.5 A. Allowable Unit Stresses. — All components of the structure
shall be so proportioned that the unit stress, in pounds per square inch, shall
not exceed the allowable stress specified in the appropriate section of Part 28
for the particular component.
1.5.1. Structural Steel.
1.5.1.1. Tension. — On the net section, except at pin holes
Ft = 0.60JV
On the net section at pin holes in eyebars, pin-connected plates or built-up
members
Ft = 0A5FV
1.5.1.2. Shear. — On the gross section
Fv = 0A0Fy
For shear calculation, the gross section of beams and plate girders may be
taken as the product of the overall depth and the thickness of the web. (See
Sect. 28-1.10 for reduction required for thin webs.)
1.5. 1.3 A. Compression.
1.5.1.3.1. — On the gross section of axially loaded compression members
Kl
when — , the largest effective slenderness ratio of any unbraced segment as
r
defined in Sect. 28-1. 8 A, is less than Ce
F.
(237)
Fa = —* Formula (1)
r .b.
Sees. 1.5.1.3.1-1.5.1.4.1
where
„« e . , , . 5 3(gg/r) (JQ/r)»
F.S. = factor of safety = - H - — L-jl-
J 3 T 8CC 8CC3
and
1.5.1.3.2. — On the gross section of axially loaded columns when i/r ex-
ceeds Cc
149,000,000
Fa = (Kl/ry F°rmula (2)
1.5. 1.3.3 A. — On the gross section of axially loaded bracing and secondary
members, when l/r exceeds 120 and the end conditions are such as to provide
restraint with respect to rotation,
Fa (by Formula 1 or 2)
Fa» = — : Formula (3)
1.6 - —
200r
in which I is the full unbraced length of the member.
1.5.1.3.4. — On the gross area of plate girder stiffeners
Fa = 0.60Fj,
1.5.1.3.5. — On the web of rolled shapes at the toe of the fillet (crippling,
see Sect. 28-1.10.10)
Fa = 0.75FV
1.5.1.4. Bending.
1.5.1.4.1. — Tension and compression on extreme fibers of laterally sup-
ported compact rolled shapes and compact built-up members having an axis
of symmetry in the plane of loading
Fb = 0.66^
(In order to qualify as a compact section the width-thickness ratio of
projecting elements of the compression flange shall not exceed 1,600/V/^,
except that, for rolled shapes, an upward variation of 3 percent may be
tolerated. The width-thickness ratio of flange plates in box sections and
flange cover plates included between longitudinal lines of rivets, high
strength bolts or welds shall not exceed 6,000/"\/ Fy. The depth-thickness
ratio of the web, d/t, shall not exceed 13,300/v Fy. When subjected
to combined axial force and bending moment d/t shall not exceed
13,300(1 -lA3fa/Fa)/VFy except that it need not be less than 8,000\//?V
Flanges of compact built-up sections shall be continuously connected to the
web or webs. Such members are deemed to be supported laterally when
the distance, in inches, between points of support of the^compression flange
does not exceed 2,4006// VFy nor 20,000,000^//^.)
(238)
Sees. 1.5.1.4.1.-1.5. 1.4.5A
Beams and girders which meet the requirements of the preceding paragraph
and are continuous over supports or are rigidly framed to columns by means
of rivets, high strength bolts or welds, may be proportioned for %o of the
negative moments produced by gravity loading which are maximum at points
of support, provided that, for such members, the maximum positive moment
shall be increased by Ho of the average negative moments. This reduction
shall not apply to moments produced by loading on cantilevers. If the nega-
tive moment is resisted by a column rigidly framed to the beam or girder, the
Ho reduction may be used in proportioning the column for the combined axial
and bending loading, provided that the unit stress, fa due to any concurrent
axial load on the member, does not exceed 0.1 5Fa.
1.5. 1.4.2 A. — Tension and compression on extreme fibers of members, except
channels, unsymmetrical about the plane of loading supported as in Sect. 28-
1.5.1.4.1 in the region of compression stress
Fb = O.QOFy
1.5.1.4.3. — Tension and compression on extreme fibers of box-type members
whose proportions do not meet the provisions of a compact section but do
conform to the provisions of Sect. 28-1.9
Fb = 0.60F„
1.5.1.4.4. — Tension on extreme fibers of other rolled shapes, built-up
members and plate girders
Fb = 0.60Fj,
1.5. 1.4.5 A. — Compression on extreme fibers of rolled shapes, plate girders
and built-up members having an axis of symmetry in the plane of their web
(other than box-type beams and girders), the larger value computed by
Formulas (4) and either (5A) or (5B) as applicable, but not more than 0.60F„
Fb = [l.O - |0^] 0.60/V Formula (4)
Id 40,000,000
In case — < = use
Af~ Fy
F-(a67-i5^r>^ (5A)
Id 40,000,000
In case — - > - use
Af Fy
12,000,000
ft = -^— (5B)
where I is the unbraced length of the compression flange; r is the radius of
gyration of a tee section comprising the compression flange plus one-sixth of
♦Where l/r is less than 40, stress reduction according to Formula (4) may be neglected.
(239)
Sees. 1.5.1.4.5A-1.5.2.1A
the web area, about an axis in the plane of the web; A/ is the area of the
compression flange; Cc is defined in Sect. 28-1.5.1.3 and C&, which can con-
servatively be taken as unity, is equal to
/Mi\ /MA2
Cb = 1.75 - 1.05 ( — J + 0.3 ( — J , but not more than 2.3
where Mi is the smaller and M2 the larger bending moment at the ends of
the unbraced length, taken about the strong axis of the member, and where
Mi/ M2, the ratio of end moments, is positive when M i and M2 have the same
sign (single curvature bending) and negative when they are of opposite signs,
(reverse curvature bending). When the bending moment at any point within
an unbraced length is larger than that at either end of this length the ratio
Mi/ Mi shall be taken as unity. See Sect. 28-1.10 for further limitation in
plate girder flange stress.
1.5. 1.4.6 A. — Compression on extreme fibers of channels, loaded in the plane
parallel to the web which passes through the shear center, the value computed
by Formulas (5), or (5B), but not more than
Fb = 0.60^
1.5.1.4.7. — Tension and compression on extreme fibers of pins
Fb = 0.90F„
1.5.1.4.8. — Tension and compression on extreme fibers of rectangular
bearing plates
Fb = 0.75Fy
1.5.1.5. Bearing (on contact area).
1.5.1.5.1." — Milled surfaces, including bearing stiffeners, and pins in reamed,
drilled orabored holes, pounds per square inch
Fp = 0.90Fy*
1.5.1.5.2. — Expansion rollers and rockers, pounds per linear inch
/Fy* - 13,000\ „„OJ
p \ 20,000 /
where d is"the diameter of roller or rocker in inches.
1.5.2A. Rivets and Bolts.
1.5.2.1 A. — Allowable unit tension and shear stresses on rivets, bolts and
threaded parts (pounds per square inch of area of rivets before driving or
unthreaded body area of bolts and threaded parts) shall be as given in Table
28-1.5.2.1A
* When parts in contact have different yield points, Fv shall be the smaller value.
(240)
Sees. 1.5.2.1A-1.5.3.I
Table 28-1.5.2.1A
Tension
(Ft)
Shear (Fv)
Description of Fastener
Friction-
Type
Connections
Bearing-
Type
Connections
A141 hot-driven rivets
20,000
27,000
14,000
OAOFy
30,000
30,000
37,500
37,500
15,000
15,000
20,000
20,000
15,000
A195 and A406 hot-driven rivets . . .
A307 bolts and threaded parts of A7
and A373 steel
20,000
10,000
Threaded parts of other steels
A325 bolts when threading is not
excluded from shear planes
A325 bolts when threading is ex-
A354, Grade BC, bolts when thread-
ing is not excluded from shear
0.30Fy
15,000
22,000
20,000
A354, Grade BC, when threading is
excluded from shear planes
24,000
1.5.2.2. — Allowable bearing stress on projected area of bolts in bearing type
connections and on rivets
Fp = 1.35Fy
where Fy is the yield point of the connected part. (See footnote to Sect.
1.5.1.5.)
(Bearing stress not restricted in friction-type connections assembled with
A325 and A354, Grade BC, bolts.)
1.5.3. Welds (stress in pounds per square inch of throat area).
1.5.3.1. Fillet, Plug, Slot and Partial Penetration Groove Welds.
Stress in fillet, plug, and slot welds, tension stress transverse to the axis
of partial penetration groove welds and shear in such welds, when made with
A233 Class E60 series electrodes or by submerged arc welding Grade SAW-1
on all steels, or with A233 Class E70 series electrodes or by submerged arc
welding Grade SAW-2 on A7 and A373 steels 13,600
Stress in fillet, plug, and slot welds, tension stress transverse to the axis
of partial penetration groove welds and shear in such welds, when made
with A233 Class E70 series electrodes or by submerged arc welding Grade
SAW-2 on A36, A242 and A441 steels 15,800
(241)
Sees. 1.5.3.2.-1.6.1 A
1.5.3.2. Groove Welds.
The full stresses allowed by Sect. 1.5 A for the connected material shall
apply to complete penetration groove welds stressed in tension, compression,
bending, shear and bearing and to partial penetration groove welds stressed
in compression, in bearing or in tension parallel to the axis of the weld.
(See Sect. 1.17.2 for electrodes and submerged arc welding process to be
employed on various grades of steel.)
1.5.4. Cast Steel and Steel Forgings. — Allowable stresses same as those
provided in Sect. 1.5.1, where applicable.
1.5. 5 A. Masonry Bearing. — Refer to Parts 24 and 26 of this Code.
1.5.6. Wind and Seismic Stresses. — Allowable stresses may be increased
one-third above the values provided in Sect. 28-1.5.1, 28-1.5.2A, 28-1.5.3,
28-1.5.4 and 28-1. 5.5A when produced by wind or seismic loading, acting
alone or in combination with the design dead and live loads, provided the
required section computed on this basis is not less than that required for the
design dead and live load and impact (if any), computed without the one-third
stress increase, nor less than that required by Sect. 28-1.7, if it is applicable.
Sect. 28- 1.6 A. Combined Stresses.
1.6.1 A. Axial Compression and Bending. — Members subject to both axial
compression and bending stresses shall be proportioned to meet the following
requirements:
K fa/Fa <0.15,
it is rec
Ufa/Fa > 0.15,
it is required: —■ + — < 1.0 Formula (6)
it is required: ~ + — ^-^r < 1.0 Formula (7a)
Fa 0-F->
provided, however, that if there are points braced in the plane of bending,
it is also required:
+ £■ < 1.0 Formula (7b)
0.6Fj, Fh
The nomenclature in the preceding provisions of this subdivision 1.6.1 A
shall be construed as follows:
Fa = axial stress that would be permitted if axial force alone existed
Fb = compressive bending stress that would be permitted if bending
moment alone existed
149,000,000
F'e-
V n >
(242)
')•
(In the expression for Fe> h is the actual unbraced length in the plane of
bending and r& is the corresponding radius of gyration. K is the effective
length factor in the plane of bending. As in the case of Fa, Ft and 0.6^
as used in Formula (7b), F'e may be increased one-third in accordance with
Sect. 28-1.5.6.)
Cm = a coefficient whose value shall be as follows:
A. For compressoin members in frames subject to joint translation (side-
sway), Cm — 0.85.
B. For restrained compression members in frames braced against joint
translation and not subject to transverse loading between their supports in
Mi
the plane of bending, Cm = 0.6 + 0.4 — - , but not less than 0.4, where M\/M%
M %
is the ratio of the smaller to the larger moments at the ends of that portion of
the member, unbraced in the plane of bending, under consideration. Mi/Mt
is positive when the member is bent in single curvature and negative when it
is bent in reverse curvature.
C. For compression members in frames braced against joint translation
in the plane of loading and subjected to transverse loading between their
supports, the value of Cm may be determined by rational analysis. However,
in lieu of such analysis, the following values may be used: (a) for members
whose ends are restrained, Cm — 0.85, (b) for members whose ends are unre-
strained, Cm = 1.
Values of Cm for Categories A, B, and C are shown in Table C 1.6.1.1.
(243)
Cate-
gory
Loading
conditions
{fa > 0.15FJ
Computed mo-
ments maxi-
mum at end;
joint translation
not prevented
Computed mo-
ments maxi-
mum at end; no
transverse load-
ing; joint trans-
lation pre-
vented
Transverse load-
ing; joint trans-
lation prevented
Table C 1.6.1.1
Mi
s
M2
S
M2
S
Using
Formula
(7b)
Mi
s
Using
Formula
(7a)
a
0.85
M2
0.6^
but not
less than
0.4
1 + <A A.
Remarks
<t
Mt
Mi
ztvr
&
H
.. ,, Mi
Mi < M2; — - positive as
Mi
shown
Check Formulas (7a) & (7b)
-Q.
Mt
*Z<w?
M2^.
leek both Formulas
(7a) & (7b)
Mi jt
HlUUJiQWllJlJiUi'
k
c
M3
M2
Check both Formulas
(7a) & (7b)
When bending occurs simultaneously about both axes of a column the second
(bending) term in Formula (7a) shall be evaluated as the sum of two terms, as
Cmfb Ismxfbx | ^myjby
where the subscripts x and y refer to the principal axes of bending of the
column profile.
Category (C) is exemplified by the compression chord of a truss, subject to
transverse loading between panel points. For this case the value for Cm can
be computed using the expression
(244)
where
7T ■ 8qEI
*= M0l\ "
5o = maximum deflection due to transverse loading
Mo = maximum moment between supports due to transverse loading-
Values for \p for several conditions of loading and end restraint shall be.
determined in accordance with the following Table C 1.6.1.2.
Table C 1.6.1.2
Case
1.0
s-5-i~--»-
SrJ
HT
-0.3
-0.4
1 -.3
fa_
F'
1 A * °
1 — '4-rr
F'
tJ±
-0.2
-0.4
-0.6
(245)
F'e
F'e
F'e
Sees. 1.6.2 A- 1. 7.2
1.6.2 A. Axial Tension and Bending. — Members subject to both axial
tension and bending stresses shall be proportioned to satisfy the requirement
of Formula (7b) where fb and Fb are taken, respectively, as the computed
and permitted bending tensile stress. However, the computed bending
compressive stress, taken alone, shall not exceed the value permitted by
Formulas (4), (5A) or (5B).
1.6.3 A. Shear and Tension. — Rivets and bolts subject to combined shear
and tension due to force applied to the connected parts, shall be so proportioned
that the tension stress produced by the force shall not exceed the following:
For A141 rivets Ft = 28,000 - 1.6% < 20,000
For A195 and A406 rivets Ft = 38,000 - 1.6/, < 27,000
For A307 bolts Ft = 20,000 - 1.6% < 14,000
For A325 bolts in bearing-type joints Ft = 37,500 - 1.6/v < 30,000
For A354, Grade BC, bolts in
bearing-type joints Ft = 45,000 - 1.6/„ < 37,500
where /„, the shear stress produced by the same force, shall not exceed the
value for shear given in Sect. 28-1. 5.2A.
For bolts used in friction-type joints, the shear stress allowed in Sect. 28-
1.5.2 A shall be reduced so that:
For A325 bolts Fv < 15,000(1 - ftAb/Tb)
For A354, Grade BC, bolts Fv < 20,000(1 - ftAb/Th)
where ft is the tensile stress due to applied load and Tb is the proof load of
the bolt.
Sect. 28-1.7. Members and Connections Subject to Repeated Variation
of Stress.
1.7.1. Up to 10,000 Complete Stress Reversals. — The stress-carrying area
of members, connection material and fasteners* need not be increased because
of repeated variation or reversal of stress unless the maximum stress allowed
by Sect. 28-1.5 and 28-1.6 is expected to occur over 10, 000 1 times in the life
of the structure.
1.7.2. 10,000 to 100,000 Cycles of Maximum Load. — Members, connection
material and fasteners (except high stranoth bolts in friction-type joints)
subject to more than 10,000 Dut not over 100,000$ applications of maximum
design loading shall be proportioned, at unit stresses allowed in Sect. 28-1.5
and 28-1.6 for the kind of steel and fasteners used, to support the algebraic
difference! of the maximum computed stress and two-thirds of the minimum
computed stress, but the stress-carrying area shall not be less than that required
in proportioning the member, connection material and fasteners to support
either the maximum or minimum computed stress at the values allowed in
Sect. 28-1.5 and 28-1.6 for the kind of steel and fasteners used.
* As used in this Section, "fasteners" comprise welds, rivets and bolts,
t Approximately equivalent to one application per day for 25 years,
t Approximately equivalent to ten applications per day for 25 years.
§ In determining the algebraic difference, tensile stress is designated as positive and com-
pression stress as negative.
(246)
Sees. 1.7.3-1.8.2A
1.7.3. 100,000 to 2,000,000 Cycles of Maximum Load. — Members, con-
nection material and fasteners (except high strength bolts in friction-type
joints) subject to more than 100,000 but not more than 2,000,000^f applications
of maximum design loading shall be proportioned at unit stresses allowed in
Sect. 28-1.5 and 28-1.6 for A7 steel, A141 rivet steel and E60XX and sub-
merged arc Grade SAW-1 welds to support the algebraic difference of the
maximum computed stress and % of the minimum computed stress, but the
stress-carrying area shall not be less than that required in proportioning the
member, connection material and fasteners to support either the maximum or
minjmum computed stress at the values allowed in Sect. 28-1.5 and 28-1.6 for
the kind of steel and fasteners used.
1.7.4. Over 2,000,000 Cycles of Maximum Load. — Members, connection
material and fasteners (except high strength bolts in friction-type joints)
subject to more than 2,000,000 applications of maximum design loading shall
be proportioned at two-thirds of the unit stress allowed in Sect. 28-1.5 and
28-1.6 for A7 steel, A141 rivet steel and E60XX and submerged arc Grade
SAW-1 welds to support the algebraic difference of the maximum computed
stress and three-quarters of the minimum computed stress, but the stress-
carrying area shall not be less than that required in proportioning the member,
connection material and fastener to support either the maximum or minimum
computed stress at the values allowed in Sect. 28-1.5 and 28-1.6 for the kind
of steel and fasteners used.
1.7.5. Details. — Members subject to the provisions of Sect. 28-1.7.2,
28-1.7.3 and 28-1.7.4 shall have no sharp notches, sharp copes or attachments
of clips, brackets or similar details, at locations where the stress exceeds
75 percent of those allowed in this section.
1.7.6. High Strength Bolted Connections. — High strength bolts in friction-
type joints shall be proportioned at the unit stresses allowed in Sect. 28-1.5.2
and 28-1.6.2 to resist the largest stress on the joint produced by any single
application of the design loads.
Sect. 28-1.8A. Slenderness Ratios.
1.8.1 A. Definition.
In determining the slenderness ratio of an axially loaded compression
member, except as provided in Sect. 28-1.5.1.3.3A, the length shall be taken
as its effective length Kl, and r as the corresponding radius of gyration.
1.8.2A. Sidesway Prevented. — In frames where lateral stability is pro-
vided by diagonal bracing, shear walls, attachment to an adjacent structure
having adequate lateral stability, or by floor slabs or roof decks secured
horizontally by walls or bracing systems parallel to the plane of the frame,
and in trusses, the effective length factor K for the compression members shall
be taken as unity, except as otherwise permitted in Sect. 28-1. 8.3 A.
If Approximately equivalent to 200 applications per day for 25 years.
(247)
Sec. 1.8.3A
1.8.3 A. Determination of Effective Length. — The effective length Kl of
compression members in a frame which depends upon its own bending stiffness
for lateral stability, shall be determined by a rational method and shall not
be less than the actual unbraced length.
Figs. 1 and 2 may be used to determine the effective length factor K which
depends upon the end restraints and which when multiplied by the actual
length gives the effective length for use in Formulas (1) and (2).
Figure 1 may be used in case effective means to prevent sidesway of the
column are employed. Figure 2 shall be used in case sidesway is possible.
In figures 1 and 2 the subscripts A and B refer to the joints at the two ends
of the column section being considered. G is given by
G
in which ]£ indicates a summation for all members, other than those the
principal function of which is to resist tensile axial forces, rigidly connected
to that joint as in Class A construction and lying in the plane in which buckling
of the column is being considered, Ic is the moment of inertia and Le the un-
supported length of column section, and I0 is the moment of inertia and Lg the
unsupported length of a girder or other restraining member. Ie and Ig shall
be taken about axes perpendicular to the plane of buckling being considered.
In Figures 1 and 2, having determined Ga and Gb for a column section,
K is obtained by constructing a straight line between the appropriate points
ton the scales for Ga and Gb. For example, in Figure 1, if Ga is 0.5 and Gb is
1.0, K is found to be 0.73.
(248)
Sec. 1.8.3A
6/
i K GB
50.0=1
-1.0
/CD
rso.o
10.0-=
r!0.0
5.0-
4.0-
3.0-
-0.9
~z 5.0
- 3.0
2.0-
- 2.0
-0.8
-
1.0-
0.9-
0.8-
- 1.0
- 0.9
- 0.8
0.7-
- 0.7
0.6-
0.5-
-0.7
- 0.6
- 0.5
0.4-
- 0.4
0.3-
- 0.3
0.2-
-0.6
- 0.2
o.i-
- 0.1
0-
-0.5
- 0
(FIG. 1)
Sidesway Prevented
(249)
Sec. 1.8.3A
Ga
K G
'B
CD — ]
100.0 -
50.0 =
6
3
-20.0
: io.o
— CD
-soao
- 50.0
30.0-
-
7 5.0
- 30.0
20.0-
- 4.0
- 20.0
10.0-
9.0-
8.0-
7.0-
- 3.0
- 10.0
- 9.0
~ 8.0
- 7.0
6.0-
- 6.0
5.0-
- 5.0
4.0-
- 2.0
- 4.0
3.0-
•
- 3.0
2.0-
- 2.0
- 1.5
1.0-
- 1.0
—
0-
- 1.0
- 0
(FIG. 2)
Sidesway Permitted
(250)
Sees. 1.8.3A-1.9.1
In case Class C "semi-rigid framing" is employed the values of — shall be
decreased sufficiently to fully reflect the effect of changes in angle between
columns and girders or other restraining members.
For the case in which sidesway is permitted and the far end of a girder or
other restraining member with respect to a given column is free to rotate in
the plane of the frame (virtually hinged) the value of — shall be reduced by
50 percent. °
Refinements in the value of -—■ and K may be made provided they are fully
Lg
substantiated by analysis supplemented if necessary by tests
For column ends supported by but not rigidly connected to a footing or
foundation, G may be taken as 10 unless the support is designed as a true
friction-free pin in which case G shall be taken as infinity. If the column end
is rigidly attached to a properly designed footing, G may be taken as 1.0.
Smaller values may be used if justified by analysis.
1.8.4. Maximum Ratios. — The slenderness ratio of compression members
shall not exceed 200.
The slenderness ratio of tension members, other than rods, preferably should
not exceed:
For main members 240
For bracing and other secondary members 300
Sect. 28-1.9. Width-Thickness Ratios.
1.9.1. Projecting Elements Under Compression. — Projecting elements of
members subjected to axial compression or compression due to bending shall
have ratios of width-to-thickness not greater than the following:
Single-angle struts; double-angle struts with separators 2,400/VFj,
Struts comprising double angles in contact; angles or
plates projecting from girders, columns or other com-
pression members; compression flanges of beams;
stiffeners on plate girders 3,000/Vr y
Stems of tees 4,000/VF^
The width of plates shall be taken from the free edge to the first row of
rivets, bolts or welds ; the width of legs of angles, channels and zees, and of the
stems of tees, shall be taken as the full nominal dimension the width of flanges
of beams and tees shall be taken as one-half the full nominal width. The
thickness of a sloping flange shall be measured halfway between a free edge
and the corresponding face of the web.
When a projecting element exceeds the width-to-thickness ratio prescribed
in the preceding paragraph, but would conform to same and would satisfy the
stress requirements with a portion of its width considered as removed, the
member will be acceptable.
(251)
Sees. 1.9.2=1.10.4
1.9.2. Compression Elements Supported Along Two Edges. — In com-
pression members the unsupported width of web, cover or diaphragm plates
between the nearest lines of fasteners or welds, or between the roots of the
flanges in case of rolled sections, shall not exceed 8,000/ VFV times its thickness.
When the unsupported width exceeds this limit, but a portion of its width
no greater than 8,000/v Fy times the thickness would satisfy the stress re-
quirements, the member will be considered acceptable.
The unsupported width of cover plates perforated with a succession of
access holes, may exceed 8,000/vFy, but shall not exceed 10,000/vFj,, times
the thickness. The gross width of the plate less the width of the widest access
hole shall be assumed available to resist compression.
Sect. 28-1.10. Plate Girders and Rolled Beams.
1.10.1. Proportions. — Riveted and welded plate girders, cover-plated
beams and rolled beams shall in general be proportioned by the moment of
inertia of the gross section. No deduction shall be made for shop or field
rivet or bolt holes in either flange, except that in cases where the reduction
of the area of either flange by such holes, calculated in accordance with the
provisions of Sect. 28-1.14.3 exceeds 15 percent of the gross flange area, the
excess shall be deducted.
1.10.2. Web. — The clear distance between flanges in inches, shall not
exceed
14,000,000
VFy (Fv + 16,500)
times the web thickness.
1.10.3. Flanges. — The thickness of outstanding parts of flanges shall
conform to the requirements of Sect. 28-1.9.
Each flange of welded plate girders shall in general consist of a single plate
rather than two or more plates superimposed. The single plate may comprise
a, series of shorter plates, laid end-to-end and joined by complete penetration
butt welds.
Unstiffened cover plates on riveted girders shall not extend more than
3,000/ VFy times the thickness of the thinnest outside plate beyond the outer
row of rivets or bolts connecting them to the angles. The total cross-sectional
area of cover plates of riveted girders shall not exceed 70 percent of the total
flange area.
1.10.4. Flange Development. — Rivets, high strength bolts or welds con-
necting flange to web, or cover plate to flange, shall be proportioned to resist
the total horizontal shear resulting from the bending forces on the girder.
The longitudinal distribution of these rivets, bolts or of intermittent welds
shall be in proportion to the intensity of the shear. But the longitudinal
spacing shall not exceed the maximum permitted, respectively, for compression
or tension members in Sect. 28-1.18.2.3 or 28-1.18.3.1. Additionally, rivets
(252)
Sees. 1.10.4=1.10.5.2
or welds connecting flange to web shall be proportioned to transmit to the
web any loads applied directly to the flange unless provision is made to transmit
such loads by direct bearing.
Partial length cover plates shall be extended beyond the theoretical cut-off
point and the extended portion shall be attached to the beam or girder by
Tivets, high strength bolts (friction-type joint), or fillet welds adequate, at
stresses allowed in Sect. 28-1. 5. 2A or 28-1.5.3 or Sect. 28-1.7, to develop the
cover plate's portion of the flexural stresses in the beam or girder at the
theoretical cut-off point. In addition, for welded cover plates, the welds
connecting the cover plate termination to the beam or girder in the length a! ,
denned below, shall be adequate, at the allowed stresses, to develop the cover
plate's portion of the flexural stresses in the beam or girder at the distance a'
from the end of the cover plate.* The length a , measured from the end of
the cover plate, shall be:
1. A distance equal to the width of the cover plate when there is a
-continuous weld equal to or larger than % of the plate thickness across the
end of the plate and continued welds along both edges of the cover plate
in the length a' .
2. A distance equal to V/2 times the width of the cover plate when there
is a continuous weld smaller than z/i of the plate thickness across the end of
the plate and continued welds along both edges of the cover plate in the
length a'.
3. A distance equal to 2 times the width of the cover plate when there
is no weld across the end of the plate but continuous welds along both edges
of the cover plate in the length a'.
1.10.5. Stiff eners.
1.10.5.1. — Bearing stiffeners shall be placed in pairs at unframed ends on
the webs of plate girders and, where required, f at points of concentrated loads.
Such stiffeners shall have a close bearing against the flange, or flanges, through
which they receive their loads or reactions, and shall extend approximately to
the edge of the flange plates or flange angles. They shall be designed as
columns subject to the provisions of Sect. 28-1.5.1, assuming the column
section to comprise the pair of stiffeners and a centrally located strip of the
web whose width is equal to not more than 25 times its thickness at interior
stiffeners or a width equal to not more than 12 times its thickness when the
stiffeners are located at the end of the web. The effective length shall be taken
as not less than % of the length of the stiffeners in computing the ratio l/r.
Only that portion of the stiffener outside of the angle fillet or the flange-to-web
welds shall be considered effective in bearing.
1.10.5.2. — The largest average web shear fv in any panel between stiffeners
(total shear force divided by web cross-sectional area), in pounds per square
* This may require the cover plate termination to be placed at a point in the beam or girder
that has lower bending stress than the stress at the theoretical cut-off point,
t For provisions governing welded plate girders see Sect. 28-1.10.10.
(253)
Sees. 1.10.5.2-1.10.5.4
inch, computed for any condition of complete or partial loading, shall not
exceed the value given by Formula (8) or (9), as applicable.
*• " £k lC° + / " °V 1 Formula (8)
2.89 I 1.15V 1 + (a/h)2 J
when Cv is less than 1.0;
F« " £t <C»> Formula (9)
but not more than 0AFy, when Cv is more than 1.0 or when intermediate
stiffeners are omitted;
where
a = clear distance between transverse stiffeners, in inches
h = clear distance between flanges, in inches
45,000,000& , _ . . x, no
Cv = — , when Cv is less than 0.8
V y\fl/t)
6,000 fk : „ .
= — — \ — , when Cv is more than 0.8
h/t VFy'
t — thickness of web, in inches
5.34
k = 4.00 H : , when a/h is less than 1.0
(a/h)*
= 5.34 H '■ . when a/h is more than 1.0
When a/h is more than 3 its value shall be taken as infinity. In this case
Formula (8) reduces to Formula (9) and k = 5.34.
1.10.5.3. — Intermediate stiffeners are not required when the ratio h/t is
less than 260 and the maximum web shear stress fv is less than that permitted
by Formula (9).
The spacing of intermediate stiffeners, when stiffeners are required, shall be
such that the web shear stress will not exceed the value for Fv given by Formulas
, /260V
(8) or (9), as applicable, and the ratio a/h shall not exceed ( TT.) nor 3.0.
The spacing between stiffeners at end panels and panels containing large
holes shall be such that the smaller panel dimension, a or h, shall not exceed
11,000*
Vfv
1.10.5.4. — The gross area, in square inches, of intermediate stiffeners spaced
in accordance with Formula (8) (total area, when stiffeners are furnished in
pairs) shall be not less than that computed by Formula (10).
Att _ LlSl f« **/*>' 1 YDht Formula (10)
2 lh Vl + (a/h)*}
(254)
Sees. 1.10.5.4=1.10.6
where
Cv, a, h and t are as defined in Sect. 28-1.10.5.2
yield point of web steel
yield point of stiffener steel
D = 1.0 for stiffeners furnished in pairs
= 1.8 for single angle stiffeners
= 2.4 for single plate stiffeners
When the greatest shear stress /„ in a panel is less than that permitted by
Formula (8) this gross area requirement may be reduced in like proportion.
The moment of inertia of a pair of stiffeners, or a single stiffener, with
reference to an axis in the plane of the web, shall not be less than (h/50)*.
Intermediate stiffeners may be stopped short of the tension flange a distance
not to exceed 4 times the web thickness, provided bearing is not needed to
transmit a concentrated load or reaction. When single stiffeners are used
they shall be attached to the compression flange, if it consists of a rectangular
plate, to resist any uplift tendency due to torsion in the plate. When lateral
bracing is attached to a stiffener, or a pair of stiffeners, these, in turn, shall
be connected to the compression flange to transmit 1 percent of the total flange
stress, unless the flange is composed only of angles.
Intermediate stiffeners required by the provisions of Sect. 28-1.10.5.3 shall
be connected for a total shear transfer, in pounds per linear inch of single
stiffener or pair of stiffeners, not less than that computed by the formula
fvt = h
\V3,400/
where Fy = yield point of web steel.
This shear transfer may be reduced in the same proportion that the largest
computed shear stress /„ in the adjacent panels is less than that permitted by
Formula (8). However, rivets and welds in intermediate stiffeners which are
required to transmit to the web an applied concentrated load or reaction shall
be proportioned for not less than the applied load or reaction.
Rivets connecting stiffeners to the girder web shall be spaced not more than
12 inches on center. If intermittent fillet welds are used, the clear distance
between welds shall not be more than 16 times the web thickness nor more
than 10 inches.
1.10.6. Reduction in Flange Stress. — When the web depth-to-thickness
ratio exceeds 24,000/^^6, *ne maximum stress in the compression flange shall
not exceed
F'h < Fb |~1.0 - 0.00O5 y(j- Ta^)1 Fonnula ai)
where
Ff, = applicable bending stress given in Sect. 28-1.5.1
Aw = area of the web
A/ = area of compression flange
(255)
Sees. 1.10.7-1.10.10.2
1.10.7. Combined Shear and Tension Stress. — Plate girder webs subject
to a computed average shear stress in excess of that permitted by Formula (9)
shall be so proportioned that bending tensile stress, due to moment in the
plane of the girder web, shall not exceed 0.6 Fy nor
N).825 - 0.375 y) Fy Formula (12)
where
fv = computed web shear stress (total shear divided by web area)
Fv = allowable web shear stress according to Formula (8) or (9)
1.10.8. Splices. — Butt welded splices in plate girders and beams shall be
complete penetration groove welds and shall develop the full strength of the
smaller spliced section. Other types of splices in cross-sections of plate girders
and in beams, shall develop the strength required by the stresses, at the point
of splice, but in no case less than 50 percent of the effective strength of the
material spliced.
1.10.9A. Horizontal Forces. — The flanges of plate girders supporting
cranes or other moving loads shall be proportioned to resist the horizontal
forces produced by such loads. (See Part 23)
1.10.10. Web Crippling.
1 . 1 0. 1 0. 1 . — Webs of beams and welded plate girders shall be so proportioned
that the compressive stress at the web toe of the fillets, resulting from concen-
trated loads not supported by bearing stiffeners, shall not exceed the value of
0.7 5Fy pounds per square inch allowed in Sect. 28-1.5.1; otherwise, bearing
stiffeners shall be provided. The governing formulas shall be:
For interior loads,
R
not over 0.7 5Fy pounds per square inch Formula (13)
t(N + 2k)
For end-reactions,
R
= not over 0.7 bFy pounds per square inch Formula (14)
t(N + k)
where
R = concentrated load or reaction, in pounds
t = thickness of web, in inches
N = length of bearing in inches (not less than k for end reactions)
k = distance from outer face of flange to web toe of fillet, in inches
1.10.10.2. — Webs of plate girders shall also be so proportioned or stiffened
that the sum of the compression stresses resulting from concentrated and
distributed loads, bearing directly on or through a flange plate, upon the
compression edge of the web plate, and not supported directly by bearing
stiffeners, shall not exceed
["_.... 4 110,000,000 . ' .
5.5 + 7 — ttt~ — 7TT\ pounds per square inch Formula (15)
L {a/h)*J (h/t)2
(256)
Sees. 1.10.10.2-1.11.2.1
when the flange is restrained against rotation, nor
r 4 "110,000,000 _ . _ _ ,i/s'
I 2 + / „N„ — TTm — pounds per square inch Formula (16)
L (a/h)2J Qi/ty
when the flange is not so restrained.
These stresses shall be computed as follows:
Concentrated loads and loads distributed over partial length of a panel
shall be divided by the product of the web thickness and the girder depth
or the length of panel in which the load is placed, whichever is the lesser
panel dimension.
Any other distributed loading, in pounds per linear inch of length, shall
be divided by the web thickness.
Sect. 28-1.11. Composite Construction.
1.11.1. Definition. — Composite construction shall consist of steel beams
or girders supporting a reinforced concrete slab, so inter-connected that the
beam and slab act together to resist bending. When the slab extends on both
sides of the beam, the effective width of the concrete flange shall be taken as
not more than one-fourth of the span of the beam, and its effective projection
beyond the edge of the beam shall not be taken as more than one-half the clear
distance to the adjacent beam, nor more than eight times the slab thickness.
When the slab is present on only one side of the beam, the effective width of
the concrete flange (projection beyond the beam) shall be taken as not more
than one-twelfth of the beam span, nor six times its thickness nor one-half the
clear distance to the adjacent beam.
Beams totally encased 2 inches or more on their sides and soffit in concrete
poured integrally with the slab may be assumed to be interconnected to the
concrete by natural bond, without additional anchorage, provided the top of
the beam is at least V/2 inches below the top and 2 inches above the bottom
of the slab, and provided that the encasement has adequate mesh or other
reinforcing steel throughout the whole depth and across the soffit of the beam.
When shear connectors are provided in accordance with Sect. 28-1.11.4,
encasement of the beam to achieve composite action is not required.
1.11.2. Design Assumptions.
1.11.2.1. — Encased beams shall be proportioned to support unassisted all
dead loads applied prior to the hardening of the concrete (unless these loads
are supported temporarily on shoring) and, acting in conjunction with the slab,
to support all dead and live loads applied after hardening of the concrete,
without exceeding a computed bending stress of 0.66/^, where Fy is the yield
point of the steel beam. The bending stress produced by loads after the
concrete has hardened shall be computed on the basis of the moment of inertia
of the composite section. Concrete tension stresses below the neutral axis of
the composite section shall be neglected. Alternatively, the steel beam alone
(257)
Sees. 1.11.2.1-1.11.4
may be proportioned to resist unassisted the moment produced by all loads,
live and dead, using a bending stress equal to Q.76FV, in which case temporary
shoring is not required.
1.1 1.2.2. — When shear connectors are used in accordance with Sect. 28-
1.11.4 the composite section shall be proportioned to support all of the loads
without exceeding the allowable stress prescribed in Sect. 28-1.5.1.4.1 or
28-1.5.1.4.4, as applicable. The moment of inertia Itr of the composite
section shall be computed in accordance with the elastic theory. Concrete
tension stresses below the neutral axis of the composite section shall be neg-
lected. The compression area of the concrete above the neutral axis shall be
treated as an equivalent area of steel by dividing it by the modular ratio n.
For construction without temporary shoring the value of the section modulus
of the transformed composite section used in stress calculations (referred to
the tension flange) shall not exceed
Str = U.35 + 0.35 ^r\ S, Formula (17)
where Ml and Md are, respectively, the live load and dead load moments
and S8 is the section modulus of the steel beam (referred to its tension flange)
and provided that the steel beam alone, supporting the loads before the
concrete has hardened, is not stressed to more than the applicable bending
stress given in Sect. 28-1.5.1.
1.1 1.3. End Shear. — The web and the end connections of the steel beam
shall be designed to carry the total dead and live loads.
1 . 1 1 .4. Shear Connectors. — Except in the case of encased beams as defined
in Sect. 28-1.11.1, the entire horizontal shear at the junction of the steel beam
and the concrete slab shall be assumed to be transferred by shear connectors
welded to the top flange of the beam and embedded in the concrete. The
total horizontal shear to be thus resisted between the point of maximum
positive moment and each end of the steel beam (or between the point of
maximum positive moment and a point of contraflexure in continuous beams)
shall be taken as the smaller value using the formulas
Vh = °-85{/<4c Formula (18)
and
Vh = ^-^ Formula (19)
where
f c — specified compression strength of concrete at 28 days
Ac — actual area of effective concrete flange defined in Sect. 28-1.11.1
A a = area of steel beam
The number of connectors resisting this shear, each side of the point of
maximum moment, shall not be less than that determined by the relationship
Vh/qt where q, the allowable shear load for one connector, or one pitch of a
spiral bar, is as given in Table 28-1.11.4.
(258)
Sees. 1.11.4-1.13
Table 28-1.11.4
Allowable Horizontal Shear Load
(q) (kips)
Connector
(Applicable only to concrete made
with ASTM C33-61T aggregate)
f'e = 3,000
fe = 3,500
fe = 4,000
Yl' diam. X2" hooked or headed stud
5.1
5.5
5.9
%" diam. X 2%" hooked or headed stud
8.0
8.6
9.2
y±" diam. X 3" hooked or headed stud
11.5
12.5
13.3
Y%' diam. X %lA" hooked or headed stud
15.6
16.8
18.0
3" channel, 4.1 lb.
4.3w?
4.7w
5.0u>
4" channel, 5.4 lb.
4.6w
5.0w
5.3w?
5" channel, 6.7 lb.
4.9w
5.3iy
5.6w>
%" diam. spiral bar
11.9
12.4
12.8
h/%' diam. spiral bar
14.8
15.4
15.9
%n diam. spiral bar
17.8
18.5
19.1
w = length of channel in inches.
The required number of shear connectors may be spaced uniformly between
the sections of maximum and zero moment.
Shear connectors shall have at least 1 inch of concrete cover in all directions.
Sect. 28-1. 1 2 A. Simple and Continuous Spans.
1.1 2.1 A. Simple Spans. — When beams, girders and trusses are designed
on the basis of simple spans, the effective length shall be taken as the distance
between centers of gravity of the members to which they deliver their end
reactions.
1.12.2. End Restraint. — When designed on the assumption of full or
partial end restraint, due to continuous, semi-continuous or cantilever action,
the beams, girders and trusses, as well as the sections of the members to which
they connect, shall be designed to carry the shears and moments so introduced,
as well as all other forces, without exceeding at any point the unit stresses
prescribed in Sect. 28-1.5.1 except that some non-elastic but self-limiting
deformation of a part of the connection may be permitted when this is essential
to the avoidance of overstressing of fasteners.
Sect. 28-1.13. Deflections. — Beams and girders supporting floors and
roofs shall be proportioned with due regard to the deflection produced by the
design loads.
Beams and girders supporting plastered ceilings shall be so proportioned
that the maximum live load deflection will not exceed 1/360 of the span.
The depth of beams and girders supporting flat roofs shall be not less than
/fc/600,000 times their span length whether designed as simple or continuous
spans.
(259)
Sees. 1.14-1.14.6
Sect. 28-1.14. Gross and Net Sections.
1.14.1. Definitions. — The gross section of a member at any point shall be
determined by summing the products of the thickness and the gross width of
each element as measured normal to the axis of the member. The net section
shall be determined by substituting for the gross width the net width computed
in accordance with Sect. 28-1.14.3 to 28-1.14.6 inclusive.
1.14.2. Application. — Unless otherwise specified, tension members shall
be designed on the basis of net section. Compression members shall be
designed on the basis of gross section. Beams and girders shall be designed
in accordance with Sect. 28-1.10.1.
1.14.3. Net Section. — In the case of a chain of holes extending across a
part in any diagonal or zigzag line, the net width of the part shall be obtained
by deducting from the gross width the sum of the diameters of all the holes
in the chain, and adding, for each gage space in the chain, the quantity
where
s = longitudinal spacing (pitch, in inches) of any two consecutive holes
g = transverse spacing (gage, in inches) of the same two holes
The critical net section of the part is obtained from that chain which gives
the least net width; however, the net section taken through a hole shall in no
case be considered as more than 85 percent of the corresponding gross section.
In determining the net section across plug or slot welds, the weld metal shall
not be considered as adding to the net area.
1.14.4. Angles. — For angles, the gross width shall be the sum of the width
of the legs less the thickness. The gage for holes in opposite legs shall be the
sum of the gages from back of angles less the thickness.
1.14.5. Size of Holes. — In computing net area the diameter of a rivet or
bolt hole shall be taken as }/% inch greater than the nominal diameter of the
rivet or bolt.
1.14.6. Pin-Connected Members. — Eyebars shall be of uniform thickness
without reinforcement at the pin holes. * They shall have "circular" heads in
which the periphery of the head beyond the pin hole is concentric with the
pin hole. The radius of transition between the circular head and the body
of the eyebar shall be equal to or greater than the diameter of the head.
The width of the body of the eyebar shall not exceed 8 times its thickness,
and the thickness shall not be less than 3^ inch. The net section of the head
through the pin hole transverse to the axis of the eyebar, shall not be less
than 1.33 nor more than 1.50 times the cross-sectional area of the body of the
♦Members having a different thickness at the pin hole location are termed "built-up."
(260)
Sees. 1.14.6-1.14.7
eyebar. The diameter of the pin shall not be less than Y% the width of the
body of the eyebar. The diameter of the pin hole shall not be more than
1^2 inch greater than the diameter of the pin.
The minimum net section across the pin hole, transverse to the axis of the
member, in pin-connected plates and built-up members shall be determined at
the stress allowed for such sections in Sect. 28-1 .5.1.1. The net section beyond
the pin hole, parallel to the axis of the member, shall not be less than % of
the net section across the pin hole. The corners beyond the pin hole may be
cut at 45° to the axis of the member provided the net section beyond the pin
hole on a plane perpendicular to the cut is not less than that required beyond
the pin hole parallel to the axis of the member. The parts of members built
up at the pin hole shall be attached to each other by sufficient fasteners to
support the stress delivered to them by the pin.
The distance transverse to the axis of a pin-connected plate or any separated
element of a built-up member from the edge of the pin hole to the edge of the
member or element, shall not exceed 4 times the thickness at the pin hole.
The diameter of the pin shall preferably not be less than 5 times the thickness
of the member or separated element at the pin hole. If a smaller size is used,
the bearing stress shall not exceed that allowed by Sect. 28-1.5.1.5.1. The
diameter of the pin hole shall not be more than \$i inch greater than the
diameter of the pin.
1.14.7. Effective Areas of Weld Metal. — The effective area of butt and
fillet welds shall be considered as the effective length of the weld times the
effective throat thickness.
The effective shearing area of plug and slot welds shall be considered as the
nominal cross-sectional area of the hole or slot, in the plane of the faying
surface.
The effective area of fillet welds in holes and slots shall be computed as
above specified for fillet welds, using for effective length, the length of center-
line of the weld through the center of the plane through the throat. However,
in the case of overlapping fillets, the effective area shall not exceed the nominal
cross-sectional area of the hole or slot, in the plane of the faying surface.
The effective length of a fillet weld shall be the overall length of full-size
fillet including returns.
The effective length of a butt weld shall be the width of the part joined.
The effective throat thickness of a fillet weld shall be the shortest distance
from the root to the face of the diagrammatic weld.
The effective throat thickness of a complete penetration butt weld (i.e., a
butt weld conforming to the requirements of Sect. 28-1.23.6) shall be the
thickness of the thinner part joined.
The effective throat thickness of single-V or single-bevel groove welds having
no root opening and having partial penetration into their joints shall be }/i inch
less than the depth of the V or bevel groove. The effective throat thickness
of single- J or single-U groove welds having no root opening and having partial
penetration into their joints shall be the depth of the J or U groove. The
(261)
Sees. 1.14.7-1.15.5
effective throat thickness of any of these partial penetration groove welds shall
be not less than X^U/6, where U is the thickness of the thinner part connected
by the weld.
Sect. 28-1.15. Connections.
1.15.1. Minimum Connections. — Connections carrying calculated stresses,
except for lacing, sag bars, and girts, shall be designed to support not less
than 6,000 pounds.
1.15.2. Eccentric Connections. — Axially stressed members meeting at a
point shall have their gravity axes intersect at a point if practicable; if not,
provision shall be made for bending stresses due to the eccentricity.
1.15.3. Placement of Rivets, Bolts and Welds. — Except as hereinafter
provided, the rivets, bolts or welds at the ends of any member transmitting
axial stress into that member shall have their centers of gravity on the gravity
axis of the member unless provision is made for the effect of the resulting
eccentricity. Except in members subject to repeated variation in stress, as
denned in Sect. 28-1.7, disposition of fillet welds to balance the forces about
the neutral axis or axes for end connections of single angle, double angle, and
similar type members is not required. Eccentricity between the gravity axes
of such members and the gage lines for their riveted or bolted end connections
may be neglected.
1.15.4. Unrestrained Members. — Except as otherwise indicated by the
designer, connections of beams, girders or trusses shall be designed as flexible,
and may ordinarily be proportioned for the reaction shears only.
Flexible beam connections shall permit the ends of the beam to rotate
sufficiently to accommodate its deflection by providing for a horizontal dis-
placement of the top flange determined as follows:
e = 0.007d when the beam is designed for full uniform load and for
live load deflection not exceeding 1/360 of the span
when the beam is designed for full uniform load pro-
where
3,600,000 Cueing the unit stress fb at mid-span
e = the horizontal displacement of the end of the top flange, in the
direction of the span, in inches
fb = the flexural unit stress in the beam at mid-span, in pounds per
square inch
d = the depth of the beam, in inches
L = the span of the beam, in feet
1.15.5. Restrained Members. — Fasteners or welds for end connections
of beams, girders and trusses not conforming to the requirements of Sect. 28-
1.15.4 shall be designed for the combined effect of end reaction shear and
tensile or compressive stresses resulting from moment induced by the rigidity
of the connection when the member is fully loaded.
(262)
Sees. 1.15.6-1.15.10
1.15.6. Fillers. — When rivets or bolts carrying computed stress pass
through fillers thicker than \i inch, except in friction-type connections as-
sembled with high strength bolts, the fillers shall be extended beyond the
splice material and the filler extension shall be secured by enough rivets or
bolts to distribute the total stress in the member uniformly over the combined
section of the member and the filler, or an equivalent number of fasteners
shall be included in the connection.
In welded construction, any filler }/i inch or more in thickness shall extend
beyond the edges of the splice plate and shall be welded to the part on which
it is fitted with sufficient weld to transmit the splice plate stress, applied at
the surface of the filler as an eccentric load. The welds joining the splice
plate to the filler shall be sufficient to transmit the splice plate stress and shall
be long enough to avoid overstressing the filler along the toe of the weld. Any
filler less than Y/i inch thick shall have its edges made flush with the edges of
the splice plate and the weld size shall be the sum of the size necessary to
carry the splice plate stress plus the thickness of the filler plate.
1.15.7. Connections of Tension and Compression Members in Trusses. —
The connections at ends of tension or compression members in trusses shall
develop the strength required by the stress, but not less than 50 percent of
the effective strength of the member. Groove welds in connections at the
ends of tension or compression members in trusses shall be complete pene-
tration groove welds.
1.15.8. Compression Members with Bearing Joints. — Where compression
members bear on bearing plates, and where tier-building columns are finished
to bear, there shall be sufficient rivets, bolts or welds to hold all parts securely
in place.
Where other compression members are finished to bear, the splice material
and its riveting, bolting or welding shall be arranged to hold all parts in line
and shall be proportioned for 50 percent of the computed stress.
All of the foregoing joints shall be proportioned to resist any tension that
would be developed by specified lateral forces acting in conjunction with
75 percent of the calculated dead load stress and no live load.
1.15.9. Combination of Welds. — If two or more of the general types of
weld (butt, fillet, plug, slot) are combined in a single joint, the effective ca-
pacity of each shall be separately computed with reference to the axis of the
group, in order to determine the allowable capacity of the combination.
1.15.10. Rivets and Bolts in Combination with Welds. — In new work,
rivets, A307 bolts, or high strength bolts used in bearing-type connections,
shall not be considered as sharing the stress in combination with welds. Welds,
if used, shall be provided to carry the entire stress in the connection. High
strength bolts installed in accordance with the provisions of Sect. 28-1. 16.1 A
as a friction-type connection prior to welding may be considered as sharing
the stress with the welds.
(263)
Sees. 1.15. 10-1. 16.1A
In making welded alterations to structures, existing rivets and properly
tightened high strength bolts may be utilized for carrying stresses resulting
from existing dead loads, and the welding need be adequate only to carry all
additional stress.
1.15.11. High Strength Bolts (in Friction- Type Joints) in Combination
with Rivets. — In new work and in making alterations, rivets and high
strength bolts, installed in accordance with the provisions of Sect. 28-1. 16.1 A
as friction-type connections, may be considered as sharing the stresses resulting
from dead and live loads.
1.15.12. Field Connections. — Rivets, high strength bolts or welds shall
be used for the following connections:
Column splices in all tier structures 200 feet or more in height.
Column splices in tier structures 100 to 200 feet in height, if the least
horizontal dimension is less than 40 percent of the height.
Column splices in tier structures less than 100 feet in height, if the least
horizontal dimension is less than 25 percent of the height.
Connections of all beams and girders to columns and of any other beams
and girders on which the bracing of columns is dependent, in structures
over 125 feet in height.
Roof-truss splices and connections of trusses to columns, column splices,
column bracing, knee braces and crane supports, in all structures carrying
cranes of over 5-ton capacity.
Connections for supports of running machinery, or of other live loads
which produce impact or reversal of stress.
Any other connections stipulated on the design plans.
In all other cases field connections may be made with A307 bolts.
For the purpose of this Section, the height of a tier structure shall be taken
as the vertical distance from the curb level to the highest point of the roof
beams, in the case of flat roofs, or to the mean height of the gable, in the case
of roofs having a rise of more than 2% in 12. Where the curb level has not
been established, or where the structure does not adjoin a street, the mean
level of the adjoining land shall be used instead of curb level. Penthouses
may be excluded in computing the height of structure.
Sect. 28-1. 16 A. Rivets and Bolts.
1.1 6.1 A. High Strength Bolts. — Use of high strength bolts shall conform
to the provisions of the Specifications for Structural Joints Using ASTM A325
Bolts as approved by the Research Council on Riveted and Bolted Structural
Joints, March 1962, except that A354, Grade BC, bolts meeting the dimensional
requirements of the Council's specification and tightened to their proof load,
may be substituted for A325 bolts at the working stresses permitted in Sects.
28-1. 5A and 28-1. 6A.
(264)
Sees. 1.16.2-1.16.6
1.16.2. Effective Bearing Area. — The effective bearing area of rivets and
bolts shall be the diameter multiplied by the length in bearing, except that for
countersunk rivets and bolts half the depth of the countersink shall be
deducted.
1.16.3. Long Grips. — Rivets and A307 bolts which carry calculated stress,
and the grip of which exceeds five diameters, shall have their number in-
creased 1 percent for each additional ^6 inch in the grip.
1.16.4. Minimum Pitch. — The minimum distance between centers of
rivet and bolt holes shall be not less than 2% times the nominal diameter of
the rivet or bolt but preferably not less than 3 diameters.
1.16.5. Minimum Edge Distance. — The minimum distance from the
center of a rivet or bolt hole to any edge, used in design or in preparation of
shop drawings, shall be that given in Table 28-1.16.5.
Table 28-1.16.5
Minimum Edg
;e Distance for
Punched, Reamed or Drilled Holes
Rivet or Bolt
Diameter
(Inches)
(Inches)
At Sheared
At Rolled Edges of
Edges
Plates, Shapes or Bars
or Gas Cut Edges f
A
Vz
y*.
5A
IVs
A
%
w
1
Vs
IA*
IA
l
IK*
1M
w
2
\A
IX
2H
l5A
Over 1M
1 % X Diameter
1% X Diameter
* These may be 1 }4 inches at the ends of beam connection angles.
t All edge distances in this column may be reduced y% inch when the hole is at a point where
stress does not exceed 25 percent of the maximum allowed stress in the element.
1.16.6. Minimum Edge Distance in Line of Stress. — In bearing-type con-
nections of tension members, where there are not more than two fasteners in
a line parallel to the direction of stress, the distance from the center of the end
fastener and that end of the connected part toward which the stress is directed
shall be not less than
(a) for riveted connections: the area of the fastener divided by the
thickness of the connected part for fasteners in single shear, and twice this
distance for fasteners in double shear.
(b) for high strength bolted connections: \A times the distances given
in (a).
(265)
Sees. 1.16.6-1.17.2
The end distance may, however, be decreased in such proportion as the
fastener stress is less than that permitted under Sect. 28-1. 5. 2 A, but it shaD
not be less than the distance specified in Sect. 28-1.16.5 above.
When more than two fasteners are provided in the line of stress the provisions
of Sect. 28-1.16.5 shall govern.
1.16.7. Maximum Edge Distance. — The maximum distance from the
center of any rivet or bolt to the nearest edge of parts in contact with one
another shall be 12 times the thickness of the plate, but shall not exceed
6 inches.
Sect. 28-1.17. Welds.
1.17.1. Welder and Welding Operator Qualifications. — Welds shall be
made only by welders and welding operators who have been previously
qualified by tests as prescribed in the Standard Code for Arc and Gas Welding
in Building Construction of the American Welding Society, to perform the type
of work required, except that this provision need not apply to tack welds not
later incorporated into finished welds carrying calculated stress.
1.17.2. Qualifications of Weld and Joint Details. — Weld grooves for
complete penetration welds which are accepted without welding procedure
qualification under the Standard Code for Welding in Building Construction
or the D 1.0-63 Standard Specification for Welded Highway and Railway
Bridges D2.0-63 of the American Welding Society may be used under this
Specification without welding procedure qualification.
Weld grooves of the 60° single-V, 45° single-bevel, single-J or single-U
form, conforming to the details for such grooves provided in the above AWS
Standards but having partial penetration with an effective throat thickness as
defined in Sect. 28-1.14.7 and no root opening, may be used under this Specifi-
cation without welding procedure qualification. However, they shall not be
used in butt joints to resist tensile stress acting in a direction normal to the
plane of the weld throat, except in splices or connections of columns or other
members subject primarily to axial compressive stress.
Joint forms or welding procedures other than those included in the fore-
going may be employed provided they shall have been qualified in accordance
with the requirements of these AWS Standards.
ASTM-A233 class E60 and E70* series electrodes for manual arc welding
and Grade SAW-1 or Grade SAW-2* submerged arc process may be used for
welding A7, A373 and A36 steel. Only E70 low-hydrogen electrodes for
manual arc welding or Grade SAW-2 for submerged arc welding shall be used
with A441 or weldable A242 steel, except that fillet welds or partial penetration
groove welds may be made with E60 series low-hydrogen electrodes and Grade
SAW-1 submerged arc process.
Welding A 440 steel is not recommended.
* See allowable stresses, Sect. 28-1.5.3.
(266)
Sees. 1.17.3=1.17.5
1.17.3. Submerged Arc Welding. — The bare electrodes and granular
fusible flux used in combinations for submerged arc welding shall be capable
of producing weld metal having the following tensile properties when de-
posited in a multiple pass weld
Grade SAW-1
Tensile strength 62,000 to 80,000 psi
Yield point, min 45,000 psi
Elongation in 2 in., min 25%
Reduction in area, min 40%
Grade SAW-2
Tensile strength 70,000 to 90,000 psi
Yield point, min 50,000 psi
Elongation in 2 in., min 22%
Reduction in area, min 40%
1.17.4. Minimum Size of Fillet Welds. — In joints connected only by fillet
welds, the minimum size of fillet weld to be used shall be as shown in Table
28-1.17.4 weld size is determined by the thicker of the two parts joined, except
that the weld size need not exceed the thickness of the thinner part joined
unless a larger size is required by calculated stress:
Table 28-1.17.4
Material Thickness of
Minimum Size of
Thicker Part Joined
Fillet Weld
(Inches)
(Inches)
To Yz inclusive
Kt
Over Y2 to %
H
Over Mto IY2
%
Over \Yl to 2M
Vs
Over 2i£ to 6
y*
Over 6
Vs
1.17.5. Maximum Effective Size of Fillet Welds. — The maximum size of a
fillet weld that may be assumed in the design of a connection shall be such that
the stresses in the adjacent base material do not exceed the values allowed in
Sect. 28-1.5.1. The maximum size that may be used along edges of connected
parts shall be:
1. Along edges of material less than }/i inch thick, the maximum size
may be equal to the thickness of the material.
2. Along edges of material x/i inch or more in thickness, the maximum
size shall be \{* inch less than the thickness of he material, unless the weld
is especially designated on the drawings to be built out to obtain full throat
thickness.
(267)
Sees. 1.17.6=1.17.11
1.17.6. Length of Fillet Welds. — The minimum effective length of a
strength fillet weld shall be not less than 4 times the nominal size, or else the
size of the weld shall be considered not to exceed one-fourth of its effective
length.
If longitudinal fillet welds are used alone in end connections of flat bar
tension members, the length of each fillet weld shall be not less than the
perpendicular distance between them. The transverse spacing of longitudinal
fillet welds used in end connections shall not exceed 8 inches, unless the design
otherwise prevents excessive transverse bending in the connection.
1.17.7. Intermittent Fillet Welds. — Intermittent fillet welds may be used
to transfer calculated stress across a joint or faying surfaces when the strength
required is less than that developed by a continuous fillet weld of the smallest
permitted size, and to join components of built-up members. The effective
length of any segment of intermittent fillet welding shall be not less than 4
times the weld size with a minimum of 114. inches.
1.17.8. Lap Joints. — The minimum width of laps on lap joints shall be
5 times the thickness of the thinner part joined and not less than 1 inch. Lap
joints joining plates or bars subjected to axial stress shall be fillet welded along
the edge of both lapped parts except where the deflection of the lapped parts
is sufficiently restrained to prevent opening of the joint under maximum loading.
1.17.9. End Returns of Fillet Welds. — Side or end fillet welds terminating
at ends or sides, respectively, of parts or members shall, wherever practicable,
be returned continuously around the corners for a distance not less than
twice the nominal size of the weld. This provision shall apply to side and top
fillet welds connecting brackets, beam seats and similar connections, on the
plane about which bending moments are computed. End returns shall be
indicated on the design and detail drawings.
1.17.10. Fillet Welds in Holes and Slots. — Fillet welds in holes or slots
may be used to transmit shear in lap joints or to prevent the buckling or
separation of lapped parts, and to join components of built-up members.
Such fillet welds may overlap, subject to the provisions of Sect. 28-1.14.7.
Fillet welds in holes or slots are not to be considered plug or slot welds.
1.17.1 1. Plug and Slot Welds. — Plug or slot welds may be used to trans-
mit shear in a lap joint or to prevent buckling of lapped parts and to join
component parts of built-up members.
The diameter of the holes for a plug weld shall be not less than the thickness
of the part containing it plus % inch, rounded to the next greater odd ^ inch,
nor greater than 234 times the thickness of the weld metal.
The minimum center-to-center spacing of plug welds shall be 4 times the
diameter of the hole.
The length of slot for a slot weld shall not exceed 10 times the thickness of
the weld. The width of the slot shall be not less than the thickness of the
part containing it, plus % inch, rounded to the next greater odd ^6 inch, nor
shall it be greater than 234 times the thickness of the weld. The ends of the
(268)
Sees. 1.17.11-1.18.2.3
slot shall be semicircular or shall have the corners rounded to a radius not less
than the thickness of the part containing it, except those ends which extend to
the edge of the part.
The minimum spacing of lines of slot welds in a direction transverse to
their length shall be 4 times the width of the slot. The minimum center-to-
center spacing in a longitudinal direction on any line shall be 2 times the length
of the slot.
The thickness of plug or slot welds in material Y% inch or less in thickness
shall be equal to the thickness of the material. In material over % inch in
thickness, it shall be at least one-half the thickness of the material but not
less than Y% inch.
Sect. 28-1.18. Built-Up Members.
1.18.1. Open Box- Type Beams and Grillages. — Where two or more
rolled beams or channels are used side-by-side to form a flexural member,
they shall be connected together at intervals of not more than 5 feet. Through-
bolts and separators may be used, provided that in beams having a depth of
12 inches or more, no fewer than 2 bolts shall be used at each separator loca-
tion. When concentrated loads are carried from one beam to the other, or
distributed between the beams, diaphragms having sufficient stiffness to
distribute the load shall be riveted, bolted or welded between the beams.
Where beams are exposed, they shall be sealed against corrosion of interior
surfaces, or spaced sufficiently far apart to permit cleaning and painting.
1.18.2. Compression Members.
1.18.2.1. — All parts of built-up compression members and the transverse
spacing of their lines of fasteners shall meet the requirements of Sects. 28-1.8
and 28-1.9.
1.18.2.2. — At the ends of built-up compression members bearing on base
plates or milled surfaces, all components in contact with one another shall be
connected by rivets or bolts spaced longitudinally not more than 4 diameters
apart for a distance equal to V/2 times the maximum width of the member, or
by continuous welds having a length not less than the maximum width of
the member.
1.18.2.3. — The longitudinal spacing for intermediate rivets, bolts or
intermittent welds in built-up members shall be adequate to provide for the
transfer of calculated stress. However, where a component of a built-up
compression member consists of an outside plate, the maximum spacing
shall not exceed the thickness of the thinner outside plate times 4,000/V/^
when rivets are provided on all gage lines at each section, or when intermittent
welds are provided along the edges of the components, but this spacing shall
not exceed 12 inches. When rivets or bolts are staggered, the maximum
spacing on each gage line shall not exceed the thickness of the thinner outside
plate times 6,000/Vi'V nor 18 inches. The maximum longitudinal spacing
of rivets, bolts or intermittent welds connecting two rolled shapes in contact
with one another shall not exceed 24 inches.
(269)
Sees. 1.18.2.4=1.18.2.7
1.18.2.4. — Compression members composed of two or more rolled shapes
separated from one another by intermittent fillers shall be connected to one
another at these fillers at intervals such that the slenderness ratio l/r of either
shape, between the fasteners, does not exceed the governing slenderness ratio
of the built-up member. The least radius of gyration r shall be used on com-
puting the slenderness ratio of each component part.
1.18.2.5. — Open sides of compression members built up from plates or
shapes shall be provided with lacing having tie plates at each end, and at
intermediate points if the lacing is interrupted. Tie plates shall be as near
the ends as practicable. In main members carrying calculated stress the end
tie plates shall have a length of not less than the distance between the lines
of rivets, bolts or welds connecting them to the components of the member.
Intermediate tie plates shall have a length not less than one-half of this dis-
tance. The thickness of tie plates shall be not less than 1/50 of the distance
between the lines of rivets, bolts or welds connecting them to the segments
of the members. In riveted and bolted construction the pitch in tie plates
shall be not more than 6 diameters and the tie plates shall be connected to
each segment by at least three fasteners. In welded construction, the welding
on each line connecting a tie plate shall aggregate not less than one-third the
length of the plate.
1.18.2.6A. — Lacing, including flat bars, angles, channels or other shapes
employed as lacing, shall be so spaced that the ratio l/r of the flange included
between their connections shall not exceed the governing ratio for the member
as a whole. Lacing shall be proportioned to resist a shearing stress normal to
the axis of the member equal to 2 percent of the total compressive stress in
the member. The ratio l/r for lacing bars arranged in single systems shall
not exceed 140. For double lacing this ratio shall not exceed 200. Double
lacing bars shall be joined at their intersections. In determining the required
section for lacing bars, Formula (1) or (3) shall be used, Kl being taken as the
unsupported length of the lacing bar between rivets or welds connecting it to
the components of the built-up member for single lacing and 70 percent of
that distance for double lacing. The inclination of lacing bars to the axis
of the member shall preferably be not less than 60 degrees for single lacing
and 45 degrees for double lacing. When the distance between the lines of
rivets or welds in the flanges is more than 15 inches, the lacing shall preferably
be double or be made of angles.
1.18.2.7. — The function of tie plates and lacing may be performed by
continuous cover plates perforated with a succession of access holes. The
width of such plates at access holes, as defined in Sect. 28-1.9.2, is assumed
available to resist axial stress, provided that: the width-to-thickness ratio
conforms to the limitations of Sect. 28-1.9.2; the ratio of length (in direction
of stress) to width of hole shall not exceed 2; the clear distance between holes
in the direction of stress shall be not less than the transverse distance between
nearest lines of connecting rivets, bolts or welds; and the periphery of the holes
at all points shall have a minimum radius of 13^ inches.
(270)
Sees. 1.18.3-1.21.1
1.18.3. Tension Members,
1.18.3.1. — The longitudinal spacing of rivets, bolts and intermittent
fillet welds connecting a plate and a rolled shape in a built-up tension member,
or two plate components in contact with one another, shall not exceed 24
times the thickness of the thinner plate nor 12 inches. The longitudinal spac-
ing of rivets, bolts and intermittent welds connecting two or more shapes in
contact with one another in a tension member shall not exceed 24 inches.
Tension members composed of two or more shapes or plates separated from
one another by intermittent fillers shall be connected to one another at these
fillers at intervals such that the slenderness ratio of either component between
the fasteners does not exceed 240.
1.18.3.2. — Either perforated cover plates or tie plates without lacing
may be used on the open sides of built-up tension members. Tie plates shall
have a length not less than two-thirds the distance between the lines of rivets,
bolts or welds connecting them to the components of the member. The
thickness of such tie plates shall not be less than 1/50 of the distance between
these lines. The longitudinal spacing of rivets, bolts or intermittent welds
at tie plates shall not exceed 6 inches. The spacing of tie plates shall be such
that the slenderness ratio of any component in the length between tie plates
will not exceed 240.
Sect. 28-1.19. Camber.
1.19.1. Trusses and Girders. — Trusses of 80 feet or greater span should
generally be cambered for approximately the dead load deflection. Crane
girders of 75 feet or greater span should generally be cambered for approxi-
mately the dead and half live load deflection.
1.19.2. Camber for Other Trades. — If any special camber requirements
are necessary in order to bring a loaded member into proper relation with the
work of other trades, as for the attachment of runs of sash, the requirements
shall be set forth on the plans and on the detail drawings.
1.19.3. Erection. — Beams and trusses detailed without specified camber
shall be fabricated so that after erection any minor camber due to rolling or
shop assembly shall be upward. If camber involves the erection of any
member under a straining force, this shall be noted on the erection diagram.
Sect. 28-1.20. Expansion. — Adequate provision shall be made for ex-
pansion and contraction appropriate to the service conditions of the structure.
Sect. 28-1.21. Column Bases.
1.21.1. Loads. — Proper provision shall be made to transfer the column
loads, and moments if any, to the footings and foundations.
(271)
Sees. 1.21.2=1.23.4
1.21.2. Alignment. — Column bases shall be set level and to correct
elevation with full bearing on the masonry.
1.21.3. Finishing. — Column bases shall be finished in accordance with the
following requirements:
1. Rolled steel bearing plates, 2 inches or less in thickness, may be used
without planing, provided a satisfactory contact bearing is obtained; rolled
steel bearing plates over 2 inches but not over 4 inches in thickness may be
straightened by pressing; or, if presses are not available, by planing for all
bearing surfaces (except as noted under Requirement 3 of this Section), to
obtain a satisfactory contact bearing; rolled steel bearing plates over
4 inches in thickness shall be planed for all bearing surfaces (except as
noted under Requirement 3 of this Section).
2. Column bases other than rolled steel bearing plates shall be planed
for all bearing surfaces (except as noted under Requirement 3 of this Section).
3. The bottom surfaces of bearing plates and column bases which are
grouted to insure full bearing contact on foundations need not be planed.
Sect. 28-1.22. Anchor Bolts. — Anchor bolts shall be designed to provide
resistance to all conditions of tension and shear at the bases of columns, in-
cluding the net tensile components of any bending moments which may
result from fixation or partial fixation of columns.
Sect. 28-1.23. Fabrication.
1 .23. 1 . Straightening Material. — Rolled material, before being laid off
or worked, must be straight within the tolerances allowed by ASTM specifi-
cation A6-62T. If straightening is necessary, it shall be done by methods
that will not injure the metal.
1.23.2. Gas Cutting. — Gas cutting shall preferably be done by machine.
Gas cut edges which will be subjected to substantial stress or which are to
have weld metal deposited on them shall be free from gouges; any gouges that
remain from cutting shall be removed by grinding. All re-entrant corners
shall be shaped notch free to a radius of at least XA inch.
1.23.3. Planing of Edges. — Planing or finishing of sheared or gas cut edges
of plates or shapes will not be required unless specifically called for on the
drawings or included in a stipulated edge preparation for welding.
1.23.4. Riveted and Bolted Construction — Holes. — Holes for rivets or
bolts shall be V& mch larger than the uominal diameter of the rivet or bolt.
If the thickness of the material is not greater than the nominal diameter of
the rivet or bolt plus }4, inch, the holes may be punched. If the thickness of
the material is greater than the nominal diameter of the rivet or bolt plus
}/% inch, the holes shall be either drilled from the solid, or sub-punched and
reamed. The die for all sub-punched holes, and the drill for all sub-drilled
holes, shall be at least ^6 inch smaller than the nominal diameter of the
rivet or bolt.
(272)
Sees. 1.23.5=1.23.6
1.23.5. Riveted and High Strength Bolted Construction — Assembling. —
All parts of riveted members shall be well pinned or bolted and rigidly held
together while riveting. Drifting done during assembling shall not distort the
metal or enlarge the holes. Holes that must be enlarged to admit the rivets
or bolts shall be reamed. Poor matching of holes shall be cause for rejection.
Rivets shall be driven by power riveters, of either compression or manually-
operated type, employing pneumatic, hydraulic or electric power. After
driving they shall be tight and their heads shall be in full contact with the
surface.
Rivets shall ordinarily be hot-driven, in which case their finished heads
shall be of approximately hemispherical shape and shall be of uniform size
throughout the work for the same size rivet, full, neatly finished and con-
centric with the holes. Hot-driven rivets shall be heated uniformly to a
temperature not exceeding 1950°F; they shall not be driven after their tem-
perature has fallen below 1000°F.
Rivets may be driven cold if approved measures are taken to prevent
distortion of the riveted material. The requirements for hot-driven rivets
shall apply except as modified in the Tentative Specification for Cold-Driven
Rivets of the Industrial Fasteners Institute.
Surfaces of high strength bolted parts in contact with the bolt head and
nut shall not have a slope of more than 1 : 20 with respect to a plane normal to
the bolt axis. Where the surface of a high strength bolted part has a slope of
more than 1:20, a beveled washer shall be used to compensate for the lack
of parallelism. High strength bolted parts shall fit solidly together when
assembled and shall not be separated by gaskets or any other interposed
compressible materials. When assembled, all joint surfaces, including those
adjacent to the washers, shall be free of scale except tight mill scale. They
shall be free of dirt, loose scale, burrs, and other defects that would prevent
solid seating of the parts. Contact surfaces within friction-type joints shall
be free of oil, paint, lacquer or galvanizing.
All A325 and A354, Grade BC, bolts shall be tightened to a bolt tension
not less than the proof load given in the applicable ASTM Specification for
the type of bolt used. Tightening shall be done with properly calibrated
wrenches or by the turn-of-nut method.
Bolts tightened by means of a calibrated wrench, shall be installed with a
hardened washer under the nut or bolt head, whichever is the element turned
in tightening. Hardened washers are not required when bolts are tightened
by the turn-of-nut method.
1.23.6. Welded Construction. — Surfaces to be welded shall be free from
loose scale, slag, rust, grease, paint and any other foreign material except that
mill scale which withstands vigorous wire brushing may remain. Joint
surfaces shall be free from fins and tears. Preparation of edges by gas cutting
shall, wherever practicable, be done by a mechanically guided torch.
Parts to be fillet welded shall be brought in as close contact as practicable
and in no event shall be separated by more than % inch. If the separation is
(273)
Sec. 1.23.6
J/fe inch or greater, the size of the fillet welds shall be increased by the amount
of the separation. The separation between faying surfaces of lap joints and
butt joints on a backing structure shall not exceed ^6 inch. The fit of joints
at contact surfaces which are not completely sealed by welds, shall be close
enough to exclude water after painting.
Abutting parts to be butt welded shall be carefully aligned. Misalignments
greater than H inch shall be corrected and, in making the correction, the
parts shall not be drawn into a sharper slope than 2 degrees (% inch in
12 inches).
The work shall be positioned for flat welding whenever practicable.
In assembling and joining parts of a structure or of built-up members, the
procedure and sequence of welding shall be such as will avoid needless distor-
tion and minimize shrinkage stresses. Where it is impossible to avoid high
residual stresses in the closing welds of a rigid assembly, such closing welds
shall be made in compression elements.
In the fabrication of cover-plated beams and built-up members, all shop
splices in each component part shall be made before such component part is
welded to other parts of the member. Long girders or girder sections may be
made by shop splicing not more than three sub-sections, each made in ac-
cordance with this paragraph.
All complete penetration butt welds made by manual welding, except when
produced with the aid of backing material or welded in the flat position from
both sides in square-edge material not more than % inch thick with root open-
ing not less than one-half the thickness of the thinner part joined, shall have
the root of the initial layer gouged out on the back side before welding is
started from that side, and shall be so welded as to secure sound metal and
complete fusion throughout the entire cross-section. Butt welds made with
use of a backing of the same material as the base metal shall have the weld
metal thoroughly fused with the backing material. Backing strips may
be removed by gouging or gas cutting after welding is completed, provided no
injury is done to the base metal and weld metal and the weld metal surface
is left flush or slightly convex with full throat thickness.
Butt welds shall be terminated at the ends of a joint in a manner that will
ensure their soundness. Where possible, this should be done by use of ex-
tension bars or run-off plates. Extension bars or run-off plates, if used, shall
be removed upon completion of the weld and the ends of the weld made smooth
and flush with the abutting parts.
No welding shall be done when the ambient temperature is lower than 0°F.
Base metal shall be preheated as required to the temperature called for in
Table 28-1.23.6 prior to tack welding or welding. When base metal not other-
wise required to be preheated is at a temperature below 32°F, it shall be pre-
heated to at least 70°F prior to tack welding or welding. Preheating shall
bring the surface of the base metal within 3 inches of the point of welding to
the specified preheat temperature, and this temperature shall be maintained
as a minimum interpass temperature while welding is in progress. Minimum
preheat and interpass temperatures shall be as specified in Table 28-1.23.6.
(274)
Sees. 1.23.6=1.23.8.2
Where required, multiple-layer welds may be peened with light blows from
a power hammer, using a round-nose tool. Peening shall be done after the
weld has cooled to a temperature warm to the hand. Care shall be exercised
to prevent scaling, or flaking of weld and base metal from overpeening.
Table 28-1.23.6
Minimum Preheat and Interpass Temperatures
Thickness of
Thickest Part at
Point of Welding
Other Than
Low-Hydrogen
Welding Processes1
Low-Hydrogen
Welding Processes2
A373
Steel
A7, A36
Steel
A441
Steel
A373
Steel
A7, A36
Steel
A441
Steel8
To 1" incl.
Over 1* to 2", incl.
Over 2"
None*
100°F
200°F
None*
200°F
300°F
Welding with this
process not recom-
mended
None*
None*
100°F
None*
50°F
150°F
None*
100°F
200°F
1 Welding with ASTM A233 E60XX or E70XX electrodes other than a low-hydrogen class.
2 Welding with properly dried ASTM A233 EXX15, 16, 18 or 28 electrodes or submerged
aro welding with properly dried flux.
8 Preheating for weldable A242 steel may need to be either higher or lower than these re-
quirements, depending on composition of steel.
* Except when base metal temperature is below 32°F.
The technique of welding employed, the appearance and quality of welds
made, and the methods used in correcting defective work shall conform to
Section 4 — Workmanship, of the Standard Code for Welding in Building
Construction of the American Welding Society D 1.0-63.
1.23.7. Finishing. — Compression joints depending upon contact bearing
shall have the bearing surfaces prepared to a common plane by milling,
sawing or other suitable means.
1.23.8. Tolerances.
1.23.8.1. Straightness. — Structural members consisting primarily of a
single rolled shape shall, unless otherwise specified, be straight within the
appropriate tolerances allowed by ASTM Specification A6-62T or as pre-
scribed in the following paragraph. Built-up structural members fabricated
by riveting or welding, unless otherwise specified, shall be straight within the
tolerances allowed for wide flange shapes by ASTM Specification A6 or by the
requirements of the following paragraph.
Compression members shall not deviate from straightness by more than
1/1000 of the axial length between points which are to be laterally supported.
Completed members shall be free from twists, bends and open joints.
Sharp kinks or bends shall be cause for rejection of material.
1.23.8.2. Length. — A variation of J^ inch is permissible in the overall
length of members with both ends finished for contact bearing as in Sect.
28-1.23.7.
Members without ends finished for contact bearing, which are to be framed
to other steel parts of the structure, may have a variation from the detailed
length not greater than lX% inch for members 30 feet or less in length, and not
greater than }/% inch for members over 30 feet in length.
(275)
Sees. 1.24A-1.24.7A
Sect. 28- 1.24 A. Protection and Painting.
1.24.1. General Requirements. — Unless subjected to deteriorating con-
ditions, steelwork which will be concealed by interior building finish need
not be painted; steelwork to be encased in concrete shall not be painted.
Unless specifically exempted, all other steelwork shall be given one coat
of shop paint, applied thoroughly and evenly to dry surfaces which have
been cleaned in accordance with the following paragraph, by brush, spray,
roller coating, flow coating, or dipping, at the election of the fabricator.
After inspection and approval and before leaving the shop, all steelwork
specified to be painted shall be cleaned by hand-wire brushing, or by other
methods elected by the fabricator, of loose mill scale, loose rust, weld slag or
flux deposit, dirt and other foreign matter. Oil and grease deposits shall be
removed by solvent. Steelwork specified to have no shop paint shall, after
fabrication, be cleaned of oil or grease by solvent cleaners and be cleaned of
dirt and other foreign material by thorough sweeping with a fiber brush.
The shop coat of paint is intended to protect the steel for only a short period
of exposure, even if it is a primer for subsequent painting to be performed in
the field by others.
1.24.2. Inaccessible Surfaces. — Surfaces inaccessible after assembly
shall be treated in accordance with Sect. 28-1.24.1 before assembly.
1 .24.3. Contact Surfaces. — Contact surfaces shall be cleaned in accordance
with Sect. 28-1.24.1 before assembly but shall not be painted.
1.24.4. Finished Surfaces. — Machine finished surfaces shall be protected
against corrosion by a rust-inhibiting coating that can be easily removed prior
to erection or which has characteristics that make removal unnecessary prior
to erection.
1.24.5. Surfaces Adjacent to Field Welds. — Unless otherwise provided,
surfaces within two inches of any field weld location shall be free of materials
that would prevent proper welding or produce objectionable fumes while
welding is being done.
1.24.6 A. — After erection and after touch-up of shop coat, steel, unless
specifically exempted in this Section 28-1 .24A, shall be given a field coat of
approved metal protection of another color.
Primary frame steel built into exterior masonry walls shall have adequate
protection against corrosion by encasing in one and one-half inches of Portland
cement mortar or by a mastic asphalt or pitch one-eighth inch thick or its
approved equivalent.
1.24.7A. Protection of Light Gage Steel Construction. — All individual
structural members and assembled panels of light gage cold-formed steel
construction, except where fabricated of approved corrosion-resistive steel.
(276)
Sees. 1.24.7A-I.26.2
or of steel having a corrosion-resistive metallic or other approved coating,
shall be protected against corrosion with an acceptable shop coat of paint,
enamel, or other approved protection.
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 cold-
formed steel construction shall be given an additional coat of acceptable
protection.
Exposed siding or sheathing shall be fabricated of approved corrosion-resistive
steel or otherwise protected at the ground level for sufficient height above
grade as determined by the depth of average snowfall (40 inches).
Floor or roof construction which extends into an exterior wall shall be
adequately waterproofed and protected from the weather to prevent corrosion.
Sect. 28-1.25. Erection.
1.25.1. Bracing. — The frame of steel skeleton buildings shall be carried
up true and plumb, and temporary bracing shall be introduced wherever
necessary to take care of all loads to which the structure may be subjected,
including equipment and the operation of same. Such bracing shall be left
in place as long as may be required for safety.
Wherever piles of material, erection equipment or other loads are carried
during erection, proper provision shall be made to take care of stresses resulting
from such loads.
1.25.2. Adequacy of Temporary Connections. — As erection progresses,
the work shall be securely bolted, or welded, to take care of all dead load, wind
and erection stresses.
1.25.3. Alignment. — No riveting, permanent bolting or welding shall be
done until as much of the structure as will be stiffened thereby has been
properly aligned.
1.25.4. Field Welding. — Any shop paint on surfaces adjacent to joints
to be field welded shall be wire brushed to reduce the paint film to a minimum.
Sect. 28- 1.26 A. Inspection.
1.26.1. General. — Material and workmanship at all times shall be subject
to the inspection of experienced engineers representing the purchaser.
1 .26.2. Cooperation. — All inspection as far as possible shall be made at
the place of manufacture, and the contractor or manufacturer shall cooperate
with the inspector, permitting access for inspection to all places where work
is being done.
f277)
Sees. 1.26.3=1.27.2
1.26.3. Rejections. — Material or workmanship not conforming to the
provisions of this Code may be rejected at any time defects are found during
the progress of the work.
1.26.4A. Inspection of Welding and High Strength Bolts. — The inspection
of welding shall be performed in accordance with the provisions of the Standard
Code for Welding in Building Construction, American Welding Society Dl.0-63.
Inspection of high strength bolts shall be performed by a competent in-
spector qualified by experience and training and approved by the Building
Commissioner and shall comply with the provisions of the 1962 Specifications
For Structural Joints Using ASTM A-325 bolts.
1.26.5. Identification of High Strength Steels. — Steel which is used for
main components and which is required to have a yield point greater than
36,000 psi shall, at all times in the fabricator's plant, be marked to identify
its ASTM specification. Identification of such steel in completed members
or assemblies shall be marked by painting the ASTM specification designation
on the piece, over any shop coat of paint, prior to shipment from the fabri-
cator's plant.
Sect. 28-1.27A. Open Web Steel Joists.
1.27.1. General. — Open Web Steel joists shall mean any open-webbed
beam or truss, twenty-four inches or less in depth, produced directly by
rolling, cold-forming or pressing. Joists may be fabricated from rolled, cold-
formed or pressed shapes by welding, riveting or expanding.
Steel joists shall not be used in the first floor of a building where there is
not a basement or cellar below, unless it has clearance above the ground of at
least twenty-four inches, and the space below is ventilated either to a heated
basement or to the outside air. Ventilation of such space to a heated base-
ment shall consist of at least two remote openings in the basement wall having
a total area of at least two square feet for each twenty-five linear feet of wall.
Ventilation of such space to outside air shall consist of one or more openings
in each exterior wall thereof, well distributed, except that openings need not
be provided in the front wall when the space is ventilated in the rear and both
side walls. The aggregate area of openings shall be not less than two square
feet for each twenty-five linear feet of wall. Openings in exterior walls shall
be protected by non-corrodible wire mesh with openings not greater than
one-half inch.
1.27.2. Design. — The provisions of this Part for design and materials
shall apply to Open Web Steel Joists. Steel members hot-rolled to shape shall
be designed in accordance with the provisions of Sections 28-1.0 through
28-1 .27 A; steel members cold-formed to shape shall be designed in accordance
with the provisions of Section 28-1. 28 A.
Where Open Web Steel Joists are used for other than simple spans under
uniformly distributed loading their stresses shall be investigated and be limited
to those allowed by this Part. Adequate top flange and lateral bracing shall
be provided to support the joist in proper alignment under such loads.
(278)
Sees. 1.27.2-1.28.1.1
The clear span of joists shall not exceed 24 times their depth in roof con-
struction and shall not exceed 20 times their depth in floor construction.
The deflection due to design live load shall not exceed 1/360 of the clear
span for all floors and roofs where a plaster ceiling is attached or suspended,
and 1/240 of the clear span in all other cases.
1.27.3. End Bearing. — The ends of steel joists shall extend a distance of
not less than 4 inches over masonry or concrete supports and not less than
2^ inches over steel supports, except where opposite joists butt over a narrow
steel support and positive attachment is made by welding or bolting, a shorter
end bearing length may be used when the bearing stresses are within the
allowable working stresses permitted in this Part.
1.27.4. Anchorage. — Joists resting on masonry or concrete supports shall
be bedded in mortar and anchored thereto with an anchor equivalent to a
%-inch round steel bar not less than 8 inches long. Every joist in floors and
roofs shall be anchored.
In roofs where parapet walls are not present, two H-inch anchor bolts or
other equal means shall be used in lieu of the steel bar. The ends of all steel
joists resting on steel supports shall be positively attached thereto by either a
minimum of two welds 1 inch long or one bolt H inch diameter. If uplift
forces are a consideration, the anchorage shall be capable of resisting such
uplift forces.
1.27.5. Bridging. — Bridging shall be provided for steel joists to afford
lateral support during and after erection and to distribute concentrations of
live load among adjacent joists. Bridging shall be of approved rigid type.
Attachment shall be by welding or mechanical means and shall be capable of
resisting a horizontal force of not less than 500 pounds. The ratio of unbraced
length to least radius of gyration (l/r) of the bridging member shall not
exceed 300. Bridging shall be provided at intervals of not more than 7 feet
for spans up to 21 feet, nor more than 8 feet for spans over 21 feet. The ends
of all bridging terminating at walls or beams shall be anchored thereto at both
top and bottom chords.
Sect. 28-1. 28A. Light Gage Cold-Formed Steel Construction.
1.28.1. Design. — All computations for safe load, stress, and deflection of
light gage cold-formed steel structural members shall be in accordance with
the provisions specified herein.
Where design criteria or applications are not specifically covered in Sect.
28-1.28, the design shall be in accordance with the 1962 Edition of the Specifi-
cation for the Design of Light Gage Cold-Formed Steel Structural Members
of American Iron and Steel Institute.
Properties of sections shall be based on the full cross-section of the members
(or net section where the use of a net section is customary) except where the
use of a reduced cross-section, or "effective design width," is required.
1.28.1.1. — Maximum allowable overall flat-width ratios, w/t, disregarding
intermediate stiff eners and taking as "t" the actual thickness of the element,
shall be as follows:
(279)
Sees. 1.28.1.1.-1.28.2.4
(a) Stiffened compression element having one longitudinal edge connect-
ed to a web or flange element, the other stiffened by:
Simple lip 60
Any other kind of stiffener 90
(b) Stiffened compression element with both longitudinal edges
connected to a web or flange element (U-type or box-type
sections) 500
(c) Compression element stiffened at only one edge 60
1.28. 1.2. — The ratio h/t of the webs of flexural members shall not exceed 150
where
h = clear distance between flanges, inches
t — thickness of web, inches
Where a web consists of two or more sheets, the h/t ratio of the individual
sheets shall not exceed , 150
1 .28.2. Allowable Design Stresses. — The maximum allowable unit stresses
to be used in design shall be as follows:
1.28.2.1. — Tension on the net section of tension members, and tension and
compression, /&, on the extreme fibers of flexural members shall not exceed the
value specified below, except as otherwise specifically provided in this section.
fb - 0.6F„
1.28.2.2. — Except as permitted by this^section, allowable stresses shall be
based upon the specified minimum properties of the plain material. Utili-
zation, for design purposes, of any increase in material strength that results
from a cold-forming operation is permissible provided the increase in strength
obtains for the kind of stress, tension of compression, that is to be imposed
on the final product in service; and under the limitations prescribed in this
section.
1.28.2.3. — The provisions of Section 28-1.28.2.2 shall apply only to the
following, regardless of whether the stress to be imposed on the member in
service is tension or compression:
1. Axially loaded members, and flanges of flexural members, whose pro-
portions are such that when treated as compression members the quantity
Q, determined n accordance with the provisions of Section 28-1.28-2.10
is unity. This includes tubular members composed of flat elements.
2. Cylindrical tubular members in which the ratio D/t of mean diameter
to wall thickness does not exceed 3,300,000/Fy.
1.28.2.4. — Application of the provisions of Section 28-1.28.2.2 shall be on
the following basis:
1. Application a* +he provisions of Section 28-1.28.2.2 shall be confined
to the following:
(280)
Sees. 1.28.2.4-1.28.2.6
- Basic Design Stress
- Compression on Elements stiffened at only one edge, Paragraph (1) only
- Laterally unbraced Single Web Beams
- Axially Loaded Compression Members
- Combined Axial and Bending Stresses
- Wind or Earthquake Stresses
- Cylindrical Tubular Members
Application of all other provisions shall be based upon the properties of
the plain material before forming.
2. The effect, on mechanical properties, of any welding that is to be
applied to the member shall be determined on the basis of tests of full section
specimens containing, within the gage length, such welding as the manu-
facturer intends to use. Any necessary allowance for such effect shall be
made in the structural use of the member.
1.28.2.5. — Compression, fc, in pounds per square inch, on a flat element
stiffened at only one edge parallel to the direction of stress:
1. For w/t not greater than 10:
fe -/ft
except when fb exceeds 30,000 psi the maximum w/t ratio for which fc may
be taken equal to fb shall not exceed
300,000
/ft
In the case of such higher values of fb the allowable value of fc for w/t ratio
less than 10 but greater than the ratio established by this section shall be
obtained by straightline interpolation is to be made between (1 ) the value of
/ft at w/t as specified in this section and (2) /«. = 30,000 psi at w/t equal to 10.
2. For w/t greater than 10, but not greater than 25:
fc = (1.667/6 - 8640) - (1/15) (/ft - 12,950)u>/«
For steels with yield point in excess of 50,000 psi the value of fb to be used
for the determination of fe when w/t exceeds 10 shall be 30,000 psi.
3. For w/t from 25 to 60:
For Angle Struts: fc = 8,090,000/ (w/t)2
For all Other Sections: fc = 20,000 - 2S2(w/t)
1.28.2.6. — To prevent lateral buckling, the maximum compression stress
f'e , in pounds per square inch, on extreme fibers of compression flanges or
laterally unsupported straight I-, Z- or channel-shaped flexural members (not
including multiple-web deck, U- and closed box-type members and curved of
arch members), shall not exceed the allowable stress as specified in Sections
28-1.28.2 or 28-1.28.2.5 nor the following maximum stresses:
(281)
Sees. 1.28.2.6-1.28.2.10
1. For I- or channel-shaped sections:
When l/ry is greater than 10,050/V^ but less than 22,400/V^:
J c 9Jb 907 x 106 \rj
When l/ry is equal to or greater than 22,400/VA:
fc = 280,000,000/ (Z/r„)»
2. For Z-shaped sections:
When l/ry is greater than 7,100/VA but less than 15,900/ V7b:
Jc 9Jb 453X106VV/
When l/ry is equal to or greater than 15,900/V/&:
fc = 140,000,000/ (*Av)8
where
I = the unbraced length of the member, inches.
ry = the radius of gyration of the entire section of the member
about its gravity axis parallel to the web, inches.
1.28.2.7. — The maximum average shear stress, v, in pounds per square inch,
on the gross area of the flat web of a beam shall not exceed:
64,000,000 . , . „._.„
v = — — with a maximum of y%fb
Where the web consists of two or more sheets, each sheet shall be considered
as a separate member carrying its share of the shear.
1.28.2.8. — The compressive stress fw in pounds per square inch in the flat
web of a beam due to bending in its plane, shall not exceed/b nor shall it exceed:
520,000,000
~ (h/ty
1.28.2.9. — For webs of beams subject to both bending and shear stresses,
the member shall be so proportioned that such stresses do not exceed the
allowable values specified in Sections 28-1.28.2.7 and 28-1.28.2.8 and that the
quantity
(j'b/fw)2 + (v'/v)2 does not exceed unity
where
520,000,000
u = wy
64,000,000
(h/ty
f b = actual compressive stress at junction of flange and web, psi.
v = actual average shear stress, i.e., shear force per web divided by
web area, psi.
1.28.2.10. — The average axial stress, P/A, in compression members shall
not exceed the values of Fa, as follows:
(282)
Sees. 1.28.2.10=1.28.2.12
24,200 „ /QFJ/r\*
l/r less than _^_ : Fa . 0.515QFs _ (_*L)
24,200 „ 149,000,000
Z/r equal to or greater than — 7= — 7= : F 0 = ~ ; . . —
VFyVQ d/r)2
In the above formulas,
P = total load, lbs.;
A = full, unreduced cross-sectional area of the member, sq. inches;
Fa = maximum allowable average axial stress in compression, psi;
I = unbraced length of member, inches; in frames which depend upon
their own bending stiffness for lateral stability, the effective
length I in the plane of the frame shall be determined by a
rational method and shall not be less than the actual unbraced
length.
r = radius of gyration of full, unreduced cross-section, inches;
Fy — yield point of steel, psi;
Q = a factor determined as follows:
1. For members composed entirely of stiffened elements, "Q" is the ratio
between the effective design area, as determined from the effective design
widths of such elements, and the full or gross area of the cross-section. The
effective design area used in determining Q is to be based upon the basic
design stress /& as defined in Section 28-1.28.2.1.
2. For members composed entirely of unstiffened elements, "Q" is the
ratio between the allowable compression stress fc for the weakest element of
the cross-section (the element having the largest flat-width ratio) and the
basic design stress /&; where fc is as defined in Section 1.28.2.5.
3. For members composed of both stiffened and unstiffened elements the
factor "Q" is the product of a stress factor Qs computed as outlined in
paragraph (2) above and an area factor Qa computed as outlined in para-
graph (1 ) above, except that the stress upon which Qa is to be based shall
be that value of the unit stress fc which is used in computing Qs; and the
effective area to be used in computing Qa shall include the full area of all
unstiffened elements.
The maximum allowable ratio l/r of unbraced length, I, to radius of gyration,
r, of compression members shall not exceed 200, except that during construction
only l/r shall not exceed 300.
1.28.2. 11. — Members subject to both axial compression and bending stresses
shall be proportioned to meet the requirements of Section 28-1. 6 A with the
exception that the value of Fa and Fb shall be determined in accordance with
this section, and formula (7b) is to be used as shown here:
fa +fj>
0.515QFV Fb
shall not exceed unity (applicable only at braced points).
1.28.2.12. — The ratio, D/t, of mean diameter to wall thickness of a cylin-
drical tubular member in compression or bending shall not exceed 3,300,000/Fy.
(283)
Sees. 1.28.2.12=1.28.3.3
For compression members, the allowable unit stress, P/A, under axial load
shall be prescribed by Section 28-1.28.2.10 with Q = 1.
1.28.3. Connections.
1.28.3.1. — The following requirements govern bolted connections of light
gage steel structural members:
1. The clear distance between bolts which are arranged in rows parallel
to the direction of force, also the distance from the center of any bolt to
that end or other boundary of the connecting member towards which the
pressure of the bolt is directed, shall not be less than 1 Y^d nor less than P/fbt.
where
d = diameter of bolt, inches
P = force transmitted by bolt, lb.
t = thickness of thinnest connected sheet, inches
fb = basic design stress, as defined elsewhere, psi.
If the ratio of tensile strength to yield point is less than 1.35, a stress
equal to the specified minimum tensile strength of the material divided by
2.2 shall be used instead of fb in applying the provisions of this section.
2. The tension stress on the net section of a bolted connection shall not
exceed fb nor shall it exceed
(0.1 + Sd/s)fb
where
s == spacing of bolts perpendicular to line of stress, inches. In the
case of a single bolt, s = width of sheet.
d and fb are as previously defined.
3. The bearing stress on the area (d X t) shall not exceed 3.5/&.
4. Shear on bolts, under dead and live load, shall not exceed the values
given in Section 28-1. 5.2A.
1 .28.3.2. — For all grades of steel, fusion welds shall be proportioned so that
the unit stresses therein do not exceed 13,600 psi in shear on the throat of fillet
or plug welds. The allowable unit stress in tension or compression on butt
welds shall be the same as prescribed for the base metal being joined, provided
the weld penetrates 100 percent of the section. Stresses due to eccentricity
of loading, if any, shall be combined with the primary stresses; and the com-
bined unit stresses shall not exceed the values given above.
1.28.3.3. — In sheets joined by spot welding (including projection welding)
the allowable shear per spot shall be as follows:
Thickness of
Allowable Shear
Thickness of
Allowable Shear
Thinnest Out-
Strength per
Thinnest Out-
Strength per
side Sheet,
In.
Spot, lb.
side Sheet,
In.
Spot, lb.
.010
50
.080
1075
.020
125
.094
1375
.030
225
.109
1650
.040
350
.125
2000
.050
525
.155
3000
.060
725
.185
4000
(284)
Sees. 1.28.4-1.29.2.1
1.28.4. Protection. — Refer to Sect. 28-1.24.7A.
Sect. 28-1.29. Concrete- Filled Pipe Columns.
1. 29.1. A Material. — Pipe for such columns may have round, square,
or rectangular cross sections.
Steel equal in quality to that described in Section 28-1.4 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
thickness of square and rectangular pipe shall not be less than %j inch.
Filling shall be standard weight, machine-mixed, stone or gravel concrete
and shall have a minimum compressive strength of 3,500 pounds per square
inch when proportioned and tested by procedures described in Part 26. Con-
crete 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 of ASTM Standards A373-58T, A7-61T or A36-62T. 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.
Longitudinal steel having a yield point approximating that of the pipe may
be used to increase the strength of the columns. Such steel shall be new,
straight and continuous for the entire length of the column with ends so
detailed as to develop the computed stress. The ends of such steel shall be
arranged for even bearing with the pipe and milled after filling if necessary
to obtain uniform bearing. The strength of this reinforcement shall be
calculated by adding its area to the area of the steel pipe and including it
in the calculations.
Material surrounding a filled pipe column for fire protection shall not be
considered as either load-bearing or as increasing the stiffness.
1.29.2. Design.
1.29.2.1. — The axial load Pa shall not exceed that obtained from Formulas
(l) and (2), Section 28-1.5.1.3A multiplied by the effective transformed area
A tr and with Pa substituted for Fa and rtr2 substituted for r2. The values of
Atr and rtr2 shall be evaluated by
Atr = A8 + ~r rtr2 = — :
In which
In
A 8 = area of the pipe and reinforcing steel
Ac = area of the concrete filling
Ic = moment of inertia of the concrete filling
IB = moment of inertia of steel pipe and reinforcing
(285)
Sees. 1.29.2.1-1.29.2.4
E E 483
n =
Ec 60,OOOV/77~c VT'c
f'c = concrete compressive strength, psi
1.29.2.2. — 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 Mr may be approximated by
CmM
_ Pc{Kl/rtrY
149,000,000Air
in which Cm shall be evaluated in accordance with Section 28-1 .6.1 A with Pc
substituted for fa and Pa substituted for Fa.
M = bending moment neglecting the effect of the axial load on the deflection
Pc = applied axial load
At braced points Mr may be taken equal to M .
1.29.2.3. — Provided that no part of the concrete filling is stressed in tension,
columns subjected to bending as well as axial load shall be so proportioned that
^ + -A__<i
Pa 21,000 -
in which fb is the compressive bending stress based on the moment given by
Formula 27 — at the point under consideration. The above expression applies
directly to columns flexed about one principal axis and to round columns. In
the latter case moments acting about several axes shall be added vectorially
and fb obtained from the resultant moment. For square and rectangular
columns the second (bending) term shall be treated as
fbx + fby
21,000
At braced points Pa in the above formula may be computed for = 0
and Cm = 1. rtr
1.29.2.4. — If bending is sufficient to cause net tension at some point in the
concrete fill the column shall be so proportioned that
Pc Mr - SPC <
Pb + M0 ' ~
In the above
Pb =
Pa + 21,000A*r
rtr2
s — kern distance for the uncracked section = —
c
c = distance from centroid to extreme fiber
(286)
Sees. 1. 29.2.4- 1. 30.3
M0 = allowable moment with Pc — 0 which can be approximated as 21,0005
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 moment.
For square or rectangular columns with bending about both principal axes,
the section shall be so proportioned that
i 77 H 77 ^ 1
^femin. Mox May
where the subscripts x and y indicate that the quantity is computed with
respect to the xor y axis independently and Pbmm. is the smaller of Pbx and Pby.
1.29.3. Tests. — Copies of sanction tests of filled pipe columns subjected
to axial loads made in accordance with this section shall be filed with the
Commissioner for each size of column produced by a manufacturer. These
tests shall be made on specimens the length of which approximates 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 Pa shall not be
less than the factor of safety in Formulas (1) and (2), modified as in sec. 1.29.2.1
above excepting that in computing Pa for sanction tests n rather than 2n
shall be used.
1.29.4. Identification. — Columns shall be labeled with manufacturer's
name and date of manufacture.
Sect. 28-1. 30A. Cast-iron Columns.
1.30.1. — Cast-iron columns shall not be used in the primary structural
frames of buildings the height of which exceeds one hundred feet or twice the
width at the ground level. Cast iron shall not be used for columns required
to have four-hour fire-resistive protection.
1 .30.2. — The ends of cast-iron columns shall be machined to a smooth plane
surface perpendicular to the axis to provide full bearing for the entire cross
section of the column.
1.30.3. — Hollow cast-iron columns, except when open at both ends and
without flanges, shall have two three-eighths inch holes drilled in the shell to
exhibit the thickness thereof. If the columns are cast on the side, both holes
shall be at mid-height at ninety degrees from one another about the axis of
the column. Additional holes shall be drilled when required by the Com-
missioner. If the core of a cast-iron column is found to have shifted more
than one-quarter the thickness of the shell, the strength shall be computed
assuming the thickness all around to be that of the thinnest part.
(287)
Sees. 1.30.4-2.3
1 .30.4. — Cast-iron columns shall not be smaller than six inches in outside
diameter or side, and the thickness of metal shall not be less than three-fourths
inch or less than one-twelfth the outside diameter or widest side.
1.30.5. — Cast-iron columns supporting a floor shall not be longer than
seventy times the least radius of gyration or twenty-four times the outside
diameter or least side. Cast-iron columns supporting roof loads only shall not
be longer than ninety-six times the least radius of gyration or thirty times the
outside diameter or least side.
1.30.6. — Cast-iron columns shall not be used where the loading is so ec-
centric as to cause tension, nor shall they be used in garages or other structures
where they may be subject to impact from vehicles.
Sect. 28-2.0. Plastic Design.
Sect. 28-2.1 A. Scope. — Subject to the limitations contained herein,
simple or continuous beams, one and two-story rigid frames classified as
Class A construction in Sect. 28-1. 2A and similar portions of structures rigidly
constructed so as to be continuous over at least one interior support,* may
be proportioned on the basis of plastic design, i.e., of their maximum strength.
This strength, as determined by rational analysis, shall not be less than that
required to support 1.70 times the given live load and dead load for simple
and continuous beams. For continuous frames it shall not be less than 1.85
times the given live load and dead load, nor 1.40 times these loads acting in
conjunction with 1.40 times any specified wind or earthquake forces.
Connections joining a portion of a structure designed on the basis of plastic
behavior with a portion not so designed need be no more rigid than ordinary
seat-and-cap angle or standard web connections.
Where plastic design is used as the basis for proportioning continuous beams
and structural frames, the provisions relating to allowable working stress,
contained in Sects. 28-1.0 through 28.1.26.5 are waived. Except as modified
by these rules, however, all other pertinent provisions of these Sections shall
govern.
Crane runways shall not be designed continuous over interior vertical
supports on the basis of maximum strength. However, rigid frame bents
supporting crane runways may be considered as coming within the scope of
the rules.
Sect. 28-2.2A. Structural Steel. — Structural steel shall conform to one of
the following specifications.
Steel for Bridges and Buildings, ASTM A7-61T
Structural Steel for Welding, ASTM A373-58T
Structural Steel, ASTM A36-62T
Sect. 28-2.3. Columns. — In the plane of bending of columns which would
develop a plastic hinge at ultimate loading, the slenderness ratio l/r shall not
* As used here, "interior support" may be taken to include a rigid frame knee formed by the
junction of a column and a sloping or horizontal beam or girder.
(288)
Sec. 2.3
exceed 120, 1 being taken as the distance center-to-center of adjacent members
connecting to the column or the distance from such a member to the base of
the column. The slenderness ratio of columns covered by Formula (21) shall
not exceed 100. The maximum axial load P at ultimate loading shall not
exceed 0.6Py, where Py is the product of yield point stress times column area.
Columns in continuous frames, where sides way is not prevented (a) by
diagonal bracing, (b) by attachment to an adjacent structure having ample
lateral stability or (c) by floor slabs or roof decks secured horizontally by walls
or bracing systems parallel to the plane of the continuous frames, shall be so
proportioned that
2P I
— + ■ — < 1.0 Formula (20)
Py 70r ~
Except as otherwise provided in this section, M0/Mp, the ratio of allowable
end moment to the full plastic bending strength of columns and other axially
loaded members, shall not exceed the value given by the following formulas,
where they are applicable:
Case I. — For columns bent in double curvature by moments producing
plastic hinges at both ends of the columns
M0 = Mp when P/Pv < 0.15
M0
Mp
< 1.18 - 1.18 (—) < 1.0 when P/Pv > 0.15 Formula
(21)
Case II. — For pin-based columns required to develop a hinge at one end
only, and double curvature columns required to develop a hinge at one end
when the moment at the other end would be less than the hinge value
M0
Mp
<B -G f — J < 1.0 Formula (22)
the numerical values for B and G, for any given slenderness ratio in the plane
of bending l/r, being those listed in Tables 4-33 and 4-36. Where l/r in the
plane of bending is less than 60, and P/Py does not exceed 0.15, the full plastic
strength of the member may be used (M0 — Mp).
Case III. — For columns bent in single curvature
S-U)-*©--/(0 Formula(23)
the numerical values for H and J being those given in Tables 5-33 and 5-36.
In no case shall the ratio of axial load to plastic load exceed that given by
the following expression:
P 8 700 I
— = -7— when - > 120 Formula (24)
Pv (l/r)2 r
where I and r are the unbraced length and radius of gyration of the column in
the plane normal to that of the continuous frame under consideration.
(289)
Sees. 2.4-2.6
Sect. 28-2.4. Shear. — Unless reinforced by diagonal stiffeners or a doubler
plate, the webs of columns, beams, and girders shall be so proportioned that
Vu < 0.00055Fywd
where Vu is the shear, in kips, that would be produced by the required ultimate
loading, d is the depth of the member, and w is its web thickness.
(Shear stresses are generally high within the boundaries of the connection
of two or more members whose webs lie in a common plane. The foregoing
provisions will be satisfied, without reinforcing the web within the connection,
when its thickness w, in inches, is greater than 23,QQ0M/AbcFy, M being the
algebraic sum of clockwise and counter-clockwise moment (in kip-feet) applied
on opposite sides of the connection web boundary, and Abe the planar area of
the connection web, expressed in square inches, and Fy is given in pounds per
square inch. When the thickness of this web is less than that given by the
above formula the deficiency may be compensated by a pair of diagonal
stiffeners or by a reinforcing plate in contact with the web over the connection
area.)
Sect. 28-2.5. Web Crippling. — Web stiffeners are required on a member
at a point of load application where a plastic hinge would form.
At points on a member where the concentrated load delivered by the flanges
of a member framing into it would produce web crippling opposite the com-
pression flange or high tensile stress in the connection of the tension flange,
web stiffeners are required
, , Af
opposite the compression flange when w < r
tb + 5k
opposite the tension flange when tj < OAVAf
where
w = thickness of web to be stiffened
k = distance from outer face of flange to web toe of fillet of member
to be stiffened
t/ = thickness of flange of member to be stiffened
tb — thickness of flange delivering concentrated load
Af = area of flange delivering concentrated load
The area of such stiffeners, A8t, shall be such that
Ast > A/ — w(tb + 5k)
Their ends shall be fully welded to the inside face of the flange opposite the
concentrated tensile load. They may be fitted against the inside face of the
flange opposite the concentrated compression load. When the concentrated
load delivered by a beam occurs on one side only, the web stiffener need not
exceed one-half the depth of the member, but the welding connecting it to the
web shall be sufficient to develop FyA$t.
Sect. 28-2.6. Minimum Thickness (Width-Thickness Ratios). — Pro-
jecting elements that would be subjected to compression involving plastic
(290)
Sees. 2.6-2.8A
hinge rotation under ultimate loading, shall have width-thickness ratios no
greater than the following:
Flanges of rolled shapes and flange plates of similar built-up shapes: 8H>
except that for rolled shapes an upward variation of 3 percent may be
tolerated. The thickness of sloping flanges may be taken as their average
thickness. Stiffeners and that portion of flange plates in box sections and
cover plates included between the free edge and the first longitudinal row
of fasteners or connecting welds: 83^.
The width-thickness ratio of flange plates in box sections and flange cover
plates included between longitudinal lines of connecting rivets, high strength
bolts or welds, shall not exceed 32.
The depth-thickness ratio of beam and girder webs subjected to plastic
bending without axial loading shall not exceed 70 and, when subjected to
combined axial force and plastic bending moment at ultimate loading, the
value given by the formula
d P
< 70 - 100 — Formula (25)
W Py
with a minimum value of 43.
Sect. 28-2.7. Connections. — All connections, the rigidity of which is
essential to the continuity assumed as the basis of the design analysis, shall
be capable of resisting the moments, shears and axial loads to which they would
be subjected by the ultimate loading.
Corner connections (haunches), tapered or curved for architectural reasons,
shall be so proportioned that the full plastic bending strength of the section
adjacent to the connection can be developed, if required.
Stiffeners shall be used, as required, to preserve the flange continuity of
interrupted members at their junction with other members in a continuous
frame. Such stiffeners shall be placed in pairs on opposite sides of the web
of the member which extends continuously through the joint.
Rivets, welds and A307 bolts shall be proportioned to resist the forces pro-
duced at ultimate load using unit stresses equal to 1.67 times those given in
Sects. 28-1. 16A and 28-1.17.
In general, groove welds are preferable to fillet welds, but their use is not
mandatory when the strength of the latter at 1.67 times the stress given in
Sect. 28-1.17 is sufficient to resist the ultimate load imposed upon a joint.
High strength bolts may be proportioned, on the basis of their minimum
guaranteed proof load, to resist the tension produced by the ultimate loading.
When used to transmit shear produced by the ultimate loading, one bolt may
be substituted for a rivet of the same nominal diameter. High strength bolts
may be used in joints having painted contact surfaces when these joints are
of such size that the slip required to produce bearing would not interfere with
the formation, at ultimate loading, of the plastic hinges assumed in the design.
Sect. 28-2.8A. Lateral Bracing. — Members designed on the basis of ulti-
mate load shall be adequately braced to resist lateral and torsional displace-
(291)
Sees. 2.8A-2.9
ments at the plastic hinge locations associated with the failure mechanism.
The laterally unsupported distance, lcr, from such braced hinge locations to
similarly braced adjacent points on the member or frame shall not exceed
lcr = (60 - 40 — J ry Formula (26)
except that it need not be less than 35^
where
ry = the radius of gyration of the member about its weak axis
M = the lesser of the moments at the ends of the unbraced segment
and
M/Mp , the end moment ratio, is positive when the segment is bent
in single curvature and negative when bent in double
curvature.
Any greater laterally unbraced length for these segments must be justified
by an analysis based upon the predictable amount of restraint present at the
ends of the segment in the plane of the computed bending moments.
The foregoing provisions need not apply in the region of the last hinge to
form in the failure mechanism assumed as the basis for proportioning a given
member, nor in members oriented with their weak axis normal to the plane of
bending. However, in the region of the last hinge to form, and in regions not
adjacent to a plastic hinge, the maximum distance between points of lateral
support shall be such as to satisfy the requirements of Formulas (4), (5A),
(5B) and (6) in Sections 28-1.0 through 28-1.26.5 of this Code. For this
case the value of fa and fb shall be computed from the moment and axial
force at ultimate loading, divided by the applicable load factor.
Members built into a masonry wall and having their web perpendicular to
this wall can be assumed to be laterally supported with respect to their weak
axis of bending.
Sect. 28-2.9. Fabrication. — The provisions of Sects. 1.7.5 through 1.26.5
with respect to workmanship shall govern the fabrication of structures, or
portions of structures, designed on the basis of maximum strength, subject to
the following limitations:
The use of sheared edges shall be avoided in locations subject to plastic
hinge rotation at ultimate loading. If used, they shall be finished smooth
by grinding, chipping or planing.
In locations subject to plastic hinge rotation at ultimate loading, holes for
rivets or bolts in the tension area shall be subpunched and reamed or drilled
full size.
(292)
TABLE 28-4-33
POR 33 KSI SPECIFIED YIELD POINT STEEL
Formula (22)
Mp \PyJ
M <M
l/r
B
G
l/r
B
G
l/r
B
G
16
1.140
1.172
51
1.164
1.271
86
1.201
1.616
17
1.140
1.174
52
1.165
1 . 276
87
1.202
1.633
18
1.141
1.177
53
1.165
1.281
88
1.204
1.651
19
1.141
1.179
54
1.166
1.286
89
1.205
1.669
20
1.142
1.182
55
1.167
1.292
90
1.206
1.688
21
1.142
1.184
56
1.168
1.297
91
1.207
1.707
22
1.143
1.187
57
1.169
1.303
92
1.209
1.726
23
1.143
1.189
58
1.170
1.310
93
1.210
1.746
24
1.144
1.191
59
1.171
1.316
94
1.211
1.767
25
1.145
1.194
60
1.172
1.323
95
1.213
1.788
26
1.145
1.196
61
1.173
1.330
96
1.214
1.810
27
1.146
1.198
62
1.174
1.337
97
1.215
1.832
28
1.146
1.200
63
1.175
1.344
98
1.217
1.855
29
1.147
1.203
64
1.176
1.352
99
1.218
1.879
30
1.148
1.205
65
1.177
1.360
100
1.220
1.903
31
1.148
1.207
66
1.178
1.369
101
1.221
1.928
32
1.149
1.209
67
1.179
1.377
102
1.222
1.953
33
1.150
1.212
68
1.180
1.386
103
1.224
1.979
34
1.150
1.215
69
1.181
1.396
104
1.225
2.006
35
1.151
1.217
70
1.182
1.406
105
1.227
2.033
36
1.152
1.220
71
1.183
1.416
106
1.228
2.061
37
1.152
1.222
72
1.184
1.426
107
1.230
2.090
38
1.153
1.225
73
1.186
1.437
108
1.231
2.119
39
■1.154
1.228
74
1.187
1.448
109
1.233
2.149
40
1.155
1.231
75
1.188
1.460
110
1.234
2.179
41
1.155
1.234
76
1.189
1.472
111
1.236
2.211
42
1.156
1.237
77
1.190
1.485
112
1.237
2.243
43
1.157
1.240
78
1.191
1.497
113
1.239
2.275
44
1.158
1.243
79
1.192
1.511
114
1.240
2.309
45
1.159.
1.247
80
1.194
1.524
115
1.242
2.343
46
1.159
1.251
81
1.195
1.539
116
1.243
2.378
47
1.160
1.254
82
1.196
1.553
117
1.245
2.414
48
1.161
1.258
83
1.197
1.568
118
1.247
2.450
49
1.162
1.263
84
1.198
1.584
119
1.248
2.487
50
1.163
1.267
85
1.200
1.600
120
1.250
2.525
(293)
TABLE 28->l~36
FOR 36 KSI SPECIFIED YIELD POINT STEEL
Formula (22)
8— °te)
M <M,
l/r
B
G
l/r
B
G
l/r
B
G
16
1.137
1.173
51
1.163
1.285
86
1.203
1.693
17
1.137
1.176
52
1.164
1.291
87
1.204
1.713
18
1.138
1.179
53
1.165
1.296
88
1.206
1.734
19
1.139
1.182
54
1.166
1.303
89
1.207
1.755
20
1.139
1.184
55
1.166
1.309
90
1.208
1.777
21
1.140
1.187
56
1.167
1.316
91
1.210
1.799
22
1.140
1.189
57
1.168
1.323
92
1.211
1.822
23
1.141
1.192
58
1.170
1.330
93
1.213
1.846
24
1.142
1.194
59
1.171
1.337
94
1.214
1.870
25
1.142
1.196
60
1.172
1.345
95
1.215
1.895
26
1.143
1.199
61
1.173
1.354
96
1.217
1.921
27
1.143
1.201
62
1.174
1.362
97
1.218
1.947
28
1.144
1.204
63
1.175
1.371
98
1.220
1.974
29
1.145
1.206
64
1.176
1.380
99
1.221
2.002
30
1.145
1.209
65
1.177
1.390
100
1.223
2.030
31
1.146
1.211
66
1.178
1.400
101
1.224
2.059
32
1.147
1.214
67
1.179
1.410
102
1.226
2.089
33
1.148
1.216
68
1.180
1.421
103
1.227
2.120
34
1.148
1.219
69
1.181
1.432
104
1.229
2.151
35
1.149
1.222
70
1.183
1.444
105
1.231
2.183
36
1.150
1.225
71
1.184
1.456
106
1.232
2.216
37
1.151
L.228
72
1.185
1.468
107
1.234
2.249
88
1.151
1.231
73
1.186
1.481
108
1.235
2.283
39
1.152
1.234
74
1.187
1.494
109
1.237
2.318
40
1.153
1.237
75
1.189
1.508
110
1.239
2.354
41
1.154
1.241
76
1.190
1.522
111
1.240
2.391
42
1.155
1.244
77
1.191
1.537
112
1.242
2.429
43
1.155
1.248
78
1.192
1.552
113
1.244
2.467
44
1.156
1.252
79
1.194
1.568
114
1.245
2.506
45
1.157
1.256
80
1.195
1.584
115
1.247
2.546
46
1.158
1.260
81
1.196
1.601
116
1.249
2.587
47
1.159
1.265
82
1.197
1.618
117
1.250
2.628
48
1.160
1.270
83
1.199
1.636
118
1.252
2.671
49
1.161
1.275
84
1.200
1.654
119
1.254
2.714
50
1.162
1.280
85
1.201
1.673
120
1.256
2.759
(294)
TABLE 28-5-33
FOR 33 KSI SPECIFIED YIELD POINT STEEL
M <M,
Formula (23)
S---* (£)-'©'
l/r
H
J .
l/r
H
J
l/r
H
J
1
.434
.753
41
1.015
.149
81
1.824
- .738
2
.449
.736
42
1.032
.133
82
1.850
- .769
3
.463
.720
43
1.048
.116
83
1.877
- .801
4
.478
.703
44
1.064
.0998
84
1.903
- .833
5
.492
.687
45
1.081
.0832
85
1.930
- .866
6
.506
.671
46
1.097
.0663
86
1.958
- .900
7
.520
.655
47
1.114
.0492
87
1.986
- .934
8
.534
.640
48
1.131
.0318
88
2.014
- .969
9
.548
.624
49
1.148
.0143
89
2.042
-1.004
10
.562
.609
50
1.166
-.0036
90
2.071
-1.041
11
.576
..594
51
1.183
-.0217
91
2.101
-1.077
12
.590
.579
52
1.201
-.0401
92
2.130
-1.115
13
.604
.564
53
1.219
-.0588
93
2.161
-1.153
14
.619
.549
54
1.237
- . 0777
94
2.191
-1.192
15
.633
.534
55
1.256
-.0970
95
2.222
-1.231
16
.647
.519
56
1.274
-.117
96
2.254
- 1 . 272
17
.661
.504
57
1.293
-.137
97
2.286
-1.313
18
.675
.490
58
1.312
-.157
98
2.318
- 1 . 354
19
.689
.475
59
1.332
-.177
99
2.350
-1.397
20
.703
.461
60
1.351
-.198
100
2.384
-1.440
21
.717
.447
61
1.371
-.220
101
2.417
-1.484
22
.731
.432
62
1.391
-.241
102
2.451
-1.529
23
.746
.418
63
1.411
-.263
103
2.486
- 1 . 575
24
.760
.403
64
1.432
-.286
104
2.521
-1.621
25
.774
.389
65
1.452
-.309
105
2.556
- 1 . 668
26
.789
.374
66
1.473
-.332
106
2.592
-1.716
27
.803
.360
67
1.495
-.356
107
2.628
- 1 . 765
28
.818
.345
68
1.516
-.380
108
2.665
-1.814
29
.832
.331
69
1.538
-.404
109
2.703
-1.865
30
.847
.316
70
1.560
-.429
110
2.741.
-1.916
31
.862
.301
71
1.583
-.455
111
2.779
-1.968
32
.877
.287
72
1.605
-.481
112
2.818
-2.021
33
.892
.272
73
1.628
-.507
113
2.857
-2.057
34
.907
.257
74
1.652
-.534
114
2.897
-2.123
35
.922
.242
75
1.675
-.562
115
2.937
-2.185
36
.937
.227
76
1.699
-.590
116
2.978
-2.242
37
.953
.211
77
1.724
-.618
117
3 . 020
- 2 . 300
38
.968
.196
78
1.748
-.647
118
3.062
-2.358
39
.984
.180
79
1.773
-.677
119
3 . 104
-2.417
40
1.000
.165
80
1.799
-.707
120
3.147
-2.478
(295)
TABLE 28-5-36
FOR 36 KSI SPECIFIED YIELD POINT STEEL
M <M0
Formula (23)
M0
Mr
- 1.0 -H
©-
M <M„
l/r
H
J
l/r
H
J
l/r
H
J
1
.435 .
.753
41
1.036
.137
81
1.904
- .817
2
,450
.736
42
1.053
.121
82
1.932
- .851
3
.464
.719
43
1.070
.104
83
1.961
- .888
4
.479
.702
44
1.087
.0867
84
1.990
- .922
5
.494
.686
45
1.105
.0692
85
2.020
- ,958
6
.508
.670
46
1.122
' .0516
86
2.050
- .996
7
.523
.654
47
1.140
.0336
87
2.080
-1.034
8
.537
.638
48
1 . 158
.0154
88
2.111
-1.072
9
.552
.622
49
1.176
-.0031
89
2.142
-1.112
10
.566
.607
50
1.195
-.0219
90
2.174
-1.152
11
.581
.591
51
1.213
-.0411
91
2.206
-1.193
12
.595
.576
52
1.232
-.0605
92
2.239
-1.234
13
.610
.561
53
1.251
-.0803
93
2.272
-1.277
14
.624
.546
54
1.271
-.100
94
2.306
-1.320
15
.639
.531
55
1.290
-.121
95
2.340
- 1 . 364
18
.653
.516
56
1.310
-.142
96
2.375
- 1 . 409
17
.668
.501
57
1.330
-.163
97
2.410
-1.455
18
.682
.486
58
1.351
-.185
98
2.445
-1.501
19
.697
.472
59
1.371
-.207
99
2.482
-1.54S
20
.711
.457
60
1.392
-.229
100
2.518
-1.597
21
.726
.442
61
1.413
-.252
101
2 . 555
- 1 . 646
22
.741
.428
62
1.435
-.275
102
2.593
-1.698
23
.755
.413
63
1.456
-.299
103
2.631
-1.747
24
.770
.398
64
1.478
-.323
104
2.670
-1.799
25
.785
.384
65
1.501
-.348
105
2.709
-1.852
26
.800
.369
66
1.523
-.373
106
2.749
-1.906
27
.815
.354
67
1.546
-.399
107
2.789
-1.960
28
.830
.340
68
1.570
-.425
108
2.830
-2.016
29
.845
.325
69
1.593
- . 452
109
2.871
-2.073
Ov)
.860
.310
70
1.617
-.479
110
2.914
-2.130
31
.876
.295
71
1.641
-.507
111
2.956
-2.189
no
.891
.280
72
1.666
-.535
112
2.999
-2.248
33
.907
.265
73
1.691
-.564
113
3.043
-2.309
34
.922
.249
74
1.716
-.593
114
3.087
-2.371
35
.938
.234
75
1.742
-.623
115
3.132
-2.433
36
.954
.218
76
1.768
-.654
116
3.178
-2.497
37
.970
.202
77
1.794
-.685
117
3.224
-2.562
I 38
.987
.186
78
1.821
-.717
118
3.271
-2.627
1
39
1.003
.170
79
1.848
-.750
119
3.318
- 2 . 694
1 40
1
1.020
.154
80
1.876
- .783
120
3.366
-2.762
(296)
PART 29
EXCAVATIONS AND FOUNDATIONS
ACKNOWLEDGEMENTS
The revision of Part 29 of the Building Code, as amended by Ordinance
and published herein, was accomplished by the Technical Committee whose
members are listed below. Months and years were spent in accumulating
and compiling the data in this part of the code. Many technical societies
and professional organizations, representative of the building industry of
Boston, assisted in this work by valuable criticism and suggestion. The
work was finally reviewed and recommended for approval by an Advisory
Committee appointed by Mayor John F. Collins.
TECHNICAL FOUNDATION COMMITTEE
Me. H. A. Mohr, Consulting Engineer, Chairman
Prop. Arthur Casagrande, Professor of Soil Mechanics and Foundation
Engineering, Harvard University
Mr. Henry Brask, President, Brask Engineering Company
Mr. F. E. Brown, Chief Civil Engineer, Cleverdon, Varney & Pike, Consulting
Engineers
Mr. James F. Haley, Haley & Aldrich, Consulting Soil Engineers
Mr. 0. G. Julian, Chief Structural Engineer, Jackson & Moreland, Inc.
Mr. Harry J. Keefe, Chief Engineer, Maginnis & Walsh & Kennedy
Mr. William J. LeMessurier, Wm. J. LeMessurier & Associates, Inc.
Mr. Frank L. Lincoln, Fay, Spofford & Thorndike, Inc.
Mr. Mark Linenthal, Linenthal & Becker, Engineers
Mr. Paul W. Norton, Nichols, Norton & Zaldastani, Engineers
Mr. Maurice A. Reidy, Jr., Maurice A. Reidy Associates, Engineers
Mr. Richard C. Tousley, Shepley, Bulfinch, Richardson <& Abbott, Architects
Dr. Othar Zaldastani, Nichols, Norton & Zaldastani, Engineers
ADVISORY COMMITTEE
C. Clark Macomber, Chairman
Col. Robert E. York, Building Commissioner
Mr. Neil MacKenzie, Representative of Labor
Mr. Frederick W. Westman, Whelan & Westman, Architects
Mr. Edward C. Keane, Fay, Spofford & Thorndike, Inc.
Mr. Frank A. Marston, Metcalf & Eddy, Engineers
Mr. John C. Cronin, C. H. Cronin, Inc.
Mr. Lawrence Moore, Assistant Corporation Counsel
(297)
PART 29
EXCAVATIONS AND FOUNDATIONS
Ordinances op 1962, Chapter 10
Chapter 479 of the Acts of 1938 was amended, by striking out Part 29
as amended by chapter 8 of the Ordinances of 1943, and chapter^ of the Ordi-
nances of 1955, and inserting in place thereof a new Part 29.
Passed by the City Council, October 1, 1962.
Approved by the Mayor, October 3, 1962.
February 25, 1963
(298)
Sec. 2901
PART 29.
EXCAVATIONS AND FOUNDATIONS.
Section
2901 — Excavations.
2902 — General Requirements for Foundations.
2903 — Soil Information.
2904 — Classification of Bearing Materials and Allowable Bearing
Values.
2905 — Foundation Loads.
2906 — Foundation Design.
2907 — Footings and Foundation Piers.
2908 — Driven Piles — General Requirements.
2909 — Allowable Load on Piles.
2910 — Wood Piles — General Requirements.
291 1 — Precast Concrete Piles.
2912 — Cast-in-Place Concrete Piles.
2913 — Steel and Steel Concrete Piles.
2914 — Composite Piles.
2915 — Bearing Tests.
2916 — Settlement Analysis.
Section 2901. Excavations. — (a) Until provision for permanent sup-
port has been made, excavations shall be properly guarded and protected by
the persons causing them to be made so as to prevent such excavation from
becoming dangerous, in the opinion of the commissioner, to life or limb, or to
prevent adjoining soil from moving or caving, or to preserve or protect any
wall, building, or structure from injury. Where necessary, excavations shall
be sheet-piled, braced, or shored, and permanent excavations shall be pro-
tected by retaining walls or other permanent structures to prevent movement
or caving of the adjoining soil.
(b) Structures near an excavation and owned by another than the person
causing the excavation to be made shall be supported as follows:
(1) Where an excavation is carried below the curb grade, at the com-
mon property line, or below the surface of the ground where there is no
such curb grade, the person causing such excavation to be made shall,
at all times, if accorded the necessary license to enter upon the adjoining
land, and not otherwise, at his own expense, preserve and protect from
injury any wall, building, or structure, the safety of which may be affected
by said excavation, and shall support it by proper foundations. If the
necessary license is not accorded to the person making such excavation
then it shall be the duty of the owner refusing to grant such license to make
such wall, building, or structure safe and to support it by proper founda-
tions; and, when necessary for that purpose, such owner shall be permitted
to enter upon the premises where such excavation is being made.
(2) Where a party wall is intended to be used by the person causing
the excavation to be made, he shall, at his own expense, preserve such
party wall from injury and shall support it so that the said party wall shall
be eafe for the purposes intended.
(299)
Sees. 2901-2902
(c) If the person whose duty it shall be under the provisions of this sec-
tion to guard and protect an excavation, or to prevent adjoining soil from
moving or caving, or to preserve or protect any wall, building, or structure
from injury, shall neglect or fail so to do, the commissioner may enter
upon the premises, and make safe such excavation, wall, building, or other
structure as provided in section 116 of Part 1.
Sect. 2902. General Requirements for Foundations. — (a) The
foundations of every permanent structure shall be supported by satisfactory
bearing material which shall mean:
(1) Natural deposits of rock, gravel, sand, rock flour (inorganic silt),
inorganic clay, or any combination of these materials;
(2) Compacted fills which satisfy the provisions of Section 2904 (a) (4);
(3) Natural deposits or artificial fills which can be changed into satis-
factory bearing materials by preconsolidation with a temporary surcharge
in accordance with the provisions of Section 2904 (a) (5).
(b) 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.
(c) Foundations shall be constructed so that freezing temperatures will
not penetrate into underlying soils that contain more than five 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 2902 (d), shall be carried down at least four
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 urless adequately protected.
(d) Foundations of detached garages or similar accessory structures not
exceeding eight hundred square feet in area and not over one story high, and
grade beams of all structures, need not be carried more than one foot below
an adjoining surface exposed to natural freezing if the underlying soil to a
depth of at least four feet beneath the surface, and extending at least four
feet outside the budding, is sand, gravel, cinders, or other granular materials
containing not more than five per cent (by weight) passing a No. 200 mesh
sieve.
(e) Foundations subject to hydrostatic uplift shall have adequate pro-
visions to prevent heaving.
(f) Basements and cellars shall be waterproofed up to the maximum
probable ground-water level. Under boilers, furnaces, and other heat-
producing apparatus, suitable insulation shall be installed to protect the
waterproofing against damage from heat as specified in Part 21. Founda-
tions under heat-producing units shall be so insulated as to prevent evapora-
tion of moisture from any underlying soil that is subject to shrinkage, and
to protect the heads of wood piles against damage from heat.*
(300)
Sees. 2903-2904
Sect. 2903. Soil Information. — (a) Before issuing a permit for the
erection of a permanent structure, or for the alteration of a permanent
structure that may affect its foundation, the commissioner shall be furnished
with adequate soil data by the applicant. Where borings or tests are re-
quired, 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 analysis, as are necessary in the opinion of the commissioner.
When it is proposed to support the structure directly on bedrock, the com-
missioner may require drill holes or core borings to be made into the rock to a
sufficient depth to prove that bedrock has been reached.
(b) Duplicate copies of the results obtained from all completed and un-
completed borings, plotted to true relative elevation and to scale, and of all
test results or other pertinent soil data shall be filed with the commissioner.
Sect. 2904. Classification of Bearing Materials and Allowable
Bearing Values. — (a) The terms used in this section shall be interpreted
in accordance with generally accepted engineering nomenclature. In addi-
tion, the following more specific definitions are used for bearing materials in
the Greater Boston area:
(1) Rocks
Shale — A soft, fine-grained sedimentary rock.
Slate — A hard, fine-grained metamorphic rock of sedimentary origin.
Roxbury Puddingstone — A hard, well-cemented conglomerate.
(2) Granular Materials
Gravel — A mixture of mineral grains at least seventy 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 per cent (by weight)
of which passes a No. 4 mesh sieve and which contains not more than
fifteen per cent (by weight) passing a No. 200 mesh sieve.
Coarse Sand — A sand at least fifty per cent (by weight) of which is
retained on a No. 20 mesh sieve.
Medium Sand — A sand at least fifty per cent (by weight) of which passes
a No. 20 mesh sieve and at least fifty per cent (by weight) is retained on a
No. 60 mesh sieve.
Fine Sand — A sand at least fifty 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 per cent and seventy per cent (by weight)
passing a No. 4 mesh sieve, between ten and forty per cent (by weight)
passing a No. 20 mesh sieve, and containing not more than eight per cent
(by weight) passing a No. 200 mesh sieve.
(3) Cohesive Materials
Hardpan — A glacial till that generally lies directly over bedrock and
consists of a highly compacted, heterogeneous mixture ranging from very
fine material to coarse gravel and boulders. It can be identified from
geological evidence and from the very high penetration resistance en-
countered in earth boring and sampling operations.
(301)
Sec. 2904
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.
Rock Flour and 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.)
(4) Compacted Granular Fill.
(a) A fill consisting of gravel, sand-gravel mixtures, coarse or medium
sand, crushed stone, or slag, containing not more than five per cent (by
weight) passing a No. 200 mesh sieve, shall be considered satisfactory
bearing material when compacted by one of the following methods:
I. In six-inch layers, each layer with at least four coverages with the
treads of a crawler-type tractor with a total weight, including equip-
ment, of not less than fifteen tons and operated at its top speed;
II. In twelve-inch layers, with at least three coverages with the
wheels of a rubber-tired roller having four wheels abreast and weighted
to a total load of not less than thirty-five tons;
III. Other types of materials and other compaction equipment,
such as vibrators, may be approved by the Commissioner on the
basis of sufficient evidence that they will achieve compacted fills
having satisfactory properties.
(b) Application of water is permitted, and for some sands may be
required in order to achieve satisfactory traffic-ability and compaction.
(c) The commissioner 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. When-
ever the commissioner 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 require-
ments of Section 2915. A copy of all these records and test data shall
be filed with the commissioner.
(5) Preloaded Highly Compressible Materials.
The Commissioner may allow the use of certain otherwise unsatisfactory
natural soils and uncompacted fills for the support of one story structures,
(302)
Sec. 2904
after these materials have been preloaded to not less than one hundred and
fifty per cent of the stresses which will be induced by the structure.
The commissioner may require the loading and unloading of a sufficiently
large area, conducted under the direction of a competent engineer, approved
by the commissioner, who shall submit a report containing a program which
will allow sufficient time for adequate consolidation of the material, and an
analysis of the preloaded material and of the probable settlements of the
structure.
(b) The maximum pressure on soils under foundations shall not exceed
the allowable bearing values set forth in the following table, except when
determined in accordance with the provisions of Section 2915, and in any
case subject to the modifications of subsequent paragraphs of this section.
Allowable Bearing
Value in Tons per
Class Material Square Foot (*)
1 Massive igneous rooks and Rozbury Puddingstone, all in sound condi-
tion (sound condition allows minor cracks) 100
2 Slate in sound condition (minor cracks allowed) 50
3 Shale in sound condition (minor cracks allowed) 10
4 Residual deposits of shattered or broken bedrock of any kind except
shale 10
5 Hardpan 10
6 Gravel, well-graded sand and gravel 5
7 Coarse sand 3
8 Medium sand 2
9 Fine sand 1 to 2 (J)
10 Hard clay 5
11 Medium clay 2 (t)
12 Soft clay 1 (f)
13 Rock flour, inorganic silt, shattered shale, or any natural deposit of
unusual character not provided for herein (J)
14 Compacted granular fill 2 to 5 (J)
15 Preloaded highly compressible materials (J)
* The allowable bearing value given in this section, or when determined in accordance
with the provisions of Section 2915, will assure that the soils will be stressed within limits
that lie safely below their strength. However, such allowable bearing values for Classes 9 to
12, inclusive, do not assure that the settlements will be within the tolerable limits for a given
structure.
f Alternatively, the allowable bearing value shall be computed from the unoonfined com-
pressive 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: for intermediate ratios interpolation may be used.
% Value to be fixed by the commissioner in accordance with Sections 2915 and 2903.
(c) The tabulated bearing values for rocks of Classes 1 to 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 per
cent for each foot of additional depth, but shall not exceed three times the
tabulated values.
(d) The allowable bearing values of materials of Classes 4 to 9, inclusive,
may exceed the tabulated values by five per cent for each foot of depth of the
(303)
Sees. 2904-2905
loaded area below the minimum required in Section 2906 (c), but shall not
exceed twice the tabulated values. For areas of foundations smaller than
three feet in least lateral dimension, the allowable design bearing values
shall be one third of the allowable bearing values multiplied by the least
lateral dimension in feet.
(e) The tabulated bearing values 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 the tabulated bearing values. Whenever there is
any doubt about the settlements of a proposed structure or the effect on
neighboring structures, the commissioner shall require that the magnitude
and distribution of the probable settlements be investigated as specified in
Section 2916.
(f) The computed vertical pressure at any level beneath a foundation
shall not exceed the allowable bearing values 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 degrees with the horizontal; but the area con-
sidered as supporting the load shall not extend beyond the intersection of
sixty degree planes of adjacent foundations.
Sect. 2905. Foundation Loads. — (a) The loads to be used in comput-
ing the pressure upon bearing materials directly underlying foundations
shall be the live and dead loads of the structure, as specified in Part 23,
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-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.
(b) Eccentricity of loading in foundations shall be fully investigated and
the maximum pressure on the basis of straight-line distribution shall not
exceed the allowable bearing values.
(c) Where the pressure on the bearing material due to wind is less than
one third of that due to dead and live loads, it may be neglected in the founda-
tion design. Where this ratio exceeds one third, foundations shall be so
proportioned that the pressure due to combined dead, live, and wind loads
shall not exceed the allowable bearing values by more than one third.
(d) One-story structures without masonry walls and not exceeding eight
hundred square feet in area may be founded on a layer of satisfactory bearing
material not less than three feet thick, which is underlain by highly com-
pressible material, provided that the stresses induced in the unsatisfactory
material by the live and dead loads of the structure and the weight of any new
fill, within or adjacent to the building area, will not exceed two hundred and
fifty pounds per square foot.
(304)
Sees. 2905-2907
(e) The pressures against foundation walls and other types of retaining
walls shall be fully investigated. Particular attention shall be paid to re-
straints which may cause substantially larger earth pressures than the active
earth pressure, and to the type of backfill and drainage. In addition to earth
pressure, such walls shall be designed and constructed to resist hydrostatic
pressures corresponding to the maximum probable ground water level.
Sect. 2906. Foundation Design. — (a) Foundations shall be designed
to distribute to the supporting materials all vertical, horizontal and inclined
loads, as specified in Section 2905, without exceeding the allowable stresses
specified elsewhere in this Code for the materials of which the foundations
are to be constructed.
(b) Plain concrete in foundations shall have a minimum compressive
strength at twenty-eight days of two thousand pounds per square inch.
Reinforced concrete in foundations shall have a minimum compressive
strength of twenty-five hundred pounds per square inch at twenty-eight
days.
(c) The bottom surface of any footing resting on material of Classes 4 to
15, inclusive, shall be at least eighteen inches below the lowest ground surface
or the surface of a floor slab bearing directly on the soil immediately adjacent
to the footing;
(d) Whenever, in an excavation, soil and ground water conditions are
such that an inward or upward seepage is produced in the bearing material,
special excavating methods and control of ground water shall be employed
to prevent disturbance of the bearing material in the excavation or under
existing structures. If there is evidence of disturbance of the bearing ma-
terial, the extent of the disturbance shall be evaluated and appropriate
remedial measures taken, satisfactory to the commissioner.
Sect. 2907. Footings and Foundation Piers. — (a) The footings of
foundation walls or piers shall be of plain or reinforced concrete or other
satisfactory masonry, or steel grillages. Structural steel grillage foundations
shall have at least six inches of concrete cover below the bottom of the steel
and shall have at least four inches of concrete cover above the steel and
between the sides of the steel and the adjacent soil. Footings of wood may
be used under temporary structures.
(b) A foundation pier is here defined as a structural member which ex-
tends 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.
(1) The manner of construction shall be by non-displacement methods
and shall permit inspection of the bearing material in place.
(2) The bases of foundation piers may be enlarged by spread footings,
pedestals or belled bottoms.
(3) Bell-shaped bases shall have a minimum edge thickness of four
inches. The bell roof shall slope not less than sixty degrees with the hori-
zontal unless the base is designed in accordance with Part 26.
(305)
Sees. 2907-2908
(4) Foundation piers may be designed as concrete columns with con-
tinuous lateral support. The unit compressive stress in the concrete at
the least cross section shall not exceed twenty-two and one half per cent
of the twenty-eight day strength of the concrete nor nine hundred pounds
per square inch.
(5) When the center of cross section of a foundation pier at any level
deviates from the resultant of all forces more than one sixtieth of its height,
or more than one tenth of its diameter, it shall be reinforced as provided
in Part 26. The restraining effect of the surrounding soil may be taken
into account.
(6) With approval of the commissioner, concrete may be placed through
still water by means of a properly operated tremie or bottom-dump bucket.
(7) The owner shall engage a competent inspector, qualified by ex-
perience and training and satisfactory to the commissioner, to be present
at all times while foundation 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 con-
struction. A copy of these records shall be filed in the office of the com-
missioner.
Sect. 2908. Driven Piles — General Requirements. — (a) Types of pile
construction not specifically provided for in this part shall meet such addi-
tional requirements as may be prescribed by the commissioner.
(b) A detached column supported by piles shall rest upon|not less than
three piles, at least one of which is offset; except that for one story buildings
a detached column may rest upon two piles when its axis is not more than
one and one half inches off the line connecting the centers of the two 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 inches off the center of the pile.
(c) A foundation wall, restrained laterally so as to ensure^stability both
during and after construction, may be supported by a single row of piles.
(d) The method of driving shall be such as not to impair the strength
of the pile and shall meet with the approval of the commissioner. Measure-
ments to determine the value of "s" shall not be made immediately after the
introduction of fresh cushion block material, or an interruption in the driving
operation or when the pile head is shattered, broomed, crumpled, or other-
wise damaged.
The cushion block, where used, shall be of hardwood with itsjjrains parallel
with the axis of the pile and be enclosed in a tight-fitting steel housing, or an
approved 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 or hood suitable for encasing
the pile head and to protect it from being damaged during driving.
(306)
Sees. 2908-2909
(e) Jetted piles shall be driven to the required resistance after the flow
of jet water has stopped, except as provided in Section 2909 (c) (5).
(f ) When piles have been damaged in driving, or driven in locations 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.
(g) Concrete for capping piles shall be proportioned for a minimum
compressive strength at twenty-eight days of at least twenty-five hundred
pounds per square inch. The concrete shall extend not less than twelve
inches above the pile heads and shall fill the space between and around the
piles for a depth of at least three inches. The minimum horizontal distance
from the edge of the pile cap to the nearest pile surface shall be six inches
and there shall be at least two inches of concrete between the top of a pile
and steel reinforcement.
(h) Where piles are driven through soft soil to hard bearing material
providing high point resistance, the grades of all piles or pile casings previ-
ously driven or redriven shall be measured to detect uplift; and if uplift of
one half 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.
(i) 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 applicable provisions of this code.
(j) The owner shall engage a competent inspector, qualified by experience
and training and satisfactory to the commissioner, 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 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 commissioner.
Sect. 2909. Allowable Load on Piles. — (a) The supporting capacity
of piles shall be obtained from bearing upon or embedment in bearing ma-
terials as defined in Section 2904.
(b) The allowable load on a single pile shall be limited by the requirement
that such load shall not cause excessive movement of the pile relative to the
soil. Satisfactory proof of this load can be obtained from load tests conducted
in accordance with Section 2915. In the absence of such proof of the support-
ing capacity, except for the types of piles covered in Sections 2912 (d) and
2913 (d), the load on a single pile shall not exceed the higher of the two values
determkied in accordance with Sections 2909 (c) and 2909 (d).
(307)
Sec. 2909
(c) (1) The allowable load may be computed by means of the following
driving formula:
1.7 E
R =
I wp
where
R — allowable pile load in pounds
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
manufacturer. For batter piles, proper allowance shall
be made for the resultant loss of energy.
Wn
— = the ratio of the weight wp of the pile and other driven parts to the
wr
weight wr 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
inches of driving, except that if an abrupt high increase
in resistance is encountered, "s" shall be taken as th«
average penetration per blow for the last five blows. The
minimum value of "s" which may be used in the formula
is five hundredths of an inch.
(2) The energy E per blow in foot-pounds delivered by the hammer
shall be numerically not less than fourteen per cent of R in pounds and
w
— - shall not be greater than 3.5.
w,
(3) The value of "s" must be determined with the hammer operating
at not less than ninety per cent of the maximum number of blows per minute
for which the hammer is designed.
(4) If the driving of the pile has been interrupted for more than one
hour, the value of "s" shall not be determined until the pile is driven at
least an additional twelve inches, except when it encounters refusal on or
in a material of Classes 1 to 5, inclusive.
(5) 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 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.
(d) The allowable load on a pile stopped in inorganic clay as found in
Greater Boston, may be based on a friction value of five hundred pounds per
square foot of embedded pile surface for a design load not to exceed twenty-
two tons, or on a friction value determined from pile load tests. The em-
(308)
Sees. 2909=2910
bedded length shall be the length of the pile below the surface of the inorganic
clay, or below the surface of immediately overlying satisfactory bearing
material. The area of embedded pile surface shall be computed by multiply-
ing the embedded length by the perimeter of the smallest circle or polygon
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 ma-
terials.
(e) In case piles in clusters are driven under the provisions of Section
2909 (d), the allowable load shall be computed for the smaller of the following
two areas: (1) the sum of the embedded pile surfaces of individual piles;
(2) the area obtained by multiplying the perimeter of the polygon circum-
scribing the cluster at the surface of the satisfactory bearing material by the
average embedded length of pile.
(f) The allowable load on a single pile installed by jacking shall not
exceed one half the load applied to the pile at the completion of jacking,
provided that the final load is kept constant for a period of four hours and
that the settlement during that period does not exceed one twentieth of an
inch.
(g) 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 all piles in a foundation shall not exceed the allowable bearing values
of such materials, as given in Section 2904, or determined in accordance with
the provisions of Section 2915. Piles or pile groups shall be assumed to
transfer their loads to the underlying materials by spreading the load uni-
formly at an angle of sixty 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 degree planes of adjacent
piles or pile groups.
(h) 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.
(i) The allowable bearing value of a pile shall not be limited to the value
obtained by multiplying its point area by the allowable bearing value given
in Section 2904.
Sect. 2910. Wood Piles — General Requirements. — (a) Every wood
pile shall be in one piece, cut from a sound live tree, and free from defects
which may materially impair its strength or durability.. It shall be butt-cut
above the ground swell, and shall have substantially uniform taper from
butt to point. Wood piles shall measure at least six inches in smallest diameter
at the point and at least ten inches in smallest diameter at the cut-off, these
measurements being taken under the bark. The axis of a wood pile shall not
deviate from a straight line more than one inch for each ten feet of length nor
more than six inches for the entire length.
(309)
Sec. 2910
(b) The load on a wood pile shall not exceed the allowable load specified
in Section 2909 and, for a pile of the minimum dimensions specified in this
section, shall not exceed twelve tons for Spruce, Norway Pine, and woods of
similar strength which will be referred to as Type A, nor sixteen tons for Oak,
Southern Yellow Pine, and woods of similar strength which will be referred
to as Type B. These loads may be increased for each full inch by which both
the cut-off and point diameters exceed the minima specified, by three tons
for woods of Type A, but not to exceed a total load of twenty-four tons,
and by four tons for woods of Type B, but not to exceed a total load of thirty
tons.
(c) The load on wood piles driven to bearing on materials of Classes
1 to 5, inclusive, shall be not more than sixty per cent of that allowed in
Section 2910 (b).
(d) Piles shall be cut to sound wood before capping is placed.
(e) The center-to-center spacing of wood piles shall be not less than two
and one half times the cut-off diameter.
(f) 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. The
total driving energy in foot-pounds for six inches of penetration shall for all
types of hammers be numerically no greater than the point diameter in inches
times twenty-two thousand for woods of Type A or times thirty-two thousand
for woods of Type B. For the last inch of penetration the energy in foot-
pounds shall not exceed numerically the point diameter in inches multiplied
by six thousand. In any case driving shall be stopped immediately when
abrupt high resistance to penetration is encountered.
(g) The cut-off grade for untreated wood piles shall be below the probable
permanent ground-water level, and shall be subject to the commissioner's
approval.
(h) The Commissioner may require the owner to install and maintain in
good condition at least one ground-water observation well within the building,
which shall be accessible to the commissioner.
(i) Additional Requirements for Treated Piles
(1) Timber piles pressure treated with creosote or creosote-coal-tar
solution, ana conforming to the requirements of this section, may be cut
off above permanent ground water level when used for the support of build-
ings not exceeding two stories in height.
(2) Before any treated piles are driven, the commissioner shall be
furnished three copies of a certificate of inspection, issued by an approved
independent testing laboratory, 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.
(3) Treated piles shall be of Norway Pine, Southern Yellow Pine, or
Douglas Fir and shall be impregnated with preservative in accordance with
specifications of the American Wood Preservers' Association, as follows:
(310)
Sees. 2910-2911
Cl-61, "Standard for Preservative Treatment by Pressure Processes —
All Timber Products" and C3-60, "Standard for the Preservative Treat-
ment of Piles by Pressure Processes."
(4) Piles exposed to sea water shall be Southern Yellow or Norway
Pine, and the preservative used shall conform to the requirements for
Grade B of P2-58, "Standard for Creosote-Coal-Tar Solutions" of the
American Wood Preservers' Association. For piles not exposed to sea
water, the preservative used shall conform to Pl-54, "Standard for Creo-
sote" of the American Wood Preservers' Association.
(5) The retention of preservative shall be not less than twenty pounds
per cubic foot for piles exposed to sea water and not less than twelve pounds
per cubic foot for other piles.
(6) After being cut to grade, the top surface of the pile shall be brush
treated with not less than three heavy coatings of the treating material
applied hot.
Sect. 2911. Precast Concrete Piles. — (a) Precast concrete 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. The minimum lateral dimension of a precast concrete pile shall be
twelve inches except that the lower six feet may taper to eight inches at the
point exclusive of the metal point, if used. Each pile shall be cast in one
piece. The concrete shall have a minimum compressive strength of four
thousand pounds per square inch. No pile shall be handled or driven until
it has cured sufficiently to develop the necessary strength as shown by standard
test specimens made from the same batches of concrete cured under similar
conditions.
(b) Except as otherwise specified herein, piles shall be proportioned so
as to satisfy the requirements of Part 26. Additional requirements for steel
reinforcement are as follows: For a length equal to at least three times the
minimum lateral dimension at both ends of the pile, lateral ties shall be spaced
not over three inches center-to-center or an equivalent spiral shall be pro-
vided. Steel reinforcement shall be embedded in concrete forming the body
of the pile a net distance of at least one and one half inches from any exposed
surface and in piles exposed to sea water such coverage shall be at least three
Inches.
(c) The maximum water-cement ratio and the minimum cement content
of the concrete for piles exposed to sea water shall be four and one half gallons
per sack and eight sacks per cubic yard, respectively.
(d) The minimum spacing center-to-center of precast concrete piles shall
be two and one half times the square root of the cross-sectional area at the
butt.
(e) When precast concrete piles are 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.
(f) The load on a precast concrete pile shall not exceed the allowable
load specified in Section 2909, and shall not exceed fifty tons for a pile of one
(311)
Secs.291 1-2912
square foot cross-sectional area. For piles of larger cross-section, this limit
of load may be increased in proportion to increase in area, but not to exceed
a total load of ninety toDS.
Sect. 2912. Cast-in-PIace Concrete Piles. — (a) 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 or drive-pipe that is installed in the ground either permanently or
temporarily. A compacted-concrete pile is formed by placing concrete having
zero slump, in small batches, and compacting each batch.
(b) 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 pounds per square inch. While placing the concrete,
the casing or drive-pipe shall be free of water.
(c) Poured-Concrete Piles
(1) The diameters of metal-cased poured-concrete piles, when measured
on the outside of a plain cylinder, or the outside of horizontal, helical or
vertical corrugations, shall be not less than eight inches, one foot above the
point, nor less than twelve inches at cut-off. 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 adjoining
cylinders not exceeding one inch.
(2) For uncased poured-concrete piles (i.e., when no metal casing is
left in the ground) the inside diameter of the drive-pipe shall be not less
than fourteen and one half inches.
(3) The load on poured-concrete piles shall not exceed the allowable
load specified in Section 2909, nor twenty-two and one half per cent of the
twenty-eight day strength of the concrete, but not exceeding nine hundred
pounds per square inch, when applied to the cross-sectional areas computed
on the following bases:
I. 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 or a combination of bearing materials of Classes 5
and 6, using the diameter at tne surface of the bearing stratum, and as
further specified in Section 2912 (c) (1).
II. For metal-cased piles, driven through compressible materials,
including Classes 11, 12, 13, and 15 and into a bearing stratum consisting,
of one or a combination of bearing materials of Classes 5 to 10, inclusive,
using the diameter at the surface of the bearing stratum and as further
specified in Section 2912 (c) (1).
III. For uncased piles driven to or into any bearing material, using
the inside diameter of the drive-pipe minus three inches.
IV. In no case shall the maximum load on a poured-concrete pile
exceed ninety tons.
(312)
Sec. 2912
(4) 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 per cent from the original value, (b) the
point of the casing shall not deviate more than ten per cent of the length
of the pile from the design alignment, and (c) the casing shall not deviate
by more than four per cent of the length of the casing from a straight line
connecting the midpoints 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.
(5) The spacing of poured-concrete piles shall be such as to ensure
the preservation of the full cross-section. The spacing center-to-center
shall be not less than two and one half times the outside diameter of the
drive-pipe or of the casing at midlength. No casing or drive-pipe shall be
filled with concrete until all casings or drive-pipes within a radius of seven
feet, or within the heave range, whichever is the greater, have been driven
to the required resistance.
(d) Compacted Concrete Piles
The load on compacted concrete piles shall be limited by the provisions of
Section 2909 (g), 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 feet or more below said junction; and the allowable load
on a compacted concrete pile shall not exceed one hundred and twenty tons.
The installation of such piles shall fulfill the following listed requirements:
(1) The drive-pipe used for installing the pile shall be not less than
twenty inches outside diameter.
(2) The enlarged base of the pile shall be formed on or in bearing
materials of Classes 1 to 8, inclusive.
(3) The concrete shall have minimum compressive strength at twenty-
eight days of four thousand pounds per square inch, shall be of zero slump,
and shall be placed in batches not to exceed five cubic feet in volume.
(4) The last batch of concrete shall be driven into the enlarged base
with not less than twenty blows, each of not less than one hundred and
thirty thousand foot-pounds.
(5) As the drive pipe is being withdrawn, not less than two blows of
at least thirty thousand foot-pounds each shall be applied to compact
each batch of concrete in an uncased shaft.
(6) An uncased shaft shall not be formed through inorganic clay or
inorganic silt unless an excavation at least equal to the inside diameter of
the drive-pipe is first auger ed through such soil, or the individual piles
are located more than nine feet apart.
(7) An uncased shaft shall not be formed through peat or other organic
soils.
(8) A permanent metal-cased shaft, not less than sixteen inches in
diameter, shall be installed through inorganic clay or inorganic silt if
requirement (6) is not fulfilled. The permanent metal casing shall be
(313)
Sees. 2912-2913
fastened to the enlarged base in such a manner that the two will not sepa-
rate. 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 feet have been driven.
The stresses in metal-cased shafts shall not exceed nine hundred pounds
per square inch on the concrete and, in addition, eight thousand five hun-
dred pounds per square inch on the steel casing, provided that its wall
thickness is at least two-tenths of an inch.
(9) The center-to-center spacing of piles shall be not less than four
feet and six inches.
Sect. 2913. Steel and Steel-Concrete Piles. — (a) At locations where
steel and steel-concrete piles will be in contact with cinders, slag, organic
soils, or other materials that might cause corrosion of steel, one of the follow-
ing procedures shall be used:
(1) Remove all such objectionable material from within the area of
the structure and replace with inorganic soil.
(2) Deduct one-eighth of an inch in thickness from all surfaces in contact
with the objectionable material when computing the area of steel for
support of load. This reduction shall be applied from pile cut-off grade
to a grade fifteen feet below the bottom of the objectionable material.
(3) Effectively protect the steel surface from pile cut-off grade to a
grade fifteen feet below the bottom of the objectionable materials; e.g., by
means of cathodic protection or by a cover of at least three inches of con-
crete.
At locations where steel and steel-concrete piles will be in contact with sea
water, the steel from a grade ten feet below the ground surface to at least
five feet above mean high tide shall be protected by at least three inches of
concrete. The maximum water-cement ratio and the minimum cement
content of the concrete shall be four and one half gallons per sack, and eight
gacks per cubic yard, respectively.
(b) Concrete-Filled Pipe Piles
(1) Piles consisting of steel pipes and concrete-filled after driving,
shall have an outside diameter of not less than ten and three quarters inches
and a pipe wall thickness of at least two-tenths of an inch. The material
of the pipe shall meet the requirements for Grade 2 in Specifications for
Welded and Seamless Steel Pipe Piles, (A252-59) of the American Society
for Testing Materials. Splices shall be welded to one hundred per cent of
the strength of the pipe. Pipes may be driven open-ended or closed-ended,
and the provisions of the section apply to both types.
(2) After driving all pipes within a seven foot radius, and immediately
before filling with concrete, the inside of the pipe shall be thoroughly
cleaned to the bottom and inspected by lowering a fight bulb, or by means
of a light beam. To be acceptable: (a) the diameter shall not vary more
than twenty per cent from the original value, (b) the point of the pile shall
not deviate more than ten per cent of the length of the pile from the design
alignment and (c) the pile shall not deviate by more than six per cent of the
(314)
Sec. 2913
length of the pile from a straight line connecting the midpoints of the ends
of the pile. If the bottom of the pile is out of sight, or cannot be seen be-
cause 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.
(3) Pipes shall be filled with concrete having a minimum compressive
strength at twenty-eight days of three thousand pounds per square inch,
and as further specified in Part 26. Concrete shall not be placed through
water, except that the Commissioner may approve the use of a bottom-dump
bucket for concreting a bottom section of a pile, provided that the pile is
proven to be free of other materials.
(4) The center-to-center spacing of concrete-filled pipe piles shall be
not less than two and one half times the outside diameter of the pipe.
(5) The load on concrete-filled pipe piles shall not exceed the allowable
load determined in accordance with Section 2909, nor a load computed
on the basis of stress in the concrete at twenty-two and one half per cent
of the twenty-eight day strength, but not exceeding nine hundred pounds
per square inch, and stress in the steel at eight thousand five hundred
pounds per square inch, nor shall the load carried by the steel on this basis
exceed one half the total load on the pile.
(c) H Piles
(1) Rolled steel H or other approved sections shall meet the require-
ments of the Specifications for Steel for Bridges and Buildings (A7-61T)
of the American Society for Testing Materials. The minimum thickness
of metal shall be four tenths of an inch. If piles are spliced, the splice
shall develop one hundred per cent of the strength of the section.
(2) The center-to-center spacing of such piles shall be not less than two
and one half times the width of the flange or the depth of the section,
whichever is the greater.
(3) The load on such piles shall not exceed the allowable load deter-
mined in accordance with Section 2909, nor a load based on stress of seven
thousand five hundred pounds per square inch on the cross-section.
(d) Concrete-Filled Pipes with Steel Cores
(1) Concrete-filled pipes with steel cores may be used only when the
pipes can be firmly seated in bedrock of Classes 1 or 2, and shall be of
sufficient diameter to permit the inspection of the bedrock socket. Pipe
shall meet the requirements stated in Section 2913 (b) (1). If pipes are
spliced, the splices shall be welded to develop one hundred per cent of the
strength of the pipe.
(2) 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 ac-
cordance with Section 2904 (b) and (c), acting together with a bond stress
on the perimeter surface of the socket of one hundred 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 satis -
(315)
Sees. 2913=2915
factory to the Commissioner. This inspection may be performed by meang
of an underwater television camera, the position of which is readily con-
trollable to permit thorough inspection of the exposed rock surface in the
socket.
(3) The steel core shall consist of a structural steel member. The
mating ends of the sections shall be spliced so as to safely withstand the
stresses to which they may be subjected. The steel core shall be centered
in the steel pipe and shall rest in a layer of cement grout on the bottom
of the socket.
(4) The center-to-center spacing of such piles shall be not less than two
and one half times the outside diameter of the pipe.
(5) Concrete shall have a minimum compressive strength of four
thousand pounds per square inch at twenty-eight 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 concrete.
(6) 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 Commissioner for approval.
(7) The load on concrete-filled pipe piles with steel cores shall not
exceed the allowable load determined in accordance with the provisions of
Section 2913 (d) (2) nor that computed on the basis of nine hundred pounds
per square inch on the area of the concrete plus eight thousand five hundred
pounds per square inch on the net area of the steel pipe plus fifteen thousand
pounds per square inch on the area of the steel core.
Sect. 2914. Composite Piles. — (a) A composite pile shall consist of a
combination of not more than two of any of the different types of piles pro-
vided for in this part. The pile shall fulfill the requirements for each type
and in addition the provisions of this section. The connection between the
two types of piles shall be constructed so as to prevent their separation, to
maintain their alignment, to support the load, and to be watertight where
concrete must be placed subsequent to the driving. The design and the
details of the connection shall be subject to the Commissioner's approval.
(b) The requirements of Section 2912 (c) (4) shall apply to the entire
length of a pipe-composite pile.
(c) Wood-composite piles shall not be used for support of buildings ex-
ceeding two stories in height.
(d) The center-to-center spacing shall be governed by the larger of the
spacings, required in this part, for the types composing the pile.
(e) The allowable load on composite p;les shall be that allowed for the
weaker of the two sections. For wood-composite piles the allowable load shall
not exceed eighty per cent of that allowed for the wood section alone.
Sect. 2915. Bearing Tests. — (a) Whenever the allowable bearing value
on bearing materials on single piles or groups of piles is in doubt, the com-
missioner may require bearing tests to be made and the results analyzed
under the direction of a competent engineer approved by the commissioner.
(316)
Sec. 2915
(b) Before any bearing test is started, a sketch of the proposed test
arrangement and an outline of the procedure to be followed shall be sub-
mitted to the commissioner and shall have his written approval.
(c) Bearing tests shall be conducted in the presence of an inspector, quali-
fied by experience and training, and who is satisfactory to the commissioner.
A copy of the test results obtained and a graph of the time-settlement curve
for each increment of load and of the load-settlement and rebound curve for
the entire test shall be submitted to the commissioner at the completion of
each test.
(d) The load shall be applied by direct weight or by means of a newly
calibrated hydraulic jack. The application of the test load shall be in steps
equal to not more than one half the contemplated design load, to at least
twice the contemplated design load, except as provided in Section 2915 (g).
The unloading shall be in at least two steps, to the design load and then to
zero load. During the loading cycle the contemplated design load and twice
the contemplated design load shall be maintained constant for at least twenty-
four hours and until settlement or rebound does not exceed two hundredths
of an inch in twenty-four consecutive hours. The load for all other load steps
including the zero load at the end of the test shall be maintained constant for
a period of not less than four hours. Sufficient readings for each load step
shall be made to define properly the time-deflection curve.
(e) Observation of vertical movement shall be made with dial exten-
someters graduated to at least one thousandth of an inch. The readings shall-
be sufficient in number to define the progress of the settlement or rebound
and shall be referred to a beam, the ends of which rest on or are fixed to
reliable supports located at least eight feet from the center of the test. In
addition, the elevation of the supports shall be checked frequently with
reference to a fixed benchmark. The entire measuring setup shall be pro-
tected against direct sunlight, frost action, and other disturbances that
might affect its reliability. Temperature readings, both inside and outside
the test enclosure, shall be made when the vertical movements are recorded.
(f) Additional Requirements for Soil Bearing Tests
(1) 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.
(2) The excavation immediately surrounding an area to be tested shall
be made no deeper than one 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.
(3) For bearing materials of Classes 1 to 5, inclusive, the loaded area
shall be not less than one square foot and for other classes not less than
four square feet. For bearing materials of Classes 1 to 3, inclusive, the
commissioner may permit compression tests on rock cores to be substituted
for bearing tests. Each test specimen shall have a height not less than
twice its diameter.
(4) The proposed design load shall be allowed provided that the re-
quirements of Section 2904 are fulfilled and the settlements under the
(317)
Sees. 2915-2916
design load and twice the design load do not exceed three eighths of an
inch and one inch, respectively.
(g) Additional Requirements for Pile-Bearing Tests
(1) A single pile shall be load tested to not less than twice the design
load. When two or more piles are to be tested as a group, the total load
shall be not less than one and one half times the design load for the group.
(2) 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
inch, the maximum design load shall be the load allowed in this part for
the type of pile or one half of the maximum applied load, whichever is less.
(3) 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, the results of the pile
test shall be analyzed so as to evaluate the actual support furnished by
the bearing stratum*
Sect. 2916. Settlement Analysis. — (a) Whenever a structure is to
be supported by medium or soft clay (materials of Classes 11 and 12), the
settlements of the structure and of neighboring structures due to consolida-
tion of the clay shall be given careful consideration, particularly if there are
large variations in thickness of the clay or the structure has substantial
variation in net load at foundation grade. The commissioner may require a
settlement analysis to be made by a competent engineer with specialized
training and experience in soil mechanics in case the live and dead loads of
the structure, as specified in Part 23, minus the weight of the excavation,
induce a maximum stress greater than four hundred pounds per square foot
at midheight of the underlying soft clay, computed by means of a procedure
that is generally accepted in soil mechanics.
(b) The settlement analysis will be usually 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 soil and other
loads under which the clay was fully consolidated. The appraisal of the live
loads may be based on surveys of actual live loads of existing buildings with
similar occupancy. The soil compressibility data may be derived on the
basis of one or more of the following data:
(1) A review of settlement records and behavior of other buildings
in Greater Boston having similar subsoil profiles.
(2) Consolidation tests on undisturbed specimens with a diameter of
at least two and one half inches. The report shall include a description
of the method of sampling and of the quality of the samples.
(3) Consolidation test data from other projects in Greater Boston
where the clay is found to be similar when compared on the basis of the
natural water content and the liquid and plastic limits.
(c) Should the analysis indicate that the settlements would cause ex-
cessive stresses in the structure or would impair its usefulness, the design
of the foundation and/or the superstructure shall be modified so that the
anticipated settlements will be reduced to tolerable values.
(318)
Sees. 3001-3002
PART 30.
FIRE EXTINGUISHING APPARATUS.
Section
3001 — Fire Extinguishing Apparatus Required.
3002 — Fire Department Standpipes.
3003 — First Aid Standpipes.
3004 — Piping for Standpipes.
3005 — Automatic Sprinklers.
3006 — Sprinkler Control.
3007 — Water Supply for Fire Extinguishing.
3008 — Portable Fire Extinguishers.
3009 — Inspection and Tests of Fire Extinguishing Apparatus.
[3010 — Access Panel for Fire Extinguishing Apparatus.]
♦Section 3001. Fire Extinguishing Apparatus Required. — (a) The
owner of a building in which fire extinguishing apparatus is to be installed,
altered or repaired (except repair of leaks and other minor repairs) pursuant
to the requirements of this part, or connected to the water supply of the city of
Boston, shall first make application to the building commissioner and obtain
a permit therefor, in the manner specified in section ten of Part 1 and follow-
ing sections relating to permits.
(b) Fire extinguishing apparatus shall be installed in buildings where
specified in Parts 3 to 12, inclusive. The commissioner shall require auto-
matic sprinklers in the basement or basements of pre-code buildings of occu-
pancies of Groups E and F or of either of the two combined with occupancies
of Groups H or I, when in his judgment public safety demands such protection.
(c) Such fire extinguishing apparatus shall conform to the requirements
of this part and to such additional requirements as are specified in Parts 3 to 12,
inclusive.
(d) All devices used in connection with fire extinguishing systems shall
have the approval of a recognized testing laboratory and the approval of the
commissioner or shall comply with the recommendation of the National Fire
Protection Association.
[ *As amended by Ord. 1943, ch. 8 ]
Sect. 3002. Fire Department Standpipes. — (a) A fire department
standpipe shall consist of a vertical pipe with fire department connection and
outlet valves with connections for hose at convenient points in a building, by
means of which the fire department may distribute water through the building
to hose to be attached by the fire department for extinguishing a fire and pro-
tection against fire in an adjoining building.
(b) Fire department standpipes, where required, shall be of such number
and so located that a stream from a nozzle on not more than one hundred feet
of hose connected to a standpipe can be played upon every part of each story,
assuming the stream to reach fifty feet from the nozzle.
(319)
Sec. 3002
(c) Fire department standpipes shall be not less than five inches in internal
diameter throughout, and in buildings higher than ninety feet, or where the
standpipe has a roof outlet, not less than six inches.
(d) Every fire department standpipe shall extend to every story of the
building and above the roof unless the requirement of a roof outlet is waived
by the commissioner. Such standpipe shall be located in a stair enclosure or
other approved location and shall have, in every story above the first, an
outlet two and one half inches in inside diameter threaded for standard fire
hose coupling, and an approved angle globe valve. The outlet above the roof
shall have two such hose connections, each with a valve. Hose outlets shall
be not more than five feet above the floor, roof or stair landing. Neither the
standpipe, outlet nor valve shall project within the width required for a
stairway as an exit. Convenient to every roof outlet shall be provided and
properly stored not less than fifty feet of approved two and one half inch linen
hose and a tapered nozzle with one and one eighth inch smooth orifice.
(e) Every fire department standpipe shall have a fire department con-
nection in an exterior wall of the building, fronting on a street, in an approved
location not less than ten inches nor more than forty-eight inches above the
sidewalk or ground. Two or more standpipes may have a common fire depart-
ment connection. Where a building is required to have two or more fire
department standpipes and faces on two streets it shall have two fire depart-
ment connections remote from one another. The fire department connection
shall be of approved design, shall have two couplings and if it serves two or
more standpipes, shall have three couplings of not less than two and one half
inches inside diameter threaded to receive standard city of Boston fire hose,
and protected by approved caps.
(f ) Where a building contains two or more fire department standpipes and
two or more fire department connections, they shall be cross connected, but
the commissioner may waive this requirement subject to such condition as he
may in any case specify. Each fire department standpipe connection shall
be marked by a cast bronze or brass plate embossed to indicate its connection
to a standpipe.
(g) A fire department standpipe shall be connected to an adequate source
of water supply and if subject to freezing shall be equipped with an approved
control valve. An approved check valve shall be installed in the water
supply pipe which will prevent water from the fire department connection
from backing up in the supply pipes, and a check valve and automatic drain
shall be installed between the standpipe and the fire department connection
to prevent water from reaching a point where it would freeze.
(h) For protection against fire during construction, in a building required
to have one or more fire department standpipes, they shall be installed with
fire department connection and extended upward with the building, always
reaching within one story of the highest constructed floor. During construc-
tion of the building, such standpipes shall be connected to an approved
source of water supply and the outlets thereof shall be provided with hose
and nozzles as required by the commissioner. Water shall be kept turned
on in such standpipes during construction except in freezing weather and
when the pipe is being extended. The shut-off valve shall be accessible and
the standpipes in readiness for use at all times.
(320)
Sees. 3003-3005
♦Sect. 3003. First Aid Stand pipes. — (a) A first aid standpipe shall
consist of a pipe or system of pipes connected to an adequate source of water
supply, with valves, hose connections, hose and nozzles at convenient points
inside the building for use of the occupants in extinguishing a fire.
(b) Where first aid standpipes are required they shall have hose stations
in every story in such number and so located that a stream from a nozzle on
the length of hose connected to an outlet can be played on every part of the
story required to have such protection, assuming the stream to reach twenty
feet from the nozzle. Pipes shall be so located as to be safe from injury by
frost or otherwise.
(c) The risers of first aid standpipes shall be not less than two and one
half inches internal diameter. Branches to single hose stations shall be not
less than one and one half inches.
(d) A first aid hose station shall consist of an angle globe valve, threaded
hose coupling, not more than fifty feet of approved linen hose, all one and
one half inches in diameter, and a tapered nozzle with one half inch smooth
orifice, attached, ready for use and mounted in an approved rack or reel, pref-
erably in a cabinet. The valve and hose shall be not over five feet above the
floor.
(e) First aid hose stations shall be located in corridors or other approved
locations and shall be visible and accessible at all times.
(f ) A fire department standpipe may serve as piping for a first aid stand-
pipe if it is connected to an adequate water supply as provided in section
thirty hundred and two but there shall be no interference between first aid
hose stations and fire department outlets.
[ *As amended by Ord. 1943, ch. 8 ]
fSect. 3004. Piping for Standpipes. — (a) Pipe for fire department
or first aid standpipes shall be of wrought iron or steel of standard weight
except that extra heavy pipe and fittings shall be used where the normal
water pressure may exceed one hundred and seventy-five pounds per square
inch.
(b) Piping shall be connected by screw fittings, flanges or unions; right
and left fittings shall not be used. Fittings for changes in direction in pipes
more than two inches in diameter shall be standard fittings. Reduction in
pipe size shall be made by reducing fittings.
[ ^As amended by Ord. 1943, ch. 8 ]
JSect. 3005. Automatic Sprinklers. — (a) Where automatic sprin-
klers are required, the system of sprinklers and piping shall be designed to
spray walls, ceilings and every portion of the floor space in accordance with
the requirements of this part, except that arrangement and placement of
sprinklers in accordance with the requirements of the National Fire Protec-
tion Association or the National Board of Fire Underwriters, shall be accepted
as meeting the requirements of Sections 3005, 3006 and 3007 of this code.
(b) Where ceilings are smooth and unbroken there shall be a sprinkler
for approximately every one hundred square feet and the spacing in a line
shall not exceed twelve feet.
(321)
Sec. 3005
(c) Where ceilings are of wooden joist construction the spacing of sprin-
klers shall not exceed eight feet at right angles to the joists nor ten feet parallel
to the joists and sprinklers shall be staggered at third points of the spacing
in lines at right angles to the joists.
(d) Where ceilings have beams not less than five nor more than twelve
feet apart on centers, sprinklers shall be placed midway between beams not
over twelve feet apart and with not more than one hundred square feet of
ceiling for each sprinkler.
(e) Sprinklers shall be placed under all soffits, inclined surfaces, decks,
tables, benches, shelving, mezzanines, balconies or other similar construction
more than forty-two inches wide when fixed against walls and more than
sixty inches wide when such fixtures are clear of walls or partitions, within
floor areas where sprinklers are required.
(f) Sprinklers shall not be placed closer than twelve inches from posts,
walls, hangers or other vertical construction. Sprinklers, where required,
shall be placed not further from walls and partitions than half the allowed
spacing in the given direction, and under a joisted ceiling, not more than two
feet.
(g) Sprinklers shall be placed preferably upright and the deflector shall
be not more than ten inches nor less than three inches from the ceiling or
soffit to be sprayed, the stream from the orifice perpendicular thereto.
(h) Sprinklers shall be of a type and construction approved by the com-
missioner and shall be designed to release at not more than seventy-five
degrees Fahrenheit above the maximum temperature to be expected at the
location where installed.
(i) Pipe for sprinkler systems shall be of wrought iron or steel, of standard
weight and size, or other approved pipe, and shall have not less than the fol-
lowing inside diameters, depending on the number of sprinklers within one
story and fire division supplied through each section of pipe.
Minimum Pipe Sizes for Automatic Sprinklers.
Number of Sprinklers.
Minimum Pipe
Size (Inches).
1
3
2
1
3
1*
5
H
10
2
20
2?
36
3
55
Sh
80
4
140
5
200
6
400
8
(322)
Sees. 3005-3006
(j) In buildings of Type I and Type II construction, the commissioner
may allow not more than two hundred and fifty sprinklers to be supplied
through a six-inch pipe and not more than five hundred sprinklers through
an eight-inch pipe, in one story and fire division.
(k) Piping shall be connected by screw fittings, flanges, or unions; right
and left fittings shall not be used. Fittings for changes in direction in mains
and risers shall be standard fittings. Reduction in pipe size shall be made
by reducing fittings.
(1) The system of sprinkler piping shall be well supported and pitched to
drain completely. Piping and equipment shall be safe from injury by frost
or otherwise.
(m) Sprinkler systems or portions thereof subject to freezing shall be
equipped with approved dry pipe valves. The capacity of a system depending
upon a single dry valve shall not exceed three hundred twenty-five gallons
unless provided with a quick opening device, in which case the capacity shall
not exceed five hundred seventy-five gallons. The air pressure maintained
in a dry pipe system shall not exceed thirty-five pounds. Every dry pipe
valve shall be equipped to give an alarm upon operation. The commissioner
may allow that part of an automatic sprinkler system controlled by a cold
weather valve to be shut off and drained in cold weather subject to such
conditions as he shall in any case specify and the Fire Commissioner so notified
in writing by the department.
(n) Nothing in this code shall be construed to prohibit the installation
of a system of sprinklers containing twenty-five or less heads attached to the
domestic water supply, provided the system is not mandatorily required
elsewhere by this code.
[$As amended by Ord. 1943, ch. 8 and Ord. 1955, ch. 2\
*Sect. 3006. Sprinkler Control. — (a) The main supply pipe of a
sprinkler system and each connection to the service main, if more than one,
shall have a gate valve of approved indicator pattern with bronze stem, a
check valve, test pipe and pressure gage, installed in approved locations.
The main supply pipe of the system shall have a visible flow test pipe not
less than one and one half inches in diameter with approved discharge. Valve
stems shall not be placed below the horizontal and shall be within seventy-
eight inches from the floor or shall be made accessible by permanent ladders
fixed in place, or other approved means. Where sprinklers in two or more
fire divisions are supplied through one or a set of two or more service con-
nections, each fire division shall have a separate branch supply pipe with
control valve and drain. Every required sprinkler system shall have a fire
department connection, except that the commissioner may waive this require-
ment, subject to such conditions as he may specify, where the protected
space is visible and directly accessible from a street or alley or where the
number of sprinklers in any story and fire division does not exceed twenty-five,
(b) A fire department connection shall be of approved design and threaded
for two and one half inch standard city of Boston fire hose and protected by
approved caps. The pipe leading therefrom shall have a check valve and an
automatic drain to prevent water from reaching a point where it would freeze.
(323)
Sees. 3006-3007
(c) Every fire department sprinkler connection shall be marked with
a cast bronze or brass plate embossed to indicate its connection to sprinklers.
(d) Every system of automatic sprinklers shall be connected to a per-
manent and adequate water supply as provided in section thirty hundred
and seven.
(e) An inspector's test valve shall be installed at the top of every auto-
matic sprinkler system.
(f ) Where a main supply pipe serves automatic sprinklers in a basement
or sub-basement concealed from view, or a remote building or a garage or
part of a building, an approved sprinkler alarm shall be provided unless the
commissioner shall waive this requirement.
(g) Neither goods, furniture, machinery or other materials or equipment
shall be so placed as to interfere with the effectiveness of sprinklers nor shall
sprinkler piping be used to support such materials or equipment.
[ *As amended by Ord. 1943, ch. 8 ]
jSect. 3007. Water Supply for Fire Extinguishing. — (a) Water
supply for required fire extinguishing apparatus shall be taken from the
"high service" city water mains where available and, except when general
service is permitted, shall be independent of the supply for sanitary, in-
dustrial or other purposes.
(b) In buildings where first aid standpipes or automatic sprinklers are
required and where the city water supply, with a sufficient flow properly to
supply the sprinklers, will not furnish a pressure of at least thirty-five pounds
per square inch at the highest first aid hose station, and twelve pounds per
square inch at the highest sprinkler, an auxiliary water supply for fire ex-
tinguishing apparatus shall be provided.
(c) An auxiliary water supply for fire extinguishing apparatus shall
consist of a storage tank or a fire pump or both. A storage tank shall be
either gravity or approved pressure type.
(d ) A gravity storage tank shall have a capacity not less than five thousand
gallons of water and the bottom of the tank shall be not less than twenty feet
above the highest sprinkler or hose outlet. The tank and connected pipes
shall have protection from freezing.
(e) A pneumatic pressure storage tank of such capacity (not less than
thirty-five hundred gallons of water) and design, and with such automatic
pumping equipment as will furnish as much water, at the same pressure,
at the upper outlets of the system, as the gravity storage tank specified in
paragraph (d) of this section, may be substituted therefor with the approval
of the commissioner.
(f) A fire pump, to serve as an auxiliary water supply, shall be auto-
matically controlled, shall be connected to the city mains and shall be capable
of delivering water at the rate of twenty gallons per minute for each sprinkler
up to fifty in any one story and fire division, against a head sufficient to
furnish a pressure of twelve pounds per square inch at the highest sprinklers
and of thirty-five pounds per square inch at the highest outlets of connected
(324)
Sees. 3007-3010
standpipes in the building and shall be of a type satisfactory to the commis-
sioner. A fire pump shall be connected to a permanent, reliable and approved
source of power.
(g) Auxiliary water supply equipment shall have all necessary approved
gate and check valves. Motors and other electrical equipment shall be en-
closed, or protected by a hood and by a grille or partition of incombustible
material.
[ 1[As amended by Ord. 1948, ch. 8 ]
Sect. 3008. Portable Fire Extinguishers. — (a) A portable fire
extinguisher shall consist of a container holding not less than two and one half
gallons of extinguishing liquid so arranged and equipped that pressure may
be generated and the contents discharged through a hose and nozzle; or a
portable extinguisher of other type approved as equal thereto by the fire
commissioner. The design and construction of portable fire extinguishers
shall be approved by the fire commissioner.
(b) Portable fire extinguishers, where required, shall be mounted in
corridors or other approved locations generally visible to the occupants of the
building. Where they are placed in cabinets they shall be visible and the
doors shall be unlocked or of glass which can be broken to give access to the
extinguisher in case of fire.
(c) Portable fire extinguishers shall be discharged and recharged as often
as shall be generally required by the fire commissioner for extinguishers of
each type, and shall be recharged at once after use.
JSect. 3009. Inspection and Tests of Fire=Extinguishing Ap-
paratus.— (a) Every system of automatic sprinklers and all parts thereof
shall satisfactorily meet a pressure test of two hundred pounds per square
inch and when water pressure is over two hundred pounds it shall be tested
to fifty pounds above the highest static pressure.
(b) Standpipes and all parts thereof except hose shall satisfactorily meet
a pressure test of two hundred and fifty pounds per square inch at ground
level.
(c) First aid hose and other hose required for extinguishing purposes
shall satisfactorily meet a pressure test, unless this requirement is waived by
the building commissioner, in his presence, when first installed, and shall be
thoroughly dried before it is hung in racks or reels.
(d) All required fire extinguishing apparatus, except as provided in
section three thousand and eight, shall be inspected at least once each year
and such tests shall be made as the building commissioner shall require.
Defective hose and other defective parts shall be replaced without delay on
order of the building commissioner.
(e) Piping shall not be concealed until tested and approved.
[ %As amended by Ord. 1943, ch. 8 ]
*Sect. 3010. Access Panel for Fire Extinguishing Apparatus. —
Where basement or cellar space below the ground floor of a store is used for
storage purposes of any description access panels shall be provided in open-
ings incorporated in the ground floor construction for use of fire department.
(325)
Sec. 3010
Each access panel opening shall be a minimum of ten inches square and pro-
vided with a removable cover of suitable strength to receive the live load for
which the floor is designed. This removable cover shall be easily distinguish-
able from the rest of the floor. One such opening shall be located ten feet in
from the main entrance door to store in line perpendicular to door. There
shall be additional access panel openings in the same continuous line as the
initial installation every twenty feet or portion thereof so that each opening
shall provide provisions for firejextinguishing apparatus to cover each four
hundred square feet of floor space. Where finished material of floor would
cover or conceal access panel such covering shall be painted red directly over
each opening.
Where ceiling material is provided on the under side of ground floor con-
struction the access panel openings shall be provided with a breakable glass
seal located below the removable cover. This glass seal may be located at
the level of the ceiling, if above the level of the ceiling the four sides of the
panel opening between the ceiling and the removable cover shall be finished
with the materials joining the ceiling proper, or equivalent fire-resistive
material.
The above requirements shall not apply if the basement or cellar is equipped
with an approved automatic sprinkler system.
[ *As amended by Ord. 1943, ch. 8 ]
(326)
Sec. 3101
PART 31.
PLUMBING.
Section
3101 — Plumbing in Buildings.
3102 — Definitions pertaining to Plumbing.
3103 — The Drainage System.
3104 — Soil and Waste Pipes.
3105 — Rain Water Drains.
3106 — Indirect Wastes.
3107 — Mechanically Discharged Drainage.
3108 — Traps.
3109 — Venting.
3110 — Vent Pipes.
3111 — Buildings more than One Hundred and Twenty-five Feet
High.
3112 — Materials of the Drainage System.
31 13 — Water Supply.
3114 — Hot Water Supply.
3115 — Plumbing Fixtures and Units.
3116 — Cast Iron Pipes.
3117 — Wrought Iron and Steel Pipes.
3118 — Brass, Copper and Lead Pipes.
3119 — Hangers and Supports.
3120 — Inspection and Tests.
3121 — Prohibited Fixtures, Fittings and Connections.
[ All heading as amended by Ord. 1948, ch. 8]
♦Section 3101. Plumbing in Buildings. — (a) Every building where
people live, work or assemble shall have a supply of pure and wholesome
water and a drainage system.
(b) Every building shall have such toilet accommodations and plumbing
fixtures as are specified in Parts 3 to 12, inclusive, of this code or as required
by any Massachusetts State Law or Regulation. If not so covered, to be as
directed by the Building Commissioner or Health Commissioner of the City
of Boston.
(c) Plumbing fixtures shall not be installed in rooms which do not con-
form to the requirements of this code.
(d) A permit to install, alter or repair plumbing shall not be issued unless
the work is to be performed under the supervision of a master plumber,
licensed under chapter one hundred and forty-two of the General Laws and
registered by the Commissioner. An application for a permit for plumbing
shall be signed as provided in section one hundred and ten of this code by a
licensed and registered master plumber.
(e) Every master plumber holding a certificate issued in accordance with
section three of chapter five hundred and thirty-six of the Acts of nineteen
hundred and nine, section two of chapter five hundred and ninety-seven of
(327)
Sees. 3101-3102
the Acts of nineteen hundred and ten or chapter five hundred and eighteen
of the Acts of nineteen hundred and twelve, or licensed under chapter one
hundred and forty-two of the General Laws, and has a business address in
Boston or does business in Boston, shall personally register his name and
business address with the Commissioner each year on or before the fifteenth
day of May. He shall give the Commissioner immediate notice of any change
in his business address.
[ *As amended by Ord. 1948, ch. 8 ]
tSect. 3102. Definitions Pertaining to Plumbing. — For the purpose
of this part of the code the words and terms defined in this section shall be
construed as so defined except when qualifying words or the context clearly
indicate that another meaning is intended.
Plumbing. — Plumbing is the art of installing in buildings the pipes,
fixtures and other apparatus for bringing in the water supply and removing
liquid and water-carried wastes; also, the system of pipes, fixtures, and other
apparatus installed in buildings for distributing the water supply and for
the disposal of liquid and water-carried wastes, including valves, traps, soil,
drain, waste and vent pipes.
Plumbing System. — The plumbing system of a building includes the
water supply distributing pipes; the fixtures and fixture traps; the soil,
waste and vent pipes; the storm water drainage; with their devices, appur-
tenances, and connections all within or adjacent to the building.
Master Plumber. — A plumber who is licensed under chapter one hundred
and forty-two of the General Laws as a Master plumber having a regular
place of business and who, by himself, or journeyman plumbers in his employ,
performs plumbing work.
Journeyman Plumber. — A person who is licensed as a journeyman
plumber under chapter one hundred and forty-two of the General Laws and
who installs plumbing in the employ and under the direction of a master
plumber.
Battery of Fixtures. — A group of fixtures of one type, at the same level,
not less than three in number.
Branch. — That part of a system of piping which extends from the main
to a fixture or fixtures and which serves to connect to the main the fixtures
which are not directly connected thereto.
Building Drain. — That part of the lowest horizontal piping of a building's
drainage system which receives the discharge from soil, waste and other
drainage pipes inside the walls and extends to a point ten feet outside the inner
face of the exterior walls.
Indirect Waste Pipes. — A waste pipe which is not directly connected
to the drainage system but discharges into an open sink or other fixture.
Length of Pipe. — The developed length of pipe and fittings as connected,
measured along the center line.
Main. — A general term signifying the principal line of a system of piping
from which branches extend to fixtures.
Plumbing Fixture. — A receptacle or outlet intended to receive and
discharge water, liquids or water-carried wastes into a drainage system either
(328)
Sees. 3102-3103
directly or indirectly or to some other place that the Building Commissioner
may approve.
Repair of leaks. — Such repairs as are necessary to protect property but
do not involve change in construction.
Soil Pipe. — A pipe which conveys the discharge of water-closets, with or
without the discharge of other fixtures, to the building drain.
Stack. — A general term for vertical line of soil, waste or vent piping.
Trap. — A fitting or device so constructed as to prevent the passage of
air or gas through a pipe without materially affecting the flow through it of
sewage or waste water.
Trap Seal. — The vertical distance between the crown weir and the inver
of the trap outlet.
Vent Pipe. — A pipe provided to ventilate a drainage system and to prevent
back pressure and trap siphonage.
Waste Pipe. — A pipe which receives the discharge of any plumbing
fixture except a water closet, and conveys it to the building drain or to a soil
pipe.
Water Distribution Pipe. — A pipe which conveys water from the water
service pipe to or from a faucet, valve or any piece of equipment requiring
water.
Water Service Pipe. — The water supply pipe from the City main to the
building served.
Cross Connection. — Any connection whereby the potable water supply
may become contaminated by any other substance or liquid.
[ fAs amended by Ord. 1948, ch. 8 ]
JSect. 3103. The Drainage System. — (a) The entire drainage system
shall be so designed, constructed and maintained as to dispose of sewage
and liquid wastes with velocities of flow that will avoid the deposit of solids
and prevent clogging the pipes. The drainage pipes shall be so designed,
constructed and supported as to be free from leakage of water, air or gas
through defective materials, imperfect connections, corrosion, settlement,
vibration, temperature changes, freezing or other causes. The entire system
shall drain completely. No cement joints nor connections between iron
and cement or tile pipe or brick drain shall be made within any building.
(b) The plumbing drainage system of every building shall be separately
and independently connected, outside of the building to the public sewer if
such sewer is accessible, to an approved private sewer or, if a sewer is not
accessible, to an approved cesspool or septic tank; except that two or more
buildings may have a common sewer if approved by the Building Com-
missioner and the Commissioner of Public Works. Sewage discharge into a
cesspool shall have such treatment as the Commissioner and the Health
Commissioner shall require.
(c) No substances which will clog the drains, produce explosive mix-
tures or injure the pipes or their joints shall be allowed to enter the drainage
system or the sewer.
(d) Steam, vapor, and water at a temperature above one hundred and
thirty degrees Fahrenheit shall not be discharged into the sewer. The
(329)
Sec. 3103
blow-off of boilers, steam exhaust or drip, or hot water from any other source
destined to be discharged into a sewer shall first be condensed and cooled
to one hundred and thirty degrees Fahrenheit in a blow-off tank or other
approved device of which the size, arrangement, location, venting and all
connections shall be subject to the approval of the Commissioner and the
Commissioner of Public Works.
(e) A blow-off tank of approved design and connections, connected to
one or more high pressure boilers shall have a capacity not less than thirty
per cent of the largest boiler to which it is connected. Every blow-off tank
shall have a vapor pipe not less than two inches in size extending above the
roof and above any window within fifteen feet.
(f) Where a drainage system may be subjected to back flow of sewage
suitable provision shall be made, by means of a gate and check valve or
otherwise approved device, controlling fixture branches subject to back
flow from the main drain.
(g) The building drain shall have a Y-branch fitting with an end cleanout
or with an iron stopper near the point where it leaves the building. The
cleanout shall be in a straight line with the drain as it passes through the wall.
The drainage system shall have an adequate number of cleanouts so arranged
that any stoppage in the pipe can be readily cleared. Cleanouts in drains
under ground shall be made accessible. Other cleanouts shall be so located
as to be accessible or to be made accessible through removable panels or
otherwise.
(h) A building drain shall not be smaller in any portion than the largest
soil or waste pipe or stack entering the drain.
(i) Stable fixtures and their drainage piping shall be installed in a manner
approved by the Commissioner.
(j) A building drain shall have a fall of not less than one-eighth inch
per foot of run and its size shall not be less than required for the fixtures
which discharge through it as provided in the following table in accordance
with the number of fixture units assigned to each type of fixtures as specified
in section thirty-one hundred and fifteen. Schedule Paragraph E.
Maximum Number of Fixture Units for Pipe Size.
Pipe Line (Inches)
11
14
2
2\ — No Water Closets
3 — 1 Water Closet by permission
4
5
6
8
10
12
15
(330)
Sees. 3103-3105
(k) Changes in direction of building drains shall be made with Y-branches
or long sweep fittings. Such changes in direction of building drains shall
have full size cleanouts up to four inch in size and not less than four inch for
sizes larger, at or near the change of direction and at or near the foot of all
stacks. Cleanouts shall not be over fifty feet apart on straight runs. Drains
shall not be laid in filled ground without adequate support to the building
structure. Drain pipes passing under walls shall be free from stress.
(1) All other connections to the drainage system shall be made with
Y-branches or sweep fittings with the exception of vertical soil or waste pipe
connections which may be made with short pattern TY's. Tee connections
may be used on vents only.
(m) Offsets in vertical soil, waste, vent and conductor stacks shall be
made as direct as possible and short radius fittings shall not be used.
[ %As amended by Ord. 1948, ch. 8 )
*Sect. 3104. Soil and Waste Pipes. — (a) Soil and waste pipes from
plumbing fixtures shall discharge into the building drain.
(b) Every building drain serving water closets or pedestal urinals shall
have at least one four-inch diameter vent extension through roof. Branches
of soil or waste pipes, if more than twenty feet long, shall be extended through
roof or connected to vent stack undiminished in size, except that a two-inch
waste stack may be connected at the bottom to a three-inch waste if the
number of connected fixture units does not exceed eight.
(c) A horizontal branch of soil or waste pipe shall have a fall not less than
one-eighth inch per foot of run.
(d) The maximum developed length of one and one half inch or smaller
waste pipe shall not exceed fifty feet.
(e) No soil pipe shall be less than four inches in size, except that a three-
inch soil pipe may be used for one water closet, with the approval of the
commissioner, where it is not practicable to use a four-inch pipe.
(f ) No waste pipe where buried underground shall be less than three inches
in size.
(g) In buildings more than one hundred and twenty-five feet high, soil
stack shall be at least five inches, waste stacks serving slop sinks or urinals
shall be at least four inches and waste stacks serving lavatories shall be at
least three inches in size.
[ *As amended by Ord. 1943, ch. 8 ]
fSect. 3105. Rain Water Drains. — (a) All rain water drains from
roofs, including area drains and surface drains, shall be kept separate from
the building drainage system of a building, except as provided in this section.
Area drains and surface drains may be connected to the building drainage
system or otherwise disposed of only with the approval of the commissioner,
(b) Where a storm water sewer is accessible rain water drainage shall be
discharged therein. In locations where the commissioner shall indicate that
storm water sewers may presently be laid, the main rain water drain shall
extend at least ten feet from the inner face of the foundation wall and may
there be connected to the building sewer. Elsewhere the rain water shall be
(331)
Sees. 3105-3106
discharged into the building drain near the point where it leaves the building ,
or otherwise disposed of in such manner as not to flow upon a public way or
neighboring land.
(c) A main rain water drain outside a building, except where a storm
water sewer exists shall be laid not lower than four feet below street grade.
(d) Rain water leaders shall not project into a public way more than
seven inches.
(e) All rain water piping shall have a fall of not less than one eighth inch
per foot of run. The size of a rain water drain or leader branch shall be not
less than as provided in the following table.
Maximum Horizontal Projection of Drained Area.
Pipe Size (Inches)
Area (Square Feet)
2
600
3
1750
4
3600
5
6300
6
8000
8
16000
10
25000
12
40000
When and where the rain water and sanitary systems are combined, the
area of the combination drain pipe shall be not less than sixty-six and two-
thirds per cent of the sum of the pipe areas discharged into it.
[ ]As amended by Ord. 1943, ch. 8 ]
JSect. 3106. Indirect Wastes. — (a) Drips from refrigerators, ice
boxes or other containers in which food is stored, heated or cooled shall not be
directly connected to soil or waste pipes or any other part of the drainage
system, but shall discharge in open sight into an open fixture which shall have
a supply of running water. Wastes of instrument sterilizers, aspirators,
compressors, stills, vacuum and other similar equipment shall enter trap
through a visible broken connection of not less than one and one half inches
long. Trap to be located as close to the fixture as practicable.
(b) Indirect wastes discharging into open fixture from fish storage tanks,
corn beef tanks, or window display tanks and similar equipment shall be a
separate system and the end of the indirect waste shall be extended independ-
ently above the roof for ventilation.
(c) Each fixture and piece of equipment wasting into indirect waste pipes
shall have separate traps.
(d) An indirect waste serving two or more fixtures or pieces of equipment
shall be extended through the roof independently.
(332)
Sees. 3106-3108
(e) Vapor vents, from sterilizers and other hospital equipment, where
required shall be installed as a separate system terminating above the roof.
(f ) Layouts of all indirect waste systems shall be submitted for approval
to the building commissioner.
[ XAs amended by Ord. 1948, ch. 8 ]
*Sect. 3107. Mechanically Discharged Drainage. — (a) Floor drains,
drips from machinery and other clean wastes approved by the commissioner,
too low to drain by gravity to the sewer, may drain to an open sump or receiv-
ing tank and thence be discharged by mechanical means into the gravity
drainage system. The discharge pipe shall be equipped with a check valve,
and shall be trapped with a deep seal trap.
(b) Where the whole or a part of a drainage system receiving the discharge
of soil and waste pipes, other than those provided for in the preceding para-
graph, is too low to drain by gravity to the sewer it shall drain to a closed iron
sump or receiving tank and thence be discharged by mechanical means,
automatically operated, into the gravity building drain or directly to the
sewer. Such closed iron sump or receiving tank shall form part of the drainage
system and shall be made tight and be tested as provided for other parts of the
system. It shall be vented by means of an independent vent pipe not less
than four inches in size extended through the roof as provided for vent stacks
in section thirty-one hundred and ten, or connected to a vent stack not less
than four inches in size at least twenty feet above the tank, or may be properly
connected to the vent stack of the fixtures discharging into the sump if such
vent is four inch size or larger.
(c) The discharge pipe from a sewage ejector shall not be less than four
inches in size and shall be fitted with a check and gate valve.
(d) The plumbing fixtures which drain to a closed sump or receiving tank
for mechanical discharge shall have waste or soil pipes, traps and vent pipes
as provided for in gravity drainage. Such vent pipes shall be extended inde-
pendently through the roof or be connected to a vent stack not less than
twenty feet above the tank, or at least above the rim or over-flow point of the
lowest fixture of the gravity drainage system.
(e) Drainage discharged by mechanical means into the gravity drainage
system within a building, as provided in this section, shall discharge into the
top of the receiving drain.
(f) Where closed sumps for wastes other than sewage are used, they shall
have a chamber vent not less in size than the size of the inlet.
[ *As amended by Ord. 1943, ch. 8 ]
fSect. 3108. Traps. — (a) Except as otherwise provided in this section,
the waste pipe of every plumbing fixture shall have a separate trap to prevent
emission through the fixture of foul air from the drainage system. Such trap
shall be placed as near the fixture which it serves as is practicable.
(b) Single tray or sink may be fitted with a one and one half inch trap.
A two part or a three part tray may be considered as one fixture and shall
be fitted with a trap, the outlet of which shall be not less than two inches in
size. Two part tray, three part tray, combination of two trays and one sink
(333)
Sec. 3 1 OS
when close together, combination sink and tray, each of which may be con-
sidered as one fixture and shall be fitted with a trap, the outlet of which shall
be not less than two inches in size. Where a two inch half S trap is used, the
combined waste to the inlet side of the trap shall be not less than two inch
in size. When placed on the same level the waste pipe from the traps of two
fixtures of like type and used for the same purpose may be connected to the
branch openings of a long pattern double TY type of fitting placed in an upright
position and shall require no other vent than the continuation of the waste
serving these two fixtures undiminished in size.
(c) The waste pipes from dishwashers or sinks discharging grease in a
kitchen of a hotel, restaurant or club shall have individual grease traps of
approved capacity and type or else shall waste into a master grease trap and
system. When individual approved grease traps are used they shall be
easy of access to open and clean and placed as near as practicable to the
fixture which they serve.
(d) The waste pipe from every floor drain or other fixture from which,
in the opinion of the commissioner, grease may be discharged in such quan-
tity as to clog or injure the drain, shall have an approved grease trap. A
master grease trap will be allowed in lieu of separate grease traps when sepa-
rate system of drainage is installed for fixtures requiring a grease trap. The
master grease trap must be in an accessible location for cleaning. Master
grease trap will be required in lieu of separate grease traps on individual
fixtures, when in the opinion of the building commissioner it is necessary,
to protect the drainage system and public sewer from grease. When a
master grease trap is installed, each fixture discharging into a master grease
trap shall be fitted with individual one half S trap properly vented. Master
grease traps shall be approved by the commissioner as to capacity and type.
(e) The waste pipe from every floor drain or other fixture from which
gasoline, naphtha or other inflammable liquid may be discharged to a sewer
shall have a special trap approved by the commissioner of public works so
constructed as to prevent the passage of such liquids or gas into the sewer.
Plans of approved type may be procured at the office of the commissioner.
When a gasoline separator serves floor drains on the same level as the gaso-
line separator and each entering the gasoline separator independently and
within fifteen feet they shall require no other than the chamber vent.
(f) The waste pipe from wash stand for vehicles shall have an approved
trapped combination floor drain and sand arrestor not less than four inch in
size.
(g) The waste pipe from an area drain or surface drain shall have a deep
seal trap.
(h) Traps shall be installed in all conductor leaders terminating below
the main roof, or roofs used for any purpose, other than weather protection.
Separate traps may be omitted if main roof drain is properly trapped.
(i) Every trap installed shall be so located as to be accessible.
(j) Every trap shall have a water seal of at least one and one half inches.
Deep seal traps shall have a water seal of at least four inches.
(k) All fixture trap cleanouts shall be water sealed.
(334)
Sees. 3108-3110
(1) Blip joints or unions shall not be used on the outlets of traps.
(m) Threaded outlet connections on all screw traps shall be iron pipe
size.
(n) Iron traps less than two inch in size shall not be used where concealed.
(o) Non-syphon trap shall only be used by special permission of the
commissioner and when so used shall be of an approved type and shall have
a depth of seal not less than four inches.
[ \As amended by Ord. 1943, ch. 8 ]
JSect. 3109. Venting. — (a) The drainage system shall be so designed
that there will be circulation of air in all pipes thereof and no danger of
syphonage, aspiration or forcing of trap seals under conditions of ordinary
use.
(b) Traps, except non-syphon traps where approved, shall be protected
from syphonage or air pressure by separate vent pipes, not less in size than
the outlet of the trap they serve, except as otherwise provided in this section.
(c) The trap for the fixture having the highest connection to a soil or
waste stack need not have separate vent pipe if within five feet from the
stack and the soil or waste pipe is not connected to the soil or waste stack
below the invert of the trap, with the exception of closets and similar fix-
tures which shall be connected to soil or waste stack not more than eighteen
inches below the weir of the group.
(d) The traps of a battery of water closets, pedestal and stall urinals and
bed pan washers, may have, instead of separate vent pipes, a vent pipe con-
nected to the common waste or soil pipe just before the branch from the
fixture most remote from the waste or soil stack and between the first fixture
and the soil or waste stack. If such a battery has more than six fixtures
there shall be a similar vent pipe connection before the branch from every
sixth fixture and in no case shall there be more than five fixtures between the
vents. Vents shall not be less than four inch in size. This type of venting
may be used only when the vertical distance between the water level of the
trap and the top of the common waste or soil pipe is not more than twenty-
four inches and where the developed length of the branch waste or soil pipe
is not more than three foot six inches between the center line of the common
waste or soil pipe and the water level of the trap. Water closets and pedestal
urinals shall be considered one type. No other fixtures shall enter the battery
system. The commissioner shall prepare explanatory sketches showing the
method of construction described in this section.
(e) Single floor drains shall be separately vented unless otherwise noted.
Groups of two or more floor drains discharging through separate branch
waste pipes not more than fifteen feet long into four inch or larger main
waste pipe serving floor drains only, may be vented on the outlet side of the
end floor drain, by means of an extension of the main waste pipe undiminished
in size as a vent pipe.
[ XAs amended by Ord. 1943, ch. 8 ]
♦Sect. 3110. Vent Pipes. — (a) The vent pipes from traps and the
extension of soil and waste pipes shall be extended upward through the roof
(335)
Sec. 3110
or connected to vent stacks extended through the roof. Waste and soil
stacks shall be extended through the roof and for the purpose of this sec-
tion, the portion of a waste or soil stack above the highest fixture connected
to it shall be considered a vent stack.
(b) Vent pipes shall be connected at the bottom with a soil or waste
pipe or with the building drain in such manner as to prevent accumulation
of rust scale and properly to drip the water of condensation. The foot of all
vent stacks shall be connected to soil or waste stack through a separate Y
branch.
(c) Vent stacks shall be extended to a height of not less than two feet
above the roof and not less than one foot above the top of any window within
fifteen feet. Where a roof is to be used for purposes other than weather
protection, vent stacks shall extend not less than seven feet above the roof
and the arrangement shall be subject to the approval of the commissioner.
(d) No vent stack through roof shall be less than four inches in diameter
from a point within the building.
(e) Two or more vent pipes may be connected together but such con-
nection shall be above the fixtures served.
(f) Vent pipes shall not be connected to the trap or branched into the
waste pipe except where a continuous vent is not practicable. Vent pipes
shall be run as directly as practicable. Horizontal vent pipes when below
the top of the fixture it serves shall be installed with the shortest possible
horizontal run. The opening of these vents shall be above the center line of
the waste pipe.
(g) The size of a vent pipe, up to and including two-inch shall not be
less in size than the outlet of the trap it serves. Such vent pipe shall connect
to the waste pipe not more than eighteen inches from the trap. The size of a
vent pipe shall not be less than as provided in the following table depending
upon the number of fixture units which it serves and the length of the pipe.
Pipe Sizes (Inches)
a
u
2*
3"
4"
5"
6"
8"
Maximum Number
Maximum Length
of Fixture Units
Feet
.5
10
3
25
25*
60
100
125
250
250
500
300
1250
400
2400
Not limited
*Note exception below.
In determining the length of a vent pipe the stack and branches shall be
considered continuous.
(336)
Sees. 3110-3112
(h) A vent pipe serving water closets, pedestal urinals, bed pan washers
and service sinks shall not be less than two inches in size. Such two inch
vent pipe shall not serve more than three fixtures of the above type and shall
not be longer than forty feet.
(i) The size of a vent stack shall be at least one half of the diameter of the
waste or soil stack served. Where soil stacks are installed, fitted with con-
nections for future use, are four inch in size, a parallel vent stack not less than
three inch in size with three inch branches shall be installed. The parallel
vent stack shall be connected to the soil stack below the lowest proposed
fixture.
(j) Where three or more vent stacks are connected near the top to a single
pipe extending through the roof, the internal area of the combined stack shall
be not less than one half the sum of the area of the stacks so connected.
(k) Every vent pipe shall be free from dips or sags and shall be so graded
and connected as to drip back to the soil or waste pipe.
(1) Bow vents shall be installed only by permission of the commissioner
and in accordance with his instructions and shall be dripped at its lowest
point.
[ *As amended by Ord. 1943, ch. 8 ]
fSect. 3111. Buildings More than One Hundred Twenty=Five Feet
High. — (a) Vent stacks shall not be less than three inch in size.
(b) Vent stacks serving water closets, pedestal urinals, bed pan washers
or service sinks shall be increased to at least four inches in size at a point
eighty feet above the bottom of vent stack.
(c) Vent stacks shall not be connected to other vents or vent stacks but
shall extend through the roof independently where practicable.
(d) Vent stacks including the upper portion of soil or waste stacks, three
inches in size shall be increased to four inch in size from a point below the roof.
(e) 2" Branch vents serving water closets, pedestal urinals, bed pan
washers and service sinks shall not be more than thirty feet long and shall
serve not more than three of the above fixtures. Branch vents for other fix-
tures shall comply with the table in section 3110.
[ fAs amended by Ord. 1943, ch. 8 ]
JSect. 3112. Materials of Drainage System. — (a) Waste, soil and
vent pipe shall be of cast iron hub and spigot pipe, cast iron screw pipe,
galvanized steel or wrought iron, lead, iron size brass or copper, except that
cast iron screw pipe, and galvanized steel or wrought iron pipe shall not be
used underground. In buildings of Group I Occupancy galvanized piping
shall not be used for built-in waste piping in floor or wall construction.
(b) All sanitary and rain water drains within a distance of ten feet outside
the inner face of the foundation wall shall be cast iron hub and spigot pip.
coated with asphaltum or red lead.
(c) Waste and vent pipes, traps and fittings serving fixtures in chemical
laboratories or used for the disposal of acid or other corrosive chemicals shall
be of approved acid resisting materials. The arrangement of piping shall be
approved by the commissioner. All plumbing fixtures in large chemical
(337)
Sees. 3112-3113
laboratories shall have a separate system of drainage and vent piping inde-
pendent of other drainage system of building. When diluting chamber is
used individual vents for fixture traps in group fixtures may be omitted if
main waste is extended through roof undiminished in size, and branch from
main to fixture is not more than twenty-five feet. If branch waste to fixture
is more than twenty-five feet the end of the branch shall be extended full size
over roof or reconnected to main chemical vent stack.
The effluent from diluting tank may waste into the building drainage
system.
The design and location of the dilution tank and arrangement of the piping
shall be approved by the commissioner.
[ XAs amended by Ord. 1943, ch. 8 ]
♦Sect. 3113. Water Supply. — (a) All water piping of every descrip-
tion supplying water from city mains to all plumbing fixtures and equipment
with the exception of the distributing piping of hot water building heating
system, intercommunicating piping between various pieces of apparatus
of a boiler room plant, and engine room apparatus, shall be installed by a
journeyman plumber licensed under chapter one hundred and forty-two of
the General Laws under a permit issued to a registered and licensed Master
plumber.
(b) No water distribution system to plumbing fixtures and equipment
shall be installed until a plan submitted to the commissioner has been ap-
proved for a safe and adequate supply.
(c) Water supplied from city mains shall be distributed by a system of
piping independent of water from any other source unless such source is
approved by the health commissioner for drinking purposes.
(d) No connections to fixtures supplied with city water, or to supply
piping thereof, shall be made from other pipes, piping systems, mechanical
apparatus, equipment or device, directly or indirectly, in such manner that
in the opinion of the health commissioner, and the building commissioner,
the quality of the potable water may be adversely affected. No plumbing
fixture device or construction shall be installed which will provide a cross
connection between a distributing system of water for drinking and domestic
purposes and a drainage system, soil or waste pipe or sprinkler or process
piping system so as to permit or make possible the back flow of sewage or
waste or non-potable water into the water supply either by gravity, siphonage
or pressure.
(e) The water service pipe and distribution pipes shall be of sufficient
size to permit continuous ample flow of water to fixtures and equipment in
all stories at all times.
(f) Where the water pressure is insufficient to supply all fixtures freely
and continuously a house supply tank or pneumatic system shall be provided,
adequate for the purpose. Such tank or system shall be supplied by city pres-
sure through automatic controls, where necessary by power driven pumps.
(g) The over-flow pipe from gravity or house tank or drip pans shall be
extended to drain into suitable plumbing fixture or be connected to rain
(338)
Sec. 3113
water leader. When connected to leader over-flow shall be fitted with deep
seal trap and check valve. Over-flow pipe shall be at least twice the area of
the water supply pipe feeding the tank.
(h) All plumbing fixtures shall be provided with a sufficient supply of
water for flushing to keep them in a sanitary condition. Every water closet
and urinal shall be flushed by means of an approved flush valve or individual
tank of at least four gallons flushing capacity for water closets and at least
two gallons for urinals, and shall be adjusted to prevent the waste of water.
The flush pipe for water closet flush tanks shall be not less than one and one
quarter inches in diameter and the water from the flush tanks shall be used
for no other purpose.
(i) No plumbing fixture, mechanical apparatus, equipment or device
shall be connected with building water supply distributing system through
automatic flush valve, other valve or tank, unless such flush valve, valve or
tank is located above the fixture or equipment being served.
All water closets, urinals, slop hoppers, bed pan washers, dish washers
and other fixtures receiving their supply of water through flush valves, shall
have an approved type of vacuum breaker installed between flush valve and
fixture or equipment being served. The vacuum breaker, shall be installed
at a minimum distance of four inches from bottom of vacuum breaker to
the top of fixture or equipment.
Fixtures or equipment having water supplied through submerged inlets
shall be fitted with an approved type of vacuum breaker installed in the
water supply line between the water supply control valve and the fixture or
equipment being served and at no less than four inches above the top of the
device being served.
All vacuum breakers shall be made easily accessible for observation, in-
spection and repairs.
For all fixtures and devices supplied through faucets or equivalent, such
faucets shall be located above the top of the receptacle being served and with
a minimum approved air gap between the end of supply nozzle and the top
of receptacle.
(j) An accessible shut-off shall be provided on the main water distribution
pipe just inside the foundation wall which shall control the water supply
to the entire building. In structures, other than residences occupied by one
family, accessible shut-offs shall also be provided which shall separately
control the water supply for each flat, apartment, suite, or store of a building.
(k) Supply pipes of ferrous material shall not be installed under bath
room floors in Group I occupancy.
No pipe or fittings that have been used for other purposes, nor second
hand pipe or fittings of objectionable origin shall be used for distributing
potable water.
(1) Water supply branch of lead, copper or brass to individual fixture
shall not be less than three eighths inch size; of other material, not less than
one half inch size. Water supply branch connected to a flush valve shall
not be less than one inch size for water closet, pedestal or blow-out urinal
and not less than one hall Mich size for other type of urinal.
(339)
Sees. 3113-31 14
Slip joints on water supply system shall not be used on the pressure side
of fixture faucets or cocks.
[ *As amended by Ord. 1943, ch. 8
fSect. 3114. Hot Water Supply. — (a) Hot water storage tanks
shall be installed and connected by a licensed plumber under a permit issued
to a registered and licensed master plumber .
(b) No hot water storage tank or other vessel in which water is to be
stored or heated under pressure shall be installed or connected unless there
are plainly stamped thereon in the metal, the maker's business name, its
capacity in terms of Massachusetts standard liquid measure, maker's guar-
antee of pressure to which tank has been tested, maximum working pressure
at which tank may be installed. The test pressure shall not be less than two
hundred pounds hydraulic or hydrostatic pressure. The working pressure
shall not be greater than forty-two and one half per cent of the guaranteed
test pressure. No tank shall be installed at pressure greater than its working
pressure.
(c) Every hot water tank or boiler hereafter installed, or relocated to
which a heating device or appliance is connected, in which water is to be
heated under pressure above fifteen pounds per square inch, shall be equipped
with pressure relief, temperature relief and vacuum relief valves placed in
an accessible location. These valves are to be placed on the hot water tank
or boiler, or on the piping to or from the hot water tank as hereinafter de-
scribed. No make of such valves shall be used unless approved by the
building commissioner.
(d) Individual Pressure Relief Valves: Pressure relief valves shall
have a disc which is kept closed by a spring on which tension can be varied
to take care of different static pressures. The valve shall be set to open at a
pressure not more than fifteen pounds higher than the working pressure
stamped thereon in the metal of the tank or boiler. Valve may be placed
on the hot or cold water supply above tank or boiler between control valve
and tank or boiler.
(e) Temperature Relief Valves: Fusible Plug Type: Temperature
relief valves of the fusible plug type shall be placed in a separate tapping in
the shell of the tank or boiler within twelve inches of the top of the tank
or boiler, or on the hot water flow pipe from tank or boiler. Where tem-
perature relief valve is installed on the flow pipe, it shall be within eight
inches, developed length, from the top of the tank or boiler and the fusing
element shall be installed within two inches of the flowing water. The
fusing element of the individual temperature relief valve shall fuse and begin
to discharge hot water from the te.nk or boiler when the temperature of the
water has reached a point not greater than two hundred and twelve degrees
Fahrenheit.
(f) Temperature Relief Valves: Automatic Type: Temperature
relief valves of the automatic type shall be placed in a tapping in the shell
of the tank or boiler within twelve inches of the top of the tank or boiler, or
shall be installed on the flow pipe from the top of the tank or boiler within
eight inches, developed length, from the top of the tank or boiler and shall be
(340)
Sec. 3114
installed within two inches of the flowing water, and shall begin to discharge
hot water from the tank or boiler when the temperature has reached a point
not greater than two hundred and twelve degrees Fahrenheit and shall close
tight when the temperature of water in tank or boiler has been reduced
approximately thirty-five degrees lower than the relief temperature. The
capacity of the temperature relief valve shall be governed by the maximum
heating rate of the hot water heater. A differential of ten degrees plus or
minus from closing temperature will be considered satisfactory.
(g) Vacuum Relief Valves: Vacuum relief valves shall be constructed
so as to relieve vacuum instantly at a minus pressure not greater than one
inch of vacuum in the tank or boiler.
The relieving element of the vacuum valve shall be of materials that will
not corrode or hold fast to the seat after prolonged use.
The valve shall not leak under an internal pressure of from ten pounds
to one hundred and twenty-five pounds per square inch.
Valves of the ball check type shall not be approved.
Vacuum relief valves shall be placed on the cold water supply pipe to tank
or boiler above top of tank or boiler.
Where cold water supply enters below the top of tank or boiler from a
water supply located below the tank or boiler, the supply pipe shall rise to-
above the top of tank or boiler forming a loop and the vacuum valve shall be
placed on top of loop above tank.
(h) All internal parts of pressure relief valves, fusible plug valves or
automatic relief valves shall be of materials impervious to corrosion equal
to eighty-five per cent copper, five per cent tin, five per cent lead and five per
cent zinc, except fusing element.
(i) The casing of each valve shall be stamped, or have a metal strap
attached to it stating in plain lettering the manufacturer's name, type of
valve, limit of pressure relief settings, capacity of B. T. U. discharge and
melting point of fuse plug.
(j) Pressure relief, temperature relief valves shall have the discharge end
of the valves extended to an open fixture or to the basement of the building
near to the floor if open fixture is not available.
(k) The valve shall be designed so that it will discharge water at a rate
that will prevent any increase in the water temperature in the tank or boiler
when the valve is in operation.
(1) The area of the discharge pipe from the relief valves shall not be less
than the area of the valve. When two or more valves are connected to the
same discharge pipe the pipe area shall not be less than the aggregate area
of all the valves it serves. The discharge pipe shall be of brass or copper
and pitch down from the valve it serves to prevent the trapping of water.
(m) Combination pressure and temperature relief valves may be used if
they comply with all of the requirements as described for individual valves.
Temperature relief of the fusible plug type or automatic type will be accept-
able.
(341)
Sees. 3114-3115
(n) In all hot water tanks or boilers having a capacity of one hundred
gallons or larger the pressure relief valve shall be fitted with a lever type
handle to allow for periodic tests by inspectors.
(o) Tankless Hot Water Heaters: All tankless heaters connected to
or part of heating boilers operated at more than five pounds pressure shall be
equipped with approved type pressure relief valve. Pressure relief shall not
be set more than one hundred and twenty-five pounds. Pressure relief valve
shall be placed between control valve and heating coil.
(p) Cistern Pressure Hot Water Tank: Cistern pressure hot water
tanks in which water is to be heated or stored shall have an expansion pipe
extended from the highest point of the hot water system or from the top of
the hot water tank, over the top of the supply tank that supplies the water
to the hot water tank. No valve of any description shall be installed on
the expansion pipe between the top of the hot water tank and its opening
above the supply tank. The expansion pipe shall be of non-ferrous material.
(q) No check valves or non-by-pass pressure regulators shall be installed
on the cold water supply to the hot water tank.
(r) When check valve or pressure regulator is installed the installation
shall be approved by the Commissioner.
(s) No shut off valve shall be installed to prevent the circulation of water
between the hot water tank and its heater, unless approved by the Com-
missioner.
[ fAs amended by Ord. 1948, ch. 8 ]
JSect. 3115. Plumbing Fixtures and Units. — (a) The orifice of the
jet of every drinking fountain shall be placed above the rim of the fixture and
shall throw an inclined stream. The water supply issuing from the orifice
shall be of sufficient volume and height so that persons using the fountain
need not come in direct contact with the orifice.
(b) Earthenware integral fixture traps shall have a flange on the fixture
bolted to a flange on the end of the waste or soil pipe, the joint made tight
with red or white lead or other approved compound, or with an approved
gasket. A rubber gasket shall not be used. If the waste or soil pipe is of
lead the flange on its end shall be of heavy brass soldered to the lead pipe;
if of cast iron, the flange shall be of extra heavy cast iron caulked or screwed
to the pipe. Such floor flanges for water closets, slop sinks or urinals shall
be not less than three sixteenths inch thick. The ioint between flange and
lead bend or start shall be examined by the Plumbing Inspector before the
fixture is permanently set.
The waste or soil pipe to floor or wall outlet earthenware fixtures where
used with a flange shall terminate at the finished floor or wall line.
Brass floor or wall flanges shall be of heavy pattern with no openings
except for bolts and waste openings.
Lead closet bends or starts shall be limited to one connection, which shall
be used for vent only, except in replacement of the closet bend or start existing
wastes may be connected to new bend or start.
The lead bend or start shall be connected to the drainage system by means
of a heavy bell shaped brass ferrule with full size wiped solder joint.
(342)
(c)
Sec. 3115
No trough or multiple type urinal or water closet shall be installed*
except for exterior temporary use, unless approved by the commissioner.
(d) Minimum size of floor drain shall be 3" except as noted for refrig-
erator wastes in table below.
(e) The following schedule shall be used for determination of the minimum,
diameters of fixture traps and the equivalent unit of value.
Fixture.
Trap Size
(Inches.)
Unit
Value.
Bath Room Group — 1 W. C. — 1 Lav. — 1 Bath Tub
Bath Room Group — 1 W. C. — 1 Lav. — 1 Bath Tub — 1 Shower Stall
Baby's Bath Slab
Bed Pan Sterilizer
Bed Pan Washer
1*
3
3
6.0
7.0
2.0
5.0
5.0
Combination Sink and tray .
Commercial laundry tray -
discharge
Revolving type — 7\ gallon per minute
2.0
4.0
Dish washer — Hotel
Dental Cuspidor
Drinking Fountain. . .
Restaurant — Club ,
2
14
6.0
0.5
0.5
Floor Drain — Unrated Fixtures — for each gallon per minute discharge!
Floor Drain — For Refrigerator Wastes — Minimum Trap Size 2". . .
Foot Bath
1*
2.0
0.5
2.0
Instrument Sterilizer.
Laundry Tray.
Lavatory
Pedestal Urinal.
1J
1*
n
0.5
2.0
1.0
5.0
Bar Sink
Fish Sink
Kitchen Sink
Kitchen Sink — Hotel — Restaurant — Club
Laboratory Sink
Lunch Counter Bar Sink — Combination of Same
Pot Sink
Scullery Sink — Hotel — Restaurant — Club
Sewage Ejectors — For Each 25 Gallons per Minute Discharge.
1*
2
H
2
If
2
2
2
2.0
4.0
2.
4.0
2.0
4.0
4.0
4.0
50.0
(343)
Sees. 3115-3116
Fixture.
Trap Size
(Inches.)
Unit
Value.
•Shower Stall
Slop or Service Sink — Group H and I Occupancy.
Slop or Service Sink
Stall Urinal
Surgeon's Sink
Restaurant Glass Sink
Restaurant Silver Sink
Vegetable Sink — Hotel — Restaurant — Club
Wall Hung Urinal .
Water Closet
Water Still
Utensil Sterilizer.
Unit value of fixtures not contained in the above table shall be determined by the commissioner.
[ J As amended by Ord. 1948, ch. 8 and Ord. 1955, ch. 2 ]
*Sect. 3116. Cast Iron Pipe. — (a) Cast iron pipe shall be sound,
.cylindrical and smooth, free from cracks, sand holes and other defects, of
uniform thickness and of the grade known in commerce as extra heavy.
If buried underground it shall be coated with asphaltum or red lead; otherwise,
it shall be uncoated until inspected and approved. The weight of cast iron
pipes per length, in lengths to lay five feet, shall not be less than listed in
the following table:
Minimum Weights of Cast Iron Pipe.
Diameter (Inches)
Weight
per
Length
(Pounds)
Single Hub.
1 Double Hub.
2
25
45
60
75
95
150
215
270
375
26
3
47
63
5
78
100
8
157
10
225
12
285
15
395
(344)
Sees. 3116-3117
(b) Fittings for cast iron hub and spigot pipe shall be of the weight
known in commerce as extra heavy and shall comply with the weights and'
dimensions to the cast iron soil pipe fittings as approved by American Stand-
ards Association.
(c) Joints in cast iron hub and spigot pipe shall be made with hemp or
oakum and molten lead run full and caulked to make gas and water tight
without the use of wax or any compound.
(d) No double hub or sleeve shall be used on cast iron drain, soil, waste,
or vent pipes. The drilling, tapping or welding of cast iron, hub and spigot
drain, waste, soil or vent pipes, and the use of saddle hubs or bands are
prohibited.
(e) Caulking ferrules shall be of approved quality bell shaped cast brass,
not less than four inches long and not less than diameter and weight listed in
the following table:
Minimum Diameter and Weight of Cast Brass Ferrules.
Diameter (Inches)
Weight (Ounces)
2|
16
3£
28
4|
40
(f) Cleanouts in cast iron hub and spigot pipe shall have brass or iron
bodies. Cleanouts shall be the full size of the pipe up to four inches and
not less than four inches for larger pipes. The caps shall be of cast brass not
less than one quarter inch thick, shall have square or hexagonal nuts not
less than three quarter inch high and one and one half inches in least diameter,
or recesses for special wrenches, and shall have not less than six tapered
threads standard for iron pipe. Caps as described above shall also be used
for cleanouts in screw pipe drainage systems.
(g) Where steel or wrought iron pipe, two inches or less in diameter, is
connected to cast iron hub and spigot pipe the joint shall be made by means-
of an approved caulking sleeve or fitting.
(h) Caulking hubs when used on screw pipe shall be heavy pattern.
Caulking sleeves shall not be used as hubs.
[ *As amended by Ord. 1943, ch. 8 ]
fSect. 3117. Wrought Iron and Steel Pipe. — (a) Galvanized
wrought iron or galvanized steel pipe shall be of not less than the following
thickness and weight per linear foot: —
(345)
Sees. 3117-31 18
Size
Diameter
(Inches)
Thickness
(Inches)
Weight Per Foot
(Pounds)
Plain Ends
External
Internal
%
.675
.840
1.050
1.315
1.660
1.900
2.375
2.875
3.500
4.000
4.500
5.563
6.625
8.625
10.750
12.750
.493
.622
.824
1.049
1.380
1.610
2.067
2.469
3.068
3.548
4.026
5.047
6.065
8.071
10.136
12.090
.081
.109
.113
.133
.140
.145
.154
.203
.216
.226
.237
.258
.280
.277
.307
.330
0.567
%
0.850
*A
1.130
a
1.678
\\i
2.272
114
2.717
2
3.652
2\i
5.793
3
7.575
Z\i
9.109
4
10.790
&
14.617
%
18.974
8
24.696
10
34.240
12..
43.775
(b) Nipples when used shall be cut from standard weight pipe.
(c) Fittings for wrought iron or steel soil, waste or drain piping shall be
cast iron, recessed and threaded drainage fittings, with smooth interior
water-way and threads tapped so as to provide a uniform slope in branches
from vertical pipe of not less than one quarter inch per foot. Fittings for
wrought iron or steel vent piping shall be cast pattern.
(d) All screw pipe used for soil, waste and vent shall be reamed to eliminate
burp.
[ ]As amended by Ord. 1948, ch. 8 ]
JSect. 3118. Brass, Copper and Lead Pipes. — (a) Brass and copper
pipe for soil, waste and vent pipes shall be of the weight and thickness known
in commerce as iron pipe size.
(b) Fittings for brass or copper soil, waste or drain pipes shall be recessed
heavy cast brass or cast iron drainage fittings with smooth interior water-way
and iron pipe size threads tapped so as to provide a uniform slope in branches
from vertical pipes of not less than one quarter inch per foot.
(c) Lead pipes for soil, waste and vent pipes including bends and traps,
shall be not less than the following average thickness and weight per linear
foot and not more than the following lengths:
(346)
Sees. 3118-3119
Size (Inches)
Thickness
(Inches)
Weight per
Linear Foot
(Pounds)
Maximum
Lengths
(Feet)
«
2.
2i
3.
4.
1/8
1/8
1/8
9/64
11/64
5/32
2.50
3.00
4.00
5.00
8.00
10.00
6
10
10
10
4
4
(d) The use of lead pipes in a drainage system is restricted to the above
table. Concealed horizontal lines of lead pipe shall be supported for their
entire length. All other lead pipes shall be properly supported to prevent
sagging.
(e) Branch connections of lead pipe shall be full size wiped solder joints;
connections of lead pipe to cast iron and screw pipe shall be made by means
of brass ferrules and soldering nipples respectively to which the lead pipe
shall be full size wiped solder joints, other connections in lead pipe shall be
made by means of a round or flanged full size wiped solder joint. Overcast
or cup joints are prohibited.
(f ) Soldering nipples for the connection of lead pipe to screw pipe shall
be of approved quality cast brass or of brass pipe, iron pipe size. If cast
they shall have not less than the weight listed in the following table:
Minimum Weights of Cast Brass Soldering Nipples.
Diameter (Inches)
Weight (Ounces)
H
8
2
14
2\
22
3
32
4
56
[ JAs amended by Ord. 1948, ch. 8
*Sect. 3119. Hangers and Supports. — Drainage System: All drain
waste and vent piping shall be securely supported with approved metal
hangers or supports, in such a manner as to prevent sagging or swaying.
Drainage piping placed in filled ground or other shifting soil shall be securely
hung from the building structure by brass rod of approved diameter and rust
proof hangers.
(347)
Sees. 3119-3121
Drainage piping placed in filled ground or other shifting soil outside or
inside the building structure, shall be properly supported in such manner as
to prevent settling of the pipe.
Vertical stacks shall be supported at each floor.
Horizontal lines shall be supported at approximately five feet on centers
when of calked lead joint construction and approximately eight feet on
centers when of screw pipe construction.
Inserts for concrete construction shall be of malleable iron, cast iron or
pressed steel. When pressed steel is used it shall be rust proof and not less
than twelve gauge.
Expansion shields when used shall be of an approved type.
Friction clamps when used shall not be made of less than one and one
•quarter inch by one quarter inch stock.
Three eighth inch rod shall be the minimum size used.
Rod sizes, when used with band or ring type hanger, shall be as follows:
piping up to and including two inch in size, three eighth inch, piping two
«,nd one half inch and up to and including six inch in size, one half inch
piping above six inch in size five eighth inch.
Hangers consisting of rod only shall be in the U form and both ends of the
U shall be fastened to the structure, and of sizes called for above.
Water Supply Piping: All water supply piping shall be securely supported
with approved metal hangers or supports, in such a manner as to prevent
sagging or swaying.
Wire hangers shall not be used for supporting pipes larger than one inch
in size. When wire hangers are used the wire shall be not less than one eighth
inch gauge.
Horizontal lines of pipe shall be supported as follows: pipes one quarter
inch and up to one half inch in size, approximately eight feet on centers and
pipes three quarter inch or larger approximately ten feet on centers.
Vertical lines of water supply piping shall be properly supported.
[ *As amended by Ord. 1943, ch. 8 ]
fSect. 3120. Inspection and Tests. — (a) No part of a plumbing
system shall be covered or concealed from view until it has been examined
by the plumbing inspector or tested in the presence of a plumbing inspector
and approved by the commissioner, who shall examine or test it within two
working days after receiving written notice that the work is ready for inspec-
tion, weather permitting. No part of a plumbing system shall be used unless
the drain, soil, waste, vent and the water supply pipes, when roughed in,
have been tested by the plumber in the presence of the plumbing inspector
as hereinbefore provided at a time when such test is practicable.
(b) Tests shall be made by water if practicable, or air pressure in such a
manner as to disclose all leaks and imperfections in the work.
[ ]As amended by Ord. 1943, ch. 8 ]
JSect. 3121. Prohibited Fixtures, Fittings and Connections. —
The following list of fixtures, fittings, connections, and devices are hereby
prohibited:
(348)
Sec. 3121
Fixtures: Submerged flushometer closets.
Second hand fixtures of objectionable origin, unless approved
by the commissioner.
Unlined wooden sinks or trays for restaurants and laundries.
Long hoppers.
Enameled iron water closets and urinals.
Wash sinks or basins so fitted as to retain water to be used
simultaneously by more than one person.
Fittings: Double hubs.
Sleeves used as hubs.
Saddle hubs and bands.
Repair clamps.
Connections: Slip and union joints on sewer side of trap.
Drilling or tapping of drain, soil, waste or vent pipes.
Devices: Traps depending on partitions to form seal.
Iron bath traps up to two inch.
Water jacketed grease traps.
Fire pot hot water generators except on gravity supply hot
water systems.
Three quarter and full S traps under three inch in size.
No trap or water supply piping shall be exposed to freezing
without adequate protection.
[ tAs amended by Ord. 1943, ch. 8 ]
(349)
Sees. 3201-3405
PART 32.
VALIDITY.
Section 3201. The invalidity of any section or provision of this act shall
not invalidate any other section or provision hereof.
PART 33.*
WAR PROVISION.
Section 3301. During the continuance of the existing state of war
between the United States and certain foreign countries, and for the period of
six months following the termination of such existing state of war, the Build-
ing Commissioner may grant a permit allowing the substitution of specified
building materials and methods of construction for the materials and methods
now required by this code, whenever he shall find that the materials required
by the code are not available or cannot be obtained because of a Federal
law, rule, or regulation, and that the substitution shall not conflict with the
spirit and intent of this code.
[*As inserted by Ord. 1948, ch. 9]
♦PART 34.
FALL-OUT SHELTERS.
Section 3401. Fall-Out Shelters are hereby defined as structures designed
and intended to afford reasonable protection against the radio active fall-out
from any nuclear explosion when said shelter is beyond the range of destruction
of such nuclear explosion. Fall-Out Shelters are not designed or intended to
afford protection from blast and radiation effects of the nuclear explosion
itself.
Section 3402. The provisions of Parts 2 to 32, inclusive, of this Code
shall not apply to Fail-Out Shelters designed for use by 10 or less persons.
Section 3403. Fail-Out Shelters shall equal or exceed the minimum
standards prescribed by the National Civil Defense Agency as to size, ma-
terials, thickness and strength of materials, floor space requirements per
person, ventilation, and protection against radiation.
Section 3404. A Fall-Out Shelter constructed within or abutting an
existing structure shall have at least one exit leading directly from the helter
to the outside ground surface without passing through the existing structure.
Section 3405. Fail-Out Shelters shall not be converted to other uses unless
they comply with the Building Code in its entirety and pertinent zoning regu-
lations in every respect for such use.
[ *As amended by Ord. 1961, ch. 5 ]
(350)
Sees. 1=5
GASFITTING REGULATIONS.
City of Boston Gas Fitting Regulations formulated January 23, 1952, under
authority of Chapter 479 of the Acts of 1938 as amended, Section 116 (i),
were superseded on February 1, 1961 by the "Massachusetts Code for Instal-
lation of Gas Appliances and Gas Piping" established under Chapter 737
of the Acts of 1960.
Section 5. Section one hundred and sixteen of chapter four hundred and
seventy-nine of the acts of nineteen hundred and thirty-eight is hereby
amended by striking out paragraph (i) and inserting in place thereof the
following paragraph: —
(i) The owners of buildings in Boston shall comply with, and all ma-
terials used and work performed in gas fitting in Boston shall be in accord-
ance 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 com-
missioner of the city of Boston shall severally have power to inspect from
time to time gas fixtures and appliances in any and all buildings in Boston
and to compel compliance in Boston with the rules and regulations aforesaid.
[ Ch. 737, I960, Sec. 5, Approved Oct. 27, 1960}
(351)
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 commis-
sioners' line; thence by said harbor commissioners' 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 east-
erly 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
centre 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.
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 southerly 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 intersection; and by the centre lines of Columbia road, Blue
Hill avenue, Seaver street, Columbus avenue, Atherton and Mozart streets,
Chestnut avenue, Sheridan, 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
(352)
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 extended 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 includ-
ing area within the boundaries of the first fire zone.
Also those portions of Hyde Park upon or within 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 loca-
tion of the Boston and Providence Railroad 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 oppo-
site 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 Fairmount avenue to a point three
hundred feet northeasterly therefrom; Grove street; Pierce street from
Fairmount avenue to a point three hundred feet northeasterly therefrom;
Knott street from Fairmount avenue to a point three hundred feet easterly
therefrom; Railroad avenue from Fairmount avenue to a point three hun-
dred 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 Fairmount avenue to a point one hundred
and twenty-five feet westerly therefrom.
[Ord. 1913, ch. 4 and Rev. Ord. 1947, ch. 41, sec. 1\
(353)
INDEX TO BUILDING CODE
Section
Qroup A— THEATRES 301
Group B — HALLS (Churches, gymnasiums, dance halls with main floor over 900 square
feet) 401
Qroup C — SCHOOLS (Buildings partly or wholly so used) 501
Qroup D— HOSPITALS, JAILS, ASYLUMS, HOMES FOR AGED, ORPHAN-
AGES, SANITARIUMS, NURSERIES 601
Qroup E— COMMERCIAL BUILDINGS OF HAZARDOUS OCCUPANCY (Plan-
ing mills, woodworking plants, box or mattress manufacturing, dry
cleaning) 701
Qroup F— OFFICES AND COMMERCIAL BUILDINGS, RESTAURANTS,
WHARF BUILDINGS, POLICE AND FIRE STATIONS, MU-
SEUMS, LIBRARIES. Also buildings for storage and sale of goods,
wholesale and retail stores and factories and workshops (materials
handled not highly flammable), and printing plants and buildings for
storage of transient freight; garages for more than six; cars and hangars, 801
Qroup G— COMMERCIAL BUILDINGS OF NON-HAZARDOUS OCCUPANCY
(Ice, power and pumping plants, cold storage plants, creameries, brew-
eries; also factories and workshops using incombustible and non-
explosive materials) 901
Qroup H— HOTELS, DORMITORIES, LODGING HOUSES, CONVENTS,
MONASTERIES AND CLUB HOUSES (With sleeping accommoda-
tions for ten or more persons or for more than three families). Also
apartment houses accommodating more than three families 1001
Qroup I — DWELLINGS (For not over three families), and dormitories, lodging houses,
clubs, convents and monasteries (with sleeping accommodations for less
than ten persons) 1101
Qroup J — MISCELLANEOUS STRUCTURES,. Tanks, towers, signs, amusement
park structures, grandstands, reviewing stands and garages for six cars
or less 1201
Section
ACCESS PANEL for fire extinguishing apparatus 3010
ACCESSORY STRUCTURES 2902-d
ACOUSTICAL CEILING CONSTRUCTION in Buildings of Type 1 1602-f
ADMINISTRATION
Abandon application after six months 110-g
Actions pending on effective date of Code 103
Acts repealed 102
Amendments of Code by City Council 105A
Annual Report 115
Appeals (see Board of Appeal) 118, 119
Application of other statutes to Building Department 104
Applications for permit 110
Appointment of employees ' 109-d,e
Building Commissioner — qualifications 109-b
Building height allowed 136
Boards (see Boards of)
Civil Service rights of employees 109-c
Courts and jurisdiction 123
Deputy Commissioner may be appointed 109-e
Dynamos — Applications for 1 10-a
Elevators and escalators — Installation of 135
Employees not to engage in other work 109-f
Employees — Reappointment 109
Examination of plans 1 10-h
Extension of application may be granted 110-g
Extension of permit may be granted 11 1-e
Fees . . 112
Inspection 113
Inspectors — Appointments and qualifications 109-d
Maintenance of furnaces and boilers 110-a
Organization of department 109
Permits Ill
Plans — Submit, with specific information 110-e,f
Powers and duties of Building Commissioner 116
Records 109-g
Refusal of permits 111-b
Scope of Code 107
(354)
Section
AFFIDAVITS FROM ARCHITECTS AND ENGINEERS 110-i, 111-h
AGGREGATE (see Concrete)
AISLES (see Group — Occupancies under Exits or Assembly rooms)
AISLES AND SEATING in class rooms 506
ALLOWABLE BEARING VALUE ON SOIL FOR FOUNDATION .. .2904-a, 2905-b
ALLOWABLE LOAD ON PILES 2909-b, d, e, f , g
ALLOWABLE STRESSES (see under Stresses)
ALTERATON of pre-Code buildings 107-c, d, e, f, g, and 1414
AMUSEMENT PARK STRUCTURES 1201 to 1207
ANCHORAGE OF
Columns, steel and iron 2819
Masonry veneer 1415-b
Masonry walls 1408-b,o
Reinforced concrete walls 1405— k
Reinforcements 2644, 2645
Steel joists 2818-h,i
Web reinforcements 2646
Wood floors— Type III. 1604-h
Wood joists, beams and girders 1605-d, 2506-i
APARTMENTS, Houses (Group H-Part 10)
Assembly halls _ 1001-c
Boiler rooms to have two-hour separation 1009-d
Construction of ceiling and first floor 1001-d
Corridor and stairway to be lighted 1005-f
Corridor walls 1005-d
Corridor width 1005-d
Doors to roof not to be locked ; 1005-e
Exit from an apartment to be not more than 50 feet from nearest exit 1005-c
First floor more than 2,000 square feet and more than three stories high shall
be of Type I or Type II. Basement ceiling of all other more than 2,000
square feet and three stories to be of one-hour fire resistance 1001-d
Kitchens, light and ventilation 1006
Partition separating apartments 1001-e
Sleeping rooms 1007
Sprinklers 1008
To have one room 120 square feet 1007-a
Toilets _ 1006, 1007-d, 1009-a,o
Type V construction not to be used / . 1001-b
Type VI not to be used for more than four families or more than two families
above first story 1001-f
Windows 1006
APPEAL (see Board of Appeal)
APPLICANT to submit borings and test before issuance of permit 2903-a
APPLICATION for Permits 110-a
May be extended ninety days 1 10-g
Number of persons to be served by an exit to be stated on 1803
APPROVAL OF PILES not specifically covered in code 2908-a
ARBITRARY moment coefficients 2636
ARCHES, MASONRY 2414
AREA (see Group — Occupancies and 305-b and 106)
Within a stairway in Group C 501-c
Within a stairway not to be used for storage 1507
ASSEMBLY HALLS, Lights and Ventilation 408
In Group B under Exits and Entrances 405
(see Group Occupancies also) 1001-c, 1008-a, 1803
ASSUMED STRENGTH OF CONCRETE MIXTURES 2611
ATTICS, Exits 1804-b
AUDITORIUM, DANCE HALLS, ETC., One person per 6 square feet 1803
AUTOMATIC SPRINKLERS IN PRE-CODE BUILDINGS, in Groups E and F, 3001-b
(see also under Sprinklers)
AWNINGS, roof drains 1703-a
BAKERY OVENS (see also Sec. 25, Gas Regulations) 2119
BACKFLOW OF SEWAGE 3103-f
BALCONIES, CONNECTING 1815-f,g
BALCONY RAILING 2309
BASEMENT, CEILING To be at least one-hour fire resistant 1001-d, 1101-c
LIVING AND SLEEPING ROOMS 1007-O
Not to have wooden columns or partitions 1507-b, 1604-d
TO BE WATERPROOFED (if surrounded by water-bearing soil), 2902-f
BATHROOM, windows not less than one eighth floor area and not less than
6 square feet 1006-a
(355)
Section
BEAMS, Built-up, wooden 2506-g
Deflection 2808-f
Encased in concrete 2650
Notches in wooden 2506
Reinforced concrete beams that serve as walls to meet requirements of
non-bearing walls 1405-f
Spandrel 2651
Steel beams and girders 2808
Structural steel beams framed into wall to have protection against fire. . 1405-j
Support on hollow masonry 1410-a
BEARING, On concrete footings 2682
Partitions of masonry for one-story to have thickness of one-twentieth
the height or length, etc 1406-e
PARTY WALLS of masonry not less than 12 inches thick 1406-f
TESTS 2915-a
WALLS, exterior 1406-d
Panel 1406-g
BELL-SHAPED BASES (caissons) 2907
BLOW-OFF TANK 3103-e
BOARD OF APPEAL 117
Appeals to 118
Decisions of 119
BOARD OF EXAMINERS 120
OF QASFITTERS 121
BOILER OR FURNACE, Maintenance of 110
Permit for installation required 2119
Waterproofing to be protected against damage 2902 -f
IN ASSEMBLY HALL NEAR STAGE, to have two-hour separation, 410
BOILER ROOMS
In buildings more than three stories, to have two-hour separation 1009-d
In Group D buildings, to have three-hour separation 608
In Group H buildings, to have two-hour separation 1009-d
In schools, to have two-hour separation 510
In Type IV and Type VI buildings, more than one family 1101-c
BOILERS 2105-b, 2108-a, 2109
Water pressure in 3114
BOND IN MASONRY 2412
BONDING OF FRESH AND HARDENED CONCRETE 2623
BORINGS TO BE SUBMITTED TO BUILDING DEPARTMENT 2903-a
BOTTOM SURFACE OF FOOTING 18 INCHES BELOW GROUND (MINI-
MUM) 2906-c
BOUNDARIES OF FIRE ZONES 202
BOUNDARY LINE OF A LOT 1006-f
BRACES IN WOODEN WALLS 1417-e
BRASS PIPE 3118
BREWERIES 901
BRICK 2202. 2403
UNIT COMPRESSIVE STRESS 2413-a
BRIDGING, Steel 2818-g
Walls and partitions 2508-a-c
Wood . 2506-e
BUILDING COMMISSIONER 109-a.b
HEIGHT ALLOWED 136
INSPECTION 113
LICENSE 120
BY TYPE OF CONSTRUCTION 124
CLASSIFICATION AS TO TYPE 125
FIRE RESISTANCE 124
BUILDING DRAI NS, for waterclosets and urinals 3104-b
BUILDINGS ON WHARVES USED FOR STORAGE 801-d
GROUP C, in first or second fire zone shall be of Type I or Type II
construction 203-h
To have a supply of pure water 3101-a
To have toilet accommodations 3101-b
IN first or second fire zones erected as garages for more than four
cars to be of Type I or Type II 203-g
MORE THAN 125 FEET HIGH, soil stack at least 5 inches. . . 3104-g
MORE THAN THREE STORIES HIGH, first floor commercial,
and more than two families above second floor; sprinklers 3101-b
(356)
Section
BUILDINGS— Continued
OF TYPES III, IV, VI, wooden roof not to extend beyond wall, 1701-e
OF TYPE VI — Not to be used for more than four families 1001-f
For dwellings in second fire zone 203-d
V — In second fire zone 203-e
BUILT-UP GIRDERS, wooden 2506
BULKHEADS, for display windows 1902-j
CAPPING OF PILES 2908-g
CASED PILES (Metal) 2912-c,l, 2912-c,3(II)
CAST IN PLACE PILES (Concrete) 2912-a,b
IRON 2805
COLUMN CAPS 1604-*
PIPE 3116
STEEL 2804
STONE 2405
CATHODIC PROTECTION OF PILES 2913-a,3
CEILINGS of buildings more than 2,000 square feet and three stories high, one-
hour fire resistance 1001-c, 1101-c
Acoustical in Type II, of wood or other combustible material 1602-f
Finished in wood — Type I and Type II 1602, 1603
BASEMENT, in buildings more than three stories high, one-hour fire
resistance 1101— j, 2210
In Group D, Division 2, buildings 601-0
CEILING UNDER ROOF (see also under Floor Construction) 1701-b
CELLAR 1603-f, 1608, 1902
CEMENT MORTAR SHALL BE COMPOSED OF 2411-h
PLASTER SHALL BE COMPOSED OF 2202
CERTIFICATE OF INSPECTION FOR TREATED PILES 2910-i,2
CHANGE OF OCCUPANCY 107, 133
CHASES, RECESSES, CORBELS AND LINTELS 1405-i, 1411
CHIMNEY FLUE LINING 2102
FOUNDATION 1411-g, 2101
IN APARTMENT OR HOTEL 1009-e
NOT TO BE BUILT NEAR WOODEN MEMBERS. .2103, 2104, 2105
CHIMNEYS (see Part 21)
CHURCHES— Group B 401
CHUTES AND DUMB-WAITERS 1503-h
CLASSIFICATION OF BUILDINGS BY TYPE OF CONSTRUCTION 124
AND ALLOWABLE LOADS ON FOUNDATION BEAR-
ING MATERIALS 2904
Of bearing material 2904-a
CLAY TILE 2102, 2407
For chimney construction 2407
CLEARANCE AND DIMENSIONS OF PILE CAPS 2908-g
CLEARANCES
Ends of wooden beams resting upon masonry to have four-inch clearance .... 2506-1
Furnace 2109
Over hot plates 2112
Pipes and chimneys 2104, 2111
Range hoods 2114
Smoke stacks 2105
Steel joists 2818-j
CLEAN-OUTS IN DRAINS 3103-g
CLOSETS on or under stairways 1507, 1808-n
COLUMN BASES OF STEEL AND IRON 2819
COLUMNS
Cast iron 2810, 2816
Combination 2677
Concrete 2669 to 2674, 2677
Concrete filled pipe columns 2811
Steel 2807
Type 1 1602-b
Wood 2505
Wooden, not to be used in basement 1604-d, 1607-b
COMBINATION AND RIBBED SLABS 2653
COMPACTED CONCRETE PILES 2912-d
COMPACTED GRANULAR FILL 2904-a, 4 (III)
(357)
Section
COMPOSITE BEAMS 2808-h
PILES 2914
COMPRESSIVE STRENGTH OF CONCRETE IN PIPE PILES ASSUMING
3000 LBS. PSI 2913-b, 3
CONCEALED OPENINGS THROUGH FLOORS 2508-d
CONCENTRATED LOADS 2306, 2652
CONCENTRATION OF HEAVY LOAD 2820-e
CONCRETE (see Part 26)
Aggregate 2606
Anchorage 2644, 2645, 2646
Assumed strength of mixtures '. 2611
Average 2611
Axial and bending stresses 2676
Beams, compressive reinforcement 2649
Bearing on footings 2682
Bonding to fresh or hardened concrete 2623
Cement 2605
Columns 2669, 2674
Combined footings 2680-d
Construction joints 2622, 2668
Controlled 2610, 2612
Cover for reinforcement 2627
Reinforcement in, for pile caps 2907-f
Curing 2621
Depositing in cold weather 2620
Exposed to weather 2611, 2612
Filled pipe piles 2908-g, 2913-b, 3
Filled pipe piles with steel core 2913-b, 3
For capping piles 2913-d, l,2913-h,4
Forms and equipment 2615
Not to be placed through water 2913-h, 4
Inspection of 2603
Moment coefficient 2636
Openings in flat slabs 2667
Placed through water 2907-b, 6
Placing 2619
Point of inflection in flat slabs 2660
Proportions and consistencies 2614
Reinforcement 2608
Ribbed slabs 2653
Shrinkage reinforcement 2651
Slenderness ratio 2807-b
of reinforced concrete beam 2647
Spandrel beams 2651-b
Stress 2629, 2630
Structural concrete 2610
T beams 2648
Table of stresses 2629, 2630
Temperature reinforcement 2651
Test of materials 2604, 2612, 2613
Transporting 2618
Two-way slabs 2654
CONCRETE BLOCKS 2202, 2406
CLASS I AND CLASS II 2202
DEPOSITED IN COLD WEATHER 2620
FILL 2202
FILLED PIPE COLUMNS 2811
STEEL PILES 2913
FOOTINGS 2642, also 2679 to 2682
INSPECTION 2603
REINFORCEMENT
Bending 2624
Compression in beams and girders 2649
Placing 2625
Protective cover 2627
Shrinkage and temperature 2651
Splices in 2626
Web reinforcement 2639, 2640
WALLS 1405, 2678
CONDUIT EMBEDDED IN CONCRETE 2202-g, 2628
CONNECTING BALCONIES 1815-f
CONSTRUCTION JOINTS IN CONCRETE 2622
FLAT SLABS 2668
TYPES OF 125
WITHIN FIRE ZONES 203
(358)
Section
COPINQS..... 1703-a
COPPER, Pipe 3118
CORNICES, Metal l$9%~d
Rain water discharging on a public way 1703-a
Wood (not in fire zones) 1402-d
CORRIDORS, General (see Group — Occupancy)
And passageways 1805
And stairways in Group H to be lighted 1005-f
Group C 505
Group H 1005-d
Not to have any obstruction 1005-c
Space to lobby 1814
Walls in Group H to be one-hour fitre resisting 1005-d
Width of, in Group H 1005-d
CORROSION OF STEEL 2913-a,
COURT WALLS 1402-e
CREOSOTED PILES 2910-i, I
CUSHION BLOCK MATERIAL 2910-i, I
CUT-OFF GRADE
Creosoted piles above water level, buildings not over 2 stories 2908-d
Steel pile, protection against corrosion 2913-a, 3
Untreated piles 2910-g
DAMAGED PILES, During driving 2908-d
DANCE HALLS, Steel deck floor not to be used 2830-e
DEDUCT ONE-EIGHTH INCH FOR CORROSION OF FOUNDATIONS... 2913-a, 2
DEFINITIONS
Concrete 2601
Foundation pier 2907-b
General 106
Masonry 2402
Pertaining to plumbing 3102
Walls and partitions 1401
DEFLECTION OF STEEL BEAMS, 1/360 of span 2808-f
DEPTH OF FOUNDATION 2902-o,d
DESIGN, Of wood 2501
DETACHED COLUMN, Resting on piles 2908-b
DETACHED GARAGES, Foundation of 2902-d
DETERMINATION OF VALUE OF "S" — DAMAGED CUSHION
BLOCK 2908-d, 2909-c
DEVIATION OF PIPE PILES FROM DESIGN ALIGNMENT 2913-b, 2
DIAGONAL FLOOR FRAMING 2507-b
DINING ROOMS, Light and ventilation 1006-c,e
DISPLAY WINDOWS 1902-j
DISTANCE FROM LOT LINES (see Group— Occupancies under Exterior Walls)
DOORS, FROM STAIRWAY TO ROOF NOT TO BE LOCKED 1005-e
FIRE, CONSTRUCTION 2214
fire-resistive requirements 2213
on each side of party wall openings 1901-c,4
General requirements 1302, 1901, 2213, 2214
To swing in direction of egress 1806-d,e, 1817-0
AUTOMATIC SELF-CLOSING 1901
DOORWAYS IN ENCLOSURES 1503-f
AS EXITS 1806
NEAR FIRE ESCAPES 1812
DOWELS, from Pedestal to Column 2682
DOWNWARD FRICTIONAL FORCES for a pile or group of piles placed in sub-
siding fill or soil 2909-h
DRAINAGE, Filling, on roof of Type I and Type II 1701-c, 1703, 2620
Mechanically discharged 3107
SYSTEM AND MATERIALS 3112
System design and method of construction 3103
DRAINS 3103
DRAINS FOR RAIN WATER 3105
DRINKING FOUNTAIN 3115
DUCTS, Ventilating 1506
DUMB-WAITER AND CHUTES 1503-f
(359)
Sectkw
DUTIES OF THE COMMISSIONER 116
DYNAMOS, Application for 110-a
ECCENTRICITY OF LOADING IN FOUNDATIONS 2905-b
EFFECTIVE DEPTH of reinforced concrete beams and slabs 2634
EGRESS, Pre-code buildings to have at least two in number (see also Exits, Part 18) 107-e
ELECTRIC PLATES 106, 2112
ELEVATORS, ESCALATORS AND ELEVATOR SHAFTS 135
As exits 1814
Fire protection on support for elevator guides and elevator machines 1602-b
Group A buildings 304-b
Group B buildings 404
Group C to Group G, same as in 504-a
Passenger enclosure doorways 1503-f
Shafts to be ventilated at top 1503-i
Shaft windows 1902
ENCLOSURE OF CHUTES AND DUMB-WAITERS 1503-h
VERTICAL OPENINGS (see also Group— Occupancy) 1504
TO BE USED FOR PURPOSE FOR WHICH IT WAS CON-
STRUCTED 1507
ENGINES, Applications for 110-a
ERECTION OF STEEL 2817
EXCAVATION, Removal of water 2617, 2901
EXEMPT FROM CODE 107-a
EXISTING MASONRY WALLS 1414
EXITS (see Group — Occupancies)
And entrances, Group B — Part 4 . 405
Corridors not to have any obstructions 1805
Description and kind of exits 1802
Distance to an exit from an occupancy 1804-h,i
Enclosures • • • • • • J817
Exit doors shall swing in direction of egress 305-k, 1806-e
From a flat roof occupied by persons 1804-b
From an apartment — must not be over 50 feet from nearest exit 1005-e
From H and I occupancies 1005-b,g, 1105
From or to an attic Jfm
General requirements, Part 18 1801
Group C— Part 5, Schools 505
In Group E no point in story to be over 100 feet from nearest exit 705-b
Lighting and maintenance 18 19
Must be in a continuous path • • • • J|02-e
Number and location of 18U3, 18U4
Number of persons served by, based on square feet per person 1803
Number of persons to be served by, to be stated in application for permit 1803-a
One from every story must be an interior stairway 1802-f
Passageways to and from required exits not to be obstructed. 1808-m
Room or group of rooms more than 2,500 square feet, or containing more than
75 persons, to have two remote exits 1804-c
Siens 3<>7> 1802-e, 1818
To^eiighVedV. V.'.: 307'10°t5i
To be satisfactory to the Commissioner on!i
Two remote from each story 1804-e
EXPANSION AND CONTRACTION OF STEEL 2814
JOINTS 2651-c
EXTENSION OF APPLICATION 110-g
WOODEN RAFTERS BEYOND MASONRY WALLS 1701-e
EXTERIOR BEARING WALLS, Thickness of . . . . . . . ... ... ...... ... ........ 1406-c
Of masonry 1/16 height or length between
lateral supports in top story, or 1/20 in
all other stories, and not less than 8 inches
in Type V or Type VI 1406-e
AND BEARING WALLS OF REINFORCED CONCRETE shall
be anchored to floors, etc 1405-k
BEARING WALLS OF REINFORCED CONCRETE to have 1/25
height or length 1405-d
EXTERIOR MASONRY PANEL WALLS 1406-g,h i
NON-BEARING WALLS 1406-g
STAIRWAYS AND RAMPS 1811
STAIRWAY FROM A LOT LINE " 1811-a,c
to be enclosed if less than 15 feet from a lot line 181 1-c
OUTSIDE PASSAGEWAY to be as wide as an interior passageway, 1805-h
WOOD FRAME WALLS 1417
WALL (see also Group — Occupancies) 1402-d
OPENINGS 1402-d
(360)
EXTERIOR— Continued Section
WALLS, TYPE III, MAY BE 2-HOUR FIRE RESISTANT, 2201-e
IV, MAY BE 2-HOUR FIRE RESISTANT, 2201-d
BEARING WALL, WOOD TRIMMINGS 1402-d
FACTORIES AND WORK SHOPS, One person per 35 square feet 1803
FEES 11 2-*
FENCE 107
FINISH, Outside 1402-j
FIRE DAMAGE, restoration of 107-d
DOORS 2213, 2214
in fire walls 1302-g
stop walls 1417-e
ESCAPES, As exits 1812
EXTINGUISHING APPARATUS (Part 30)
Access panel 3010
Water supply 3007
LIMITS 201
boundaries of 202
PLACE 2107
PROTECTION, For—
Cast-iron columns 2204
Reinforced concrete beams 2207
Reinforced concrete columns 2205
Reinforced floors and roofs 2208
Steel beams, girders and trusses 2206
Steel columns 2203
PROTECTIVE, Covering injured by moving vehicles 2202-h
RESISTIVE
Bearing walls and partitions 2211
Brick of Grade B 2403-g
Ceiling construction 2210
Doors 2213
Fire door construction _ 2214
Materials, construction and minimum qualities 2202
Non-bearing walls and partitions 2212
Requirements, Commissioner may not alter 116-1
Roof and floor construction 2209
Roof covering 2217
Shutters 2215
Windows 2216
STOPPING 1604-a, 1607-a, 2202-i. 2508-d
and nogging masonry may be supported on wood 1406-b
STOP WALLS 403-g, 1402-a, 1411-e, 2202-i, 2508-d
TOWERS 1810
WALL, Definition (see also 134, 1301, 1302-g) 1401
Openings, fire door on each side of 1302-g
FIRE WINDOWS 2216
As substitute for firedoor, doors 1302-1
ZONES 201
Boundaries 202
FIRST FLOOR, More than 2,000 square feet in Type I or Type II 1001-d
FLAG-POLES, Not part of building 136-0, 2003-c
FLAT SLABS 2641, 2655, 2657 to 2668
FLOOR CONSTRUCTION, Within enclosures 1504
CONSTRUCTION:
To be three-hour fire resistive 1602-a
To conform to code as to design 1601
TYPE I— FIREPROOF 1602-a
Ceiling may be finished in wood 1602-f
May be covered with wood 1602-c
Mezzanine floor may be of wood 1602-d
No hollow apace under flooring 1602-O
TYPE II— SEMI-FIREPROOF 1603
Ceilings may be finished in wood 1603-f
May be wood covered 127, 1603-c, 2209
Steel joists with ceiling 1603-e
TYPE HI — Thickness of steel stirrups and column caps 1604-e
Wood not to be used for columns in basement 1604-d
TYPE IV 1605
TYPES I and II — May be covered with wood — no hollow space
under flooring , 1602-c , 1603
(361)
FLOOR CONSTRUCTION— Continued Section
TYPE I — Mezzanine may be of wood 1602-d
TYPES I and II— CEILINGS, May be wood finished 1602-f, 1603-e
Floor of steel joists with ceiling 1603-e
TYPE IV — No "structure of combustible material to support seats
or aisles to be superimposed on floor construction 401-b
GROUP H — First floor more than 2,000 square feet and more than
three stories shall be of Type I or Type II. Basement ceilings of
all others less than 2,000 square feet and three stories to be one-
hour fire resistive 1001-d
WOOD NOT TO BE USED for columns or partitions in basement. . 1604-d
FRAMING, Diagonal 2507-b
LOADS, Posting 114
Steel Joists— Type II 127, 1603, 2209
Unprotected against fire 1605, 1607
Wooden 1405-b, 2507
Not to be used for finish in garages 1208
FOOTINGS 2642, 2679, 2907-a
And foundations 2907-a
At different levels % 2902-b
Supported at different levels from footings of adjacent structures .... 2906-a
Wooden 2907-a
FOUNDATIONS (General— Part 29)
Allowable loads on piles 2909
Borings and test pits 2903-a
Cast in place concrete piles 2912
Classification and allowable load of foundation bearing materials 2904
Composite piles 2914
Concrete filled cylindrical piles 2913-b
Depth of — 4 feet minimum 2902
Excavation 2617, 2901
Footings, caissons and pier caps 2907
For detached garages 2902-d
For 1-story structures 2906-a
Foundation design 2906-a
loads 2905
load tests 2915
to be supported on natural deposits . 2902-a
Grade beams and footings due to frost carried 4 feet below adjoining surface.. 2902-c
Hydrostatic uplift 2902-e
Load testa on bearing material 2916
Loads used to compute pressure on bearing material 2905-a
Not to be placed in freezing weather 2902-c
Not to be placed on frozen ground 2902-c
Of detached garages 2902-d
Piles, general requirements 2908
loading tests 2917
precast concrete 291 1
wooden 2910
Special permit 111-d
Supporting permanent structures, satisfactory bearing material 2905-a
Wall resting on single row of piles 2908-c
Walls 1405-e, 1412
Walls, reinforced concrete, not less than 8 inches 1405-e, 1412
Wood, not to be used 2501-d
FRANKI PILES, Provision 2912-d
FRICTION PILES 2909-d
FURNACES 2110, 211 1
AND BOILERS, Maintenance 110-a
FUTURE FLOOR, Present roof in Type I and Type II, the filling for drainage may
be of wood 1701-c
GARAGE SEPARATION 801-f to 805, 1102, 1201, 1202-a. 1301-d
GARAGES, To be Type I— Section 203-g 801-f, 805
Cast iron columns not to be used in 2810-f
Finish floor in, wood not to be used for 1208
Foundation for detached 2902-d
Over six cars — Type VI not to be used 801-b
Six cars or less 1201-b
Steel deck construction not to be used for floors 2820-e
To have sprinklers if more than 10,000 square feet in area or if five
stories or more in height 807-f
GASFITTER'S LICENSE 121
GIRDERS, Wooden built-up 2506
GREENHOUSES 1903-a,b
GRILLAGE, Structural steel 2907
(362)
Section
GROUND WATER OBSERVATION WELL 2910-h
QROUP C BUILDINGS in first or second Fire Zone to be of Type I or Type II
construction 203-h
QYMNASIUM, Steel deck floor not to be used 2820-c
GYPSUM, General— (Part 27) 2202
Plain 2202-b
Concrete 2410
Concrete design and stress 2701
Not to be used for a wearing surface 2701-g, 2706
Not to be used in floors of garages, dance halls 2701-g, 2706
Tile 2408
H PILES 2913-c, 1
HALLS 401
HAMMER SIZE FOR WOOD PILES 2910-f
HANGARS— Section 801-Division 5
HANGERS, For wooden joists 2506-d
And support for drainage system 3119
HEATING, Apparatus given (Part 21)
Apparatus support 2117, 2119
And PLUMBING — Group H 1009
HEIGHT (see Group — Occupancies)
HORIZONTAL EXITS 1815
HOT PLATES 2112-a,b
WATER SUPPLY 3114
Heater, tankless 3ll4-o
Tank, cistern pressure 3114-p
Tank pressure 31 14
HYDROSTATIC UPLIFT 2902-e
IMPACT 2308, 2504-c
INCINERATORS 2116
INCREASE in area or in number of stories 107-f
INSPECTION 113
AND TEST OF FIRE EXTINGUISHING APPARATUS,
HOSE, ETC 3009
PLUMBING 3120
OF GAS FIXTURES 116-i
OF COMPACTED GRANULAR FILL .2904-a, 2904-c
OF PIPE PILES WITH STEEL CORE 2913-c, 2, 2913-d, 1
OF PILE BEFORE CONCRETING 2912-c, 4
OF BEARING TESTS 2915-c
OF CONCRETE FOUNDATION PIERS (Caissons) 2907-b, 7
OF INSTALLATION OF DRIVEN PILES 2908-j
INSULATION, Filling FOR ROOF 1701-c
INTAKE, FRESH AIR, IN COURTS 1006-b
INTERIOR BEARING WALLS AND PARTITIONS, THICKNESS OF 1406-e
RAMPS. , 1809
STAIRWAYS 1808-n
Closet under stairway 1808-i
If enclosed corridor is omitted then basement and first floor to have automatic
sprinklers 1805-d
No obstruction on stairway or landing 1808-m
Spiral stairs not to be used 1808-m
To be enclosed above the second story 1817-b
To extend to roof 1808
Tread, rise and landings 1808-f ,g,h
Width of stairway not to be less than 30 inches 1808-d
INTERPRETATION OF CODE BY COMMISSIONER 111-g
INWARD OR UPWARD SEEPAGE PRODUCED IN BEARING MA-
TERIAL 2906-d
IRON PIPE PLUMBING 3116, 3117
JETTED PILES 2908-e
JOISTS, WOODEN NAILING STRIPS 2506-k
JUNIOR BEAMS _ 2818
KITCHEN FLOOR AREA MORE THAN 70 SQUARE FEET 1006-a,c
not to be less than six feet wide and 48 square feet minimum 1007-a
VENTILATION 1006-a,c,d
WINDOWS, one-third of floor area and not less than 11 square feet. . 1006
(363)
Section
LADDERS AS EXITS 1813
LATERAL FORCES 2309
BRACING OF BEAMS 2803-d, 2808-b
BRACING OF STEEL FLOOR FRAMING 1602-b
not to be of wood 1603-b
SUPPORT OF WALLS 1403, 1408
LEAD PIPE IN PLUMBING 3118
LENGTH OF PILE ABOVE GROUND CONSIDERED AS UNSUP-
PORTED COLUMN 2908-i
LENGTH OF PILE BELOW GROUND TO BE CONSIDERED AS A
PLAIN COLUMN WITH LATERAL SUPPORT 2908-i
LIBRARIES 801
LIGHT, exit 307, 1819-c
and ventilation 806, 1006-a, 1106
in assembly halls 408
LIME PLASTER 2202
LIMITED HABITATION (Group I) 1101-1107
LINTELS NEED NOT BE FI REPROOFED, if span is not over 6 feet in bearing
walls or 10 feet in non-bearing walls 1602-b
LIVING ROOM 1006-a, 1106
FLOOR, and floor on ground 1007-e
LOAD
On compacted pile 2912-d
On composite pile 2914-e
On concrete filled pipe piles 2913-b, 5
On concrete filled pipe piles with steel core. 2913-d, 7
On friction piles 2909-d,e
On H piles 2913-c, 3
On poured concrete piles — not to exceed 90 tons 2912-c,3(IV)
On precast concrete piles 291 1-f
On wood piles 2910-c
LOAD TESTS OF STRUCTURES 2313
LOADS, LIVE AND DEAD (Part 23) 2301 to 2312
Due to partitions 2304
LODGING HOUSES, READING ROOMS, One person per 25 square feet l?03-a
LOT LINE BOUNDARY, For light and ventilation 1006-f
STAIRS, Not nearer than five feet from 1811-a
LOUVRES 1505-a,l
LUMBER, To be grade marked 2504-f
SECOND-HAND 2504-f
MAINTENANCE OF BUILDINGS 108
FURNACES AND BOILERS 110-a
MASONRY ARCHES 2414
CHASES, RECESSES, CORBELS AND LINTELS 1411
DEFINITION OF 2202, 2402
PIERS 1409
REINFORCED 2415
SECOND-HAND MATERIALS 2416
STRUCTURAL, not to be supported on wooden floor 1405-b, 1607-e
UNIT STRESS 2413
VENEER 1405-h, 1415-b
WALL ANCHORAGES 1406-d, 1408-b
WALLS 1406 to 1412
Existing 1414
Non bearing 1406-g
OR PIERS not to be supported on wood 1406-b
MATERIALS AND METHODS NOT COVERED BY CODE 116-1
OF DRAINAGE SYSTEMS 3112
MAXIMUM PRESSURE ON SOIL UNDER FOUNDATION 2904-b
MECHANICAL VENTILATION 1006-d
MECHANICALLY DISCHARGED DRAINAGE 3107
METAL CASED CONCRETE PILES 2912-c, 3(1)
METHOD OF DESIGN AND INSTALLATION OF CONCRETE FILLED
PIPE PILES WITH STEEL CORE 2913-d,2,6
(364)
Section
METHOD OF LOADING FOR BEARING TEST 2915-d
MEZZANINE FLOOR 1004-0, 1602-d
MINIMUM STRENGTH OF CONCRETE FOR CAST IN PLACE CON-
CRETE PILES 2912-b
MINIMUM THICKNESS OF STEEL. 2818
MOMENT COEFFICIENTS 2636
MORTAR, CEMENT 2411
MOVING, TYPE VI BUILDINGS 107-h, 203-d
PICTURE HOUSES 301, 401
MULTIPLE OCCUPANCIES 124-b, 134, 1301
TYPE URINALS 3115-c
WATER CLOSET 3115-0
NAILING STRIPS for wooden joists on girdera 2506-k
NON-BEARING PARTY WALLS OF MASONRY to be not less than eight
inches thick 1406-f
PARTITIONS OF MASONRY to have thickness 1/45 the
height or length between lateral supports and at least
3 inches 1406-f
PARTITIONS OF REINFORCED CONCRETE to have
thickness 1/60 the height or length between lateral sup-
ports and at least 3 inches 1405-f
WOOD PARTITIONS may be used in Types I, II, III and V
under certain conditions 1417
In Group F and Group G to subdivide space occupied by
one tenant 1417-b
In Group H and Group I to subdivide apartment occupied
by one tenant 1417-b
OBSERVATION WELL 2910-h
OBSTRUCTIONS IN AISLES PROHIBITED 306-c, 406-c
OCCUPANCIES, Number of persons for certain area 1803
BY GROUPS 132-a
CHANGE OF 133
MULTIPLE 134
OIL BURNERS 1152
ONE-STORY STRUCTURES WITHOUT MASONRY WALLS not exceed-
ing 800 square feet 2905-d
OPENINGS, IN MASONRY WALLS 1411-h
IN FLAT SLABS 2667
FLOOR OR ROOF, not covered by trap door to have railing
30 inches high 1501-b
ROOF 1501-d
FOR VENTILATING SHAFTS 1505
FOR WALLS, percentage allowed according to fire resistance 1302
OUTSIDE FINISH 1402-d
PASSAGEWAYS from a building 1805-h
PAINTING STEEL AND IRON 2816
PANIC BOLTS 305-k
PARAPET WALLS 1413-a,b, 1414, 1415, 1701-a,b,e
PARTITIONS, BETWEEN ADJOINING APARTMENTS, 1-hour fire resistant, 1001-e
Covered with acoustical material in Type II 1603-f
PARTY WALLS 1401-a,5,1405-g,j, 1406-h
IN BUILDINGS OF TYPES III, IV, VI, To extend through
roof 1405-j
TO HAVE FIRE DOORS 1901-a,c,f,h, 1901-c,4
PASSAGEWAY 1805
PASSENGER ELEVATORS ENCLOSURE DOORWAYS 1503-f
PEDESTALS, PLAIN 2685
PENALTIES, For violation of Code 122
PENTHOUSES 2002
PERMITS, Applications for 110-a
May be revoked 11 1-d
Shall become invalid 1 1 1-d
PHOTOGRAPHIC STUDIO SKYLIGHT 1903-b
PIERS 2907
MASONRY 1409
(365)
Section
PILE
Bearing test 2915-g
Driven through soft soil toward bearing material 2908-g
Exposed to sea water 2908-g
Formulae 2908-g
Groups — to transfer loads to underlying material by spreading uniformly
at 60 degree angle 2910-i, 4
In contact with sea water 2909-b
Length above ground surface as unsupported column 2913-a,3
Length below ground surface as a plain column laterally supported 2908-i
Placed in subsiding soil or fill 2909-h
Placing of concrete by means of tremie 2907-b,6
Plain concrete in a foundation 2906-b
Pneumatic caissons 2907-b
Poured concrete piles 2912-0
Precast concrete pile reinforcement 291 1-a
Precast concrete piles 2911-b
Preload — highly compressible material 2904-c, 5
PILE CAPS 2907-f
REINFORCEMENT in cover for 2907-f
LOADING TEST 2917
PILES, GENERAL REQUIREMENTS 2908
INSPECTION OF, WHILE DRIVING 2908-i
PIPE AND CONDUIT EMBEDMENT 2202-g, 2628
PLASTER AND MORTAR 2202, 2402
PLUMBING FIXTURES AND UNITS 3114
DEVICES PROHIBITED 3121
AND HEATING (Group H Buildings) 1009
POINT OF INFLECTION in flat slabs 2660
in reinforced concrete beams 2637
POLICE STATIONS 801-0
PORTABLE FIRE EXTINGUISHERS 3008-b
POSTING FLOOR LOADS 114
POWERS AND DUTIES OF THE BUILDING COMMISSIONER 116
Buildings to be made safe or removed _ 116-d
Commissioner can order any alteration on a Pre-Code building if not specif-
ically covered by Code 1 16-g
Condemn any unsafe building 116-a
Enter any building or premises in line of duty 116-a
Examinations of dangerous buildings 116-h
Exits satisfactory to Commissioner 116-d, 1802-d
3Tine for hindering the Commissioner 116-d
Inspection of gas fixtures 1 16— i
Opening in fire wall — Commissioner may vary ; 1302-h
Provisions of Section 116 to apply to Pre-Code buildings 116-k
Rules and regulations 116— i
Substitution of materials and methods 1 16—1
Work may be stopped : 116-b, 1302-b
Working stresses may not be altered by Commissioner 116-1
PRECAST CONCRETE PILES 2911
PRE-CODE BUILDINGS 107, 116-g,k, 124-c, 1414
ENLARGED IN AREA OR NUMBER OF STORIES 107-f
MOVED TO ANOTHER LOCATION 107-e
OF GROUP "C" (Schools), To conform to new code 501-g
SECTIONS WHICH APPLY TO 107-b
TO HAVE ELECTRICAL FIRE ALARM SYSTEM 107-e
SAFE EGRESS 107-e
PRESSURE AGAINST FOUNDATION 2905-e
PRESSURE RELIEF VALVE 3114-d
PROJECTION ROOM 314
PROTECTION OF STRUCTURAL STEEL 2202-d
AGAINST CORROSION 2816
OF EXCAVATIONS 2901-a
PROTECTIVE COVERING OF REINFORCEMENTS 2627
PROPERTY LINE, walls less than ten feet from, two-hour fire resistant 1003-a
(366)
Section
PROSCENIUM 310
RAILING, BALCONY 2309
RAIN WATER, Discharged from cornices or copings on a public way 1703-a
Drains to be laid not lower than four feet below street grade. . . . 3105
RANGE HOODS 2114
RAT-PROOFING 1608, 1902-i
RECESSES, CHASES AND CORBELS 1411
REDRIVING OF PILES 2908-h
REDUCTION OF LIVE LOAD 2310
REINFORCED CONCRETE WALLS 1405
FOUNDATIONS 2906-b
MASONRY 2415
REINFORCEMENTS, in concrete exposed to weather to have two-inch cover. . . 2627-a
REMOVAL OF WATER FROM EXCAVATION 2617
RESTAURANTS, RETAIL STORES, ETC. one person for every 15 square feet, 1803
RETAIL STORES 901
Stairways and ramps serving basement only 804-c
RETAINING WALLS 2905-e
REVIEWING STANDS 203-c, 1204-a
REVOLVING DOORS 1806-f
RIBBED SLABS 2653
RIVET CONNECTIONS 2809
RIVETS 2815, 2817-0
ROLLED STEEL H PILES 2913-c, 1
ROOF CONSTRUCTION, roofing 107-g, 1417-f , 1700, 2003, 2217
COVERING 2217
DRAINAGE. 1703
of Marquees 1703-0
FILLINGS, For drainage of future floor in Type I or Type II may be of
wood 1701-0
ROOF GUTTERS, CORNICES, ETC., In Types I, II, III and IV buildings
outside fire limits may be of wood 1402-d
LOADS 2311
PROJECTION, Maximum of 12 inches to form eaves, except in first or
second fire zones 1701-e
ROOFS SHALL BE SLOPED, To drain at a pitch of not less than 1 inch in 10 feet, 1703-a
ROOMS IN APARTMENTS, Minimum 70 square feet of floor area 1007-a
LIGHTING AND VENTILATION OF, 606, 706, 806, 906, 1006, 1106, 1206
MINIMUM HEIGHT, 8 feet 1007-b
RULES AND REGULATIONS, For tearing down buildings 116-j
SALVAGED LUMBER 2504-f
SCHOOLS (see Part 5-Group C)
SCOPE OF CODE 107-a
SECOND-HAND MATERIALS, MASONRY 2416
STRUCTURAL STEEL 2802-c,d
SEPARATION, ANGLE OF 1301-g
BETWEEN FIRE DIVISION WALLS 1302-g
OF OCCUPANCIES (see Group— Occupancies), also 134, 1301, 1302
SETTLEMENT ANALYSIS 2916-
SHAPE OR DIAMETER OF METAL CASED CONCRETE PILES 2912-0,1
SHOW WINDOWS IN A STORE 1902-j
SIDEWALK LIGHTS 1904
SIGNS, EXIT 1818
FLAT 1201-c
SKYLIOHTS 1903
In stair enclosures in roofs 1501-b, 1503
Parts exposed to weather to have wire glass 1903-e
Ventilation 1006-c
SLABS, Two-way 2654
SLEEPING ROOMS 1006-a, 1106
Floor and walls on ground 1007-c,©
SLENDERNESS OF BEAMS 2647
(367)
Section
SMOKE PIPES 2106
PROOF TOWERS 1810
STACKS 2105
SOIL AND WASTE PIPE 3104
Information before issuance of permit 2912-d, 9
BEARING FOR FOUNDATIONS 2904
PIPE not to be less than four inches diameter 3104-e
SPACING
Of compacted concrete piles 2913-b, 4
Of poured concrete piles 2913-d, 4
Of concrete filled pipe piles 2914r-d
Of concrete filled pipe piles with steel core 2913-b, 4
Of composite piles 291 1-d
Of precast concrete piles 2913-c, 2
Of H piles 2913-c, 2
For pipe piles 2912-c, 5*
SPANDREL BEAMS 2651
SPECIFICATION, Of steel and iron 2802
SPIRAL COLUMNS 2671
STAIRS, Not to be used 1808-j
SPLICES, In reinforcements 2626
Lapped in longitudinal reinforcements 2671-c
SPREAD FOOTINGS, not to be supported on fill 2902-a
SPRINKLERS
Definitions 106
Group A 313
Group B 411
Group C 509
Group D 607
Group E — Higher than two stories or 10,000 feet 707-a, 1'
Cellars and basements, floor area 1,500 square feet 707-a, 2
Certain manufacturing plants 707-a, 3, 4, 5
Group F — Cellars and basements more than 1,500 square feet 807-a
Divisions 2 and 3 — six or more stories 807-b
Division 4 — Types III, IV and VI on wharves 5,000 square feet.. . 807-c
I, II and V 20,000 square feet 807-c
Garages to have sprinklers if more than 10,000 square feet 807-f
Group G — Cellars, basements, Divisions 2 and 3 — more than 1,500 square feet, 907-a
Divisions 2 and 3 of Type IV, 7,500 square feet 907-b
Group H — Cellars, basements, Types I and II — six stories high 1008-a
All others more than three stories 1008-a
Group I — Cellars, basements in buildings more than six stories 1107-a
Fire windows, exterior wall — Commissioner may allow ordinary windows
with sprinklers 1902-g, 2216-i
In pre-code buildings, Group E and F, or either, in combination with Group
H or I .••:••: .- 3001-b
Multiple Occupancies if building is more than three stories — first floor for com-
mercial and more than two families above second floor 1301-h
CONTROL 3006
Construction of 3001-a,d
OBSTRUCTIONS, Not to interfere with sprinklers 3006-a
One of the enclosed corridors in the first floor may be omitted provided the
basement and first story are equipped with automatic sprinklers 1805-d
STAIR LANDINGS in school buUdings 505
STAIRS, Group A — Rise not to exceed 7 1/2 inches. Tread not to be less than
10 1/2 inches. Flights not more than fifteen nor less than three be-
tween landings and winders 3fl »-m,n
STAIRS, Product of tread and rise to be not less than 70 inches nor more than 77
inches except in schools 1808-h
Rise and tread 7 1/2 inches and 10 inches and not more than 15 steps. . ~505-g
RISERS not more than fifteen nor less than two in flight L808-i
SPIRAL not to be used 1808-j
TREAD not less than 9 1/2 inches and rise not more than 7 3/4 inches 1808-h
STAIRWAY CLOSETS 1808-n
ENCLOSURES (see Group — Occupancies, also) 1503-b
INTERIOR, to extend to roof 1808
LANDINGS, To have no obstruction 1808-m
Over eight feet wide to have a central rail 305-p
Railing design 2309-e
To be enclosed 1004-b
STANDPIPES 1008-b
FIRE DEPARTMENT 3002
FIRST AID 3003
(368)
Section
STEEL AND IRON (Part 28) 2801 to 2820
Beams and girders 2808
Beams encased in concrete 2650
Columns 2807
Connection details 2809
Construction workmanship 2815
Deck floors and roofs 2820
Frame 2814, 2815
Frame walls 1416
Frames not to be supported on wood 1416-g
In reinforced concrete exposed to weather, two-inch protection 2627
STEEL Joists 2818, 2820
Concrete piles 2913-a
Concrete piles in contact with sea water 2913-a, I
Member, minimum thickness 2813
Not to be used in first floor of certain buildings 2818-c
Piles 2913-a
PIPE 3117
STIRRUPS, Hangers not less than 3/16 inch thick 1604-e
STONE 2202, 2404, 2405
STORE FRONTS 1902-j
STOVES AND RANGES 2113
STRESSES, Working, Commissioner may not alter 116-1
IN
Cast iron 2805
Cast steel 2804
Concrete 2629, 2630
Concrete, due to wind 2631
Due to short period loading 2504
Gypsum concrete 2701
Masonry 2413
Steel 2803
Steel, due to wind 2812
Temperature stresses 2504-a
Wood 2504
Wood, due to wind 2504
STRUCTURAL STEEL, Used in one building, not to be used in another building,
without the permission of the Commissioner 2802 -d
Members in pre-code buildings prior to 1924 not to be
stressed in excess of 8/10 of allowable stresses, and
those of 1924 and prior to 1943 not to be in excess of
9/10 of allowable stresses 2802-0
Si RUCTURES NEAR AN EXCAVATION 2901
SUBSIDING SOIL OR FILL 2909-h
SUPPORT, For drainage systems 3119
SUPPORTING CAPACITY OF PILES 2909-a
SUPPORTING STRUCTURES NEAR EXCAVATION 2901-b
TABLE OF STRESSES 2629, 2630
MINIMUM DIAMETERS FOR FIXTURE TRAPS 3115-e
TANKS ON ROOFS 2003
TEMPERATURE RELIEF VALVES 3114-e,f
TEMPORARY STRUCTURES 203-c, 2504-g
ERECTED IN FIRE ZONES 203-c, 1201-0
To be removed in one year 2504-g
TEr TS, REVIEWING STANDS, ETC. IN EITHER FIRE ZONE 1201-c
TEST AND BORINGS BEFORE ISSUANCE OF PERMIT 2903-a
TESTS FOR LOADS ON BEARING MATERIALS 2915,2916,2917
OF FIRE EXTINGUISHING APPARATUS 3009
MATERIALS 2604, 2612 ,2613
THEATRES (Part 3-Group A) 301
AND MOVING PICTURE HOUSES 301, 401
THICKNESS OF METAL IN STRUCTURAL STEEL 2812, 2813
THRESHOLDS, To be of incombustible material 1402-e
Shall not be over one inch high 1806-0
TIED REINFORCED CONCRETE COLUMNS 2672
TILE, GYPSUM 2408
TOILETS, Accommodations and plumbing 3101-b
Accommodations for schools 511
Floors of, to be tile, terazzo, etc 1007-d
(369)
Section
TOI LETS — Continued
Minimum size, 33 inches wide; 15 square feet area 1007-a
No wood work 1007-d
Number in each apartment 1009-b
Windows not less than 1/8 floor area 1006-a
TOWERS, FIRE OR SMOKEPROOF 1810
TRANSFER BY OWNER OF HIS RIGHTS AND RESPONSIBILITIES 106-d
TRAP DOORS 1502
TRAPS, For waste pipes of plumbing fixtures 3108
TREADS AND RISERS 1808-f
TREATED PILES— CREOSOTE 2910-i, 1
TRUSSES, WOOD 2509
TWO-WAY SLABS (reinforced concrete) 2659
TYPES OF CONSTRUCTION 125
TYPE V, NOT TO BE USED FOR GROUP H OR 1 1001-b, 1101
VI, FOR NOT MORE THAN FOUR FAMILIES 1001-f
VI, MOVING OF, to different location 107-h, 203-d
VI, NOT TO BE USED FOR MORE THAN SIX-CAR GARAGE. 801-b
UNCASED POURED CONCRETE PILES 2912-c, 2, 2912-c, 3(111)
UNCASED SHAFT FOR FRANKI PILES 2912-d,e
UNIT COMPRESSIVE STRESS IN MASONRY 2413
STRESS IN WOODEN STRUCTURAL MEMBERS 2504
UPLIFT OF PILES 2908-h
URINALS, Plumbing 3113-i
Multiple type 3115-0
USE OF STAIRWAY ENCLOSURE AREAS 1507
USED BUILDING MATERIALS
Lumber 2504-f
Structural steel 2802-d
UPWARD PRESSURE DUE TO LATERAL AND UPLIFT FORCES IN
ADJACENT SOILS (taking weight of soil as dimin-
ished by buoyancy, plus full hydrostatic pressure) . . . 2309-a
UPWARD PRESSURE of water in structures below grade 2309-b
VACUUM RELIEF VALVES 3114-g
VALIDITY (Part 32)
VENEER MASONRY 1405-h, 1415-b
VENT, Water closet and urinal 1505, 3104-b
VENT PIPES, to extend above roof 3110
Size of, for water closets, urinals 3110-h
VENTILATING DUCTS 1506
SHAFTS for kitchens, etc 1004-a, 1006-c, 1505
VENTILATION IN ASSEMBLY HALLS 408
VENTILATING SHAFTS 1505
AND LIGHT 806, 1106
LIGHT IN GROUP H BUILDINGS 1006
IN KITCHENS 1006-a,d
MECHANICAL 1006-d
UNDER FIRST FLOOR WITHOUT BASEMENT. .2507, 2818-j
VENTING 3109
VERTICAL OPENINGS 1104, 1500
Protection of 1104, 1500, 1502
Railing 1501
Trap doors 1502
SHAFT AND FLOOR OPENINGS 1004-a,c
WALLS AND PARTITIONS 1401, 1405
Existing masonry 1414
COVERED WITH ACOUSTICAL MATERIAL, 1603-f
OF CONCRETE 1405, 2678
OF WOOD 2508
EXTERIOR, Wooden frame 1417
FACING A COURT 1402-c
FOUNDATION, OF MASONRY 1412
REINFORCED CONCRETE 1405-e
LATERAL SUPPORT OF 1403
MASONRY 1406, 1412, 1414
(370)
WALLS — Continued Section
OF WOOD in basement 1607-b
Non-bearing, exterior 1406-g
OPENINGS IN 1302
FOR DOORS AND WINDOWS IN PARTY 1901
OPENINGS FOR DOORS AND WINDOWS IN PARTY 1901
REQUIREMENTS 1402
STEEL FRAME 1416
WALLS SUPPORTED BY SINGLE ROW OF PILES 2908-c
WAR PROVISION (Part 33)
WASTE FROM HOSPITALS or other indirect waste 3106
PIPES IN GROUND, not to be less than three inches in diameter. . . . 3104-f
STACKS SERVING LAVATORIES, to be three inches in diameter, 3104-g
FOR SLOP SINKS OR URINALS, to be four inches in
diameter 3104-g
WATER CEMENT RATIO IN CONCRETE IN PILES 2913-a, 3
WATER CLOSET BUILDING DRAIN 3104-b
AND PLUMBING 3113-i
MULTIPLE TYPE 3115-c
VENTILATION, need not have windows 1006-c,d,h
WATER FROM EXCAVATION 2617, 2901
HEATERS 2112
SUPPLY 3113
TANKS ON ROOFS 2003
WATERPROOFING OF BASEMENT 2902-f
OF BOILERS OR FURNACES, to be protected against
damage 2902-f
OF WALLS OR FLOORS of sleeping or living rooms in
contact with ground 1007-c
WEIGHT OF ELEMENTS OF CONSTRUCTION 2303
WELDING 2809-r
WHOLESALE STORES 801-a
WIDTH OF CORRIDORS AND PASSAGEWAYS 1805-a,b
WIND LOADS 2312, 2631
PRESSURE on signs 2312-d
on walls 1402-b
STRESSES in concrete 2631
in steel 2812
in wood 2504
WIND PRESSURE 2905-c
WINDOWS 1006-b, 1402-d, 1902
AS EXITS 1807
AS SUBSTITUTE for fire doors 1302-i
FRONTING UPON OPEN SPACE or ventilating shaft 1006-c
IN EXTERIOR WALL OR ELEVATOR SHAFT, to be protected by
metal bars 1902-h
Kitchen area 1006-a
Toilet area 1006-a
To open on open space 1006, 1106
WIRE GLASS IN FIRE RESISTIVE WINDOWS 2216
LATH 2202
SCREENS OVER SKYLIGHTS 1903
WOOD
Design 2501
Floors and roofs 2507, 2508
Nailing strips 2506-j,k
Notches in wooden beams 2506
Stirrups, hangers 1604-e
Stresses 2504
Trusses 2509
Wooden columns on concrete or masonry 2505-g
Wooden framing 2509
WOOD BEARING PARTITION NOT TO SUPPORT FIRST FLOOR 1607-b
WOOD FLOORS AND ROOFS
Floor boards and planking not to penetrate a party or fire wall 2507-0
Not to be used in first floor and where there is no basement 2507
Rough floors to be at an angle of not less than 45 degrees 2507-b
(371)
S "-"<-V
WOOD FRAMING, Bolts, washers and nuts 25U
Timber joints 2509-
FRAME WALLS, EXTERIOR 1417, 2508
NEAR CHIMNEYS AND HEATING APPARATUS 2104
NOT TO BE USED FOR FOUNDATION 2501-d, 2907
WORKING PLANTS 701-a
WOOD PILES *
Capacity of 2910-a
Composite 2914-c
Method of driving 2910-f
Size of hammer , 2910-f
Spacing of .' 2910-e
WOODEN BEAMS rr." 2506
Bridging .,< 2506-e
Built-up beams / 2506-g
Joists and headers to be hung in stirrups 2506-d
Joists to be doubled under partitions 2506-f
Nailers may be spiked if live load under 40 lbs. per square foot 2506-j
Nailing strips on steel girders 2506-k
Notched at end supports 2506-b,©
Resting on masonry to be separated 2506-1
Resting upon masonry walls 2506-i
That meet at columns 2506-h
WOODEN COLUMNS 2505
Wood shall not be used for columns in basement , . . . 1604-d, 1607-b
WOODEN FRAME FLOOR CONSTRUCTION 1607
JOISTS MAY REST ON CLEATS 2506-j
AND RAFTERS NOT TO EXTEND BEYOND exterior
wall 1701-e
JOISTS OR BEAMS THAT FRAME INTO EXTERIOR or party
walls 1405-j
MEMBERS UNDER ROOFS of Types III, IV, VI, _ot to extend
across exterior walls 1701-e
WOODEN PARTITIONS 1417, 1607-b
STRUCTURES
GROUP B— If less than 5,000 square feet (1 story) may be Type VI, 401-b
Exterior walls of wood to be more than ten feet from lot line 403-a
Exterior wails of wood to be more than 20 fe> '>om combustible
wall or roof on further side of street , . .' 403-b
GROUP C— If less than 5,000 square feet (1 st< may be of Type
. VI . . , 501-b
Pre-Code building, two stories, 4,000 squai i feet, may be of
Type VI 502-g
See above for wood walls 503
GROUP D— If less than 2,500 square feet aD 3 story, Type VI. . 601-b
See above for wood walls 603
GROUP E— For Type VI, see table 701-b
See above for wood walls 703
GROUP F— For Type VI, see table 801-b
Garages over six ears — No Type VI allo<- *■ 801-a
No buildings of Type VI on wharves 801-d
See above for wood walls 803
GROUP G— See table for Type VI 901-b
For exterior walls to lot line, etc 903
GROUP H— See table for Type VI 1001-b
Exterior walls less than ten feet from lo> uxie 1003-a
Exterior walls less than 15 feet from am her building, etc 1003-b
GROUP I— Type VI, three stories, 5,000 square feet 1101-b
Exterior walls more than five feet from lot line 1 103
GROUP J — Garages for six cars or less, two stories in height, less
than 1,300 square feet, no Type VI allowed 1201
Garages for three cars or less (one story), not more than 600 square
feet, may be Type VI 1201
Walls, Type VI, and floors and ceilings — every hollow space to be
fire-stopped 1402-a
TYPE VI buildings in first fire zone 203-b
TYPE VI buildings in second fire zone 203-d
WALLS NOT TO BE USED FOR PARTY, FIRE OR ENCLOSURE
WALLS, or when required to have more than one-hour fire
resistance 1417-a
WORKMANSHIP IN STEEL CONSTRUCTION 2815
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