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Full text of "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"

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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 co mmi ssioner 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. 

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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 

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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 — 

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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 

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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 

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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 well 1 
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 ] 

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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) Chimn eys 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 fu 1 ! 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 

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 sha 1 ! 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 Sin 2 $ + Q cos 2 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 



2bd a 
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 = A g -A P . 

A r — The cross-sectional area of the steel column. 

A g — Gross area of concrete column. 

Ag — Effective cross-sectional area of steel in tension in beams and slabs, or 

compression in columns. 
A v — 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 f a 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. 

E B — Modulus of elasticity of steel (thirty million pounds per square inch). 
f a — 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 (E 8 /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). 
p g — Ratio of the effective cross-sectional area of vertical reinforcement 

to the gross area A g . 
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 

[ *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 (wL 2 ) 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: 

A v f v jd (cos a -f- sin a) 

s = 

V 

For vertical stirrups this becomes — 

A v f v jd 



s = 



V 

and for stirrups or bars inclined at forty-five degrees — 

A v f y 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' ). 

(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 ' ) 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 f ). 

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 C r w L = 1/2 C w 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 (C ). 

(208) 



Sees. 2654=2655 
MARGINAL. BEAM OR WALL. 




J 
J 

I 
a 

9 

< 

m 
10 

J 
< 
z 

5 

a: 
< 
X 




\.o 


o.<? 




l.i 


\.o 











x. 

I 

to 
o 

2 
O 

P 

u 

g 



o 

< 

MI 

> 
z 



ID 



(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 CiC r 2 wL 2 = 0.33 CiC wL? 
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 (C ). 

(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 = M po + M pm + M no + M nm 

where (M po ) is the positive moment at mid-span of the column strip. 
(M pm ) is the positive moment at mid-span of the middle strip. 
(M nm ) is the negative moment at one end of a middle strip. 
(M no ) 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 (M no ) may be (0.03 M ) greater or smaller, and each of 
(M pc ), (M pm ) and (M nm ) may be (0.01 M ) greater or smaller provided that 
the sum remains not less than the value specified for (M ). 

(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. 


M P o 


0.22M o 


0.20Mo 


0.20M<> 


0.19Mo 


Mpm 


O.I6M0 


0.15M o 


0.20Mo 


0.19Mo 


Mno 


0.46M o 


0.50Mo 


0.50Mo 


0.54M o 


Mum 


O.I6M0 


0.15M o 


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. 



M P c 


0.32M o 


0.31M o 


0.30Mo 


0.29M o 


Mpm 


0.26M o 


0.25M o 


0.30M o 


0.29Mo 


Mno (ext.) 


0.05M o 


0.05M o 


0.05M o 


0.05M o 


Mnm (ext.) 


0.05Mo 


0.05M o 


0.05M o 


0.05M o 


Mno (int.) 


0.55M o 


0.60M o 


O.6OM0 


0.65M o 


Mnm (int.) 


0.19M o 


O.I8M0 


O.lOMo 


0.09M o 



(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. 



M pe 


0.29M o 


0.27M o 


0.26M o 


0.25M 


Mpm 


0.23Mo 


0.22Mo 


0.26M o 


0.25M o 


Mno (est.) 


0.22M o 


0.23M o 


0.25M o 


0.26M o 


Mnm (ext.) 


O.O8M0 


O.O8M0 


O.O6M0 


0.06M o 


Mno (int.) 


0.50M o 


0.55M o 


0.55M o 


O.6OM0 


Mnm (int.) 


O.I8M0 


O.I6M0 


O.lOMo 


O.O8M0 



Full Restraint at Discontinuous Edge. 



Mp 


0.25M o 


0.22M o 


0.22M o 


0.21Mo 


Mpm 


0.20M<> 


0.20Mo 


0.22M o 


0.21Mo 


Mno (ezt.) 


0.38M o 


0.41Mo 


0.46M o 


0.48M o 


Mnm (est.) 


O.lOMo 


O.lOMo 


O.O6M0 


O.O6M0 


Mno (int.) 


0.46M o 


0.50Mo 


0.50Mo 


0.54 Mo 


Mnm (int.) 


O.I6M0 


0.15M o 


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 f A g + A 8 f 8 . See section 2602 for symbols. 

(b) The normal working stress in the vertical column reinforcement, f B , 
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 



\A C / f' s 



p' = 0.45 

\A C 

where p' is the ratio of volume of spiral reinforcement to the volume of the 
concrete core (out to out of spirals). 

A g 

— 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' A g -f- 0.8A 8 f B 

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 p g n is 0.3 or more, the following formula shall 
be used to calculate the combined fiber stress in compression. 



f =^ 



Kl 



A g 1 + (n-1) p g 
(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 

R 2 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 f in 



f. -f. 



1 + - 
^ R 2 



1 + c iT° 



where f a 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' + f 8 pg 

f m = for spiral columns. 

1 + (n-1) p g 



[0.225 f'. + f.p«1 
1 + (n-1) p g J 



f a = 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 = A r f' r [l + 1 

L 100A r J 



where A c is the total area of the concrete = A g -A r 

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 f ) 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' . 

(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 . 25 f g 

Axial compression or bearing . 20 f g 

Bond on plain bars or wires 0.02 f g 

Bond on deformed bars or wire mesh . . . . . . . 04 f g 

Shear (straight rods or wires) 0.02 f g 

Shear (reinforcement anchored) 0.03 f g 

In this table (f g ) 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 

A e 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 

A t t Cross-sectional area of stiff ener or pair of stiff eners 

A w Area of girder web 

B Coefficient used in column formula for plastic design 

Cb Bending coefficient dependent upon moment gradient; equal to 

/MA /MA 2 

C e Column slenderness ratio dividing elastic and inelastic buckling; equal to 






C m 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)*F t 



D Factor depending upon type of transverse stiffeners 

E Modulus of elasticity of steel (29,000,000 pounds per square inch) 

E e Modulus of elasticity of concrete 

F a 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 



F p Allowable bearing stress 

Ft Allowable tensile stress 

F 9 Allowable shear stress 

F y 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 

L u 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 
M p Plastic moment 
N Length of bearing of applied load 
P Applied load 
P y Plastic axial load: equal to profile area times specified minimum yield 

point 
R Reaction or concentrated transverse load applied to beam or girder 
S 8 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 
V u 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 
f v9 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 

l er Critical unbraced length adjacent to plastic hinge, in inches 

n Modular ratio; equal to E/E e 

q Allowable horizontal shear to be resisted by a connector 

r Governing radius of gyration 

rb Radius of gyration about axis of concurrent bending 

r y 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 

F t = 0.60JV 

On the net section at pin holes in eyebars, pin-connected plates or built-up 
members 

F t = 0A5F V 

1.5.1.2. Shear. — On the gross section 

F v = 0A0F y 

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 C e 



F. 
(237) 



F a = —* 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 8C C 8C C 3 

and 






1.5.1.3.2. — On the gross section of axially loaded columns when i/r ex- 
ceeds C c 

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, 

F a (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 

F a = 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) 

F a = 0.75F V 

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 

F b = 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/"\/ F y . The depth-thickness 
ratio of the web, d/t, shall not exceed 13,300/v F y . When subjected 
to combined axial force and bending moment d/t shall not exceed 
13,300(1 -lA3fa/F a )/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// VF y 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, f a due to any concurrent 
axial load on the member, does not exceed 0.1 5F a . 

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 

F b = 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 

F b = 0.60F„ 

1.5.1.4.4. — Tension on extreme fibers of other rolled shapes, built-up 
members and plate girders 

F b = 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; C c is defined in Sect. 28-1.5.1.3 and C&, which can con- 
servatively be taken as unity, is equal to 

/Mi\ /MA 2 

C b = 1.75 - 1.05 ( — J + 0.3 ( — J , but not more than 2.3 

where Mi is the smaller and M 2 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 M 2 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 

F b = 0.60^ 

1.5.1.4.7. — Tension and compression on extreme fibers of pins 

F b = 0.90F„ 

1.5.1.4.8. — Tension and compression on extreme fibers of rectangular 
bearing plates 

F b = 0.75F y 

1.5.1.5. Bearing (on contact area). 

1.5.1.5.1." — Milled surfaces, including bearing stiffeners, and pins in reamed, 
drilled or a bored holes, pounds per square inch 

F p = 0.90F y * 

1.5.1.5.2. — Expansion rollers and rockers, pounds per linear inch 

/F y * - 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, F v shall be the smaller value. 

(240) 



Sees. 1.5.2.1A-1.5.3.I 



Table 28-1.5.2.1A 





Tension 
(Ft) 


Shear (F v ) 


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 


0.30F y 
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 

F p = 1.35F y 

where F y 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, F h 

The nomenclature in the preceding provisions of this subdivision 1.6.1 A 
shall be construed as follows: 

F a = 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 F e > 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 F a , Ft and 0.6^ 
as used in Formula (7b), F' e may be increased one-third in accordance with 
Sect. 28-1.5.6.) 
C m = a coefficient whose value shall be as follows: 

A. For compressoin members in frames subject to joint translation (side- 
sway), C m — 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, C m = 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/M t 

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 C m 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, C m — 0.85, (b) for members whose ends are unre- 
strained, C m = 1. 

Values of C m for Categories A, B, and C are shown in Table C 1.6.1.1. 



(243) 



Cate- 
gory 



Loading 

conditions 

{f a > 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 



M 2 
S 



M 2 

S 

Using 

Formula 

(7b) 



Mi 
s 

Using 

Formula 

(7a) 



a 



0.85 



M 2 



0.6^ 



but not 

less than 

0.4 



1 + <A A. 



Remarks 



<t 



M t 



Mi 



ztvr 



& 



H 



.. ,, Mi 

Mi < M 2 ; — - positive as 

Mi 

shown 
Check Formulas (7a) & (7b) 



-Q. 



Mt 



*Z<w? 



M 2 ^. 



leek both Formulas 

(7a) & (7b) 



Mi jt 

Hl UUJiQWllJlJiU i ' 



k 



c 



M 3 



M 2 



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 C m can 
be computed using the expression 



(244) 



where 



7T ■ 8qEI 

* = M l\ " 



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 F t = 28,000 - 1.6% < 20,000 

For A195 and A406 rivets F t = 38,000 - 1.6/, < 27,000 

For A307 bolts F t = 20,000 - 1.6% < 14,000 

For A325 bolts in bearing-type joints F t = 37,500 - 1.6/ v < 30,000 
For A354, Grade BC, bolts in 

bearing-type joints F t = 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 F v < 15,000(1 - ftA b /T b ) 

For A354, Grade BC, bolts F v < 20,000(1 - ftA b /T h ) 

where ft is the tensile stress due to applied load and T b 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, I c is the moment of inertia and L e the un- 
supported length of column section, and I is the moment of inertia and L g the 
unsupported length of a girder or other restraining member. I e and I g 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 
t on 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 G B 


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 


- 




(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 


- 




(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/ VF V times its thickness. 

When the unsupported width exceeds this limit, but a portion of its width 
no greater than 8,000/v F y 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 

VF y (F v + 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 f v 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 l C ° + / " ° V 1 Formula (8) 

2.89 I 1.15V 1 + (a/h) 2 J 



when C v is less than 1.0; 



F « " £t < C »> Formula (9) 



but not more than 0AF y , when C v 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 
C v = — , when C v is less than 0.8 

V y\fl/t) 

6,000 fk : „ . 
= — — \ — , when C v 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 f v 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 F v 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 



C v , 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 F y = 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 < F b |~1.0 - 0.00O5 y(j- Ta^)1 Fonnula ai) 

where 

Ff, = applicable bending stress given in Sect. 28-1.5.1 
A w = 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 F y nor 

N).825 - 0.375 y) F y Formula (12) 

where 

f v = computed web shear stress (total shear divided by web area) 
F v = 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 5F y 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 5F y pounds per square inch Formula (13) 



t(N + 2k) 

For end-reactions, 
R 



= not over 0.7 bF y 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 1 10,000,000 . ' . 

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) 2 J 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 F y 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.76F V , 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 

S tr = U.35 + 0.35 ^r\ S, Formula (17) 

where Ml and Md are, respectively, the live load and dead load moments 
and S 8 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 

V h = °- 85 { /<4c Formula (18) 

and 

V h = ^-^ Formula (19) 

where 

f c — specified compression strength of concrete at 28 days 

A c — 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/q t 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 


f e = 3,500 


f e = 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 % l A" 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*. 


5 A 


IVs 




A 


% 


w 




1 


Vs 


IA* 




IA 


l 


IK* 




1M 


w 


2 




\A 


IX 


2H 




l 5 A 


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 X A 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& m ch 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 Processes 1 


Low-Hydrogen 
Welding Processes 2 




A373 

Steel 


A7, A36 
Steel 


A441 
Steel 


A373 

Steel 


A7, A36 
Steel 


A441 
Steel 8 


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 l X% 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. 

f b - 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/F y . 

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, f c , 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 f c 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 f c 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: 

f c = (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 f e when w/t exceeds 10 shall be 30,000 psi. 

3. For w/t from 25 to 60: 

For Angle Struts: f c = 8,090,000/ (w/t) 2 

For all Other Sections: f c = 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/r y is greater than 10,050/V^ but less than 22,400/V^: 

J c 9 Jb 907 x 10 6 \rj 

When l/r y is equal to or greater than 22,400/VA: 
fc = 280,000,000/ (Z/r„)» 

2. For Z-shaped sections: 

When l/r y is greater than 7,100/VA but less than 15,900/ V7 b : 

Jc 9 Jb 453X10 6 V V / 

When l/r y is equal to or greater than 15,900/V/&: 

f c = 140,000,000/ (*Av) 8 
where 

I = the unbraced length of the member, inches. 
r y = 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 f w 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 F a , as follows: 

(282) 



Sees. 1.28.2.10=1.28.2.12 
24,200 „ /QFJ/r\* 

l/r less than _^_ : Fa . . 515QFs _ (_*L) 

24,200 „ 149,000,000 

Z/r equal to or greater than — 7= — 7= : F = ~ ; . . — 

VFyVQ d/r) 2 

In the above formulas, 

P = total load, lbs.; 

A = full, unreduced cross-sectional area of the member, sq. inches; 
F a = 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; 
F y — 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 f c for the weakest element of 
the cross-section (the element having the largest flat-width ratio) and the 
basic design stress /&; where f c 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 Q s computed as outlined in 
paragraph (2) above and an area factor Q a computed as outlined in para- 
graph (1 ) above, except that the stress upon which Q a is to be based shall 
be that value of the unit stress f c which is used in computing Q s ; and the 
effective area to be used in computing Q a 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 F a and Fb shall be determined in accordance with 
this section, and formula (7b) is to be used as shown here: 

fa + fj> 



0.515QF V F b 
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)f b 
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 P a 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 P a substituted for F a and r tr 2 substituted for r 2 . The values of 
Atr and r tr 2 shall be evaluated by 

A tr = A 8 + ~r r tr 2 = — : 



In which 



In 



A 8 = area of the pipe and reinforcing steel 

A c = area of the concrete filling 
I c = moment of inertia of the concrete filling 
I B = 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 / 7 7 ~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 M r may be approximated by 

C m M 

_ P c {Kl/rtrY 

149,000,000A ir 

in which C m shall be evaluated in accordance with Section 28-1 .6.1 A with P c 
substituted for f a and P a substituted for F a . 

M = bending moment neglecting the effect of the axial load on the deflection 

P c = applied axial load 

At braced points M r 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 

P a 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 P a in the above formula may be computed for = 

and C m = 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 M r - SP C < 

P b + M ' ~ 
In the above 



Pb = 



P a + 21,000A* r 



rtr 2 
s — kern distance for the uncracked section = — 

c 

c = distance from centroid to extreme fiber 

(286) 



Sees. 1. 29.2.4- 1. 30.3 

M = allowable moment with P c — 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. M ox 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 Pb x 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 P a 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 P a 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 0.6P y , where P y 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) 

P y 70r ~ 

Except as otherwise provided in this section, M /M p , 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 



M = M p when P/P v < 0.15 
M 



M p 



< 1.18 - 1.18 (—) < 1.0 when P/P v > 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 

M 



M p 



<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/P y does not exceed 0.15, the full plastic 
strength of the member may be used (M — M p ). 

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) 

P v (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 

V u < 0.00055F y wd 

where V u 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/Ab c F y , 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 F y 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, A 8 t, shall be such that 

A s t > 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 F y A $ 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, l cr , from such braced hinge locations to 
similarly braced adjacent points on the member or frame shall not exceed 

lcr = (60 - 40 — J r y Formula (26) 

except that it need not be less than 35^ 

where 

r y = 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 f a 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) 



M p \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 <M 



Formula (23) 
M 



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 w p 
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 
w r 

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 

Si e ns 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 r r." 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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