of the materials of which the floor is composed; if to be used as a dwelling house, apartment house, tenement house, hotel or lodging house, each floor shall be of sufficient strength in all its parts to bear safely upon every superficial foot of its surface not less than sixty pounds; if to be used for office purposes not less than seventy-five pounds upon every superficial foot above the first floor, and for the latter floor 150 pounds; if to be used as a school or place of instruction, not less than seventy-five pounds upon every superficial foot; if to be used for stable and carriage house purposes, not less than seventy-five pounds upon every superficial foot; if to be used as a place of public assembly, not less than ninety pounds upon every superficial foot; if to be used for ordinary stores, light manufacturing and light storage, not less than 120 pounds upon every superficial foot; if to be used as a store where heavy materials are kept or stored, warehouse, factory, or for any other manufacturing or commercial purpose, not less than 150 pounds upon every superficial foot. The strength of factory floors intended to carry running machinery shall be increased above the minimum given in this section in proportion to the degree of vibratory impulse liable to be transmitted to the floor, as may be required by the Commissioner of Buildings having jurisdiction. The roofs of all buildings having a pitch of less than twenty degrees shall be proportioned to bear safely fifty pounds upon every superficial foot of their surface, in addition to the weight of materials composing the same. If the pitch be more than twenty degrees the live load shall be assumed at thirty pounds upon every superficial foot measured on a horizontal plane. For sidewalks between the curb and area lines the live load shall be taken at 300 pounds upon every superficial foot. Every column, post or other vertical support shall be of sufficient strength to bear safely the weight of the portion of each and every floor depending upon it for support, in addition to the weight required as before stated to be supported safely upon said portion of said floors. For the purpose of determining the carrying capacity of columns of dwellings, office buildings, stores, stables and public buildings when over five stories in height, a reduction of the live loads shall be permissible as follows: For the roof and top floor the full live loads shall be used; for each succeeding lower floor it shall be permissible to reduce the live load by five per cent. until fifty per cent. of the live loads fixed by this section is reached, when such reduced loads shall be used for all remaining floors. (Id., sec. 130.) § 131. Load on Floors to be Distributed. The weight laced on any of the floors of any building shall be safely tributed thereon. The Commissioner of Buildings having sdiction may require the owner or occupant of any buildor of any portion thereof, to redistribute the load on y floor, or to lighten such load where he deems it to be necessary. (Id., sec. 131, rev. from L. 1882, ch. 410, § 483, as amend.) § 132. Strength of Existing Floors to be Calculated.-In all warehouses, storehouses, factories, workshops and stores where heavy materials are kept or stored, or machinery introduced, the weight that each floor will safely sustain upon each superficial foot thereof, or upon each varying part of such floor, shall be estimated by the owner or occupant, or by a competent person employed by the owner or occupant. Such estimate shall be reduced to writing, on printed forms furnished by the Department of Buildings, stating that material, size, distance apart and span of beams and girders, posts or columns to support floors, and its correctness shall be sworn to by the person making the same, and it shall thereupon be filed in the office of the Department of Buildings. But if the Commissioners of Buildings shall have cause to doubt the correctness of said estimate, they are empowered to revise and correct the same and for the purpose of such revision the officers and employees of the Department of Buildings may enter any building and remove so much of any floor or other portion thereof as may be required to make necessary measurements and examination. When the correct estimate of the weight that the floors in any such buildings will safely sustain has been ascertained, as herein provided, the Department of Buildings shall approve the same, and thereupon the owner or occupant of said building, or of any portion thereof, shall post a copy of such approved estimate in a conspicuous place on each story, or varying parts of each story, of the building to which it relates. Before any building hereafter erected is occupied and used, in whole or in part, for any of the purposes aforesaid, and before any building, erected prior to the passage of this Code, but not at such time occupied for any of the aforesaid purposes, is occupied or used, in whole or in part, for any of said purposes, the weight that each floor will safely sustain upon each superficial foot thereof, shall be ascertained and posted in a conspicuous place on each story or varying parts of each story of the building to which it relates. No person shall place, or cause or permit to be placed on any floor of any building any greater load than the safe load thereof, as correctly estimated and ascertained as herein provided. Any expense necessarily incurred in removing any floor or other portion of any building for the purpose of making any examination herein provided for shall be paid by the Comptroller of The City of New York, upon the requisition of the Board of Buildings, out of the fund paid over to said board under the provisions of section 158 of this Code. Such expenses shall be a charge against the person or persons by whom or on whose behalf said estimate was made, provided such examination proves the floors of insufficient strength to carry with safety the loads found upon them when such examination was made; and shall be collected in an action to be brought by the Corporation Counsel against said person or persons, and the sum so collected shall be paid over to the said Comptroller to be deposited in said fund in reimbursement of the amount paid as aforesaid. When the architect of record for any building has filed with his application to build the data required to determine the strength of floors, on one of the blank forms provided for that purpose, such examination shall not be required provided that the purposes and uses of the building have not been changed. (Id., sec. 132, rev. from L. 1882, ch. 410, § 483, as amend.) § 133. Strength of Temporary Supports.- Every temporary support placed under any structure, wall, girder or beam, during the erection, finishing, alteration, or repairing of any building or structure or any part thereof, shall be of sufficient strength to safely carry the load to be placed thereon. (Id., sec. 133, rev. from L. 1882, ch. 410, § 483, as amend.) Part 24.- Calculations. Strength of Materials. § 134. Safe Load for Masonry Work.-The safe-bearing load to apply to brickwork shall be taken at eight tons per superficial foot, when lime mortar is used; eleven and onerlf tons per superficial foot when lime and cement mortar thed is used. The safe bearing load to apply to rubbleroot work shall be taken at ten tons per superficial foot degrePortland cement is used; when cement other than upon ev is used, eight tons per superficial foot; when lime the weight mortar mixed is used, seven tons per superficial be more when lime mortar is used, five tons per superficial at thirty safe-bearing load to apply to concrete when horizontalment is used shall be taken at fifteen tons per lines the foot; and when cement other than Portland is superficial ons per superficial foot. (Id., sec. 134, rev. from port shall b0, § 483, as amend.) of the porties. Lennon, 12 App. Div. 356; Burke vs. Ireland, 26 support, in a to be supportits of Certain Materials.— In computing the the purpose o1, a cubic foot of brickwork shall be deemed of dwellings, ands. Sandstone, white marble, granite and buildings when tilding stone shall be deemed to weigh 170 live loads shall b foot. (Id., sec. 135, rev. from L. 1882, top floor the full end.) ing lower floor itions for Strength of Materials. The load by five per ce piece or combination of materials refixed by this secticained by computation, according to the shall be used for alhis Code. (Id., sec. 136.) § 131. Load on Hafety. Where the unit stress for any placed on any of thoed in this Code the relation of allowdistributed thereon. nate strength shall be as one to four jurisdiction may requiì tension or transverse stress; as one ing, or of any portions one to ten for natural or artificial any floor, or to lighter stones and brick or stone masonry. But wherever working stresses are prescribed in this Code, varying the factors of safety hereinbefore given, the said working stresses shall be used. (Id., sec. 137.) § 138. Strength of Columns.- In columns or compression members with flat ends of cast iron, steel, wrought iron or wood, the stress per square inch shall not exceed that given in the following tables: Five And in like proportion for intermediate ratios. eighths the values given for white pine shall also apply to chestnut and hemlock posts. For locust posts use one and one-half the value given for white pine. Columns and compression members shall not be used having an unsupported length of greater ratios than given in the tables. Any column eccentrically loaded shall have the stresses caused by such eccentricity computed, and the combined stresses resulting from such eccentricity at any part of the column, added to all other stresses at that part, shall in no case exceed the working stresses stated in this Code. The eccentric load of a column shall be considered to be distributed equally over the entire area of that column at the next point below at which the column is securely braced laterally in the direction of the eccentricity. (Id., sec. 138.) § 139. Working Stresses.-- The safe carrying capacity of the various materials of construction (except in the case of columns) shall be determined by the following working stresses in pounds per square inch of sectional area: Greenwich stone. Concrete (Portland) cement, 1; Concrete (Rosendale, or equal), cement, 1; Rubble stonework in Portland cement mortar... Brickwork in Rosendale, or equal, Brickwork in lime and cement mortar; cement, 1; lime, 1; sand, 6..... Brickwork in lime mortar; lime, 1; sand, 4.. Granites (according to test). Gneiss (New York city).. sand, 2; stone, 4, 230 sand, 2; stone, 5, 208 125 111 140 111 97 70 250 .... cement 208 160 111 1,000 to 2,400 1,200 1,300 700 to 2,300 600 to 1,200 |