FIREPROOFING. Every building to be used as a hotel, lodging-house, sehool, theatre, jail. police station,hospitabasylum or institution for the care or treatment of persons, the height of which ex ceeds :35 feet, and every other building the height of which exceeds 75 feet, except as otherwise pro vided, must be built fireproof. The stairs and staircase landings must be built entirely of brick, stone, Portland cement, concrete, iron, or steel. No woodwork or other inflammable material shall be used in any of the partitions, furrings, or ceil ings in any fireproof buildings, excepting, how ever, that when the height of the building does not exceed twelve stories, or more than 150 feet, the doors and windows and their frames, the trims, the casings, the interior finish when filled solid at the back with fireproof material, and the floo•-boards and sleepers directly thereunder may be of wood, but the space between the sleepers shall be solidly filled with fireproof materials and extend up to the under side of the floor boards. When the height of a fireproof building exceeds twelve stories, or is more than 150 feet, the floor-surfaces shall be of stone, cement, rock, asphalt, tiling, or similar incombustible material, or the sleepers and floors may be of wood treated by some process approved by the Board of Build ings to render the same fireproof. All outside window frames and sash shall be of metal, or of wood covered with metal. The inside window frames and sash, doors, trim, and other interior finish may be of wood covered with metal, or of wood treated by seine process approved by the Board of Buildings to render the same fireproof. All hall partitions or permanent partitions be tween rooms in fireproof buildings shall be built of fireproof material, and shall not be started on wooden sills or on wooden floor-boards, but be built on the fireproof construction of the floor and extend to the fireproof beams filling above. The tops of all doors and •indow-openings in such partitions shall be at least 12 inches below the ceiling-line, Fireproof floors shall be constructed with wrought-iron or steel floor-beams tied together at intervals of not more than eight times the depth of the beam. Between the wrought-iron or steel floo•-beams shall be placed brick arches springing from the lower flange of the steel beams; or hollow tile arches of hard-burnt day or porous terra-cotta of uniform density and hardness of burn; or arches of Portland cement concrete, segmental in form, which shall have a rise of not less than inches for each foot of span between the beams; or between the said beams may be placed solid or hollow burnt-clay, stone, brick, or concrete slabs in flat or curved shapes, concrete, or other fireproof composition, and any of said materials may be used in com bination with wire cloth, expanded metal, wire strands, or wrought-iron or steel bars; but in any such construction, and as a precedent condi tion to the same being used, tests shall be made.
These tests shall be made by constructing within inclosure walls a platform consisting of four rolled-steel beams, 10 inches deep, weighing each 25 pounds per lineal foot, and placed 4 feet be tween the centres, and connected by transverse tie-rods, and with a clear span of 14 feet for the two interior beams, and with the two outer beams supported on the side walls throughout their length, and with both a filling between the said beams and fireproof protection of the exposed parts of the beams of the system to be tested, constructed as in actual practice, with the quad ity of material ordinarily used in that system and the ceiling plastered below, as in it finished job. Such filling between the two interior beams shall be loaded with a distributed load of 150 pounds per square foot of its area, and all car ried by such filling; the platform so constructed being subjected to the continuous heat of a wood fire below, averaging not less than 1700' F., for not less than four hours, during which time no Marne will have passed through the platform, and no part of the load shall have fallen through, and the beams shall have been protected from the heat to the extent that after applying tc the under side of the platform at the end of the heat test a stream of water directed against the bottom and discharged through a nozzle under (10 pounds pressure, for five minutes, and after flooding the top of the platform with water under low pressure, and then again apply ing the stream of water through the nozzle under the 60 pounds pressure to the bottom fur five minutes, and after a total load of 600 pounds per square foot uniformly distributed over the mid dle hay shall have been applied and removed, after the platform shall have been cooled, the maximum deflection of the interior beams shall not exceed inches. Any system failing to meet the requirements of the test of heat, water, and weight prescribed shall be prohibited from use in any building hereafter erected.