This section is from the "Architectural Iron And Steel, And Its Application In The Construction Of Buildings" book, by WM. H. Birkmire.. Also see Amazon: Architectural Iron And Steel, And Its Application In The Construction Of Buildings.
To consolidate into one act and declare the special and local laws affecting public interests in the city of New York in so far as the same regulates the construction of buildings in said city.*
In buildings where the space under the sidewalk is utilized, a sufficient stone or brick wall shall be built to retain the roadways of the street, and the side, end or party walls of such building shall extend under the sidewalk to such wall. The roofs of all vaults shall be of incombustible material. No roof of a vault under a sidewalk shall be higher than the established grade of the street. Openings in the roofs of vaults, for the admission of coal or light, shall be covered with lens lights in iron frames, or with iron covers having a rough surface and rabbeted flush with the sidewalk; the bearing in such rabbet shall not be less than one and one-quarter inch. Open areas shall be properly protected with suitable railings. When areas are covered over with iron, or with iron and glass combined, or with stone or other materials, sufficient strength in such covering shall be provided to insure safety to persons walking on the same, and to carry the loads which may be placed thereon.
In all stores, warehouses and factories over twenty-five feet in width between walls, in which there shall be brick partition walls, or girders supported on iron or wooden columns, or piers of masonry, the partition walls, or girders, shall be so placed that the space between any two partitions or girders shall not exceed twenty-five feet, and the iron or wooden columns, or piers of masonry, and girders, shall be made of sufficient strength and diameter to bear safely the weight and any lateral strain to be imposed upon them. In case iron or wooden girders, supported by iron or wooden columns, or piers of masonry, are substituted in place of brick partition walls, the building may be seventy-five feet wide and two hundred and ten feet deep, and when the building is located on a corner, may be one hundred feet wide and one hundred and five feet deep, but not wider nor deeper, except in case of fire-proof buildings.
The front, rear, side and party walls shall be properly bonded together, or shall be anchored to each other every six feet in their height by wrought-iron tie anchors, not less than one and a half inches by three eighths of an inch. The side anchors shall be built into the side or party walls not less than sixteen inches and into the front and rear walls, so as to secure the front and rear walls to the side, or party walls, when not built and bonded together.
Every building hereafter erected or altered to be occupied as a hotel, and every dwelling-house exceeding five stories in height hereafter erected or altered to be occupied by one or more families on any floor above the first, shall have the halls and stairs inclosed with twelve-inch brick walls. But eight-inch walls, not exceeding fifty feet in their vertical measurement, may inclose said halls and stairs, and be used as bearing walls where the distance between the outside bearing walls does not exceed thirty-three feet, and the area between said brick inclosure walls does not exceed one hundred and eighty superficial feet. The floors, stairs and ceilings in said halls and stairways shall be made of iron, brick, stone or other hard incombustible materials, excepting that the flooring and sleepers underneath the same may be of wood and the treads and handrails of stairs may be of hard wood, provided that where wooden treads are used the underside of the stairs shall be entirely lathed with iron and plastered, and at least one flight of such stairs in each of said buildings shall extend to the roof, and be inclosed in a bulkhead built of fire-proof materials.
In every building used as dwelling-house, tenement-house, apartment-house, or hotel, every floor shall be of sufficient strength in all its parts to bear safely upon every superficial foot of its surface seventy pounds; and if to be used for office purposes not less than one hundred pounds upon every superficial foot; if to be used as a place of public assembly, one hundred and twenty pounds; and if to be used as a store, factory, warehouse, or for any other manufacturing or commercial purpose, from one hundred and fifty-pounds and upwards upon every superficial foot, and every floor shall be of sufficient strength to bear safely the weights to be imposed thereon in addition to the weight of the materials of which the floor is composed. The roof of all buildings 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. 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 safely supported upon said portions of said floors. The dimensions of each piece or combination of materials required shall be ascertained by computation, according to the rules given in Trautwine's Civil Engineer's Pocket-book, except as may be otherwise provided for in this title. The strength of all columns and posts shall be computed according to Gordon's formula, and the crushing weights in pounds per square inch of section for the following-named materials, shall be taken as the coefficients in said formula, viz.: cast iron, 80,000; wrought or rolled iron, 40,000; rolled steel, 48,000.