All stair and entrance halls in tenements shall be constructed as provided in this section.
1. In tenements erected after April twelfth, nineteen hundred one:
a. On every story there shall be fireproof doors and assemblies with the doors self-closing separating every such stair and entrance hall from all non-fireproof parts of the tenement.
b. There shall be no transom, sash or similar opening of any kind from such stair and entrance halls to any other part of the tenement.
c. If such tenements are non-fireproof, and are occupied by three families or more on any story or are five stories or more in height, the stair and entrance halls shall be enclosed with brick walls, except as provided in paragraph a of subdivision three.
2. In tenements erected after April fourteenth, nineteen hundred three:
a. Every entrance hall shall be at least three feet six inches in clear width from the entrance up to and including the stair enclosure, and beyond that at least three feet in clear width. If such entrance hall is the only entrance to two stairs or more, that portion of the hall between the entrance and the first stair, including the stair enclosure, shall be at least five feet three inches in clear width.
b. Such halls shall comply with the requirements of sections two hundred thirty-four to two hundred thirty-seven inclusive as to construction of stair and entrance halls, except that if such tenements are fireproof entrance hall enclosures need only withstand a fire test of two and one-half hours and angle iron construction may be substituted for brick walls.
c. In every such tenement access shall be provided from a street to the yard either in a direct line or through a court.
d. If such tenements are occupied by not more than two families on any story and are not more than four stories in height, the floors of the stair and entrance halls shall be fireproof or filled in between the floor beams with at least five inches of concrete deafening. The stairs shall be fireproof, or may be of wood provided the soffits of the stairs are fire-retarded, or covered with plaster board at least one-half inch thick, with all joints true and well pointed. The stair and entrance halls in such tenements shall be enclosed on all sides with brick walls or with partitions of angle iron and fireproof blocks four inches or more in thickness, except as provided in paragraph e.
e. If such tenements are occupied by not more than two families on any story and are not more than three stories in height, the stair and entrance halls may be enclosed in wood stud partitions, fire-retarded on both sides, or covered with plaster board at least one-half inch thick, with all joints true and well pointed and with the spaces between the studs filled in with brick to the height of the floor beams.
3. In tenements erected after April eighteenth, nineteen hundred twelve:
a. If such tenements are occupied by three or more families on any story, or are five stories or more in height, the stairs and entrance halls shall be fireproof throughout and all stairs provided with handrails, except that stair treads two inches or more in thickness and handrails may be of hard wood. All windows in such halls shall be fireproof and, except for windows opening on a street in a tenement six stories or less in height, shall be glazed with wire glass. Such halls shall be enclosed with brick walls, except that one or more sides may be left open to a street, yard or court.
b. Public halls which are more than forty feet in length and are used as a means of egress from four or more apartments shall be fireproof throughout and doors opening therefrom and their assemblies shall be fireproof with the doors self-closing.
4. In old-law tenements four stories or more in height:
a. Whenever the entrance halls of any such tenements adjoin they shall be separated by a fire-retarded wall.
b. The walls and ceilings of every entrance hall and stair hall, and every public hall connected therewith, and the soffit of every stair shall be fire-retarded. In all such halls all wood wainscoting except a flat base and stair stringers ten inches or less in height, and all wood railings, balustrades and newel posts shall be removed completely and replaced with metal or other hard incombustible materials of such size and secured in such manner as may be approved by the department, except that handrails may be of hard wood.
c. Every door opening into any entrance hall or stair, or into any public hall connected therewith, shall be self-closing; every glazed opening or glazed panel in such a door shall be glazed with wire glass, and every transom opening into any public hall shall be glazed with wire glass and permanently secured in a closed position.
d. Every interior sash, or opening other than a door, in the walls or partitions of such halls, and every window therein not opening to the outer air, shall be removed and the openings closed up and fire-retarded.