Section 238. Stair and entrance halls

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.