§ 57. Vertical and horizontal openings. In order to prevent the
vertical and horizontal spread of fire, smoke and gases, it shall, in
addition to other applicable provisions of this article, be necessary to
comply with the requirements of this section.

1. All doors opening from shafts, stair halls or stairs and the door
assemblies shall be fire-retarded with the doors self-closing and
without transoms or any other opening. Except in the case of elevator
shafts, such shafts, stair halls or stairs may be protected by an
automatic sprinkler system in lieu of fire retarding.

2. All other doors opening upon entrance halls or other public halls
or corridors in every part of the dwelling shall be self-closing, except
where such dwelling is equipped throughout with an approved type
automatic sprinkler or fire-detecting system. It shall be unlawful to
attach to or maintain on or about any door required to be self-closing
any device which prevents the self-closing of such door.

3. Every existing interior glazed sash, window or opening, other than
a door, or a fireproof sash, window or opening glazed with wire glass,
in any partition forming required enclosures around stairs or shafts
shall be removed and the openings closed up and fire-retarded.