§ 104. Bulkheads. 1. Every stair, fire-stair and fire-tower required
by this chapter to extend to the level of the roof or to any terrace
formed by a setback shall extend to and through a fireproof bulkhead or
other fireproof enclosure in such roof or terrace approved by the
department. Such bulkhead or enclosure shall give unobstructed access
at all times to such roof or terrace by means of a fireproof door and
door assembly with the door self-closing. Such a door shall never be
self-locking and shall be fastened on the inside by movable bolts, hooks
or a lock which does not require a key to open from the inside of the
dwelling. Stairs to a bulkhead or enclosure shall have a handrail. When
a dwelling has a pitched or sloping roof with a pitch or slope of more
than fifteen degrees, no bulkhead or stair leading thereto shall be
required.

2. The roof of any penthouse may for the purpose of this section be
deemed part of the main roof if unobstructed access be provided and
maintained between all required fire-stair landings on the main roof
adjoining such penthouse, on the roof of such penthouse and on the roof
of any other penthouse extending above such main roof. Such unobstructed
access, where horizontal, shall be by means of a passage at least three
feet in clear width. It may include one or more stairs necessary to
provide access from any penthouse roof to any main roof adjoining such
penthouse. Such stairs shall conform to all the requirements of section
fifty-three for stairways of fire-escapes. There shall be a passageway
at least four feet in clear width between such stairs and the parapet
wall or guard railing of the main roof.