Sec. 29. Stairway and elevator shafts.
In the buildings hereafter erected, except private dwellings,
which are used above the first floor for business purposes or for
public assemblage, or for any purpose whatever if over two stories
high, the stair shafts shall be separately and continuously enclosed
by incombustible partitions. Elevator shafts in all buildings hereafter
erected shall be enclosed in the same manner. The partitions
shall be constructed of brick or other fire-resistive material approved
by the city manager or other designated official, and all
mortar used in the construction shall be Portland cement mortar.
No hollow partition shall be less than six inches thick, no brick
partition less than eight inches thick. The stairways and landings
shall be constructed entirely of fireproof material.
All openings in elevator, stair or other shaft enclosures shall be
protected by self-closing fire doors, fire windows, fire shutters or
other approved self-closing fireproof equipment.
Doors opening into stairway shafts shall swing in the direction
of exit travel, shall be self-closing and shall be at least thirty-six
inches wide.
The enclosure walls for all elevator shafts shall extend at least
three feet above the roof, and there shall be a sufficient opening in
the shaft above the roof line to provide for the release of smoke
or gases. (Id., § 494(21).)
