52§ 915.8.1 General. Means of egress must comply with the provisions of Section
915.8.
§ 915.8.1 Stairway enclosures. All stairways used for exiting must be protected by
an exit enclosure designed in accordance with the California Building Code, Section
1020.1 and this Section.
§ 915.8.2.1 Construction. Construction of stairway enclosures must in accordance
with the California Building Code, Section 1005.3.3.2
§ 915.8.2.2 Extent of Enclosure. Stairway enclosures must be continuous and
must fully enclose all portions of the stairway. Exit enclosure must exit directly to the
exterior of the building or include an exit passageway on the ground floor, leading to
the exterior of the building. Each exit enclosure must extend completely through the
roof and be provided with a door that leads onto the roof.
§ 915.8.2.3 Openings and Penetrations. Openings and Penetrations must be as
specified in the California Building Code, Section 1020.1.1.
§ 915.8.2.4 Pressurized Enclosures. All required stairway enclosures in a Mid -Rise
building must pressurized as specified in the California Building Code, Section
909.20.
§ 915.8.2.4.1 Vestibules. Pressurized stairway enclosures, serving Mid -Rise
buildings must be provided with a pressurized entrance vestibule on each floor that
complies with the California Building Code, Section 909.20.
§ 915.8.2.4.1.1 Vestibule Size. Vestibule size must be not less than 44 inches in
width and not less than 72 inches in the direction of travel.
§ 915.8.2.4.1.2 Vestibule Construction. Vestibules must have walls, ceilings and
floors of not less than two -hour fire resistive construction.
§ 915.8.2.4.1.3 Vestibule Doors. Vestibule doors must be in accordance with the
California Building Code, Section 909.20.
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