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Unformatted text preview: . (11) Stairway to Roof. In every building four or more storeys in height, one stairway shall
extend to the roof unless the roof has C slope greater than 1 in 3.
(12) Headroom. Every required stairway shall have a headroom clearance of not less than
2.00 meters. Such clearance shall be established by measuring vertically from a plane parallel and
tangent to the stairway tread nosing to the soffit above all points.
(f) Ramps. A ramp conforming to the provisions of this Code may be used as an exit. The
width of ramps shall be as required for corridors.
(g) Horizontal Exit. If conforming to the provisions of this Code, a horizontal exit may be
considered as the required exit. All openings in a separation wall shall be protected by a fire assembly
having a fire-resistive rating of not less than one hour. A horizontal exit shall not lead into a floor area
having a capacity for an occupant load not less than the occupant load served by such exit. The capacity
shall be determined by allowing 0.30 square meter of net floor area perambulatory occupant and 1.90
square meters per non-ambulatory occupant. The dispersal area into which the horizontal exit leads shall
be provided with exits as required by this Code.
(h) Exit Enclosures. Every interior stairway, ramp, or escalator shall be enclosed as specified in
this Code: Except, that in other than Group D Occupancies, an enclosure will not be required for
stairway, ramp, or escalator serving only one adjacent floor and not connected with corridors or
stairways serving other floors. Stairs in Group A Occupancies need not be enclosed.
(1) Enclosure walls shall not be less than two-hour fire-resistive construction. There shall be
no openings into exit enclosures except exit doorways and openings in exterior walls. All exit doors in
an exit enclosure shall be appropriately protected.
(2) Stairway and ramp enclosures shall include landings and parts of floors connecting
stairway flights and shall include a corridor on the ground floor leading from the stairway to the exterior
of the building. Enclosed corridors or passageways are not required for uneclosed stairways.
(3) A stairway in an exit enclosure shall not continue below the grade level exit unless an
approved barrier is provided at the ground floor level to prevent persons from accidentally continuing
into the basement.
(4) There shall be no enclosed usable space under stairways in an exit enclosure, nor shall
the open space under such stairways be used for any purpose.
(i) Smokeproof Enclosures
A smoleproof enclosure shall consist of a vestibule and a continuous stairway enclosed from the
highest point by walls of two-hour fire-resistive construction. In buildings five storeys or more in
height, one of the required exits shall be a smokeproof enclosure.
(1) Stairs in smokeproof enclosures shall be of incombustible construction.
(2) There shall be no openings in smokeproof enclosures, except exit doorways and openings
in exterior walls. There shall be no op...
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- Fall '12