14X-5-505.9.1.2 Winders.

Winders must have a minimum tread depth of 9 inches (229 mm) at a point 18 inches (457 mm) from the narrowest edge.

14X-5-505.9.1.3 Uniformity.

Stair treads and risers must be of uniform size and shape. The variance between the largest and smallest riser height or between the largest and smallest tread depth must not exceed 1/2 inch (13 mm) in any flight of stairs.

Exception: Conditions allowed by the Chicago Building Code.

14X-5-505.9.2 Width.

Means of egress stairways must be at least 36 inches (914 mm) wide.

Exception: Conditions allowed by the Chicago Building Code.

14X-5-505.9.3 Landings.

The maximum rise between landings is 12 feet 7 inches (3835 mm).

(Amend Coun. J. 2-19-20, p. 14473, Art. V, § 28)

14X-5-505.9.4 Replacement stairways.

Existing stairways may be rebuilt. The replacement of an existing stairway is not required to comply with the new stairway requirements of the Chicago Building Code where the existing space and construction will not allow a reduction in pitch or slope or elimination of winders.

14X-5-505.9.5 Surface.

The finished surface of treads and landings must be slip-resistant under foreseeable conditions. Outdoor stairways must be designed so that water will not accumulate on walking surfaces.

14X-5-505.9.6 Spaces beneath stairways.

Usable space under interior stairways must be separated from the stairway with 1-hour fire-resistance-rated construction. Access to enclosed spaces beneath enclosed interior stairways may not be provided from within the stairway enclosure.

Enclosed usable space under exterior stairways must be completely enclosed in 1-hour fire-resistance-rated construction. Open space under exterior stairways may not be used for any purpose.

(Amend Coun. J. 2-19-20, p. 14473, Art. V, § 29; Amend Coun. J. 10-7-20, p. 21791, Art. V, § 7)