PDFWAC 51-51-0311

Section R311—Means of egress.

R311.4 Vertical egress. Egress from habitable levels including habitable attics and basements not provided with an egress door in accordance with Section R311.2 shall be by a ramp in accordance with Section R311.8 or a stairway in accordance with Section R311.7.
EXCEPTION:
Stairways, alternating tread devices, ship's ladders, or ladders within an individual dwelling unit or sleeping unit used for access to areas of 200 square feet (18.6 m2) or less, are exempt from the requirements of Sections R311.4 and R311.7, where such devices do not provide exclusive access to a kitchen or bathroom. Such areas shall not be located more than 10 feet (3048 mm) above the finished floor of the space below.
R311.7.11 Alternating tread devices.Alternating tread devices shall not be used as an element of a means of egress. Alternating tread devices shall be permitted provided that a required means of egress stairway or ramp serves the same space at each adjoining level or where a means of egress is not required. The clear width at and below the handrails shall be not less than 20 inches (508 mm).
EXCEPTION:
Not adopted.
R311.7.12 Ship's ladders. Ship's ladders shall not be used as an element of a means of egress. Ship's ladders shall be permitted provided that a required means of egress stairway or ramp serves the same space at each adjoining level or where a means of egress is not required. The clear width at and below the handrails shall be not less than 20 inches (508 mm).
EXCEPTION:
Not adopted.
[Statutory Authority: RCW 19.27.031 and 19.27.074. WSR 23-23-104, § 51-51-0311, filed 11/15/23, effective 3/16/24; WSR 23-02-058, 23-12-104, and 23-20-024, § 51-51-0311, filed 1/3/23, 6/7/23, and 9/25/23, effective 3/15/24; WSR 20-03-023, § 51-51-0311, filed 1/6/20, effective 7/1/20; WSR 10-03-098, § 51-51-0311, filed 1/20/10, effective 7/1/10. Statutory Authority: RCW 19.27.074, 19.27.020, and chapters 19.27 and 34.05 RCW. WSR 07-01-090, § 51-51-0311, filed 12/19/06, effective 7/1/07. Statutory Authority: RCW 19.27.031 and 19.27.074. WSR 04-01-109, § 51-51-0311, filed 12/17/03, effective 7/1/04.]