Section 246-359-520 - Door landings, stairways and guardrails(1)Door landings. Every door must have, at a minimum, a floor area or landing with: (a) A width not less than the width of the door or the width of the stairway served, whichever is greater; and(b) A length not less than thirty-six inches.(2)Stairways. Every stairway having two or more risers must meet the following requirements:(a)Rise and run. The rise of steps and stairs must not be less than four inches nor more than eight inches. The greatest riser height within any flight of stairs must not exceed the smallest by more than three-eighths inch. The run must not be less than nine inches. Stair treads must be of uniform size and shape except the largest tread run within any flight of stairs must not exceed the smallest by more than three-eighths inch.(b)Headroom. Every stairway must have a headroom clearance of not less than 6 feet eight inches.(3)Handrails.(a) At least one handrail is required when a stairway has three or more risers;(b) The top of a handrail must be placed not less than thirty-four inches or more than thirty-eight inches above the nosing of the treads.(c) Handrails must be continuous the full length of the stairs.(d) The handgrip portion of a handrail must: (i) Not be less than one and one-quarter inches nor more than two inches in cross-sectional dimension; and(ii) Have a smooth surface with no sharp corners.(e) Handrails projecting from a wall must have a space of not less than one and one-half inches between the wall and the handrail.(4)Guardrails. Unenclosed porches, balconies, and landings, which are more than thirty inches above grade or floor below must not be less than thirty-six inches in height and must have intermediate rails spaced such that a sphere four inches in diameter cannot pass through.Wash. Admin. Code § 246-359-520
Statutory Authority: RCW 70.114A.081. 99-03-065, § 246-359-520, filed 1/18/99, effective 2/18/99.