WAC 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.
[Statutory Authority: RCW 70.114A.081. 99-03-065, §
246-359-520, filed 1/18/99, effective 2/18/99.]