Question 30
Domain 2: Building Planning, Means of Egress, and Safety ProvisionsWhat is the minimum width of a residential landing at the top and bottom of stairs per the IRC?
Correct answer: C
Explanation
The IRC requires landings at the top and bottom of stairs to be "not less than the width of the stairway served." This means the landing must match the stairway width, so the minimum width is the same as the stairs it serves.
Why each option is right or wrong
A. 24 inches
B. 30 inches
C. Not less than the width of the stairway served
IRC R311.7.6 requires a landing at each top and bottom of a stairway, and R311.7.6.1 sets the landing dimension at not less than 36 inches in the direction of travel and not less than the width of the stairway served. Because the question asks for the minimum width, the controlling requirement is that the landing cannot be narrower than the stairway it serves; the 36-inch minimum applies to the other landing dimension.
D. 42 inches