The flight is 42 inches wide, and the landing at its foot measures 42 inches across and 34 inches in the direction of travel. What is the minimum depth required in the direction of travel, and does this landing comply?
- 36 inches, so the landing is 2 inches short
- B42 inches, so the landing is 8 inches short
This applies the stair width in both directions. The width requirement governs the dimension across the landing, while the direction of travel has its own fixed minimum that does not scale with the flight.
- C30 inches, so the landing complies as built
Thirty inches is not a landing dimension in the stairway provisions, and adopting it would make the landing comply when it does not. The figure most often comes from confusing landings with other clearances.
- D48 inches, so the landing is 14 inches short
Forty-eight inches overstates the requirement. Using a number larger than the code sets is as much an error as using one too small, and it can force an unnecessary and expensive change.
Why A is correct
The landing dimension measured in the direction of travel is a flat 36 inches, while the dimension across the landing must equal the stair width. This landing is wide enough across at 42 inches but only 34 inches deep, so it falls 2 inches short of the 36-inch minimum.
What this question is testing
Whether the candidate can apply two different landing dimensions from two different rules at the same time, and does not let the stair width govern the direction of travel.
On the job
Landings get squeezed when a stair is moved during framing or when a hallway wall lands where the plan did not show it. Two inches sounds trivial, but a landing that shallow puts a person stepping off the bottom riser directly against a door or a wall. Inspectors measure both dimensions and note which rule each one comes from, because the correction differs: one may mean moving a wall, the other reframing the stair.
Memory technique
Wide as the stair, deep as three feet.
Exam tip
Across the landing, match the stair width. Along the direction of travel, 36 inches flat.
Where to look it up
IRC Chapter 3, stairways, the landings paragraph with its width and direction-of-travel dimensions.