At the bottom of a straight-run interior stairway, a rectangular landing is 42 inches wide across a 42-inch flight and 34 inches deep in the direction of travel. Under 2021 IRC R311.7.6, what minimum depth applies, and does this depth comply?
- 36 inches; the landing is 2 inches short
- B42 inches; the landing is 8 inches short
- C30 inches; the landing complies
- D48 inches; the landing is 14 inches short
Where to look it up
https://codes.iccsafe.org/content/IRC2021P1/chapter-3-building-planning
Why A is correct
R311.7.6 requires the perpendicular width to be at least the flight width. For the stated straight run, depth in the direction of travel must be at least 36 inches. The 42-inch width satisfies the width comparison; 36 − 34 = 2 inches is the depth deficiency. Nonrectangular landing geometry and a top-interior-landing exception are separate provisions. The finding requires correction but does not dictate moving a wall as the only remedy. Source: https://codes.iccsafe.org/content/IRC2021P1/chapter-3-building-planning