1011.5.4 Dimensional Uniformity
Stair treads and risers shall be of uniform size and shape. The tolerance between the largest and smallest riser height or between the largest and smallest tread depth shall not exceed 3/8 inch (9.5 mm) in any flight of stairs. The greatest winder tread depth at the walkline within any flight of stairs shall not exceed the smallest by more than 3/8 inch (9.5 mm).
- Stairways connecting stepped aisles to cross aisles or concourses shall be permitted to comply with the dimensional nonuniformity in Section 1029.14.2.
- Consistently shaped winders, complying with Section 1011.5, differing from rectangular treads in the same flight of stairs.
- Nonuniform riser dimension complying with Section 1011.5.4.1.