Section R. 408.42129 - Stairways; landings; installation; rise height and tread depth; metal pan landings and metal pan treads; guardrail systems requiredRule 2129.
(1) Stairways that will not be a permanent part of the structure on which construction work is being performed shall have landings that are not less than 30 inches (76 cm) in the direction of travel and extend not less than 22 inches (56 cm) in width at every 12 feet (3.7 m) or less of vertical rise.(2) Stairs shall be installed between 30 degrees and 50 degrees from horizontal.(3) Riser height and tread depth shall be uniform within each flight of stairs, including any foundation structure used as 1 or more treads of the stairs. Variations in riser height or tread depth shall not be more than 1/4 of an inch (0.6 cm) in any stairway system.(4) Metal pan landings and metal pan treads, when used, shall be secured in place before filling with concrete or other material.(5) Unprotected sides and edges of stairway landings shall be provided with guardrail systems.Mich. Admin. Code R. 408.42129