Section R. 408.10672 - Stair construction and loadRule 672.
(1) Iron, steel, concrete, or other approved noncombustible material shall be used for the construction of fire escape stairs, balconies, railings, and other features appurtenant thereto.(2) Balconies and stairs shall be designed to carry a load of 100 pounds per square foot, or a concentrated load of 300 pounds so located as to produce maximum stress conditions.Mich. Admin. Code R. 408.10672