R 408.10671 Fire escape stairs.

Rule 671. (1) Fire escape stairs may be used as a required exit only in existing buildings. Fire escape stairs shall not constitute more than 50% of the required exit capacity. Fire escape stairs shall not constitute any part of the required exits for a new building. (2) Fire escape stair dimensions shall be in accordance with table 4. TABLE 4 Minimum Width 22 inches clear between rails Minimum horizontal dimension of a landing or platform 22 inches Maximum rise 9 inches Minimum tread, exclusive of nosing 9 inches Spiral winders Not permitted Maximum height between landings 12 feet (3) Fire escape stairs shall have walls or approved guards, and handrails on both sides.