Section R. 400.18647 - New fire escapesRule 647. New fire escapes shall be constructed as follows:
(a) Material may be steel or nominal 2-inch lumber.(b) Tubular and spiral slide-type escapes are not permitted.(c) An outside stairway that constitutes an approved means of egress shall be designed, constructed, and maintained to support a live load of 100 pounds per square foot on platforms and landings and a concentrated load of 400 pounds on stair treads.(d) Supporting members of platforms, landings, and stairs, which are in tension and are fastened directly to the building, shall pass through the wall and be fastened securely to the framework of the building. Where practicable, an outside stairway shall be self-supporting. A counter-balanced stairway is not permitted.(e) On an outside stairway, each landing or platform adjacent to an exit doorway of the building shall be not less than 3 inches, nor more than 8 inches, below the sill level of the doorway. Each landing or platform shall be at least the full width of the doorway it serves and its depth shall be not less than the width of the widest outside stairway that leads directly to or from it. The landings or platforms shall be designed and constructed so that exit doors, when open, will not decrease the required unobstructed width of the platform or stairs.(f) An outside stairway that is considered an approved means of egress shall lead to ground level and the last step in descent to the ground shall not exceed the height of the riser immediately above.(g) A ladder shall not be used as any portion of an approved means of egress.(h) An outside stairway shall be provided with handrails on both sides 36 inches above the forward edge of the tread. Not less than 2 rails shall be provided equidistant between the handrail and the forward edge of the tread.(i) Treads shall be not less than 9 1/2 inches wide, exclusive of nosing.(j) The tread or platform shall be covered with a suitable nonslip surface.(k) Treads shall include an additional width of 1 inch as nosing when stairs are constructed with risers.(l) The riser of a stairway shall be not more than 7 3/4 inches.(m) The maximum vertical distance between platforms or landings in any flight of stairs shall not be more than 12 feet.(n) The required width of a new outside stairway shall be not less than 44 inches.(o) An outside stairway that is part of an approved means of egress shall be protected against fire in the building by blank or closed walls which are directly under such stairways and which run for a distance of 6 feet in all other directions. Windows may be allowed within an outside stairway if each window is stationary, made of steel sash, and glazed with wired glass that is not less than 1/4 of an inch in thickness.(p) An outside stairway that is considered an approved egress passage and access therefrom to a public street or alley shall be maintained in a safe condition for its intended use at all times. A stairway that forms a part of an approved means of egress shall be maintained free from ice and snow at all times. There shall be no obstruction placed upon or within a stairway or an entrance thereto and there shall be no other waste material under or adjacent to the stairway.(q) When deemed necessary by the inspection authorities, a stairway shall be provided with an approved shelter against ice and snow.(r) When iron and steel fire escapes are constructed as part of an approved means of egress from a congregate facility, the balconies and stair treads shall be in compliance with this rule and shall be made up of 3/16-inch by 1-inch straight bars set on edge, spaced 1 inch apart from center to center.Mich. Admin. Code R. 400.18647