Section R. 400.18646 - Existing fire escapesRule 646. An existing fire escape shall be in compliance with the specifications for new fire escapes, except as follows:
(a) The fire escape shall be certified, in affidavit form, by an architect or structural engineer who attests to the fire escape's structural stability if so required by the appropriate inspecting authority.(b) Handrails shall not be lower than 27 inches above the forward edge of the tread.(c) Treads shall be not less than 8 inches, exclusive of nosing.(d) Risers shall be not more than 8 1/2 inches.(e) The vertical distance between platforms or landings in any flight of stairs shall not be more than 15 feet.(f) The width of stairs shall not be less than 36 inches.Mich. Admin. Code R. 400.18646