Section SPS 375.19 - Balanced stairway(1) All "B" type fire escapes, and all fire escapes on schools, theaters, and assembly halls, either shall reach to the ground or shall have a balanced stairway reaching to the ground. "A" type fire escapes which are not on schools, theaters, or assembly halls, may terminate on a platform at least 3 feet long, located not more than 10 feet above the ground.(2) Every balanced stairway shall conform to the requirements for other stairways except that the stringers and the top rail may be lighter if they are properly trussed. The counterbalancing device shall be attached to both sides of the stairway equally, or a special attachment shall be used to prevent warping or twisting. The counterbalancing device shall operate gradually and easily as the live load is applied. Note: The use of cables and sheaves will be permitted only under exceptional conditions, as rust is almost sure to interfere with their proper operation. In such cases the sheaves shall turn on a brass pin or in brass bearings and shall be protected from the weather at the top and on all sides.
(3) Treads for "A" type balanced stairways may be made as follows: two 11/4x 11/4 x 1/4 inch angles at front and back; two 1 1/4x 1/4 inch bars between, lying flatwise; one inch space between bars. Treads for"B" type balanced stairways may be made as follows: two 11/2 x 1 1/2 x 1/4 inch angles at front and back; two 11/2 x 1/4 inch bars between, lying flatwise; one inch space between bars. All such treads shall be strongly fastened together with cross bars not more than 14 inches apart.Wis. Admin. Code Department of Safety and Professional Services SPS 375.19
1-2-56; renum., Register, September, 1974, No. 225, eff. 10-1-74.