R 408.10651 Stairs.

Rule 651. (1) Stairs serving as a required exit shall comply with the requirements of this part as to construction specifications and details, and of table 3. **** INSERT MISSING TABLE OR CHART - SEE ORIGINAL MANUSCRIPT **** (2) A variation in the width of tread or height of risers in any flight shall not exceed 3/16 inch. (3) A stair and a platform or landing used in connection therewith, in a building 4 stories or more in height, shall be of noncombustible construction throughout, except for handrails. (4) A stair, platform, landing, balcony, and stair hallway floor 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. (5) Where the material of stair treads and landings is such as to involve danger of slipping, nonslip material shall be provided on the tread surface. (6) Stairways and intermediate landings shall continue with no decrease in width along the direction of exit travel. (7) Monumental stairs, either inside or outside, may be accepted as required exits if all requirements for exit stairs are complied with, except that curved stairs may be accepted with a radius of 25 feet or more at the inner edges. HORIZONTAL EXITS, RAMPS, AND ESCALATORS