Note: | * You can use fixed ladders for climbing elevated structures, such as tanks, towers, and overhead traveling cranes, when their use is common practice in your industry. |
* You can use winding stairways on tanks and similar round structures if the structure's diameter is at least five feet. | |
* You could use a spiral stairway as an exit route in a restricted area that lacks room for a conventional stairway. |
Definitions: | * A stairway or fixed stairs is a series of steps and landings: - Leading from one level or floor to another. - Leading to platforms, pits, boiler rooms, crossovers, or around machinery, tanks, and other equipment. - Used more or less continuously or routinely by employees or only occasionally by specific individuals. - With three or more risers. * A riser is the vertical part of the step at the back of a tread that rises to the front of the tread above. * A tread is the horizontal part of the step. Tread width is the distance from the front of the tread to the back. |
Stair Components
Wash. Admin. Code § 296-800-25005
Statutory Authority: RCW 49.17.010, [49.17].040, and[49.17].050 . 01-23-060, § 296-800-25005, filed 11/20/01, effective 12/1/01; 01-11-038, § 296-800-25005, filed 5/9/01, effective 9/1/01.