R 408.42150 Guardrail specifications for scaffolding and catch platforms.

Rule 2150. (1) A guardrail for scaffolding and catch platforms shall consist of a top rail, intermediate rail, and supporting posts. The top rail shall have a smooth surface and shall be installed between 38 inches (97 cm) and 45 inches (114 cm) above the floor, ramp, platform, or runway. When conditions warrant, the height of the top edge may exceed the 45-inch (114 cm) height, provided the guardrail system meets all other criteria of this rule. The intermediate rail shall be located halfway between the top rail and the floor, ramp, platform, or runway. The top rail shall not overrun the terminal posts unless such a projection does not constitute a hazard. (2) A top rail and its supporting posts shall be constructed of wood that is not less than 2- by 4-inch nominal size with a 1- by 6-inch or 2- by 4-inch nominal size intermediate rail. The construction and fastenings shall produce a guardrail capable of withstanding a 200-pound side thrust applied at the top rail. Other material may be used if the finished product has the 200-pound capability. A guardrail that is subject to additional loads shall be constructed of heavier stock and the supporting post shall be more closely spaced. (3) Vertical supporting posts shall be placed not more than 8 feet (2.4 m) apart. (4) Banding steel shall not be used for guardrail construction. (5) Welded re-steel members shall not be used for guardrail construction.