Roofing contractors use ladder-jack scaffolds for various types of work, including gutter and metal coping installations, soffit and fascia details, mansard roof installations and siding applications. Occupational Safety and Health Administration (OSHA) rules related to setup and use of ladder-jack scaffolds are found in "Subpart L—Scaffolds" of OSHA's construction regulations and contain specific requirements for roofing contractors that apply to all ladder-jack scaffold setups without regard for the task at hand.
A ladder-jack scaffold simply is a platform or plank suspended on supports, or jacks, which are attached to the rungs of two or more ladders. The ladders are set at intervals apart from each other to accommodate the length of the platform or plank and provide intermediate support if required. A worker then can perform tasks along a portion of a building's edge by working off the plank instead of making multiple moves with a single ladder.
OSHA requires the platform or plank portion of a ladder-jack scaffold to be at least 12 inches wide. Ordinarily, aluminum scaffold planks—either fixed-length or extension-type—are used with ladder jacks because of aluminum scaffold planks' light weight and load capacity. Planks available from major scaffold equipment manufacturers generally are designed to comply with OSHA's 12-inch width requirement, and some models are 14 inches wide. They also should have a posted load rating in pounds that—in the case of fixed planks—may allow two workers to be on a plank at the same time.