Where should warning lines be erected in relation to the roof edge when no mechanical equipment is being used?

Warning lines should be erected at a distance of 6 feet from the roof edge when no mechanical equipment is being used. This distance is established to provide a buffer zone that alerts workers to the potential fall hazard without obstructing necessary work processes. The placement of warning lines helps maintain safety by visually marking the boundary while allowing workers to operate comfortably and effectively on the roof. By maintaining this distance, workers are reminded to stay clear of the edge and take necessary precautions against falling.

In the context of workplace safety regulations, the 6-foot guideline aligns with the guidelines set by OSHA, which focuses on preventing falls and ensuring safety in construction environments.