A warning line needs to be erected on a roof or edge to alert workers of the possible hazard.
Within the areas demarcated by the warning line a worker does not require a protective system (guardrail, body belt, safety net). Between the warning line and the edge then only protected workers should be allowed.
Location all around the work area:
(1) >= 6 feet from the edge for nonmechanical work
(2) >= 6 feet from the edge for mechanical work performed parallel to the edge
(3) >= 10 feet from the edge for mechanical work performed perpendicular to the edge
Elements:
(1) stanchions
(2) rope, wire or chain as barrier line
Requirements for stanchions:
(1) able to withstand a horizontal force of 16 pounds applied 30 inches above the working surface and applied perpendicular to the warning line towards the roof edge
(2) pulling on the attached line should not result in slack in adjacent sections being taken up before the stanchion tips over
Requirements for barrier line:
(1) flagged at intervals <= 6 feet
(2) located 34 to 39 inches above the working surface
(3) minimum tensile strength 500 pounds
