Additional Fall Protection Systems

Warning Line Systems

OSHA defines a warning line system as a barrier erected on a roof to warn workers that they are approaching an unprotected roof side or edge, and to designate an area in which roofing work may take place without the use of guardrails, body harnesses, or safety net systems to protect workers in the area. Warning line systems consist of ropes, wires, or chains, plus supporting stanchions. If an employer chooses to use warning line systems, the following provisions apply:

• The warning line must be erected around all sides of roof work areas.
• When mechanical equipment is not being used, the warning line must be erected at least 6 feet from the roof edge.
• When mechanical equipment is being used, the warning line must be erected in the following way:
  • At least 6 feet from the roof edge parallel to the direction of mechanical equipment operation; and
  • At least 10 feet from the roof edge perpendicular to the direction of mechanical equipment operation

OSHA defines a warning line system as a barrier erected on a roof to warn workers that they are approaching an unprotected roof side or edge, and to designate an area in which roofing work may take place without the use of guardrails, body harnesses, or safety net systems to protect workers in the area. Warning line systems consist of ropes, wires, or chains, plus supporting stanchions. If an employer chooses to use warning line systems, the following provisions apply:

• The rope, wire, or chain must be flagged at not more than 6-foot intervals with high-visibility material.
• The rope, wire, or chain must be rigged and supported so that the lowest point (including sag) is at least 34 inches from the walking or working surface; and its highest point is no more than 39 inches from the walking or working surface.
• Stanchions, after being rigged with warning lines, must be capable of resisting (without tipping over) a force of at least 16 pounds applied horizontally against the stanchion, 30 inches above the walking or working surface, perpendicular to the warning line, and in the direction of the floor, roof, or platform edge.
• The rope, wire, or chain must have a minimum tensile strength of 500 pounds. After being attached to the stanchions, it must support (without breaking) the loads applied to the stanchions.
• The rope, wire, or chain must be attached to each stanchion in such a way that pulling on one section of the line between stanchions will not result in slack being taken up in the adjacent section before the stanchion tips over.

To learn more about Fall Protection visit our Construction Fall Protection Online Training web page.