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Warning lines in roofing

Warning lines in roofing

Warning lines in roofing

Warning lines can be an effective form of fall protection when used properly on low sloped roofs. A low slope roof is defined as a roof that has a slope that is less than or equal to 4/12. If the roofs slope is greater than this, another type of fall protection must be used. OSHA details the requirements in 1926.502 (f).

What is a warning line?

A warning line is a barrier set up around the perimeter of a low sloped roof to warn workers that they are nearing and unprotected edge of the roof or walking surface.

How is a warning line set up? (All requirements below should be met)

  • A warning line should keep employees at least 6 feet back from the unprotected edge. In some instances, the distance may be further if circumstances require it, such as obstructions, weather, visibility, materials being handled etc.
  • If mechanical equipment is being used on the roof, the line should be set 10 feet back from the unprotected edge.
  • It should be set up around the entire perimeter, fully enclosing the workers inside.
  • The line can be made of wire, rope or chain. The worker should be able to feel it when backed up against. Whichever is used, it must have a tensile strength of 500 lbs.
  • High visibility flags should be attached at 6-foot intervals along the line and warning signs should be placed out as well.
  • Stanchions must be able to support at least 16 pounds without tipping over once put in place.
  • The height of the line at the lowest point must be 34 inches or higher. The highest point of the line must be 39 inches or lower.
  • The line must be attached so that when adjusted in one section it does not take up or add slack in another.
  • The walkway from the roof to the ladder should have similar protective lines in place. The path should have a similar line across the opening when not entering or exiting the roof.

No workers should enter the area between the warning line and unprotected edge unless protected by a fall protection system. In addition, all material should be set up inside the protected area as well.


This article is provided solely as a reference tool to be used for information purposes only. The information in this article shall not be construed or interpreted as providing legal or any other advice. The information material does not amend the provisions of any insurance policy issued by CompSource Mutual. It is not a representation that coverage does or does not exist for any particular claim or loss under any such policy. Coverage depends on the facts and circumstances involved in the claim or loss, all applicable policy provisions, and any applicable law.

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