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Warning Lines for Construction Activities

Yellow warning line on construction site roof

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Warning Lines Information

Warning lines shall be erected around all sides of the roof work area at least 6 feet from the roof edge when mechanical equipment is not being used. When mechanical equipment is being used, the warning lines shall be erected not less than 6 feet from the roof edge which is parallel to the direction of mechanical equipment operation, and not less than 10 feet from the roof edge which is perpendicular to the direction of mechanical equipment.

Warning lines shall consist of rope, wire, tape, or chain that meets the following:

  • Has a minimum breaking strength of 500 lbs. for construction activities (and 200 lbs. for designated areas).
  • Is installed so its lowest point, including sag, is between 34 inches and 39 inches above the walking-working surface.
  • Stanchions are capable of resisting, without tipping over, a force of at least 16 lbs. (applied horizontally against the stanchion, 30 inches above the walking surface, perpendicular to the warning line, and in the direction of the floor, roof, or platform edge).
  • Is supported in such a manner that pulling on one section of the line will not result in slack being taken up in adjacent sections causing the line to fall below 34 inches.
  • Is flagged every 6 feet with high visibility material.
  • No employee shall be allowed in the area between the roof edge and the warning line unless the employee is performing roofing work in the area.

Points of access, material handling areas, storage areas, and hoisting areas shall be connected to the work area by an access path formed by two warning lines. When the point of access is not in use, a warning line shall be placed across the path near the work area, or the path may be offset so that a person cannot walk directly into the work area.


Designated Areas for General Industry Applications

6-to-15 feet

Designated areas (DA) are permitted by OSHA when work is being performed on a low-sloped roof and work is greater than 6 feet from the unprotected edge, and is both infrequent and temporary. Designated areas may only be set up and used by trained personnel. Fall Protection User level training is required. When a designated area is being used, the following requirements apply:

  • The perimeter of the DA must be delineated with a warning line (see above).
    • Warning line is erected as close to the work area as the task permits and is erected not less than 6 feet from the roof edge for work that is both temporary and infrequent, or not less than 15 feet for other work.
    • Is clearly visible from a distance of 25 feet away and anywhere within the designated area.
  • Employees must remain within the DA while work operations are underway. Personal fall arrest systems are not required within the DA.

Within 6 feet

When work must be performed within 6 feet of an unprotected edge (i.e. outside of the Designated Area), personnel must be protected by:

15 feet or more

When work is performed 15 feet or more from the roof edge, and the work is both infrequent and temporary, fall protection is not required provided that a work rule has been implemented and enforced.

  • Work rule: Personnel are prohibited from going within 15 feet of the roof edge without the use of a fall protection system (i.e. guardrail system, safety net system, travel restraint system, personal fall arrest system, or designated area).

Contact Information

Robin McCall-Miller, Occupational Safety Program Manager