A warning line can be classified as a barrier that can be a rope or even a wire that warns individuals or workers when they are approaching the unprotected edge of a roof, a floor, or possibly an uneven work surface. There are many things to remember while staging a warning line during construction activities. This line should be set up properly to avoid risky and often fatal falls. These lines are more often than not associated with roofs and construction zones on elevated surfaces.

Warning Line System

For all work on roofs, a proper fall arrest system, guard system, or warning line system should be in place before work begins. Prevention of accidents are the real reason why warning lines are established. Conventional fall protection systems may be too cumbersome or expensive in construction zones. Warning lines in the United States must be a minimum of 6 feet away from the edge of all sides of the chosen work location.

The rope, wire, or chain shall be rigged and supported in such a way that its lowest point (including sag) is no less than 34 inches (.9 m) from the walking/working surface and its highest point is no more than 39 inches (1.0 m) from the walking/working surface.

After being erected, with the rope, wire, or chain attached, stanchions shall be capable of resisting, without tipping over, a force of at least 16 pounds (71 N) applied horizontally against the stanchion, 30 inches (.8 m) above the walking/working surface, perpendicular to the warning line, and in the direction of the floor, roof, or platform edge. Furthermore, the rope, wire, or chain shall have a minimum tensile strength of 500 pounds (2.22 kN), and after being attached to the stanchions, shall be capable of supporting, without breaking once again a force of at least 16 pounds.

The OSHA regulations also state that the line shall be attached at 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 adjacent sections before the stanchion tips over. And also, that no employee shall be allowed in the area between a roof edge and a warning line unless the employee is performing roofing work in that area.

Mechanical equipment on roofs shall be used or stored only in areas where employees are protected by a warning line system, guardrail system, or personal fall arrest system. If a warning line system is used, it must meet the OSHA requirements. Remember an once of prevention is worth a pound of cure.