Tim is a roofer who was working on a 3-story flat roof with no parapet walls when he tripped over a piece of insulation, lost his balance, and fell toward the edge of the roof, striking his shoulder against the mid-rail of a guardrail that had been installed along the perimeter of the roof. As he lay on the ground at the foot of the guardrail, he realized that his life had just been saved by that guardrail. If it had not been erected (and erected properly) he certainly would have fallen 30 feet to the parking lot below. It is not often that we talk about near-miss incidents like this, but they are impactful reminders of the importance of proper fall protection measures.
As illustrated by Tim’s incident, properly installed guardrails can prevent falls from an elevation by providing a physical barrier. A guardrail is termed a “fall prevention method,” which means it prevents a worker from falling from an elevation. This method is preferred over other types of fall protection, such as personal fall arrest systems and safety nets, which “arrest” falls after the occurrence. When these methods are employed, the worker experiences a fall and is caught by the safety equipment. On the other hand, guardrails effectively eliminate fall hazards.
A guardrail consists of a top rail at a height of 42 inches (±3 inches) above the walking/working level, a mid-rail at a height of 21 inches above the walking/working level, and a 3½ inch tall toe-board. The toe-board prevents objects on the working surface from falling to lower levels. Guardrails can protect workers from a fall not only on leading edges, but also holes in the walking/working surface, stairways, ramps, or any other unprotected edges. Guardrails can be purchased or can be made from wood or wire rope at the jobsite.
General Requirements for Guardrail Systems
- The top edge of the guardrail system must be 42 inches, ±3 inches, above the walking/working surface.
- Mid-rails must be installed between the top edge of the guardrail system and the walking/working surface.
- The guardrail system must be capable of withstanding a 200-pound force applied to the top rail in an outward or downward direction. When the 200-pound force is applied to the top rail cannot deflect to a height less than 39 inches above the walking/working surface.
- All mid-rails, screens, mesh, intermediate vertical members, or panels must be able to withstand a 150-pound force in a downward or outward direction.
- Intermediate members such as balusters, when used between posts, must not be more than 19 inches apart.
- All guardrail systems must be smoothly surfaced.
- Steel or plastic banding can NEVER be used in a railing system.
- Avoid using manila, plastic, or synthetic rope because they must be inspected often and may deteriorate rapidly.