How to safely install roof trusses

Almost every Habitat home I’ve worked on has used trusses for the roof assembly. As a risk area for serious injury, roof truss installation is right up there because truss construction occurs high above the ground and trusses are not stable until they have been properly braced and restrained.

Usually, I promote the use of personal fall arrest systems when working on the roof, but when roof trusses are being installed, anchoring high on an unstable roof truss is not the best idea. The reason being that falls usually don’t occur in the perfect scenario directly below the anchor. Trusses are designed for weight that goes directly down, and a side pull on an unsecure truss might pull the entire truss assembly down along with the worker.

It’s best to use either scaffolds, ladders or a lift if your affiliate happens to have one, until the trusses are secured. An important note here is to secure the trusses as soon as possible. Don’t wait until you have raised all 40 feet of trusses before you start bracing them off to prevent collapse. The key here is to plan ahead to make sure your truss installation goes smoothly and safely.

I would add that if the affiliate you are working with has an engineered spreader that attaches to multiple trusses, this is an acceptable anchor for a personal fall arrest system, or harness. However, a qualified person needs to determine that the trusses are stable enough for this system to be employed without any risk to the volunteer.

Once a truss section of four or more has been secured, braced and sheeted, then these trusses can be used as an attachment point for a personal fall arrest system. This may change the way you normally install trusses so be flexible in improving your safety by following these ideas.

Volunteer and work safely,

Frank Peccia
Care-A-Vanner safety coordinator 
fpeccia@habitat.org