Roof Truss Safety

Crane Lift

• The safest way to install roof trusses is to lift them with a crane. They are not extremely heavy, but are cumbersome and lifting them to a roof while standing on ladders or scaffolding can be dangerous. Lifting with a crane eases the physical part, but it still can be dangerous. Trusses need to be securely fastened with lifting straps on both sides of the peak and workers need to avoid being hit by crane parts or swinging trusses.

Guide Ropes and Hard Hats

• Place guide ropes on the ends of a truss to be lifted with a crane, so workers on the ground can guide it into position. Lift trusses with a crane with the peak up. Make sure everyone wears hard hats. Install braces at the end wall before raising the first truss. Have 2-by-4-inch boards placed against the end wall, secured to stakes in the ground, with the brace ends protruding well above the wall. Once the truss is set and plumb, nail it to the braces and wall caps. Secure each truss before lifting another.

Temporary Footing

• Use temporary scaffolding or planks across interior wall plates for safety if setting trusses without a crane. Erect tall sawhorses on the house's floor and cover them with 2-by-10 or 2-by-12-inch planks for workers to stand on to get high enough to reach wall caps. Lay 2-by-10 or 2-by-12 planks across top plates of interior walls for workers on the roof to stand on while lifting and nailing trusses. Make sure all planks are stable and do not tilt or wobble.

Lift Upside Down

• Lift trusses upside down, using workers with lifting poles, 2-by-4-inch boards notched on the ends to hold the truss bottom chords. Walk them upside down, with a lifting worker outside each wall, to the point where people on the roof can catch it and erect it. Start at the roof's back end and work forward. Brace trusses temporarily as soon as they are installed.

Ladders and Help

• Use ladders for roof workers to get on the roof, but move them so they aren't in the way as workers walk across the roof to set trusses. Try to have at least three people on it, one on each wall and one in the center, so no one has to lift, hold and nail at the same time. Try to let each person have one hand free for bracing while nailing trusses to wall caps.