How to Install Wood Trusses

Measure from each point to each point where the "heels" of the trusses need to land on their cap plates (weight supports), using a tape measure, and mark those spots with the grease pencil. Because the truss structure is commonly fastened at 24-inch intervals, start by marking in one corner of the roof, and then every 2 feet from there, to the far side. Mark the last spot on the far end as well.

Lift the trusses wherever you are most comfortable; that is, from the scaffold, the roof, or the ground. Arrange all the helpers for maximum strength, and together, lift up the first truss and lay it on the roof with its base nearest to the cap plates. Assemble everyone around it and push up from underneath to stand it into its place onto the cap plates, at the far edge of the building from where you're lifting.

Create temporary braces going up and down, and diagonally, by nailing 2-by-4 inch studs onto the structure of the truss with a hammer and supporting the braces' ends on the roof. The number that you need depends on the length of the roof and the weight of the truss, but use more than you think you need--a strong wind or incorrect placement can knock down your hard work. Repeat this procedure with the second truss.

Lift the third truss into place on its plates and brace it with studs, but do not nail them into the frame as you did for the first two pieces. Follow this procedure with the remaining trusses until you reach the far end of the roof.