DIY Installing a Roof Truss

Sort the trusses and place them in order, if they were not delivered that way. Locate two end trusses, which have more vertical supports than the internal trusses. Mark truss locations on both wall caps with a pencil or marker first, drawing lines 1 1/2 inches apart across the caps to show the truss location. Mark the first end truss at the back of the house with a line 1 1/2 inches in.

Mark the second truss location by measuring 23 1/4 inches from the end wall to draw the outside line; this will space trusses 24 inches apart on centers. Make a second line with the 1 1/2-inch spacing, then mark 1 1/2-inch truss locations at 24-inch intervals the length of the wall. Go back to the rear wall and mark the other cap identically. The last truss mark on both sides may be slightly less than 24 inches.

Lift an end truss to the roof, upside down, and have workers on the roof set it upright and plumb it vertically. Use scaffolding for two workers outside the walls to lift the trusses or lift them with lifting poles high enough that roof workers can get them. Nail the truss ends to the wall caps with a hammer and framing nails driven diagonally, two nails on one side, one nail on the other. Nail 2-by-4-inch boards to the outside of the trusses and to stakes in the ground outside to brace it.

Raise other trusses the same way, always upside down for roof workers to erect. Install temporary purlins, 1-by-4-inch boards nailed across the trusses to brace them laterally, starting with the third truss and every three thereafter. Work down the roof until the other end truss is set, always making sure each truss is plumb vertically. Place a ridge board in slots at the tops of the trusses, if that is called for; otherwise install permanent purlins across the bottom chords of the truss to hold them.

Install hurricane clips on the outside edges of all trusses. These are metal brackets which are nailed to the wall cap boards and to the truss rafters with galvanized nails, to hold trusses more securely.