Measure the distance of the roof and determine how many trusses you need to make for installation. Run a tape measure across the width of the roof and record the total measurement in inches. Divide that number by 16, which is how far apart the trusses will be spaced to get the number you will need to construct.
Lay out the metal truss pieces and cut off the ends of each piece at a 45-degree angle, one going in each direction with a hacksaw. Measure and mark the desired cut location with a black marker and cut carefully along the mark at the 45-degree angle. Butt the two pieces together to verify they fit. These pieces will butt together at the top of the roof.
Butt the two pieces together so the two 45-degree angles are pushing into one another and screw them together with a metal strap. Place the metal strap on each end of the pieces and attach the two together with sheet metal screws and a power drill through the pre-drilled holes.
Measure out 16 inches from the end of the roof on both sides and mark the location with a black marker. Stand up the piece you just constructed and have a helper walk it up to the roof on one side while you hold the other. Position the piece along the marks on each side.
Screw the truss to the horizontal plates underneath with a power drill and sheet metal screws. Insert two screws on each side of the truss you constructed and repeat the process for the truss on the other side. Make all of the remaining trusses in the exact same manner.