Fixing roof trusses to a wall plate requires a small amount of carpentry knowledge, such as the abilities to read a tape measure and operate a framing square. Otherwise, setting roof trusses onto wall plates can be done by the average do-it-yourselfer, usually in one to two days, depending on the size and scope of the project.
Measure from one end of the wall plate, marking pencil lines at 60 cm (24 inch) increments until you reach the end. These marks will represent the centre of the roof truss. Using a speed square, square the marks across the wall plate and place an X on the marks. This will denote centre marks. Measure 2 cm (3/4 inch) to the left of each of these centre marks and place another square line. However, do not place an X. This line will represent the outer edge of the roof truss.
Place the bottom of the truss onto the wall plate, aligning the left edge of the truss with the edge marks placed on the wall plate for alignment. Make sure that the roof truss is aligned properly on each side of the wall plates. For example, when setting trusses, you will rest each of the two ends of the truss onto opposite walls, which have wall plates at the top of each wall.
Insert a 6 cm (3 1/2 inch) nail through the truss base where it sets on the wall plate. Drive the nail through at an angle, beginning the nail 5 cm (2 inches) up from the bottom of the truss. Insert an additional nail on the opposite side of the truss, adjacent the previous nail. Repeat on the opposite wall, and continue to set trusses until you reach the end of the wall plate.
Attach hurricane straps to the trusses where they attach to the wall plates. Attach the straps to the truss with short strap nails and then to the wall plate. These straps will help hold down the trusses in case of high winds.