How to Set Plywood on Trusses

This plywood is being prepped for installation.

Installing plywood onto roof trusses requires a series of tried and true methods that have been established by the roofing construction industry. Because these methods have been refined, it is now possible for the do-it-yourselfer to install plywood onto trusses with little difficulty. The homeowner with average skills can complete this project in one to two days, depending on the size and scope of the project.

Things You'll Need

• 1/2-inch plywood
• Plywood clips
• 8 penny nails

Instructions

1. Measure up 48 inches from the bottom of the trusses and place a mark on each end of the roof. This mark represents the first row of plywood and must be straight so that the remaining rows will be straight. Snap a chalkline across the roof trusses, connecting these two marks.

2. Lay down the plywood beginning from the left side of the roof trusses. Place the smooth side of the plywood facing up and the rough side of the plywood facing down. Attach the plywood using 8 penny nails, spacing the nails 12 inches apart from bottom to top and 24 inches apart from left to right of the plywood. The nail pattern differs because the trusses are spaced 24 inches apart.

3. Place 1/2-inch plywood clips across the top edge of the plywood every 12 inches, beginning 12 inches from the left end of the plywood. These clips will help strengthen the plywood in between the roof trusses where there is no support.

4. Cut one sheet of plywood in half. This will give you two 48-by-48-inch plywood sheets. Place one of these sheets on the nest row above, beginning from the left end. This sheet will allow the plywood joints to stagger, thus strengthening the entire installation. The last sheet of this row may be more than 48 inches---since you made the first sheet 48 inches. If so, then use a whole sheet and cut it off at the correct length. Place clips on the top edge of this row of plywood and begin the next row above from the left end of the roof with a whole sheet of plywood. This will keep the plywood joints staggered. Continue laying the plywood down in staggered lengths---4 and 8 feet---until you have covered the roof trusses on both sides of the roof.

References

• "Wood-Frame House Construction"; Gerald E. Sherwood, Robert C. Stroh;1990
• "Do-It-Yourself Housebuilding: The Complete Handbook "; George Nash;1995