Roof Sheathing Should Be Installed

If the top chords of trusses or rafters are warped or bowed install blocking to straighten.

Roof sheathing should be installed.

Sheathing should be a minimum of 19 32 inch thick. Trusses or rafters should be shimmed as necessary to provide a level nailing surface. For plywood composite or osb boards installed on rafters it should be at least 5 8ths of an inch thick. 8d ring shank nails should be used instead.

Slide the sheet one rafter width over the end of the roof so the edge is centered on the next rafter offset one rafter spacing from the first piece of installed sheathing from the row below. This can be done with a straight piece of lumber 6 feet to 10 feet long or a long carpenter s level. There should be at least 3 8 inch of space between the fastener and the panel edge. Tongue and groove installations require thicker material at least 1 1 2 inches thick as they don t often require insulation and often double as the ceiling.

Local roof repair contractors inspect the sheathing during maintenance repairs and especially during roof replacement. Never attach roof sheathing with staples. 24 inches on center the actual distance between panel supports measured along the slope is greater than the truss spacing. Roof sheathing comes in grid marked 4 by 8 foot sheets and should be installed perpendicular to the frame.

In areas where the wind speed is greater than 130 mph nails for attaching the roof sheathing to intermediate supports should be spaced 6 inches on center for at least the first 48 inches from the ridges eaves and gable end walls. The first thing we check is the thickness of the material used. Sheathing is installed perpendicular to roof trusses.