How Thick Should Roof Sheathing Be

The answer depends mostly on how far apart the rafters are and the roof loads which vary based on the pitch of your roof.

How thick should roof sheathing be.

Sheathing should be a minimum of 19 32 inch thick. While many of the roofing shingle courses will land on the 7 1 2 increment there can be entire courses of unsecured shingles that line up on cracks in the shiplap. In this case plywood should be a minimum of 3 8 inch thick. You may see 3 8 inch plywood installed as roof sheathing and although it may feel inadequate compared to 1 2 inch plywood installed on rafters spaced 24 inches on center 3 8 inch plywood was at one time considered acceptable in some jurisdictions.

Roof sheathing comes in grid marked 4 by 8 foot sheets and should be installed perpendicular to the frame. An exception to this standard however may occur if you intend to install slate concrete or tile shingles on your roof. 8d ring shank nails should be used instead. Roof sheathing standard roof sheathing which consists of 4 by 8 sheets of plywood or oriented strand board or osb is 1 2 inch thick and attaches directly to the roof rafters or the roof trusses.

That s considered to be the minimum. Never attach roof sheathing with staples. Loads will vary with the pitch of the roof. The typical thickness range for sheathing is 3 8 to 3 4 inch.

The typical thickness of roof sheathing is about 7 16 inch which is just under 1 2 inch. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads. Roof sheathing thickness unlike with plywood siding the plywood sheet to be used for sheathing should be at least 3 8 inch thick. Minimum plywood thickness the international residential code specifies 3 8 inch plywood for sheathing walls with a standard stud spacing of 16 inches if the siding is nailed to the studs through.

You need to find a sheathing with a span rating of at least 32 16 which means either 15 32 or 1 2 thick osb. The most common scenario is a home that has rafters set approximately 16 inches apart. Creating a solid substrate. Wind gusts can then blow these poorly fastened shingles off your roof.