Roof Sheathing Thickness

Roof sheathing conforming with this table shall be deemed to meet the design criteria of section 2304 7.

Roof sheathing thickness.

The minimum thickness of lumber roof sheathing should conform to table 1 below. Most builder s use 7 16 osb with clips if a heavy roof covering applied or called for on plans. Loads will vary with the pitch of the roof. You may be able to measure the thickness of the roof decking material with a simple ruler as seen in the photo below taken during an actual inspection.

1 inch 25 4 mm 1 pound per square foot 0 0479 kn m2. Sheathing should be a minimum of 19 32 inch thick. That s considered to be the minimum. The typical thickness range for sheathing is 3 8 to 3 4 inch.

Allowable spans for wood structural panels for roof sheathing. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads. Otherwise no clips just be sure to space all edges 1 8 as listed right on the sheathing label which goes down so the inspector can read it from inside it s also the waxed side which is safer. Roof sheathing thickness unlike with plywood siding the plywood sheet to be used for sheathing should be at least 3 8 inch thick.

This minimum will only work if the rafters are set 16 inches apart at most and if the roof doesn t have too much load.