Roof Sheathing Thickness

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.

Roof sheathing thickness.

That s considered to be the minimum. The minimum thickness of lumber roof sheathing should conform to table 1 below. Sheathing should be a minimum of 19 32 inch thick. Most builder s use 7 16 osb with clips if a heavy roof covering applied or called for on plans.

Allowable spans for wood structural panels for roof sheathing. The typical thickness range for sheathing is 3 8 to 3 4 inch. Uniform load deflection limitations 1 180 of span under live load plus dead load 1 240 under live load only. Most roofs will be sheathed in plywood at least 3 8 inch thick.

Roof sheathing conforming with this table shall be deemed to meet the design criteria of section 2304 7. 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 comes in grid marked 4 by 8 foot sheets and should be installed perpendicular to the frame. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads.

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.