Roof Sheathing Thickness Requirements

Roof sheathing shall be structural wood panels plywood osb with a minimum five eighths inch thickness grade stamped for use and span.

Roof sheathing thickness requirements. N the highest uplift forces occur at roof corners edges and ridge lines. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads. Requirements for coastal construction are typically different than for non coastal areas. Never attach roof sheathing with staples.

Allowable spans for lumber floor and roof sheathing a b for si. The typical thickness range for sheathing is 3 8 to 3 4 inch. Where the sheathing thickness is greater than 15 32 inches roof sheathing is required to be fastened with astm f1667 rsrs 03 2 0 131 nails or astm f1667 rsrs 04 3 0 120 nails. N improved fasteners such as ring shank nails increase the uplift resistance of the roof sheathing.

Spacer type panel edge clips are available from some manufacturers. 8d ring shank nails should be used instead. Roof sheathing comes in grid marked 4 by 8 foot sheets and should be installed perpendicular to the frame. Some departments do not have the man power to do roof sheathing inspection inspectors can not see everything and assume that the builder knows enough to do some things right.

Installation details shall conform to sections 2304 7 1 and 2304 7 2 for floor and roof sheathing respectively. Sheathing type typically 15 32 inch or thicker panels are required in high wind areas. Minimum thickness most roofs will be sheathed in plywood at least 3 8 inch thick. Sheathing should be a minimum of 19 32 inch thick.

30 felt lapped at least 3 inches horizontally and 6 inches at end laps. Secure roof sheathing panels to the roof framing with 8d common nails spaced six inches on center at the edges and twelve inches on center at intermediate supports. Use a 10d box 0 128 inch by 3 inch nail as a spacer to gauge 1 8 inch edge and end spacing between panels. Over solid sheathing use minimum no.

Floor or roof sheathing conforming with this table shall be deemed to meet the design criteria of section 2304 7. The rsrs designation indicates the fastener is a ring shank roof sheathing nail. Loads will vary with the. Over spaced sheathing no underlayment is used except at the eaves if eaves flashing is required.