Roof Sheathing Thickness Requirements

1 inch 25 4 mm.

Roof sheathing thickness requirements.

Over spaced sheathing no underlayment is used except at the eaves if eaves flashing is required. Sheathing should be a minimum of 19 32 inch thick. 7 construction exceeding the minimum requirements6 osb or plywood is the minimum you can use without edge support. 8d ring shank nails should be used instead.

Allowable spans for lumber floor and roof sheathing a b for si. Roof sheathing shall be structural wood panels plywood osb with a minimum five eighths inch thickness grade stamped for use and span. Loads will vary with the. N the highest uplift forces occur at roof corners edges and ridge lines.

Floor or roof sheathing conforming with this table shall be deemed to meet the design criteria of section 2304 7. The typical thickness range for sheathing is 3 8 to 3 4 inch. Roof sheathing comes in grid marked 4 by 8 foot sheets and should be installed perpendicular to the frame. Over solid sheathing use minimum no.

N improved fasteners such as ring shank nails increase the uplift resistance of the roof sheathing. The rsrs designation indicates the fastener is a ring shank roof sheathing nail. 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.

Roof sheathing panel spacing hints. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads. Minimum thickness most roofs will be sheathed in plywood at least 3 8 inch thick. Requirements for coastal construction are typically different than for non coastal areas.

Spacer type panel edge clips are available from some manufacturers. 30 felt lapped at least 3 inches horizontally and 6 inches at end laps. Installation details shall conform to sections 2304 7 1 and 2304 7 2 for floor and roof sheathing respectively. Never attach roof sheathing with staples.