Plywood Roof Sheathing Span Rating

The span rating on apa rated sturd i floor underlayment and apa rated siding panels appears as a single number.

Plywood roof sheathing span rating.

Panels are available that carry apa series mobile home roof sheathing rating n 216r. Uniform loads psf on apa rated plywood sheathing. Loads will vary with the pitch of the roof. Commonly square edge but may be produced with tongue and groove edges.

Allowable load at maximum span. Panels and lap siding with a span rating of 16 oc may be applied direct to studs spaced 16 inches on center. 2 4 common performance categories and corresponding span ratings performance category span rating 3 8 24 0 7 16 24 16. Typical size is 4 ft x 8 ft but other sizes may also be produced.

All rated siding panels may be applied horizontally direct to studs 16 or 24 inches on center provided horizontal joints are blocked. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads. Sheathing panels 3 8 category may be installed perpendicular or parallel to supports spaced a maximum of 16 o c and will support a 30 psf live load without exceeding a deflection limit of 1 180. Panels and lap siding bearing a span rating of 24 oc may be used direct to studs 24 inches on center.

Most roofs will be sheathed in plywood at least 3 8 inch thick. Multi span normal duration of load dry conditions panels 24 inches or wider span rating b load governed by c strength axis a perpendicular to supports span center to center of supports inches parallel to supports span center to center of supports inches 12 16 19 2 24 30 32 36 40 48 60 12 16 24. The span ratings for apa rated sturd i floor and underlayment panels like those for apa rated sheathing are based on application of the panel with the long dimension or strength axis across three or more supports.