Plywood Roof Sheathing Maximum Span

A panel marked 32 16 may be used for roof sheathing over supports spaced up to 32 inches o c.

Plywood roof sheathing maximum span.

For face grain parallel to supports tables are based on three spans for spans of 16 and less and two spans for 24. For example if your roof is 1 500 ft 2 then it will take 47 sheets of plywood to sheath it. So dividing the area of the roof by 32 will give you the number of sheets needed. Panels and lap siding with a span rating of 16 oc may be applied direct to studs spaced 16 inches on center.

Span is permitted to be 24 inches on center where 3 4 inch wood strip flooring is installed at right angles to joist. The span rating on sheathing span panels appears as two numbers separated by a slash e g 32 16 or 48 24. Panels and lap siding bearing a span rating of 24 oc may be used direct to studs 24 inches on center. Tables 2a through 2c apply to apa rated osb sheathing apa rated osb structural i sheathing and apa rated osb sturd i floor respectively.

1 500 32 46 875 sheets. Always ensure your work site is compliant with current osha regulations. The tables do not apply directly to plywood having a single span. Use the two span condition for support spacing greater than 16 inches but no greater than 24 inches on center.

The second number is the maximum o c. Span is permitted to be 24 inches on center for floors where 1 1 2 inches of cellular or lightweight concrete is applied over the panels. That will suffice on a roof with rafters set 16 inches apart with minimal roof loads. Loads will vary with the pitch of the roof.

When the panel strength axis is placed parallel to framing supports the three span condition is used for support spacing up to and including 16 inches on center. Avoid roof complaints with proper framing sheathing and roofing techniques. For 1 2 inch panel maximum span shall be 24 inches. The first number is the maximum on center o c support spacing in inches for roof sheathing.

Table 1d applies to apa rated plywood structural i sturd i floor. A 4 8 sheet of plywood is 32 ft 2. For sanded plywood panels see table 3. Produced by apa the engineered wood association formerly the american plywood association in 1989.

The values given in tables 1 and 2 represent the maximum allowable loads for plywood or osb. Most roofs will be sheathed in plywood at least 3 8 inch thick. For face grain across supports and spans of 32 and less three spans are assumed and two spans for spans greater than 32.