Roof Sheathing Tables

The loads are based on adjusted roof snow loads from the governing building code.

Roof sheathing tables.

R803 2 3 installation wood structural panel used as roof sheathing shall be installed with joints staggered in accordance with section r803 2 3 1 for wood roof framing or with table r804 3 for cold formed steel roof framing. For sanded plywood panels see table 3. Maximum 19 percent moisture content. Floor or roof sheathing conforming with this table shall be deemed to meet the design criteria of section 2304 7.

The maximum allowable spans for wood structural panel roof sheathing shall not exceed the values set forth in table r503 2 1 1 1 or apa e30. For example if the roof pitch is 45 then sec 45 1. The primary axis is applied perpendicular to roof trusses spaced 24 inches on center. A strong resilient roof is a home s first line of defense when the roof deck is exposed to weather.

If you know the roof pitch in degrees find the secant of the slope using a scientific calculator. This video may depict some work practices that do not meet current safety standards. 8d ring shank nails should be used instead. Produced by apa the engineered wood association formerly the american plywood association in 1989.

Table 9 1 in span tables for joists and rafters figure 5 gives a required compression value of 237 psi for a span of 16 feet and bearing length of 1 5 inches. The typical thickness range for sheathing is 3 8 to 3 4 inch. Table 2304 7 2 sheathing lumber minimum grade requirements. Always ensure your work site is compliant with current osha regulations.

The tables permit a bearing length of up to 3 5 inches but since 1 5 is probably the worst case that you ll encounter for joist or rafter bearing it s a safe value. Avoid roof complaints with proper framing sheathing and roofing techniques. Sheathing should be a minimum of 19 32 inch thick. Determine allowable uniform live load and total load for 1 2 structural 1 sheathing 32 16 advantech vip for application in a roof system subject to snow loads.

Table 1d applies to apa rated plywood structural i sturd i floor. Roof sheathing comes in grid marked 4 by 8 foot sheets and should be installed perpendicular to the frame. For roof live loads less than 20 pounds per square foot psf rafter spans and required e values tabulated for 20 psf shall be permitted to be adjusted in accordance with the fol lowing table. Zip system roof assembly combines our revolutionary integrated sheathing and flashing tape or liquid flashing to provide a sealed roof for protection against moisture intrusion during construction or if high winds strip the roof covering away.

The following table provides the roof pitch multiplier for roofs of various slopes. For a more detailed explanation of the roof pitch multiplier see how to find the area of a sloped roof. The values given in tables 1 and 2 represent the maximum allowable loads for plywood or osb. 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.