Roof Rafter Span Table

Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch.

Roof rafter span table.

Rafter spans are tabulated for the most common roof loads. Maximum rafter spans for a patio roof in areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot. These 46 tables are based upon design values for visually graded southern pine dimension lumber that became effective june 1 2013. Rafter spans for southern yellow pine douglas fir and eastern spruce.

The spans in this table are based on a maximum supported rafter span of 16 feet where the supported span is the total horizontal distance spanned by the roof rafters divided in half not the diagonal distance or the length of the rafter. For pitched roofs flat roofs and ceiling joists. Total load psf duration factor live load psf roof type 55 1 15 40 snow shingle 55 1 15 30 snow tile 47 1 15 30 snow shingle 40 1 15 20 snow shingle 40 1 25 20 shingle construction or. For each application a pdf download is available.

Span configuration and load conditions. Surveyors span tables for designing roof rafters. View joist rafter tables. Click here for structural design calculations.

So this table could accommodate a house with a total rafter span or house width of 32 feet. Listed are 46 tables based on common loading conditions for floor joists ceiling joists and rafters. Visit the roof framing page for more information on cutting roof rafters and visit the roof pitch calculator for determining rafter lengths based on rise and run. Span calculator for wood joists and rafters also available for the android os.

Also available for the android os. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. Simplified maximum span tables for selected visual and mechanical grades of southern pine lumber in sizes 2 4 thru 2 12. Tables listing maximum spans for southern pine joists and rafters are detailed below.

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. Surveyors and structural engineers utilise data from tables below to help calculate the correct size strength and centres of roof timbers for the required spans and loadings. The shapes and spans shown here represent only a fraction of the millions of designs processed by alpine engineers.