Span Roof Rafters

The lengths and sizes of joists vary depending on the species and quality of the lumber used.

Span roof rafters. This calculator is to be used as an estimating tool only. Both of these are for light roof loads. So this table could accommodate a house with a total rafter span or house width of 32 feet. An syp rafter can span 11.

For example you can span a 1 grade no knots southern yellow pine a greater distance than a 2 grade with knots southern yellow pine. If you look at the rafter span chart you ll notice that 2x4s can be used for rafters on spans up to 11. Input the rafter span on the flat eave overhang and pitch of the roof. Wood beam calculator american wood council website rafter and joist span faq.

The 1 grade. 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. Live load is weight of furniture wind snow and more. 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.

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. More roof calculators roof truss calculator how to cut rafters. Dead load weight of structure and fixed loads 15 lbs ft 2. Span calculator for wood joists and rafters also available for the android os.

Also available for the android os. Click the button to calculate the stock size needed for this job. If you live in an area that requires a shed roof rafter to support a heavy load then an spf rafter can only span 7. As mentioned above a 2 4 spf shed roof rafter can span 11.

This rafter span calculator is species specific for douglas fir hemlock etc. 1 psf lb f ft 2 47 88 n m 2. Rafter stock size calculator. Douglas fir maximum horizontal roof rafter span for lumber grade selected structural and no.

The pitch and span of your roof will dictate how long of a rafter you ll need use maximum span calculator to help you find your rafter size. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. This is based upon the span of the rafter horizontal span not total rafter length live and dead loads. 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.

To size joists and rafters use the maximum span tables for southern yellow pine.