Pitched Roof Rafter Spans

For roofs that won t experience heavy snow loads a gable roof can span up to 22 with 2 4 rafters.

Pitched roof rafter spans. Input the rafter span on the flat eave overhang and pitch of the roof. Here we have a wood framed gable roof. If you look at the rafter span chart you ll notice that 2x4s can be used for rafters on spans up to 11. Our roof rafter calculator tools are handy for calculating the number of rafters needed rafter length calculator lineal feet of rafter board feed in ridge and sub facia and the total board feet in the roof.

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. 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. The following tables give details of the allowable spans and spacing for some of the more common timber sizes used in traditional roofing construction. For roofs that will experience heavy snow or wind and will span the same distance use 2 6 rafters.

Span calculator for wood joists and rafters also available for the android os. 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. You can use either 2 6 or 2 4 rafters for roofs with a 3 12 pitch or greater but it depends on the overall size of your shed. For pitched roofs flat roofs and ceiling joists.

This calculator is to be used as an estimating tool only. Floor beam span tables of residential structural design we will now look at roof rafter and beam design. The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. Continuing on from part 3.

Area span on the flat please enter area span on the flat in foot. 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. All the figures are based on roofing tiles or slates laid on timber laths over sarking felt. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal.

Surveyors span tables for designing roof rafters. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. Pitched roof timber sizes. Anything beyond that you are looking at using 2x6s for most sheds.

Click the button to calculate the stock size needed for this job. Maximum clear span of rafters in metres for roof pitches of between 15.