Pitched Roof Rafter Span Table

If you look at the rafter span chart you ll notice that 2x4s can be used for rafters on spans up to 11.

Pitched roof rafter span table.

These span tables assume installation of at least three joists or rafters that are spaced not more than 24 on center. The tables below give maximum spans for rafters and beams. 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. The calculated spans assume fully supported members properly sheathed and nailed on the top edge of the joist or rafter.

Click here for structural design calculations. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. The figures are based on quality materials. Here we have a wood framed gable 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. Floor beam span tables of residential structural design we will now look at roof rafter and beam design. In areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot. For pitched roofs flat roofs and ceiling joists.

Let s consider a basic gable wood roof framing design. 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. Straight line interpolation shall be permitted for intermediate spans and design values. 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.

Also available for the android os. The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. Surveyors span tables for designing roof rafters. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal.

For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2. Anything beyond that you are looking at using 2x6s for most sheds. Continuing on from part 3.