Pitched Roof Rafter Span Table

Continuing on from part 3.

Pitched roof rafter span table.

Surveyors span tables for designing roof rafters. 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. The tables below give maximum spans for rafters and beams. Anything beyond that you are looking at using 2x6s for most sheds.

For pitched roofs flat roofs and ceiling joists. Floor beam span tables of residential structural design we will now look at roof rafter and beam design. Let s consider a basic gable wood roof framing design. The figures are based on quality materials.

This will give us the span for each individual roof rafter. Here we have a wood framed gable roof. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. Click here for structural design calculations.

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. 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 image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. 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.