Pitched Roof Rafter Span Table

In areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot.

Pitched roof rafter span 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 figures are based on quality materials. 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.

If you look at the rafter span chart you ll notice that 2x4s can be used for rafters on spans up to 11. The tables below give maximum spans for rafters and beams. 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. These span tables assume installation of at least three joists or rafters that are spaced not more than 24 on center.

Let s consider a basic gable wood roof framing design. Anything beyond that you are looking at using 2x6s for most sheds. Surveyors span tables for designing roof rafters. Click here for structural design calculations.

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. For pitched roofs flat roofs and ceiling joists. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial.

Floor beam span tables of residential structural design we will now look at roof rafter and beam design. Continuing on from part 3. Straight line interpolation shall be permitted for intermediate spans and design values. Span calculator for wood joists and rafters also available for the android os.

Here we have a wood framed gable roof. This will give us the span for each individual roof rafter. The calculated spans assume fully supported members properly sheathed and nailed on the top edge of the joist or rafter.