Pitched Roof Rafter Span Table

This will give us the span for each individual roof rafter.

Pitched roof rafter span table.

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

Click here for structural design calculations. These span tables assume installation of at least three joists or rafters that are spaced not more than 24 on center. For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements. 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.

3265 45 3220mm total span less ridge thickness 3220 2 1610mm horizontal span each rafter will cover and before meeting the ridge now when we turn to the 30 page in the rafter ready reckoner and when looking up the common rafter lengths one of the things it tells us is. The calculated spans assume fully supported members properly sheathed and nailed on the top edge of the joist or rafter. Also available for the android os. If you look at the rafter span chart you ll notice that 2x4s can be used for rafters on spans up to 11.

Anything beyond that you are looking at using 2x6s for most sheds. 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. Let s consider a basic gable wood roof framing design. Continuing on from part 3.

The image below shows a cross section of our simple 12 x 13 house from the joist span tables section of this tutorial. Straight line interpolation shall be permitted for intermediate spans and design values. 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. Here we have a wood framed gable roof.

The figures are based on quality materials. 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.