Here we have a wood framed gable roof.
Pitched roof rafter span table.
Anything beyond that you are looking at using 2x6s for most sheds.
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.
This will give us the span for each individual roof rafter.
Span calculator for wood joists and rafters also available for the android os.
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.
These span tables assume installation of at least three joists or rafters that are spaced not more than 24 on center.
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.
For pitched roofs flat roofs and ceiling joists.
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.
Floor beam span tables of residential structural design we will now look at roof rafter and beam design.
Click here for structural design calculations.
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.
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.
In areas with mild climates patio roofs are generally designed for loads of 30 psf pounds per square foot.
Surveyors span tables for designing roof rafters.
Also available for the android os.
The tables below give maximum spans for rafters and beams.
For heavy roofs or in areas with substantial snowfall or winds call your local building department for code requirements.
The calculated spans assume fully supported members properly sheathed and nailed on the top edge of the joist or rafter.
Straight line interpolation shall be permitted for intermediate spans and design values.
Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal.
The figures are based on quality materials.
