Shed Roof Rafter Span Calculator

Anything beyond that you are looking at using 2x6s for most sheds.

Shed roof rafter span calculator.

Allow for ridge thickness when determining rafter run to outer wall. Print full scale rafter cut templates and birdsmouth templates fold template over rafter to mark or cut through. This calculator is to be used as an estimating tool only. The run for a lean to shed rafter ending into a wall should account for the ridge board nailed into the wall where the tops of the rafters rest into.

Half building width minus 1 2 ridge thickness. See rafter run to outer wall calculator below. Span calculator for wood joists and rafters also available for the android os. 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.

If you look at the rafter span chart you ll notice that 2x4s can be used for rafters on spans up to 11. In other words if there is a 1 1 2 ridge board nailed into the wall and the width of the lean to is 96 then the run will be 94 1 2 96 1 1 2 94 1 2. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. Rafter length using pitch v r 2 sqrt 1 p 2 where v overhang r roof span p pitch use our online rafter length calculator to quickly compute the length of the shed roof rafter by entering the measurements of overhead length of roof span pitch or angle.

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 preview window displays a dimensioned side view of the shed roof. To calculate a shed roof select shed from the roof type dropdown list or click on the corresponding button on the toolbar to calculate a shed roof. Also available for the android os.

Click the button to calculate the stock size needed for this job. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. Input the rafter span on the flat eave overhang and pitch of the roof.