Shed Roof Rafter Span Calculator

Half building width minus 1 2 ridge thickness.

Shed roof rafter span calculator.

The preview window displays a dimensioned side view of the shed roof. Rafter span tables use these tables to determine lengths sizes and spacing of rafters based on a variety of factors such as species load grade spacing and pitch. 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. Span calculator for wood joists and rafters 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. Also available for the android os. Allow for ridge thickness when determining rafter run to outer wall. Use the span tables below to determine allowable lengths of joists and rafters based on size and standard design loads.

See rafter run to outer wall calculator below. Click the button to calculate the stock size needed for this job. 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. Print full scale rafter cut templates and birdsmouth templates fold template over rafter to mark or cut through.

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 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. You can also use the wood beam calculator from the american wood council website to determine maximum rafter and joist lengths. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal.

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. This calculator is to be used as an estimating tool only. Anything beyond that you are looking at using 2x6s for most sheds.