Rafter Joist Construction Shed Roof Rafter Span Calculator

Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal.

Rafter joist construction shed roof rafter span calculator.

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. Span calculator for wood joists and rafters also available for the android os. Roof rise this should be calculated from the base of the roof to the highest point of the roof gable the peak. See rafter run to outer wall calculator below.

The preview window displays a dimensioned side view of the shed roof. If you look at the rafter span chart you ll notice that 2x4s can be used for rafters on spans up to 11. Rafter run outer wall this should be measured starting from the center of the roof span and then extending to the very edge of the exterior wall. Includes result for hip valley factor slope factor and the roof slope in degrees.

If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length. 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. 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. Rafter and joist span faq.

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. Here the number is 1166 66 inches. 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. The lengths and sizes of joists vary depending on the species and quality of the lumber used.

Anything beyond that you are looking at using 2x6s for most sheds. Also available for the android os. Half building width minus 1 2 ridge thickness. 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.

Print full scale rafter cut templates and birdsmouth templates fold template over rafter to mark or cut through.