Rafter Joist Construction Shed Roof Rafter Span Calculator

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.

Rafter joist construction shed roof rafter span calculator.

If you look at the rafter span chart you ll notice that 2x4s can be used for rafters on spans up to 11. Roof rise this should be calculated from the base of the roof to the highest point of the roof gable the peak. Allow for ridge thickness when determining rafter run to outer wall. 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.

The lengths and sizes of joists vary depending on the species and quality of the lumber used. For example you can span a 1 grade no knots southern yellow pine a greater distance than a 2 grade with knots southern yellow pine. Print full scale rafter cut templates and birdsmouth templates fold template over rafter to mark or cut through. Rafter and joist span faq.

The preview window displays a dimensioned side view of the shed roof. 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. 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. 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.

Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. Rafter length calculator calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement. See rafter run to outer wall calculator below. Anything beyond that you are looking at using 2x6s for most sheds.

Span calculator for wood joists and rafters also available for the android os. 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. Includes result for hip valley factor slope factor and the roof slope in degrees. Half building width minus 1 2 ridge thickness.

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.