Shed Roof Rafter Size Calculator

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.

Shed roof rafter size calculator.

This sizing guide for roof rafters will help determine what you need for your small project. 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. 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. This calculator is to be used as an estimating tool only.

Enter this measurement into the calculator and select a roof pitch and the length of the rafter will automatically returned along with the rise. 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. Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter. Includes result for hip valley factor slope factor and the roof slope in degrees.

Allow for ridge thickness when determining rafter run to outer wall. Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal. Input the rafter span on the flat eave overhang and pitch of the roof. 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. Span calculator for wood joists and rafters also available for the android os. There are several variables to consider when determining the proper rafter size. Click the button to calculate the stock size needed for this job.

Half building width minus 1 2 ridge thickness. 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. Print full scale rafter cut templates and birdsmouth templates fold template over rafter to mark or cut through. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length.