This sizing guide for roof rafters will help determine what you need for your small project.
Rafter size for 3 12 roof.
Input the rafter span on the flat eave overhang and pitch of the 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.
At this point you ve cut 1 roof rafter.
It is one of a series of sloped structural members that extend from the ridge or hip to the wall plate designed to support the.
Here the number is 1166 66 inches.
Snow load 2x6 rafters 16 centers garage 17 long 11 read more.
Roof rise this should be calculated from the base of the roof to the highest point of the roof gable the peak.
Weather you re building a shed roof or adding a dormer to your second story it is important to choose the proper size rafter.
All roof rafters should be identical so follow the same steps to measure the plumb cut tail cut and birdsmouth cut.
Click to add item 24 spreadweb residential roof truss 5 12 pitch 87 to the compare list compare click to add item 24 spreadweb residential roof truss 5 12 pitch 87 to the compare list add to list click to add item 24 spreadweb residential roof truss 5 12 pitch 87 to your list.
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.
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.
Rise and run means that a 6 12 pitch roof has 6 of rise vertical for each foot of run horizontal.
There could be many rafters supporting a roof.
Shed roof 2 12 slope.
If you re building rafters and aren t sure where to start when determining the length of your lumber you re in the right place our rafter stock size calculator shows you how long your rafters should be so you ll know what you need in terms of framing lumber dimensional lumber studs and more.
Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement.
Repeat the process for your other rafters.
Click the button to calculate the stock size needed for this job.
This calculator is to be used as an estimating tool only.
Depending on the size of your structure you will need to cut several or many more.
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.
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.
Just enter the dimensions of the roof rise and run to get started.
