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.
Roof rafter sizes.
This calculator is to be used as an estimating tool only.
If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.
Clear span on plan.
Click the button to calculate the stock size needed for this job.
Here the number is 1166 66 inches.
For example in the rafter span table below the highlighted cell in the 40 live load table indicates that 2 x 8 southern yellow pine joists that have a grade of 2 that are spaced 24 apart can have a maximum span of 10 feet 3 inches 10 3 if designing for a live load of 40 lbs ft 2.
It is always better to have a large rafter rather than be concerned with a sagging roof.
Roof rise this should be calculated from the base of the roof to the highest point of the roof gable the peak.
This is the distance between rafter centres.
Usually 400 450 or 600mm but any value can be used up to 610mm max.
Input the rafter span on the flat eave overhang and pitch of the roof.
Rafter stock size calculator.
The full version allows any size.
This calculator is to be used as an estimating tool only.
Input the rafter span on the flat eave overhang and pitch of the roof.