This calculator is to be used as an estimating tool only.
Roof rafter sizes.
Clear span on plan.
Here the number is 1166 66 inches.
Rafter stock size calculator.
This calculator is to be used as an estimating tool only.
It is always better to have a large rafter rather than be concerned with a sagging roof.
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.
Here the number is 941 86 inches.
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.
The full version allows any size.
Rafter slope min 15 max 45 degrees.
This is the distance between rafter centres.
If your project had a rafter length of 8 or less a safe and strong method is to use 2x8 framed 16 on center.
Roof rise this should be calculated from the base of the roof to the highest point of the roof gable the peak.
Input the rafter span on the flat eave overhang and pitch of the roof.
Input the rafter span on the flat eave overhang and pitch of the roof.