Rise Over Run Roof

3 of rise per 12 of run is the same as 1 of rise per 4 of run or 1 4 25.

Rise over run roof.

The run is the distance from the outside of the wall to the inside of the ridge. This will give you the rise over run or pitch. Why is the roof slope 25. The horizontal change in distance or the horizontal distance covered by an un supported rafter or truss.

Here is an online rise and run calculator which helps to calculate pitch slope and angle with the help of rise and run values. Total roof rise or change in elevation for a 38 degree sloping roof angle t with one giant rise or step of 7 8 feet to the center of the attic y 2 would have total a run x 2 of 10 feet. Pitch is written assuming a run of a foot or 12 inches so the ratio describes how much the roof rises for every foot of its run. On a 38 degree sloping roof angle t each individual vertical rise of 9 4 y 1 would have a horizontal run x 1 of 12 inches.

Last updated july 10 2020 the following table shows the roof pitch rise in run equivalents for all roof slopes in degrees from 1 to 72. That s the same as a 14 degree slope or a 25 slope. The same pitch is also sometimes written as 4 12 4 in 12 or 4 over 12. For example a roof that rises 4 inches for every 12 inches of run has a 4 12 pitch.

A 3 in 12 roof rises 3 for every 12 of run. In roof pitch calculator pitch value can be obtained by dividing n by 12 and divide s by the answer. Other than the 45 roof slope which is 12 in 12 none of the standard roof pitches 5 in 12 6 in 12 etc are equal to a whole degree.