How To Work Out The Slope Of A Roof

The horizontal distance in the ratio will be 12 while the vertical distance is the measurement you took from the rafters.

How to work out the slope of a roof.

Calculating roof slope is done by calculating the number of inches your roof slope rises vertically for every 12 inches it extends horizontally. Angle arctan pitch arctan 0 25 14. To do this you will need to write down the measurements that you have taken from the rafters. Calculate the roof pitch as the proportion of rise and run.

For example if your roof rises 7 inches for every 12 inches of horizontal run then your roof has a 7 in 12 pitch. Recalculate this value into an angle. Use a level against the underside of the rafter you re measuring to get the most accurate value. The most precise way to find the roof s slope is by measuring it from the underside.

Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m. The standard pitch of most residential roofs ranges between 4 in 12 and 9 in 12. The slope of your roof is the ratio of the vertical distance or rise of the roof to the horizontal distance or run. Access one of the rafters then take the measurement this way.

Square root width x width height x height slope length. Formula for calculating the slope the length of a slope is calculated using the pythagorean theorem. Finally you can find the roof pitch in the form of x 12.