How To Work Out The Slope Of A Roof

For example if your roof rises 7 inches for every 12 inches of horizontal run then your roof has a 7 in 12 pitch.

How to work out the slope of a roof. Formula for calculating the slope the length of a slope is calculated using the pythagorean theorem. The slope of your roof is the ratio of the vertical distance or rise of the roof to the horizontal distance or run. Use a level against the underside of the rafter you re measuring to get the most accurate value. Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m.

Access one of the rafters then take the measurement this way. This theorem is done by multiplying the square s square root by the sum of the squared width and the squared height. Locate the level s 12 inch mark. Angle arctan pitch arctan 0 25 14.

Finally you can find the roof pitch in the form of x 12. Recalculate this value into an angle. The standard pitch of most residential roofs ranges between 4 in 12 and 9 in 12. Calculate the roof pitch as the proportion of rise and run.

Calculating roof slope is done by calculating the number of inches your roof slope rises vertically for every 12 inches it extends horizontally. Pitch rise run 1 5 6 25. The most precise way to find the roof s slope is by measuring it from the underside.