How To Find Pitch Of Existing Roof

If you need to find the pitch of an existing roof all you need is a level and a tape measure.

How to find pitch of existing roof. Let s say it is equal to 1 5 m. Now it is 3 12 and can be written as 25 or 14. First measure 12 inches from one end of the level and make a mark. Put again this value into an angle.

How to measure roof pitch to measure the roof pitch you ll need an 18 or 24 inch level a tape measure and a pencil. Then in the attic place the end of the level against the bottom of a roof rafter and hold it perfectly level. Use a level against the underside of the rafter you re measuring to get the most accurate value. Angle arctan pitch arctan 0 25 14.

Compute the roof pitch as the percentage of rise and run. For a roof with the ridge above one wall the span is the same as the run. The slope is the same as the pitch. Lastly you can have the roof pitch in the form of x 12.

The most precise way to find the roof s slope is by measuring it from the underside. Measure the rise of your roof. Access one of the rafters then take the measurement this way. Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m.

For more complex roofs you may need to calculate it section by. For a simple gable roof the span wall to wall will be twice the size of the run wall to ridge horizontally. Calculate the roof pitch as the proportion of rise and run. Locate the level s 12 inch mark.

On the roof hold the level perfectly level and measure the height from the roof to the level 12 inches away from where the level touches the surface this will be the rise. X pitch 12 0 25 12 3. Working from the interior side of the roof you ll need access to a roof rafter to measure the pitch. One method to find the pitch is to climb on the roof and measure the rise for a 12 run.

Place the level horizontally along the rafter until it contacts the roof sheathing avoiding any protruding roof nails. Calculate the rafter length substituting these values into the following formula.