How Do I Figure The Pitch Of A Roof

First measure 12 inches from one end of the level and make a mark.

How do i figure the pitch of a roof.

Then in the attic place the end of the level against the bottom of a roof rafter and hold it perfectly level. One method to find the pitch is to climb on the roof and measure the rise for a 12 run. Pitch is the incline of the roof represented as the ratio of rise to the span twice the run. Finally enter the value of the rafter length and.

Let s say it is equal to 1 5 m. Calculate the rafter length substituting these values. 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. If this distance measures 4 inches you have a 4 in 12 pitch.

You ll need a level that is 12 or longer and a tape measure. For example if you used a 24 inch level and your measurement was 12 inches the pitch in your roof is 6 in 12. Measure the run length it is the horizontal distance between the roof ridge and the wall of the building. Here are the steps to follow for the roof angle calculator.

Let s assume it is equal to 6 m. On a ladder beside the roof place the level a foot or so up the roof hold it level and measure from the 12 inch mark on the level s bottom straight down to the roof. Here are a couple examples. The picture below shows the pitch of a 7 12 roof slope meaning that for 12 of horizontal measurement roof run the vertical measurement roof rise is 7.

For a simple gable roof the span wall to wall will be twice the size of the run wall to ridge horizontally. Divide the slope by two to get the pitch. Here s an easy safe way to determine the pitch from inside your attic. Divide the results by the number of 12 inch segments in your level.

Roof slope calculator example of use. If you do need to calculate the pitch an estimate or shortcut is usually more practical than measuring the roof s overall dimensions. Measure the rise of your roof. For example if the roof rises 4 feet and the span is 16 feet twice the run then the pitch is 4 16 or 1 4.

Then enter the value of the run and choose the unit of measurement from the drop down menu. 8 inches and you have an 8 in 12 pitch. This measurement is best done on a bare roof because curled up roofing shingles will impair your measurement. To measure the roof pitch you ll need an 18 or 24 inch level a tape measure and a pencil.