How Do I Figure Out The Pitch Of A Roof

Rafter rise run from the pythagorean theorem.

How do i figure out the pitch of a roof. For example if you used a 24 inch level and your measurement was 12 inches the pitch in your roof is 6 in 12. Roof pitch refers to the amount of rise a roof has compared to the horizontal measurement of the roof called the run. This free roof pitch calculator will take your roof width see the picture and rise the height of the roof and will calculate the roof pitch both as numeric value. 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.

Here are a couple examples. Divide the slope by two to get the pitch. The roof pitch measures the steepness of your shed roof and typically takes values from 1 to 12. Here s an easy safe way to determine the pitch from inside your attic.

You ll need a level that is 12 or longer and a tape measure. Pitch is the incline of the roof represented as the ratio of rise to the span twice the run. If your roof pitch is greater than 3 your roof is considered pitched read more about roof pitch at wikipedia. You can assess this in two ways either as the roof pitch angles which the rafters make with the horizontal or the proportion between the run and the rise of the roof.

Rise run pitch where pitch is expressed in percent. For a simple gable roof the span wall to wall will be twice the size of the run wall to ridge horizontally. Often you express roof pitch as the ratio between the rise and the run in the form of x 12. How to calculate roof pitch.

To measure the roof pitch you ll need an 18 or 24 inch level a tape measure and a pencil. First measure 12 inches from one end of the level and make a mark. Generally roof pitch is calculated from the same formula that describes a right triangle. If you do need to calculate the pitch an estimate or shortcut is usually more practical than measuring the roof s overall dimensions.

Then in the attic place the end of the level against the bottom of a roof rafter and hold it perfectly level. You can use the following equations to find the length of the rafter and the slope. One method to find the pitch is to climb on the roof and measure the rise for a 12 run. 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.

Divide the results by the number of 12 inch segments in your level.