How To Estimate Roof Pitch

It is often compared to slope but is not exactly the same.

How to estimate roof pitch.

Roof pitch calculator results explained slope the slope of a roof is represented as x 12 where x is the number of inches in rise for every 12 inches of run. Divide the slope by two to get the pitch. Generally roof pitch is calculated from the same formula that describes a right triangle. Rise run pitch where pitch is expressed in percent.

As aforementioned there is no standard pitch of a roof. How to calculate roof pitch. How roof pitch is calculated to accurately calculate the area of your roof you must first determine its slope or pitch. You can use the following equations to find the length of the rafter and the slope.

Thus a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs. This is very useful information for many purposes especially for roof framing the slope sometimes called pitch is calibrated on speed squares. For a simple gable roof the span wall to wall will be twice the size of the run wall to ridge horizontally. A roof s pitch is determined by how much it rises vertically for every foot it runs horizontally.

Then in the attic place the end of the level against the bottom of a roof rafter and hold it perfectly level. You ll need a level that is 12 or longer and a tape measure. In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches. Express roof pitch as the ratio of the amount of the vertical rise of a roof or rise over the corresponding horizontal distance or run you write the pitch assuming a run of 12 inches thus the ratio would describe how much a roof rises for each foot of the run.

If you do need to calculate the pitch an estimate or shortcut is usually more practical than measuring the roof s overall dimensions. Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run. One method to find the pitch is to climb on the roof and measure the rise for a 12 run. Rafter rise run from the pythagorean theorem.

Here are a couple examples.