Math Formula For Roof Pitch

Roof pitch is expressed in ratios of 12 because it is measured by the foot.

Math formula for roof pitch.

Rise and run formula. The pitch value can be obtained by dividing n by 12 and divide s by the answer. Obtain the pitch or slope angle of a roof by calculating the ratio of the change in the roof s height to the corresponding horizontal distance. Let s say it is equal to 1 5 m.

Calculate the roof pitch as the proportion of rise and run. Therefore if a roof rises four inches for every 12 inches of horizontal distance it has a 4 in 12 pitch. Pitch is a simple ratio of the rise to the run of the roof. For example a roof with a 6 12 pitch rises 6 inches for every horizontal foot.

Other formulas needed to work with roofs are as follows. The roof pitch formula is used to estimate the area coverage of the house. Calculate the rafter length substituting these values into the following formula. 48 10 4 8.

Slope factor fnd the length of the valley rafter given the following measurements. Roof angle can be obtained by diving rise by run and take the tan inverse of the result. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length. The pitch is the number of inches the roof rises compared to every 12 inches of horizontal run.

Includes result for hip valley factor slope factor and the roof slope in degrees. Divide the slope by two to get the pitch. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement. Pitch rise run 1 5 6 25.

You can also calculate roof pitch even without using a roof slope calculator. Here are the equations you may use to solve for the length of the slope and the rafter. For a simple gable roof the span wall to wall will be twice the size of the run wall to ridge horizontally. The calculator above can handle much of this math.

In civil engineering the slope is the numerical measure of the steepness of a roof. The slope is the same as the pitch. For a roof with the ridge above one wall the span is the same as the run. Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m.

The pitch of this roof is 4 8 12. Now divide the rise by the multiplier to get the pitch eg. Since pitch is the rise over a 12 inch run divide the run by 12 to get the multiplier in this case 120 12 10. Roof slope is also called as roof pitch.

It is computed by using the simple roof slope formula. By slope angle formula steepness can be obtained by dividing vertical rise by horizontal span. Use the following formula which also describes a right triangle. Rafter rise run this formula is from the pythagorean theorem.