Math Formula For Roof Pitch

For example a roof with a 6 12 pitch rises 6 inches for every horizontal foot.

Math formula for roof pitch.

In civil engineering the slope is the numerical measure of the steepness of a roof. Rafter rise run this formula is from the pythagorean theorem. Let s say it is equal to 1 5 m. Roof pitch is expressed in ratios of 12 because it is measured by the foot.

Roof slope is also called as roof pitch. 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. The pitch value can be obtained by dividing n by 12 and divide s by the answer.

Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length. Rise and run formula. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement.

The slope is the same as the pitch. 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. Therefore if a roof rises four inches for every 12 inches of horizontal distance it has a 4 in 12 pitch. Here are the equations you may use to solve for the length of the slope and the rafter.

Calculate the roof pitch as the proportion of rise and run. The pitch of this roof is 4 8 12. By slope angle formula steepness can be obtained by dividing vertical rise by horizontal span. Includes result for hip valley factor slope factor and the roof slope in degrees.

Divide the slope by two to get the pitch. Pitch rise run 1 5 6 25. The pitch is the number of inches the roof rises compared to every 12 inches of horizontal run. Calculate the rafter length substituting these values into the following formula.

Pitch is a simple ratio of the rise to the run of the roof. It is computed by using the simple roof slope formula. Slope factor fnd the length of the valley rafter given the following measurements. Measure the rise of your roof.

For a roof with the ridge above one wall the span is the same as the run. The calculator above can handle much of this math. 48 10 4 8. L 1 8 feet l 2 10 feet pitch 1 1 pitch 2 0 8 length of valley rafter a geometry sketchpad showing intersecting roofs with different pitches is attached.

Other formulas needed to work with roofs are as follows. The roof pitch formula is used to estimate the area coverage of the house. Use the following formula which also describes a right triangle. In the imperial unit of measurements the slope is expressed with the rise and run.