Math Formula For Roof Pitch

For a simple gable roof the span wall to wall will be twice the size of the run wall to ridge horizontally.

Math formula for roof pitch.

48 10 4 8. The roof pitch formula is used to estimate the area coverage of the house. In the imperial unit of measurements the slope is expressed with the rise and run. Rafter rise run this formula is from the pythagorean theorem.

Roof angle can be obtained by diving rise by run and take the tan inverse of the result. 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. 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.

Measure the rise of your roof. 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. Therefore if a roof rises four inches for every 12 inches of horizontal distance it has a 4 in 12 pitch. Other formulas needed to work with roofs are as follows.

For a roof with the ridge above one wall the span is the same as the run. Pitch is a simple ratio of the rise to the run of the roof. Pitch rise run 1 5 6 25. Divide the slope by two to get the pitch.

The pitch is the number of inches the roof rises compared to every 12 inches of horizontal run. Slope factor fnd the length of the valley rafter given the following measurements. In civil engineering the slope is the numerical measure of the steepness of a roof. Includes result for hip valley factor slope factor and the roof slope in degrees.

Roof pitch is expressed in ratios of 12 because it is measured by the foot. Rise and run formula. For example a roof with a 6 12 pitch rises 6 inches for every horizontal foot. The slope is the same as the pitch.

By slope angle formula steepness can be obtained by dividing vertical rise by horizontal span. You can also calculate roof pitch even without using a roof slope calculator. The pitch of this roof is 4 8 12. Roof slope is also called as roof pitch.

It is computed by using the simple roof slope formula. The pitch value can be obtained by dividing n by 12 and divide s by the answer. Use the following formula which also describes a right triangle. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement.

Let s say it is equal to 1 5 m. Here are the equations you may use to solve for the length of the slope and the rafter. Now divide the rise by the multiplier to get the pitch eg. Calculate the rafter length substituting these values into the following formula.