Math Formula For Roof Pitch

In the imperial unit of measurements the slope is expressed with the rise and run.

Math formula for roof pitch.

Rise and run formula. The roof pitch formula is used to estimate the area coverage of the house. Rafter rise run 1 5 6 2 25 36 38 25rafter 38 25 6 18 m. Slope factor fnd the length of the valley rafter given the following measurements.

Includes result for hip valley factor slope factor and the roof slope in degrees. By slope angle formula steepness can be obtained by dividing vertical rise by horizontal span. Roof pitch is expressed in ratios of 12 because it is measured by the foot. Pitch is a simple ratio of the rise to the run of the roof.

For a simple gable roof the span wall to wall will be twice the size of the run wall to ridge horizontally. Pitch rise run 1 5 6 25. Measure the rise of your roof. Roof slope is also called as roof pitch.

Rafter rise run this formula is from the pythagorean theorem. For example a roof with a 6 12 pitch rises 6 inches for every horizontal foot. 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. The pitch of this roof is 4 8 12.

Now divide the rise by the multiplier to get the pitch eg. 48 10 4 8. Use the following formula which also describes a right triangle. Other formulas needed to work with roofs are as follows.

Let s say it is equal to 1 5 m. In civil engineering the slope is the numerical measure of the steepness of a roof. The pitch is the number of inches the roof rises compared to every 12 inches of horizontal run. The pitch value can be obtained by dividing n by 12 and divide s by the answer.

Divide the slope by two to get the pitch. Calculate the rafter length substituting these values into the following formula. Here are the equations you may use to solve for the length of the slope and the rafter. The calculator above can handle much of this math.

The slope is the same as the pitch. Calculate the length of a rafter from the roof slope ratio of inches per foot and a building width measurement. 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. It is computed by using the simple roof slope formula.

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. If you add an eaves overhang dimension then the amount the rafter sticks passed the wall will be added to the rafter length. Roof angle can be obtained by diving rise by run and take the tan inverse of the result. For a roof with the ridge above one wall the span is the same as the run.