Roof Pitch Multiplier Table

The hip and valley factor is a number that is multiplied by the actual run horizontal distance of a common rafter to determine the length of a hip or valley rafter.

Roof pitch multiplier table.

The roof pitch multiplier table is very helpful in giving correct and reliable roof measurements and uses pythagorean theory. This roof pitch table displays a multiplier for adding for different roof pitches. Where a is the rise of the roof b is the run of the roof and c is the rafter hypotenuse of the triangle with side lengths a and b. A roof pitch multiplier also called a roof pitch factor is a number that is multiplied by the area covered by a sloped roof to produce the area of the actual surface of the roof.

The maths behind this number is that it is the square root of rise run 2 1. Make sure that this is going to be affordable for you as more materials and time are needed to construct steeper roofs. Typically the steeper the roof is the higher the price will be. Notes to the table above.

This table provides the hip and valley factor for common roof pitches as well as the underlying equation for the factor. We excluded roof multipliers for pitch below 3 and above 12 for the following reasons. Some sources consider low slope to include 3 12 pitch roofs. A roof pitch multiplier also known as a roof pitch factor is a number that when multiplied by the area covered by a sloped roof gives the actual area of the roof.

Now solving for c in the equation above gives. The first thing that you need to understand before picking any selections from a roof pitch multiplier chart is to ensure that it s affordable. Roof pitch multiplier table. The formula for the roof pitch multiplier comes from the famous pythagorean theorem.

Low slope roofs are from 0 to 3 12 in pitch. 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. It also has. For roof slopes expressed as x in 12 rise in run the roof pitch multiplier is determined by finding the square root of rise run 1.

If you know the pitch of a roof you can use the numbers in the following pitch table to do the following. Accurate roof calculations are achieved using this table and all you need to do is measure the roof width and length and then you are ready to do a roof pitch measurement. How to find your what roof pitch category. The total run is the distance from the peak to the edge of the roof which in this case is the total width divided in half which is equal to 10 feet or 120 inches.