Roof Pitch Multiplier

The chart gives a number of roof pitch multipliers for different roof slopes.

Roof pitch multiplier.

This makes measuring easier knowing that you are able to get the exact measurement of roofs by merely standing on the ground. 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. So the actual roof surface if it were laid down flat on the ground would be 1 118 times larger than the footprint of the roof. A flat roof has a pitch of 1 meaning the material needed is 1 times the size of the roof.

The pitch of this roof is 4 8 12. 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. If you know the pitch of a roof you can use the numbers in the following pitch table to do the following. Determine how many square feet of roof area a building has by measuring from the ground.

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 roof pitch multiplier is responsible for giving an accurate pitch measurement of the roof. The roof pitch multiplier is the length of the hypotenuse divided by the run. Based on the pitch you can use the multiplier to determine the amount of material needed for a roofing project.

This roof pitch chart will give you your multiplier. Now divide the rise by the multiplier to get the pitch eg. The calculator above can handle much of this math. Determine how many square feet of roof area a building has by measuring blueprints or plans.

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. After safely measuring your roof to discover the pitch you can use the graph below to calculate your roof pitch in degrees and multiplier. Roof pitch multiplier c over b. 48 10 4 8.