Roof Pitch Multiplier

Determine how many square feet of roof area a building has by measuring from the ground.

Roof pitch multiplier.

48 10 4 8. After safely measuring your roof to discover the pitch you can use the graph below to calculate your roof pitch in degrees and multiplier. 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 pitch of this roof is 4 8 12.

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. The maths behind this number is that it is the square root of rise run 2 1. Determine how many square feet of roof area a building has by measuring blueprints or plans. Take the area of the roof s footprint say it s 5 000 square feet and multiply 5 000 by 1 118.

Based on the pitch you can use the multiplier to determine the amount of material needed for a roofing project. 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. This makes measuring easier knowing that you are able to get the exact measurement of roofs by merely standing on the ground. The chart gives a number of roof pitch multipliers for different roof slopes.

A flat roof has a pitch of 1 meaning the material needed is 1 times the size of the roof. 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. The roof pitch multiplier is the length of the hypotenuse divided by the run. The roof pitch multiplier is responsible for giving an accurate pitch measurement of the roof.

This roof pitch chart will give you your multiplier. If you know the pitch of a roof you can use the numbers in the following pitch table to do the following. Roof pitch multiplier c over b. Now divide the rise by the multiplier to get the pitch eg.