Roof Pitch Multiplier

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.

Roof pitch multiplier.

The pitch of this roof is 4 8 12. After safely measuring your roof to discover the pitch you can use the graph below to calculate your roof pitch in degrees and multiplier. Also see the 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. Based on the pitch you can use the multiplier to determine the amount of material needed for a roofing project.

48 10 4 8. Determine how many square feet of roof area a building has by measuring blueprints or plans. Determine how many square feet of roof area a building has by measuring from 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.

A flat roof has a pitch of 1 meaning the material needed is 1 times the size of the roof. The roof pitch multiplier is the length of the hypotenuse divided by the run. 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. 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.

And for a roof with a slope of 6 12 that number 1 118 is your roof slope multiplier. The chart gives a number of roof pitch multipliers for different roof slopes. 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. Repeat the run not the length of a common rafter.

This roof pitch chart will give you your multiplier. The calculator above can handle much of this math. Now divide the rise by the multiplier to get the pitch eg. Take the area of the roof s footprint say it s 5 000 square feet and multiply 5 000 by 1 118.

The roof pitch multiplier is responsible for giving an accurate pitch measurement of the roof. Roof pitch multiplier c over b.