Step by step example using the roof pitch multiplier table measure the area covered by the roof.
Roof multiplier for pitch.
Take the area of the roof s footprint say it s 5 000 square feet and multiply 5 000 by 1 118.
How to calculate the pitch of a roof method one.
That gives you 5 590 square feet which is the actual area of the surface of the roof.
Another method to find the roof pitch is to go into the attic and measure the rise.
The maths behind this number is that it is the square root of rise run 2 1.
Measure from the attic.
Step 1 multiply 20 and 40 which equals 800.
Calculate the slope of the roof.
If the home measures 20 x 40 and has a 7 12 roof then to calculate the slope of the roof follow these steps.
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.
For this example let s assume your roof covers an area that is 20 feet wide and.
Step 2 find the value of 7 12 from the roof slope multiplier table which is 1 16.
Now you re ready to price out the materials.
Enter your numbers into this go to roof pitch calculator.
Get your roof size by using this roof pitch calculator.
Roof is 6 12 pitch and measures at 2 400 square feet so 2400 x 1 12 2 688 2 88 sqs added for pitch.
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.
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.
2280 1900 380 feet added for pitch.
Take your area result and multiply it by the pitch multiplier or slope correction factor found in the table above to arrive at the roof s surface area.
And for a roof with a slope of 6 12 that number 1 118 is your roof slope multiplier.
Let s assume the pitch is 8 12.
Measure from the roof.