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.
Roof multiplier for pitch.
That gives you 5 590 square feet which is the actual area of the surface of the roof.
Step 1 multiply 20 and 40 which equals 800.
The maths behind this number is that it is the square root of rise run 2 1.
For this example let s assume your roof covers an area that is 20 feet wide and.
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.
Another method to find the roof pitch is to go into the attic and measure the rise.
Measure from 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.
Let s assume the pitch is 8 12.
Step 2 find the value of 7 12 from the roof slope multiplier table which is 1 16.
You might like to use this roof slope calculator.
And for a roof with a slope of 6 12 that number 1 118 is your roof slope multiplier.
Enter your numbers into this go to roof pitch calculator.
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.
How to calculate the pitch of a roof method one.
Step by step example using the roof pitch multiplier table measure the area covered by the roof.
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.
Calculate the slope of the roof.
2280 1900 380 feet added for pitch.
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.
One method to find the pitch is to climb on the roof and measure the rise for a 12.
Get your roof size by using this roof pitch calculator.
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.