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 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.
Pitch multiplier for 5 12 roof.
Roof pitch degree table.
All you need to know is the area covered by the roof.
The pitch of the roof is the rise over a 12 inch run.
If you know the pitch of a roof you can use the numbers in the following pitch table to do the following.
This will give you the rise over run or pitch.
In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches.
The value arrived at 928 reflects the square feet of the roof.
For instance if your roof covers an area that is 20 ft by 35 ft and the pitch is 5 12 then the surface area is.
100 1 054 105 4ft 2.
Find the value of 7 12 from the roof slope multiplier table which is 1 16.
If the home measures 20 x 40 and has a 7 12 roof then to calculate the slope of the roof follow these steps.
Based on the pitch you can use the multiplier to determine the amount of material needed for a roofing project.
A flat roof has a pitch of 1 meaning the material needed is 1 times the size of the roof.
Multiply step 1 and step 2 i e.
The pitch of this roof is 4 8 12.
Roof pitch area multipliers.
Image 1 12 to 12 12 roof pitch 7 12 pitch.
800 multiplied by 1 16.
Next multiply the footprint of the roof by the multiplier below for your roof pitch to find the overall roof area.
We included a roof pitch chart below the 7 12 example image and the calculator below that.
Use our roof pitch calculator to find the pitch of your roof.
Divide the rise by the run the run is 12.
If this isn t practical then perform the same measurement on the underside of the roof.
Simply locate a roof rafter board place the end of the level against the bottom edge and measure from the 12 inch mark vertically to the bottom edge of the rafter.
48 10 4 8.
It is often compared to slope but is not exactly the same.
How to find your what roof pitch category.
Surface area area covered by roof roof pitch multiplier 20 35 1 08 700 1 08 756 square feet.
This roof pitch table displays a multiplier for adding for different roof pitches.
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.
For example a 4 12 pitch roof that is 100 square feet.
Outside of the u s a degree angle is typically used.
Now divide the rise by the multiplier to get the pitch eg.
For example if you measure 4 inches the pitch of your roof is 4 12.
Multiply 20 and 40 which equals 800.
Determine how many square feet of roof area a building has by measuring from the ground.
