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.
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.
What is the multiplier.
If this isn t practical then perform the same measurement on the underside of the roof.
This will give you the rise over run or pitch.
For instance a 7 12 roof pitch means that the roof rises 7 inches for every 12 horizontal inches.
Multiply 20 and 40 which equals 800.
48 10 4 8.
We included a roof pitch chart below the 7 12 example image and the calculator below that.
800 multiplied by 1 16.
How to find your what roof pitch category.
For example if you measure 4 inches the pitch of your roof is 4 12.
Outside of the u s a degree angle is typically used.
Use our roof pitch calculator to find the pitch of your roof.
A flat roof has a pitch of 1 meaning the material needed is 1 times the size of the roof.
The pitch of this roof is 4 8 12.
Roof pitch how much to add.
Divide the rise by the run the run is 12.
This roof pitch table displays a multiplier for adding for different roof pitches.
Image 1 12 to 12 12 roof pitch 7 12 pitch.
Multiply step 1 and step 2 i e.
Find the value of 7 12 from the roof slope multiplier table which is 1 16.
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 pitch of the roof is the rise over a 12 inch run.
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.
For example a 4 12 pitch roof that is 100 square feet.
It is often compared to slope but is not exactly the same.
The value arrived at 928 reflects the square feet of the roof.
100 1 054 105 4ft 2.
Determine how many square feet of roof area a building has by measuring from the ground.
Roof pitch degree table.
If you know the pitch of a roof you can use the numbers in the following pitch table to do the following.
Roof pitch area multipliers.
If the home measures 20 x 40 and has a 7 12 roof then to calculate the slope of the roof follow these steps.
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.
All you need to know is the area covered by the roof.
Based on the pitch you can use the multiplier to determine the amount of material needed for a roofing project.