Outside of the u s a degree angle is typically used.
Multiplier for 3 12 roof.
For example a 4 12 pitch roof that is 100 square feet.
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.
Roof pitch area multipliers.
800 multiplied by 1 16.
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.
And for a roof with a slope of 6 12 that number 1 118 is your roof slope multiplier.
Get your roof size by using this roof pitch calculator.
100 1 054 105 4ft 2.
We excluded roof multipliers for pitch below 3 and above 12 for the following reasons.
Image 1 12 to 12 12 roof pitch 7 12 pitch.
Multiply 20 and 40 which equals 800.
The value arrived at 928 reflects the square feet of the roof.
Multiply step 1 and step 2 i e.
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.
If the home measures 20 x 40 and has a 7 12 roof then to calculate the slope of the roof follow these steps.
Find the value of 7 12 from the roof slope multiplier table which is 1 16.
Use our roof pitch calculator to find the pitch of your roof.
The pitch of the roof is the rise over a 12 inch run.
The calculator above can handle much of this math.
If this isn t practical then perform the same measurement on the underside of the roof.
With pitch under 3 you can easily walk on the roof to get the exact measurements as that is usually a flat roof.
Divide the rise by the run the run is 12.
It affects walkability as well as drainage and roofs in areas of high rain.
Also the multiplier is so close to one that it does not really change the total size unless your roof is something like a 100 100.
48 10 4 8.
For instance a 7 12 roof pitch means that the roof rises 7 inches for every 12 horizontal inches.
The pitch of this roof is 4 8 12.
That gives you 5 590 square feet which is the actual area of the surface of the roof.
This will give you the rise over run or pitch.
Now divide the rise by the multiplier to get the pitch eg.
Next multiply the footprint of the roof by the multiplier below for your roof pitch to find the overall roof area.
Take the area of the roof s footprint say it s 5 000 square feet and multiply 5 000 by 1 118.
Roof pitch degree table.
For example if you measure 4 inches the pitch of your roof is 4 12.
