So 2400 x 1 12 2 688 2 88 sqs added for pitch.
12 12 roof pitch multiplier.
Why figure what your roof pitch is.
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 multiplier 13 over 12 1 08.
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.
If this isn t practical then perform the same measurement on the underside of the roof.
Once you know the roof slope multiplier for a particular slope you can use it to find the actual area of any size sloped roof with the same slope.
Find the value of 7 12 from the roof slope multiplier table which is 1 16.
The pitch of this roof is 4 8 12.
Helps determine what materials are suitable for your roof.
The calculator above can handle much of this math.
Roof is 6 12 pitch and measures at 2 400 square feet.
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.
Roof pitch degree table.
800 multiplied by 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.
For example a roof with a pitch of 1 cannot use metal shingles.
Then the roof multiplier is.
Multiply step 1 and step 2 i e.
Image 1 12 to 12 12 roof pitch 7 12 pitch.
This will give you the rise over run or pitch.
What is the multiplier.
The value arrived at 928 reflects the square feet of the roof.
We included a roof pitch chart below the 7 12 example image and the calculator below that.
A flat roof has a pitch of 1 meaning the material needed is 1.
Divide the first part of the ratio by 12 to work out the pitch.
48 10 4 8.
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.
To convert between american roofing ratios and pitch degrees follow these steps.
So in this case for every 12 inches the roof goes across horizontally b while rising 6 inches a there s actually 13 416 inches of roof c.
Multiply 20 and 40 which equals 800.
A 12 12 pitch roof has a pitch angle of 45.
Now divide the rise by the multiplier to get the pitch eg.
Get your roof size by using this roof pitch calculator.
Using the pythagorean theorem we find that for every 12 inches the roof spans horizontally there are 13 inches of actual roof.
C sqrt 5 2 12 2 sqrt 169 13 in.