12 12 Roof Pitch Multiplier

Using the pythagorean theorem we find that for every 12 inches the roof spans horizontally there are 13 inches of actual roof.

12 12 roof pitch multiplier.

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. Why figure what your roof pitch is. For example a roof with a pitch of 1 cannot use metal shingles. 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.

Roofers typically refer to it as a pitch and can be found by factoring the rise over a 12 inch run. What is the multiplier. Helps determine what materials are suitable for your roof. Roof pitch multiplier 13 over 12 1 08.

If the home measures 20 x 40 and has a 7 12 roof then to calculate the slope of the roof follow these steps. Roof is 6 12 pitch and measures at 2 400 square feet. For example if you measure 4 inches the pitch of your roof is 4 12. Get your roof size by using this roof pitch calculator.

Image 1 12 to 12 12 roof pitch 7 12 pitch. If this isn t practical then perform the same measurement on the underside of the roof. The value arrived at 928 reflects the square feet of the roof. To convert between american roofing ratios and pitch degrees follow these steps.

Multiply 20 and 40 which equals 800. C sqrt 5 2 12 2 sqrt 169 13 in. We included a roof pitch chart below the 7 12 example image and the calculator below that. A 12 12 pitch roof has a pitch angle of 45.

The pitch of this roof is 4 8 12. Roof pitch degree table. Then the roof multiplier is. Divide the first part of the ratio by 12 to work out the pitch.

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. So 2400 x 1 12 2 688 2 88 sqs added for pitch. 800 multiplied by 1 16. A flat roof has a pitch of 1 meaning the material needed is 1.

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. Find the value of 7 12 from the roof slope multiplier table which is 1 16. This will give you the rise over run or pitch. 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.

The calculator above can handle much of this math. Multiply step 1 and step 2 i e. Now divide the rise by the multiplier to get the pitch eg.