12 12 Roof Pitch Multiplier

Helps determine what materials are suitable for your roof.

12 12 roof pitch multiplier.

The calculator above can handle much of this math. 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. 800 multiplied by 1 16.

Then the roof multiplier is. 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. For example a roof with a pitch of 1 cannot use metal shingles. Using the pythagorean theorem we find that for every 12 inches the roof spans horizontally there are 13 inches of actual roof.

Roofers typically refer to it as a pitch and can be found by factoring the rise over a 12 inch run. 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. 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. Multiply step 1 and step 2 i e. 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 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.

Divide the first part of the ratio by 12 to work out the pitch. If this isn t practical then perform the same measurement on the underside of the roof. Now divide the rise by the multiplier to get the pitch eg. This will give you the rise over run or pitch.

What is the multiplier. Roof pitch degree table. The pitch of this roof is 4 8 12. A 12 12 pitch roof has a pitch angle of 45.

Image 1 12 to 12 12 roof pitch 7 12 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. A flat roof has a pitch of 1 meaning the material needed is 1. Get your roof size by using this roof pitch calculator.

For example if you measure 4 inches the pitch of your roof is 4 12. To convert between american roofing ratios and pitch degrees follow these steps. 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. We included a roof pitch chart below the 7 12 example image and the calculator below that.

C sqrt 5 2 12 2 sqrt 169 13 in. Find the inverse tangent of the pitch to find the angle in degrees. Find the value of 7 12 from the roof slope multiplier table which is 1 16.