12 12 Roof Pitch Multiplier

Helps determine what materials are suitable for your roof.

12 12 roof pitch multiplier.

Roofers typically refer to it as a pitch and can be found by factoring the rise over a 12 inch run. This will give you the rise over run or pitch. For example a roof with a pitch of 1 cannot use metal shingles. Roof is 6 12 pitch and measures at 2 400 square feet.

A 12 12 pitch roof has a pitch angle of 45. 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. The value arrived at 928 reflects the square feet of the roof. Get your roof size by using this roof pitch calculator.

The calculator above can handle much of this math. To convert between american roofing ratios and pitch degrees follow these steps. Why figure what your roof pitch is. 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. Multiply step 1 and step 2 i e. Find the value of 7 12 from the roof slope multiplier table which is 1 16. Roof pitch degree table.

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 if you measure 4 inches the pitch of your roof is 4 12. The pitch of this roof is 4 8 12. 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.

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. Now divide the rise by the multiplier to get the pitch eg. Divide the first part of the ratio by 12 to work out the pitch.

Find the inverse tangent of the pitch to find the angle in degrees. Multiply 20 and 40 which equals 800. A flat roof has a pitch of 1 meaning the material needed is 1. Roof pitch multiplier 13 over 12 1 08.

Using the pythagorean theorem we find that for every 12 inches the roof spans horizontally there are 13 inches of actual roof. Image 1 12 to 12 12 roof pitch 7 12 pitch. 48 10 4 8. 800 multiplied by 1 16.

C sqrt 5 2 12 2 sqrt 169 13 in. Then the roof multiplier is. We included a roof pitch chart below the 7 12 example image and the calculator below that.