12 12 Roof Pitch Multiplier

We included a roof pitch chart below the 7 12 example image and the calculator below that.

12 12 roof pitch multiplier.

A 12 12 pitch roof has a pitch angle of 45. 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. 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.

Using the pythagorean theorem we find that for every 12 inches the roof spans horizontally there are 13 inches of actual 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. Roof pitch degree table. Roofers typically refer to it as a pitch and can be found by factoring the rise over a 12 inch run.

Multiply 20 and 40 which equals 800. The calculator above can handle much of this math. Now divide the rise by the multiplier to get the pitch eg. 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.

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. What is the multiplier. 800 multiplied by 1 16. Helps determine what materials are suitable for your roof.

If the home measures 20 x 40 and has a 7 12 roof then to calculate the slope of the roof follow these steps. C sqrt 5 2 12 2 sqrt 169 13 in. Get your roof size by using this roof pitch calculator. Roof pitch multiplier 13 over 12 1 08.

Roof is 6 12 pitch and measures at 2 400 square feet. The value arrived at 928 reflects the square feet of the roof. So 2400 x 1 12 2 688 2 88 sqs added for pitch. If this isn t practical then perform the same measurement on the underside of the roof.

Why figure what your roof pitch is. Find the inverse tangent of the pitch to find the angle in degrees. For example if you measure 4 inches the pitch of your roof is 4 12. This will give you the rise over run or pitch.

Multiply step 1 and step 2 i e. To convert between american roofing ratios and pitch degrees follow these steps. For example a roof with a pitch of 1 cannot use metal shingles. Image 1 12 to 12 12 roof pitch 7 12 pitch.

The pitch of this roof is 4 8 12. Then the roof multiplier is. 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.