Formula Roof Pitch Multiplier

See the image below for more explanation on rise run and pitch.

Formula roof pitch multiplier. Multiply step 1 and step 2 i e. 800 multiplied by 1 16. 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. 100 1 054 105 4ft2.

Next multiply the footprint of the roof by the multiplier below for your roof pitch to find the overall roof area. A 12 in 12 pitch is a steep 45 degree angle roof. Roof pitch degree table. The formula for the roof pitch multiplier comes from the famous pythagorean theorem.

Although there s isn t any standard pitch of a roof used on all kinds of sloped roofs you can determine the range of pitches by using a roof angle calculator and by considering factors like the local climate and roofing materials. 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. A 2 b 2 c 2 where a is the rise of the roof b is the run of the roof and c is the rafter hypotenuse of the triangle with side lengths a and b. 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 example a 4 12 pitch roof that is 100 square feet. Roof pitch refers to the measurement of the slope of a roof and you express this as a ratio. A roof s pitch is determined by how much it rises vertically for every foot it runs horizontally. Roof pitch or slope is a measure of vertical rise to horizontal run expressed in inches per foot.

Thus a moderate 6 in 12 roof pitch means that the roof rises 6 inches vertically for every 12 horizontal inches it runs. The value arrived at 928 reflects the square feet of the roof. Image 1 12 to 12 12 roof pitch 7 12 pitch. Use our roof pitch calculator to find the pitch of your roof.

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. 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 roof pitch multiplier also known as a roof pitch factor is a number that when multiplied by the area covered by a sloped roof gives the actual area of the roof. The maths behind this number is that it is the square root of rise run 2 1.

Roof pitch is used to describe the slope or angle of the roof. Now solving for c in the equation above gives.