Roof Square Footage Multiplier

This nominal square footage amount is then multiplied by a factor associated with the roof s pitch.

Roof square footage multiplier.

Multiply 20 and 40 which equals 800. This roof pitch table displays a multiplier for adding for different roof pitches. 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. If you know the pitch of a roof you can use the numbers in the following pitch table to do the following.

The value arrived at 928 reflects the square feet of the roof. How to find your what roof pitch category. 100 1 054 105 4ft 2. However shingles are packaged in a way that they are light enough for the average person to carry around.

If the home measures 20 x 40 and has a 7 12 roof then to calculate the slope of the roof follow these steps. 800 multiplied by 1 16. In cases where a roof has a complex shape such as in the image to the right measuring the dimensions and areas of each part of the roof to calculate total area will result in a more accurate measurement of area. 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.

For example a 4 12 pitch roof that is 100 square feet. Find the value of 7 12 from the roof slope multiplier table which is 1 16. Measure your house at ground level then add in the roof s overhang for greater accuracy. The calculator cannot account for complex shapes based on a measurement of square footage alone.

As an example if your overhang is 12 inches you ll add 2 feet to the overall length and 2 feet to the overall width of the house. Use our roof pitch calculator to find the pitch of your roof. Determine how many square feet of roof area a building has by measuring from the ground. A square of shingles is the number of shingles needed to cover 100 sq feet of roof area.

If its pitch is 6 in 12 a pitch multiplier of 1 12 multiplying 1 152 sq ft 107 0 m 2 by 1 12 would give you an overall square footage of 1 290 square feet 120 m 2. Next multiply the footprint of the roof by the multiplier below for your roof pitch to find the overall roof area. If your roof measures 48 feet 15 m x 24 feet 7 3 m multiplying its length by its width would give you a square footage of 1 152 square feet 107 0 m 2. Roof pitch area multipliers.

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 pitches in. Multiply step 1 and step 2 i e. As a rule of thumb there are 3 bundles to a square assuming that you are using three tab strip shingles.

So continuing our example if you ve got a two story house with a total square footage of 2 700 square feet with each floor having 1 350 square feet multiply 1 350 by 1 0541 to get 1 423 square.