Roofing Square Footage Multiplier

If the home measures 20 x 40 and has a 7 12 roof then to calculate the slope of the roof follow these steps.

Roofing square footage multiplier.

Roof surfaces are measured in squares a square is an area of roof which measures 100 square feet. Roofing material is estimated by the square which is equal to 100 square feet. This roof pitch chart will give you your multiplier. In the united states a run of 12 inches 1 foot is used and pitch is measured as the rise of the roof over 12 inches.

A roof pitch multiplier also called a roof pitch factor is a number that is multiplied by. Next multiply the footprint of the roof by the multiplier below for your roof pitch to find the overall roof area. The average roof is 3 000 square feet or around 30 squares. If you know the pitch of a roof you can use the numbers in the following pitch table to do the following.

Steep roofs measure your house at ground level then add in the roof s overhang for greater accuracy. Find the value of 7 12 from the roof slope multiplier table which is 1 16. Roof pitch is the measurement of a roof s vertical rise divided by its horizontal run. For the total square footage of the roof.

Determine how many square feet of roof area a building has by measuring from the ground. 100 1 054 105 4ft 2. If your roof is flat or has no more than a 3 in 12 pitch you can calculate its total square footage by simply multiplying the length by the width. Plane 1 plane 2 24 000 sq.

Then take the product of these two dimensions and multiply it by your pitch multiplier. Determine how many square feet of roof area a building has by measuring blueprints or plans. Multiply the area by the pitch multiplier to get the roof s square footage. Multiply by the square footage of a single floor of your house.

The number you get will be an accurate estimate of how much area you have to cover for your roofing project. Multiply 20 and 40 which equals 800. It is often compared to slope but is not exactly the same. To determine the number of squares on the gable roof above simply divide its total of 24 000 square feet by 100.

Many homes have an asphalt shingle roof but some have wood metal tile and slate which can be more expensive. For example a 4 12 pitch roof that is 100 square feet. Multiply step 1 and step 2 i e.