How To Estimate Roof Size

A low pitch rises 3 inches every 12 inches of base horizontal length.

How to estimate roof size.

To calculate the size of the roof you need to measure the size of the roof as if it were flat account for roof pitch calculate square footage and finally determine how many squares of material are required for the roof the calculator above can handle all of this simply enter the length width and pitch and it will determine the size of the roof in squares. If getting onto your roof isn t an option you can also estimate its size from the ground by measuring the area of the exterior walls and multiplying that number by the roof s slope. The roof area is simply 114x18x2 plus 30x18x2 giving 5184 square feet which is perfectly adequate for estimating materials. While it is possible to estimate the amount of necessary materials using only the total roof area measurement as can be seen from the table depending how large the pitch of the roof the actual area of the roof can differ by up to 2 236 from the measured total area at a pitch of 24 12.

Keep in mind that the average size of a roof is 1 700 square feet so your total will likely be 10 higher or lower than this figure. Keep in mind that using google earth isn t going to give you a 100 percent accurate reading but it will give you a basic idea of the size of the roof for your calculations for the roofing materials. From the diagrams there are two intersecting roofs measuring 114 feet and 30 feet at the eaves with equal rake of 18 feet. To accurately calculate the area of your roof you must first determine its slope or pitch.

You will need to express this size in terms of square feet. Steps method 1 of 2. A 12 in 12 pitch is a. Low medium or high.

To estimate roofing materials start by finding the total square footage of the roof and divide the number by 100 to determine the number of squares in the roof. Since it takes 3 bundles of shingles to cover a square plan to purchase 3 bundles for each square. Roofs have one of three pitches. This is a rather complicated way to estimate a roof area and hardly suited to the diy fans.

The first step in a free roofing estimate is measuring the roof dimensions. Just use it as a starting point and you ll have a fairly basic idea of what you re dealing. A roof s pitch is determined by how much it rises vertically for every foot it runs horizontally.