How to Determine How Much Roofing I Need

Draw a detailed diagram of your home. This does not need to be to scale but it should be detailed enough to show each part of your roofing. Alternatively, take a picture of your home's roofing.

Label each part of the roofing A, B, C, etc. The roofing will be made of rectangles, squares and triangles; labeling each piece will help keep track of the measurements you are going to take.

Measure the dimensions of each section and write it down on a piece of paper. Double-check the measurements by measuring them again.

For the rectangular and square sections, measure the length of the section by the width to determine the entire square footage. Write that number down and repeat the process with the rest of the square or rectangular sections.

For triangular areas, multiply the base of the triangle by the height of the triangle and divide that number by two. Write down the number and repeat the process with the rest of the triangular sections of the roof.

For irregular sections such as the roofing over a pop-our window, measure the longest side of the rectangle and multiply it by the width. This will be a few square feet more than the actual amount of square footage, but it will help accommodate for broken or damaged shingles.

Add each section of the roof together to get the total square footage. Take this number with you when you purchase the roofing. The dealer will be able to tell you the square footage per pack of roofing material. Divide your total square footage by the square footage of each pack and round up to determine how much roofing you need.