Things You'll Need

Instructions

Instructions

1

Learn how shingles are packaged and sold. You will need to know this before you go shopping. Shingles are sold in a square. Each square of shingles will most likely contain 3 bundles. Each bundle contains 29 shingles, which are the standard 12 inches by 36 inches. Each square of shingles will cover 100 square feet of roof. If you are using a type of asphalt shingle that is heavier, such as architectural shingles, your squares will likely contain 4 or 5 bundles. These shingles are heavier and need more bundles to make a square that covers 100 square feet.
2

Determine your roof’s square footage. Most rooftops are simple enough to measure. Just take a tape measure and extend it from one end to the other to get the length. Then extend the tape measure from the front to back. Multiply those 2 numbers to get the square footage of your roof. This is called the measurement method. If your roof has different sections you will need to measure the width and length of each section, multiply the numbers of each section and then add those totals to get square footage. You can also measure your roof with the sheet count method if you are working with a roof that has no roofing material on it yet and if the structural panels measure 4 by 8 feet. These panels are 32 square feet each. Just count how many are on the roof. If there are panels that have been cut you can guess if they are cut in half or a fourth and add those numbers to your sheet count total. Remember to write down your measurements so you don’t forget the numbers.
3

Divide the roof’s measurements. The total square footage needs to be divided by 100 to get the number of shingle squares needed.
4

Figure out how many extra shingles you need. You need to add extra shingles to your total for starter shingles, which are those that go on the roof’s edge. Also needed are shingles for ridges, valleys and hips. Ridges are the horizontal lines on top of the roof. Valleys are where 2 sections of roof meet at a low angle. Hips are angles on the roof where 2 supporting walls connect. Extra shingles are also needed to account for waste, which will occur when you have to cut shingles to fit ridges, valleys and hips, or cut them to go around roof pipes and chimneys.