How to measure a roof for shingles
It's crucial to measure the surface area of your roof before you purchase materials. You can then ensure that you have enough roofing material to cover the roof planes of your home.
Set up your ladder in accordance with safety guidelines before you start measuring. Take your tape measure, a notebook and your ladder to the roof.
Measure the roof's planes
Draw an overhead sketch in a notebook as you prepare to climb up the ladder. The sketch does not need to be scaled, but should show the roof planes well enough to label them while you are taking measurements.
Measuring the width and length of your roof planes is important, as well as any overhangs. Calculate the area of each plane based on the pitch of the roof once you have measured it. This is easy if the roof is flat. Just multiply length by width. If your roof has a gable shape, you will need to use a triangle formula.
Add the total square footage of the roof to the area calculated for each plane. You can then determine the number of bundles you need to buy. You'll also need to know the size of the metal sheet or panel.
How to Measure the Roof Square Footage
Set up a ladder at the base of your roof to start measuring. Idealy, you should use a ladder that has a partner so it can be kept steady while you take measurements. Tape measure the width and length of each plane. These dimensions should be marked on the roof layout diagram. Rounding up or down these measurements will cause your calculations to be off when you need to calculate the number of shingles.
If you have three-tab standard shingles, for example, you can count how many rows of shingles are at the eaves in order to calculate the width of the roof. Multiply the width of the roof by its height in order to get its square footage. Repeat the steps for every plane of your roof. Do not forget to add peaks, valleys and dormers as well as surfaces that aren't covered in shingles, such as chimneys. When calculating the total roof square footage, these areas must be considered.
How to Measure the Roof Eaves
Each plane of a basic gable or hip roof has its own area that must be calculated. It can be dangerous to count each plane, but you can calculate it with a notepad or a partner.
Use your tape measure to start measuring. To begin your calculations, write down the measurement in inches.
Measure the length of every rafter at the eaves using the same method. To get the total roof length, add this figure to the base length of the roof. Use the chart below to calculate the slope of your roof, also known as the "roof pitch". Multiply the number by both the width and length of each plane. Multiply that number by 29, the average number of standard shingles per bundle, to determine how many bundles you will need.
Measure the roof's ridges
It's essential to know the shingle area of a roof before you buy any materials. Many people have difficulty calculating the square footage of a roof without climbing on top (or hiring a professional to do it).
Google Earth is the easiest way to calculate your roof's area. This free program lets you see your property in a bird's eye view from the ground.
Set your level at eye level on the eave edge and measure from there the distance to the top of the slope of the roof. The roof's horizontal run is measured here. Then, using your tape measure, measure the height between the ridge and the eave edge. The pitch of the roof is its vertical rise. You can adjust the roof's pitch by using the multiplier in the table below.
It's crucial to measure the surface area of your roof before you purchase materials. You can then ensure that you have enough roofing material to cover the roof planes of your home. Set up your ladder in accordance with safety guidelines before you start measuring. Take your tape measure, a notebook and your ladder to…