May 17, 2023

How To Measure A Roof For Metal Roofing Or Shingles

Roof Measurement
How to measure a roof for metal roofing

Roofing contractors have the necessary knowledge and experience to ensure that a roof is properly installed, maintained, and repaired.

However, there’s one thing that can trip up even the most experienced roofer: figuring out how much material you’ll need to cover your roofing project.

Fortunately, we’re here to help! In this blog post, we’ll walk through how to measure a roof for shingles and calculate your square footage so that you can get an accurate estimate of how much material you’ll need for your project.

How to estimate how much roofing material you need

Roofing contractors are often asked to give the client a rough estimate of how much roofing material will be required for their project. This can be a challenge, as there are many factors that will affect the amount of material needed.

It’s important to know the square footage of the roof in question, as well as its pitch, before purchasing shingles. Here’s how to do it:

Measure the roof’s square footage: In order to measure the square footage of your roof, you will need to measure the width and length of every surface of the roof. While you are at it, make sure to account for any overhangs or angles in the roof’s surface. This is important because the amount of material you need will depend on how much square footage your roof covers.

Measure the length of each plane and then multiply it by the width. This will give you the total square footage of each plane. Measure from the peak of one side to the peak of another side, then multiply that number by two (this will give you a total for both sides).

Next, measure from one end of each plane to another end, then multiply it by two (this will give you a total for both ends). Multiply this number by two again (this gives you a total for both sides). Now add up all three numbers and divide that number by 100 to get your square footage per square foot (SF/sq ft).

To find out how many squares of shingles or tiles you need, divide this number by 36 inches (the length of most shingles). For example: If my SF/sq ft is 200, then I need 50 squares. If my SF/sq ft is 100, then I need 25 squares.

What is roof slope?

Once you have figured out how much square footage the roof has, measure its pitch (or slope). The roof slope is the angle of a roofline. The steeper the slope, the more likely it is to shed water; conversely, the gentler the slope, the less likely it is to shed water.

How do you measure a roof’s slope?

The pitch is measured by dividing the vertical rise by the horizontal run—in other words, how many inches your roof rises per foot of length.

To measure a roof’s pitch, you need to use a tape measure and stand on level ground at one end of your roof plane (the horizontal plane). Then, take measurements from several points along that plane at regular intervals—say every foot or so—and average out those measurements to get an approximate average number.

If you are working with a gable roof with two planes, measure the number of squares (100 square feet) along each plane and multiply this by two to get total square footage for each plane. Multiply those numbers together to get total square footage for your entire roof surface area. 

If you are measuring a flat roof—no pitch at all—the total square footage will be the same as your home’s square footage.

Calculating roofing underlayment

Roofing underlayment is the material that goes between a roof’s shingles and the sheathing beneath them. It’s also known as felt paper or asphalt roll roofing. When it comes time to replace any roof, you’ll need enough underlayment to cover the surface of a home’s roof plane.

How Much Do I Need?

When it comes to calculating roofing underlayment, there are a few different types of roof surfaces that will determine the size of the roofing material you’ll need to buy. The amount of underlayment required depends on several factors: your home’s pitch (the angle at which your roof rises), its square footage, and whether or not it has gables (angled walls).

Roof pitch is the number of inches your roof rises in 100 feet. You can find out your roof pitch by using a tape measure and taking measurements from each end of your roof. If you have a gable roof, you’ll want to measure from one end of the gable and then down the other side.

Another factor that affects how much underlayment you’ll need is whether you have tabs (or “scallops”) on the roof’s shingles. If so, then you’ll need more than if they weren’t present.

You can also calculate how much underlayment you need by taking measurements from each plane of your roof—that is, if a house has multiple levels with different pitches or angles—and then adding up all the square footage together.

And finally, remember that when calculating how much underlayment material you’ll need for a project, 100 square feet equals roughly 1 roll of underlayment material.

Aerial roof measurements

When you’re starting a new roofing project, it’s important to know how much coverage you’ll need. That’s where aerial roof measurements come in.

Aerial roof measurements are a great way to get an accurate picture of a roof’s surface area and pitch. They can help you figure out the right amount of materials for your job, which is important because different types of roofs require different amounts of material.

EagleView Technologies has been providing aerial roof measurements since 2008, and have grown into one of the largest providers in North America. EagleView’s aerial roof measurements are made from high in the sky, using their drone technology and software. The drones take pictures of a roof from different angles and then use computer vision to calculate the pitch, square footage, and other information about any roof—all from afar. 

This saves you time and money by giving you accurate measurements before work begins on your roofing project. It also helps avoid mistakes when it comes time for installation because you know exactly what you’re working with ahead of time. Contact an expert today to learn more about aerial measurement solutions.

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