Asphalt roofing shingles are North America’s most popular roofing option. However, not every roof type is well-suited for this attractive, cost-effective material.
Before investing in a roof replacement, it’s crucial to determine if your home can accommodate asphalt roofing shingles. Fortunately, calculating your roof’s pitch is a simple, straightforward way to determine if your house is a good match for this homeowner-approved material.
Keep reading to learn everything you need to know about roof pitches—including how to tell if your roof’s slope is compatible with asphalt roofing shingles.
What Is a Roof Pitch?
Your roof pitch indicates the steepness (or angle) of your roof.
Since each roofing system is designed to accommodate your home’s climate, geographic location, and style, it’s common for houses to have different roof pitches. Popular roof styles include gable roofs, flat roofs, saltbox roofs, dormer roofs and hipped roofs.
Certain types of roofs are designed to have a higher pitch than others. For example, gable roofs tend to have a higher pitch than flat roofs since they are steeper.
Typically, homes in cold, snowy climates tend to have high-pitched roofs, so the water that accumulates from rain, snow, and ice can easily roll off. Homes in dry, sunny climates are more likely to have lower-sloped roofs since they usually don’t need to deter standing water.
How Can I Find My Roof Pitch?
Regardless of your roof’s style, it’s relatively easy to calculate the slope. Roof pitches are displayed as a fraction of the rise over the run—like 3/12 (or 3:12). This means the roof rises three inches for every twelve inches it runs.
To calculate your roof’s grade, you’ll need to do a little math. Simply divide the numerator (the top number) by the denominator (the bottom number) and move the decimal point over two spaces. For example, a roof with a 3:12 pitch has a grade of 25%.
Calculating the degree of your roof angle is a bit more complicated and requires some geometry. You can use this roof pitch calculator to automatically calculate your roof’s pitch, grade, degrees, and more after entering the rise and the run.
If you don’t already know your roof’s rise and run, we recommend contacting a trusted local contractor to help you safely (and professionally) complete the measurements.
What Roof Pitch Is Necessary for Asphalt Roofing Shingles?
Since asphalt roofing shingles aren’t designed to hold standing water, installing them on low-slope or flat roofs is prohibited per manufacturer instructions and state building code laws.
Your roof must have a pitch equal to or greater than 2:12 to install asphalt roofing shingles. For reference, 4:12 is considered a regular roof pitch, and 6:12 is a steep slope.
If your entire roof has a low slope, you’ll need to find an alternative material to cover your home. However, even if your home has a suitable pitch for asphalt shingles, you may need to use different roofing materials to protect other aspects of your house, like an attached garage or sunroom addition.
My Roof Isn’t the Right Pitch for Asphalt Roofing Shingles. Now What?
Although it’s rare, if your roof (or certain parts of it) aren’t compatible with asphalt shingles, there are plenty of other options for your roofing system, like:
- TPO membrane roofing—This single-ply white membrane made from ethylene-propylene rubber is popular for both residential and commercial properties.
- PVC membrane roofing—Also a single-ply white membrane, this material is like TPO but has a more flexible, pliable texture.
- EPDM membrane roofing—Though commonly used for commercial properties, this black, synthetic rubber material is still an option for your home.
- Standing seam metal roofing—Made from metal panels locked at the seams, standing seam metal roofing is an attractive, durable option for low-slope residential roofs.
Install Asphalt Shingles on Your Pitched Roofing System
If your home has a 2:12 pitch or greater, you’re in the clear to install asphalt roofing shingles on your Indianapolis home!
JD Hostetter is proud to install top-rated, homeowner-approved asphalt roofing shingles from Malarkey Roofing Products and Owens Corning. We offer long-lasting product and labor materials as a Malarkey Roofing Emerald Preferred Contractor, so you can be confident in the durability and lifespan of your roof.
Discover all the options available to you when you protect your pitched roof with durable, low-maintenance asphalt roofing shingles!
