What’s the Minimum Pitch for Asphalt Shingles?

If you’re considering a new roof or a roof replacement, you’ve probably heard about pitch. It’s one of those roofing terms that sounds technical, but it’s actually quite straightforward. The roof’s pitch refers to how steep your roof is, and if you’re thinking about using asphalt shingles, pitch matters a lot.

As a reputable roofing company, we talk to homeowners every day who are weighing their roofing material options. One of the most common questions we hear during this is: “Can I use asphalt shingles on a low-slope roof?” The answer depends on the pitch.

So, what’s the minimum pitch needed for asphalt shingles? Let’s break it down.

What Is Roof Pitch?

Roof pitch is the angle or how steep your roof is. Imagine a ramp. The roof pitch is how steep the ramp is. It involves a ratio of the rise and the run of your roofing system. The rise is how much higher the ramp goes (upwards), and the run is how long the ramp stretches out horizontally.

You might have seen on many websites something written as 4:12, 2:12, and more. This is how we write the slope of the roof. 

If you see the pitch ratio as 3:12, then what it means is that the roof rises 3 inches for every 12 inches it runs horizontally. The higher the first number, the steeper the roof. (The number 12 is taken as standard usually because building materials and construction products are often measured in feet and inches)

You might also hear pitches described as low-slope or steep-slope roofs.

• Low-slope roofs: Anything 4:12 and below
• Steep-slope roofs: Anything above 4:12

Why does this matter? Because water runs off steeper roofs more easily. On a flatter roof, water moves slower, and that means a greater chance of leaks if the roofing material isn’t designed for that pitch.

The Absolute Minimum Pitch for Asphalt Shingles

According to the Asphalt Roofing Manufacturers Association (ARMA) and most major shingle manufacturers, the minimum pitch for installing asphalt shingles is 2:12.

If your roof pitch is less than 2:12, asphalt shingles are not recommended. They’re not designed to handle water on low-slope roofs since water can back up under the shingles, especially during Oklahoma’s heavy rains, leading to leaks and expensive repairs.

Why Asphalt Shingles Are A Great Choice For Your Home

Asphalt shingles are one of the most popular roofing materials for a reason:

Cost-effective: They offer solid performance at a budget-friendly price, making them a smart investment for most homeowners.

Easy to install and repair: Their design and widespread availability mean faster installs and simpler fixes, saving you time and hassle.

Available in a wide range of colors and styles: Whether you’re after a modern look or something more traditional, there’s a shingle style available to match your home.

Good lifespan: With regular inspections and minor upkeep, asphalt shingle roofs can last  15 to 25 years with proper maintenance. They’re known for handling sun, rain, and hail for years without problems.

What Happens If You Install Shingles on a Pitch That’s Too Low?

Installing shingles on a pitch that’s too low is a sure way to find yourself dealing with water damage. While asphalt shingles provide protection, they rely on gravity to move excess water away from their material. This isn’t possible with a low pitch, where water is more likely to pool, seeping underneath the shingles over time, especially during storms or ice buildup.

If shingles are installed on a pitch below 2:12, you’re taking chances when it comes to keeping your manufacturer’s warranty valid and getting coverage after damage occurs. 

What Protection Should You Use On A 2:12 to 4:12 Pitch?

When you have shingles installed on a roof pitch between 2:12 and 4:12, you must take extra precautions to keep your roof in good condition and avoid water damage. This includes installing a layer called the roof underlayment over the roof deck. Ice and water shields can also be utilized for added protection before the shingles are installed. 

This added layer acts as a backup, just in case water makes it under the shingles. In a state like Oklahoma, where wind-driven rain and hail are common, that backup layer is not optional — it’s essential.

Here are the three common types of underlayment:

• Felt underlayment
• Synthetic underlayment
• Rubberized underlayment

To learn more, check out our blog post: Best Types of Roof Underlayment

What Material Should I Use If My Roof Pitch Is Below 2:12?

Roofs with pitches lower than 2:12 are classified as flat or low-slope roofs, and these systems require completely different roofing materials. 

Here are some material options you should consider for your flat roofing system: 

Modified bitumen: A tough, layered system using asphalt and reinforced fabrics, ideal for low-slope areas. It’s installed in rolls and can be torched down or cold-applied.

TPO: A single-ply white membrane that reflects heat and is heat-welded at the seams, offering energy efficiency and durability.

EPDM: A black, rubber-like membrane known for flexibility and long life, especially effective in both hot and cold weather.

Built-up roofing (BUR): A traditional system with layers of bitumen and fabric, often finished with gravel for UV protection and durability.

Hire The Pros at A. Fricker Roofing & Waterproofing 

We’ve seen it all, from roofs where shingles were improperly installed on low slopes to warped decking, mold growth, and water-stained ceilings. When it comes to determining whether your current roof pitch is designed for shingles, or something else, we’re the team of professionals you can trust. 

If you are looking to install a new asphalt shingle roof, our team can help. At A. Fricker Roofing and Waterproofing, we have years of experience in roof replacement and installation. We’ll walk you through the best options and make sure your investment is protected. Give us a call today at (918) 402-7167 to schedule a free roof inspection. We’ll inspect your current roofing system, measure the pitch, and give you honest recommendations based on experience. 

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