Asphalt shingles are the most commonly used roofing material in the United States — and for good reason. They’re durable, affordable, and easy to install. Some industry experts believe that as many as 75% of all roofs in the U.S. are covered with asphalt shingles. But have you ever wondered what they’re actually made of?
Let’s break down the layers that make up an asphalt shingle and what each one does to protect your home.
Fiberglass Mat
At the core of modern asphalt shingles is a fiberglass mat — a strong, lightweight sheet made from woven glass fibers. This mat serves as the structural backbone of the shingle, providing flexibility and resistance to tearing. It's what gives the shingle its shape and durability.
Asphalt Coating
The fiberglass mat is coated with asphalt, a sticky, tar-like substance that gives the shingle its water-repellent properties. This is the same kind of material used in road construction, but it's specially refined for roofing. The asphalt saturates and seals the mat, creating a waterproof barrier that helps your roof shed rain, snow, and moisture.
Mineral Granules
On the top surface, the shingle is covered in mineral granules. These granules serve multiple purposes:
- UV Protection: They shield the asphalt from sun damage.
- Color & Curb Appeal: They come in various colors to complement your home's exterior.
- Fire Resistance: They help the shingle meet fire safety standards.
- Impact Resistance: They add texture and thickness to improve protection from hail and debris.
Some specialty shingles may even include algae-resistant granules to prevent black streaking caused by algae growth.
Back Surface Coating
The underside of each shingle is coated with a fine sand or mineral powder to prevent them from sticking together in the packaging. This layer also helps with installation by allowing shingles to slide into place more easily.
Bonus: Self-Sealing Adhesive Strips
Many asphalt shingles include a strip of heat-activated adhesive that help them bond to the shingle below once installed and exposed to the sun. This seal prevents wind uplift and improves weather resistance.
Why It Matters
Understanding what asphalt shingles are made of helps homeowners appreciate the technology behind something that might seem simple at first glance. Every layer has a purpose—working together to protect your home from the elements, day after day.
But as time passes, Mother Nature’s ever-present barrage takes a tremendous toll on your shingles. The sun, wind, hail and rain provide a constant attack on your roof’s ability to protect itself and your home.
- Granules come loose.
- The fiberglass mat is broken by hail.
- The asphalt dries out from the sun’s immense heat through the years.
All these factors cause your shingles to become brittle, your home to lose its energy efficiency, and you to face a significant effort in replacing your roof.
Thinking about a new roof or wondering how long your shingles will last?
Let the experts at Roof Scientist evaluate your roof and help you decide whether it's time to replace, repair, or restore it with a roofing solution like Cericade, our exclusive nano-ceramic technology that brings your roof back to its original health – without the trouble and downtime of a full roof replacement. Cericade is not a temporary solution; it’s a long-term solution that protects your roof – and your family. Click here to start today!