What Are Roof Shingles Made Of? | All About Asphalt Shingles

shingled roof with satellite dish

What makes asphalt the shingles of choice for so many modern homes?

Besides being affordable and economical, asphalt shingles for homes are versatile, durable and long lasting—providing maximum protection for your roof while minimizing cost. And while they may look basic in design and fabrication, don’t be fooled: asphalt shingles are actually carefully engineered, multi-layered components whose simple appearance belies their complex structure and function.

What does an asphalt shingle consist of?

The typical asphalt shingle is composed of three distinct layers:

Fiberglass Mat

The strength for which asphalt shingles are known is a function of the fiberglass base layer, or mat, which helps give them their signature durability. As the name suggests, fiberglass is made from tiny pieces of glass that are heated to extreme temperatures, and then extruded through narrow holes to create glass filaments. The filaments are woven together to create a flat sheet, which is cut down to the size needed to create the base layer for the asphalt shingle.

Asphalt Layer

Placed over the fiberglass mat, the primary purpose of the asphalt layer is to keep moisture from seeping through. Rather than relying on the blown-in method of years past, the asphalt layer is built up through the application of a specialized asphalt compound known as styrene-butadiene-styrene. This material increases the durability of shingles by making them more impact-resistant and helping to hold the top granules firmly in place.

Granule Covering

The gritty material on the top of the asphalt shingle is typically crushed rock sealed and protected with a ceramic coating. These granules protect the asphalt layer against damaging UV rays, help make them fire-resistant, and give shingles their color—allowing consumers to create a unique aesthetic for their home’s exterior. Because granule loss can compromise the integrity of the roof, manufacturers typically apply up to 50 percent more granulations than required to cover the asphalt shingle. This overage compensates for granular erosion that can compromise the integrity of a home’s roof.

Why Choose Asphalt Shingles?

When it comes time to upgrade your roof, modern asphalt shingles are a wise choice. Their tri-layer construction of a fiberglass mat, asphalt layer, and granules contributes to excellent longevity and performance—making them a durable option that prevents damage from water and impact that can be installed affordably.