What Are Roof Shingles Made Of?

We are often thankful to have a roof over our heads, particularly when the weather gets bad, but how often do we stop to think about how it protects us? Here, we talk about what roof shingles are made of, and why they work so well for keeping rain, wind, and snow at bay. 

What Are Roof Shingles?

Roof shingles are typically flat, rectangular pieces that are adhered to the roof rafters in overlapping patterns, starting at the bottom of the roof and working upward. They can be made from a variety of materials, including wood, metal, plastic, and asphalt. Ceramic roof tiles, which are popular in some countries outside the United States, are typically referred to as roof tiles, rather than shingles.

Roof shingles are used to provide a protective layer on top of buildings. The materials they are made from and the pattern in which they are laid are designed to keep out water from rain and snow and prevent damage to the roof deck and everything beneath it. 

What Are Roof Shingles Made Of?

There are many ways to make roof shingles and roof tiles, but the most popular style in the US is asphalt shingles. Fiberglass asphalt shingles are made from a combination of fiberglass, asphalt, granules, sealant, and release film. 

  • Fiberglass: When the shingles are manufactured, a continuous web of precisely measured fiberglass fibers is used to create a thin, flat sheet that is used as a foundation for the other materials. The fiberglass fibers are held together with resins and binders.
  • Asphalt: Asphalt is processed and oxidized to improve its strength and water-resistant qualities. A fine mineral powder is added to the asphalt and mixed for an increase in weather resistance and fire resistance. Then the asphalt mixture is laid on the fiberglass foundation.
  • Granules: The next layer is the one we see the most of and is made from tiny rock granules. Hard stones (usually limestone) are crushed and inspected until they are ready for the ceramic firing process that turns them a specified color. Some granules are even made to be reflective in order to bounce away more of the sun’s heat from the roof.
  • Sealant: A laminate is used to bond the layers of the shingles together. Then a sealant is used to help shingles adhere to one another when placed on the rooftop. The sealant may be located on the top surface of the shingle or the bottom layer. This sealant also helps keep the sticky asphalt from latching onto the process roll during manufacturing and prevents shingles from sticking together when packaged.
  • Release Film: A thin, shiny layer of film is applied to the backside of shingles when they are packaged. It does not need to be removed during installation, but will prevent the sealant from activating during storage. 

Are Fiberglass and Asphalt Shingles the Same?

Fiberglass shingles are made with asphalt and are technically a type of asphalt shingle. There are also organic mat asphalt shingles, which use paper as the base layer rather than fiberglass. Unless you examine them very closely, they are the same in appearance.

Fiberglass shingles are more water-resistant and fire-resistant, and work really well in hot climates. However, they are less durable in climates that are dominantly cold. With a fiberglass base, manufacturers can use less asphalt and still maintain strength and longevity. This also makes them lighter and better for the environment.

What Is the Difference Between Composite and Asphalt Shingles?

The difference between composite and asphalt shingles is largely found in what the roof shingles are made of. Asphalt shingles are made with a paper or fiberglass base layer and asphalt on top. Composite shingles are made using a variety of materials, including wood, slate, and laminate. 

Composite shingles typically cost a bit more to install, but also last longer. They have an added protective coating that helps the shingles resist cracking and fading. Both types are great for protecting your home from the elements, so which you decide to use will come down to the number of years you plan to spend in your home and your current budget. 

If you can spend more up-front and plan to stay in your home for 30 years or more, composite shingles may be a great option. If your budget is smaller and you plan to spend less than 20 years in your home, asphalt shingles may be the better way to go.

Why Are Shingles Made of Asphalt?

Asphalt is used to make shingles because it is water-resistant and not very expensive. Asphalt shingles are one of the most popular options because they are affordable and last for decades. They are also easy to install and can sometimes be recycled.

Are Roof Shingles Toxic?

Roof shingles are mildly toxic only during installation, but this is typically not a problem. As long as you don’t drink the water runoff from your roof and are not near hot asphalt shingles during installation, you will not be harmed. If you are exposed, you may experience mild nausea or a headache and feel better within a few days.

Asphalt shingles are also not bad or toxic for the environment. They can even be recycled and used for road repairs in some areas.

DMG Exteriors

For more information about what shingles are made of and other questions about your Indiana roof, contact DMG Exteriors today.