Asphalt shingles are the most common residential roofing material in North America, and with good reason. They are versatile, durable, affordable, and easy to install.
Asphalt shingles are manufactured in a continuous web process, using a limited number of raw materials that are important to their performance. All the materials are configured in such a way as to produce durable and high-performing shingles.
Here’s a look at the layers that make up every asphalt roof shingle and how they help protect your home.
In the manufacturing process, a continuous fiberglass sheet or web is used to create the foundation on which asphalt and other materials are affixed. The fiberglass membrane is made by chopping tiny fibers of glass and mixing them with water to form a pulp.
The water is vacuumed out of the pulp and then binders and resins are applied to the mat. The fiberglass mat is sliced to appropriate widths and wound into rolls.
Asphalt is the primary water-resistant material in roofing shingles. It is a mixture of dense, sticky, highly viscous organic liquids, which can be obtained from naturally occurring deposits or as a residue from the distillation of petroleum. Although similar to the type of asphalt used for roads, roofing asphalt requires a specialized refining process to harden it to the degree that is required for optimal roofing performance.
The material then has to be oxidized through a process called blowing. Air is blown through the heated asphalt, increasing its viscosity. This process must be precise to prevent softness, brittleness, or scuffing of the blown asphalt.
A mineral stabilizer such as finely ground limestone or fly ash is added to the blown asphalt to make it more durable and to enhance its weather and fire-resistance properties. Once ready, the mineral-fortified asphalt coating is pressed on the top and bottom of the fiberglass mat.
Ceramic-coated mineral granules are the most visible part of asphalt shingles. Hard rock is crushed and sized to meet exact standards. The granules are applied to the shingle in their natural stone-colored state. They are then processed through a ceramic firing process to give the exposed part of the granules long-lasting colors.
Some types of granules contain copper to inhibit the growth of blue-green algae, which can discolor the shingles. Reflective granules are also sometimes used to reflect a higher percentage of the sun’s heat energy.
The stone granule surfacing protects the shingles from the sun’s UV rays, increases their fire resistance, and enhances the overall look of the roof.
Spots or strips of a thermally-activated asphalt sealant are applied to the shingles at the time of their production. The sealant is placed on either the top or bottom surface of the shingle. If the shingles are made up of several layers, a material called laminate is used to adhere them together during the manufacturing process.
Once the shingles are installed on a roof, they are heated by the sun, and this activates the asphaltic adhesives to bond overlapping shingles together. It also helps increase the shingles’ resistance to wind events and other roof stresses.
The final component of the asphalt roofing shingles is the release film. This looks like a shiny plastic tape located on the back of the shingles. It is designed to keep the sealant from activating prematurely and sticking the shingle surfaces together during packing and storage. The release film doesn’t need to be peeled off during installation.
Shingles are the most common and affordable roofing material, and with good reason. While all of this information may seem somewhat technical in nature, it can be helpful for homeowners to know the components of the shingles being installed on their rooftops to help them make better-informed decisions. At Alan’s roofing, we desire to give you the best roof possible for your unique home situation, and education is a part of that process.
If you need a new roof or help to repair a damaged shingle roof, Alan’s Roofing is ready to help. We are one of Central Florida’s leading roofing contractors, providing expert workmanship, quality roofing products, and honest customer service. Contact us today to learn more about asphalt shingles and to schedule your free estimate.