Asphalt shingles are the most popular type of residential roofing material. Starting at about $0.80 per square foot installed, asphalt shingles are relatively inexpensive for most installations. Asphalt shingles are manufactured in two basic types: Organic and Fiberglass.
Organic shingles are comprised of two parts that consist of an organic felt material saturated with asphalt, and a top coating of adhesive asphalt where ceramic granules are embedded. Organic shingles contain approximately 40% more asphalt per 100 square feet than their fiberglass counterpart, making them heavier and more durable.
Fiberglass shingles have a glass fiber reinforcing mat manufactured to the shape of the shingle which is coated with asphalt containing mineral fillers. The purpose of the mat is for reinforcement and it is not waterproof. What makes the fiberglass shingle waterproof is the asphalt coating. Like the organic shingle, ceramic granules are embedded into the asphalt coating of the fiberglass shingle.
The ceramic granules used in both organic and fiberglass shingles are implemented for two purposes: 1.) protecting the shingles from damaging UV rays, and 2.) aesthetical purposes.
UV rays are very damaging to asphalt and cause it to deteriorate prematurely, so ceramic granules are embedded into the asphalt to create a protective barrier. Because ceramic granules come in a variety of colors, asphalt shingles can also be manufactured in a wide variety of colors to match almost any color scheme or facade.
Life Expectancy of Asphalt Shingles
The life expectancy of asphalt shingles depends entirely upon the environment in which they are installed. In cooler climates asphalt shingles last longer, and in hot climates the life expectancy of asphalt shingles is much less. For example, studies have been performed which show that the average lifespan for a 20 year shingle in Pennsylvania was 20.8 years, while in Minnesota the lifespan averaged 19.5 years. Conversely, the average lifespan for a 20 year shingle in Phoenix, Arizona was a mere 14 years.