Asphalt shingles are those single pieces on a roof that are most likely to be used in many roofing applications in the industrialized world. Asphalt shingles are so versatile and economical that they represent up to 80 percent of all roof shingles. The shingles can represent a number of different colors, creating a custom look for nearly any home.
Asphalt shingles are made with one of two different materials, along with the asphalt. Organic asphalt shingles use an organic substance, usually a form of paper, which is coated with asphalt. Fiberglass asphalt shingles use a mat made of fiberglass that is shaped to the shingle, with an asphalt coating over it.
The most obvious parts of an asphalt shingle are the ceramic granules that are also embedded into the outer layers. These granules serve a number of different purposes. First, they reflect the sun's rays, thus extending the life of the shingle. Second, they provide coloring for the roof. This is why asphalt shingles can come in so many different colors.
The most common colors for asphalt shingles are lighter colors, such as gray or off-white. Darker shingles pose a number of different challenges. First, they tend to wear out quicker because they absorb the sun's rays, rather than reflect them. Second, that absorption can take the form of excess heat, adding more cost to cooling the home. For this reason, they may be more popular in cooler areas.
The life span of asphalt shingles is approximately 20 years, though some warranties guarantee the life of the shingle for much longer periods. Still, warranties may not be an accurate reflection of actual useful life. A number of things affect the lifespan, but temperature and variations in temperature are probably the largest contributors to aging. In general, asphalt shingles tend to last longer in cooler climates.
Replacing asphalt shingles is a relatively simple job from a technical standpoint, though the labor involved can become overwhelming, especially on hotter days. The shingle is usually laid on top of a protective layer of tar paper and then nailed or stapled into place. It is a job commonly done by home owners, but roofing companies can also be contracted for the project.
It is usually very easy to tell when asphalt shingles need replacing. A close inspection will reveal numerous cracks in older shingles. Further, if the shingles start to look swollen or bloated, it may be time to consider replacing them. Many people may be tempted to wait until further problems -- such as leaks -- develop, but this can cause substantial damage to the home and should be avoided if at all possible.