The condition of asphalt composition shingles is dictated by the condition of the granules in the joints between the tabs or cutouts in the shingles. If the granules are intact in the cutouts or joints between the tabs, the shingles are acceptable. If the granules in the cutouts are worn and the asphalt matrix is visible, the shingles are marginal because of the obvious wear and limited remaining life expectancy. Curling or cupping shingles may be an indication of wear, age, or condensation problems; however, it does not indicate failed shingles.

The life expectancy of asphalt composition is determined by the following:

1.   The slope of the roof. Shingles last longer on higher sloped roofs.

2.   The color of the roof. Lighter colored roofs last longer than darker colored roofs.

3.   Exposure to the sun. North facing shingles last longer than south facing shingles.

High slope, light color, east west facing roofs can last 25 years or more. Low­ slope, dark color, south facing roofs may fail within 15 years.

Careful attention should be given to flashings and valleys of asphalt shingle roofs. The majority of roofing problems come from these areas.

Asphalt shingles are primarily made of asphalt “flux,” a material, which is refined from petroleum in the distillation process. Asphalt flux is typically reinforced with glass fibers or cellulose fibers. Glass fiber reinforcement has performed better than organic or cellulose reinforcement. The shingle matrix then receives a granular surface. Granules protect the shingle from the sun and the weather and increase the fire resistance rating. Asphalt composition shingles typically have a fire rating; however, the primary materials in these shingles are paper and petroleum, which are flammable. Shingles come in different shapes and configurations and are normally installed on roof slopes of four inches per foot or more. The most widely used shingles are self sealing strips.