Dimensional shingles are a new generation of high-quality asphalt roofing products with distinctive, often dramatic, appearances and are among the highest quality roofing products made. They are composed of a heavy fiber glass mat base and ceramic-coated mineral granules that are tightly embedded in carefully refined, water-resistant asphalt. Recently, a new product has surfaced on the market, synthetic slate. It is an innovative roofing product that simulates the appearance, texture and contours of traditional natural slate. It is a carefully engineered polymer composite roofing product that is formulated for beauty, durability and handling.
Besides offering a surplus of good looks, most asphalt architectural shingle products have a design feature that helps prevent a common aesthetic problem: black streaks caused by algae. This is commonly seen on roofing shingles in areas with high humidity and rainfall totals. Algae-resistant shingles are coated with copper or zinc granules, which leach over time, inhibiting algae growth. Because of their greater thickness, architectural shingles have better wind tear-off resistance. Some are rated at 120 miles per hour. They are also highly fire resistant especially if they have a heavy granulated top coat. A heavy layer of top coat granules provides the highest fire rating of Class A.