The Average Life of a Composition Shingle Roof

Definition

• Composition shingles made from asphalt made their appearance on roofs around the turn of the 20th century. At first they had a foundation of felt or paper that was soaked in hot asphalt to waterproof it. The hot asphalt was then coated with tiny mineral granules to protect the asphalt from the damaging effects of the sun. They looked very much like the roof shingles we have today. Modern composition shingles usually have a stronger fiberglass foundation, asphalt and the same mineral coating that the older shingles had.

Choices

• From the beginning, composition shingles came in a variety of sizes and shapes. Diamond-shaped shingles were popular because they mimicked the appearance of concrete shingles. Color choices expanded beyond black and gray in the early 20th century. The easy-to-install, three-tab composition shingle we recognize today came into use before World War II, then became a roofing standard in the building boom following the war.

Thickness

• Generally speaking, the thicker the shingles, the better the quality. For decades, composition shingles were a mere 3/16 of an inch thick. In recent decades, however, consumers have been offered more choices. Thicker shingles, often with multiple layers of material, approximate the texture and color of slate or wood shingles. Architectural-grade shingles with multiple layers and subtle variations of color are often found on high-end or custom homes.

Life Span

• The life span of a composition roof depends mostly on quality, so the thicker the shingle, the longer it can be expected to last. Average quality, three-tab shingles can be expected to last between 10 and 20 years. The warranty for such shingles is usually 10 to 15 years. Thicker, architectural-quality shingles often come with 25- or 35-year warranties. Some manufactures offer heftier 3/8- to 1/2-inch shingles that they guarantee for 50 years.

Installation

• To enjoy the full life span of any roofing shingle, proper installation is necessary. Nailing is particularly important. The nails must meet the manufacturer's specifications in both material, length and head diameter. If your roofer skimps on nail quality--or the number of nails used on each shingle--they become vulnerable to damage from high winds, which can unnecessarily ruin a roof before its time.