Manufacturers usually offer long-term warranties that range from 20 to 50 years for commonly used roofing materials. For example, traditional, flat asphalt shingles that cover most homeowners' roofs in the U.S. typically come with warranties that last 20 to 30 years, according to the "This Old House" home-improvement website. The site notes that some thicker shingles made from asphalt or recycled rubber that resemble slate and other pricey roofing products often come with a 50-year warranty.
The National Roofing Contractors Association discourages consumers from letting the length of a warranty be their primary focus when choosing a roofing system. A lengthy warranty often comes with several limitations, so many costs associated with fixing problems may not be covered. For instance, the NRCA notes that warranties usually don't guarantee that a roofing system won't leak under any circumstances. Warranties often only guarantee that a company will repair leaks linked to specific causes.
Materials vs. Labor
Typical roof warranties often only cover materials. For instance, a manufacturer may guarantee to replace shingles for up to 20 years if the shingles are defective due to a failure in the manufacturing process. Shingles that are cracking or splitting for no apparent reason may point to a manufacturing defect. However, the NRCA indicates that a warranty may only guarantee that replacement materials will be provided in such circumstances, which means you may have to pay labor costs associated with replacing defective shingles.
Your roof warranty could outlast the company that issued it. The NRCA notes that some manufacturers issue long-term roof warranties and then go out of business, making your warranty useless. One way to protect yourself is to focus on the warranty that your roofer offers to guarantee his work. For example, find out whether the roofer pays for materials and labor costs if your roof fails due to improper installation. Get all guarantees from your roofer in writing.