The first part to be concerned with is the material warranty. It is the warranty given by the manufacturer on the product that is installed on your roof. The most important thing to remember is the warranty registration form. No matter what your contractor may tell you, if you do not send in a warranty registration to the manufacturer, you do not have a warranty!
The majority of residential roofs are protected by asphalt shingles, and their warranty lengths are represented in their descriptions. The most typical types of asphalt shingles are 25 year (3-tab shingles), and 30 year architectural shingles. There are also 40 year and lifetime shingles available. It is easy to assume that a 30 year roof has a 30 year warranty, but with most standard warranties that is misleading. Your standard shingle warranty protects against manufacturer defects to the shingles only. This does not include labor to replace the defective product, or any other accessories that must be reinstalled, such as flashing.
What is worse; after the third year, the shingle cost is prorated according to the age of the defective shingles. For example, you have 30 year shingles installed on your roof. And after 10 years the shingles loose their color, and start curling and crumbling. If the manufacturer determines that the roof was installed properly, then you are awarded a warranty claim in the amount equal to the cost of 20 years of useful life left of the shingles. If the shingles cost $4,000 you receive $2666.66. You are responsible for paying for the difference in cost for the shingles, the accessories and felt paper, and the labor.
Secondly, there are extended warranties available through almost all roofing manufactures. All extended warranty programs require your contractor to be certified through the particular manufacturer of your shingles. You should always choose a certified contractor, regardless of the extended warranty. If the roof is not installed within the manufacturer’s guidelines, it could void your standard warranty from the very beginning.