When determining which contractor, and which material, to put on your roof, compare the warranties. Coverage provided by the warranty is a good gauge of the quality and workmanship you can expect. Before going with any one brand however, it is a good idea to check for reviews regarding the manufacturer and product-line.
All contractors are required to cover the entire cost of the roof for 1 year from install. After that, the manufacturer's warranty will kick-in. This is true for all warranties.
Most manufacturers will provide a basic 10 or 15 year warranty. Such warranties usually cover only the cost of installation, and the roofing-tile, and are pro-rated over the 15-year period. It will not cover tear-off, flashing, or any other parts or labor that will be necessary to repair the roof. The materials and labor covered are often less than half of the total cost of the roof, and pro-rating will bring that coverage to 50% of that, after about 8 years.
This warranty rarely covers more than manufacturer defects, and is voided by faulty installation. Again, most contractors will only cover faulty installation for the 1-year period required by law. This means that if they put a nail in the wrong spot, and you get a leak 14 months later, you'll be paying out of pocket, and probably quickly finding more problems.
Many manufacturers will offer a longer term warranty for most of their products, covering 25, 40, or 50 year periods. Like the Basic warranty, the first year is covered by the contractor. Most such warranties cover all, or most, of the cost of the shingles and installation, up to 10 years, then prorate for the remainder of the coverage.
Additionally, many such warranties will require a contractor with at least some history, or certification, with the manufacturer. Such contractors will often be able to provide additional coverage for the other costs, providing much better coverage that may be able to recoup up to 80% of the total costs in the case of a defect in labor or materials within the first 10 years.
This is the most common warranty provided for quality roofing shingles, and it can be hard to get much better coverage.
Only a very small number of manufacturers can provide full-coverage warranties. Such coverage is often rare enough, that many homeowners are surprised to learn it even exists. These manufactures can provide warranties which cover the entire cost of the roof for the entire life of the shingle. Specific shingle product lines, installed only by contractors certified and vetted through the manufacturer, can come with 50-Year, transferable, unlimited, 100% coverage of initial cost.
This kind of coverage means that even if the contractor screwed up in 2005, you bought your home in 2007, and it started leaking in 2025, the homeowner doesn't pay a dime. Trust and security like that can be a big selling point to prospective buyers in the future, and peace of mind for anyone owning the home.
Many manufacturers come close to this ideal, offering 25-Years full-coverage, and 50-year overage on shingles and install labor. The only manufacturer we're aware of that can provide full-coverage for 50-Years, for all costs, is Certainteed. It might be worth giving them a look.