Most warranties also have limitations on coverage due to age, and are pro-rated over the life of the roof. Additional conditions are imposed based on ownership transfer and the sale of the home. The warranty normally just covers manufacturing defects, which, in my experience as a contractor, is pretty rare. 


Best Practice

I had the roof replaced on my home about 10 years ago.  I chose a product from a well-known manufacturer and had it installed by a long-established roofing company.  I had them install it for the higher wind rating of 130 mph (6 nails instead of 4), and I have not looked back. A good product properly installed should not need a warranty.  If you chose a product such as “Bubba’s Basic” and it is installed by a fly-by-night outfit then you may end up with problems, and the hope that a warranty will cover you may be just a fantasy.