Two warranties, two promises
A new roof usually comes with two separate warranties:
- The manufacturer's warranty covers the product: shingles, membrane, metal panels. It is written by the maker, and its terms often depend on the product being installed to the maker's instructions.
- The contractor's workmanship warranty covers the installation: flashing, fastening, how the system was put together. It is written by the contractor and is only as good as the contractor's business.
Ask for both in writing, with their lengths and what voids them. The code itself sends you to the manufacturer: roof coverings are installed "in accordance with" the manufacturer's installation instructions throughout IRC Chapter 9.
A warranty is not a lifespan
The number on a shingle bundle (25, 30, 50 years, "lifetime") is the length of a warranty with conditions, often prorated over time. It is not a forecast of how long the roof will last. HUD's useful-life table for capital needs assessments plans asphalt shingles at 20 years, metal at 50, slate at 75, clay or concrete tile at 60, and EPDM or TPO at 15.
A single leak on a roof with years of life left is usually a repair.
Questions to ask
- Which warranty covers which part of the roof, and for how long?
- Is the manufacturer's coverage full for a period and then prorated? From when?
- Does the manufacturer's warranty require the contractor to be one the maker lists, or to register the job? Who registers it?
- Does the warranty transfer if you sell the house, and how?
- What voids it: a later layer, rooftop equipment, solar mounting, walking on the roof?
Checking a contractor
A workmanship warranty depends on the contractor still being in business. See checking a roofing contractor for the registration or license to ask for in your state.
Questions
What is the difference between a manufacturer and a workmanship roof warranty?
The manufacturer’s warranty covers the product, such as shingles, membrane or metal panels, and often depends on installation to the maker’s instructions. The contractor’s workmanship warranty covers the installation, including flashing and fastening, and is only as good as the contractor’s business. Ask for both in writing.
Does a 30-year shingle mean the roof lasts 30 years?
No. The number on a shingle bundle is the length of a warranty with conditions, often prorated over time, not a forecast of the roof’s life. HUD’s useful-life table plans asphalt shingles at 20 years.
What can void a roof warranty?
Ask before signing what voids each warranty, such as a later layer, rooftop equipment, solar mounting or walking on the roof. Also ask whether the manufacturer requires a contractor the maker lists or job registration, and whether the warranty transfers if you sell the house.