Two Warranties, Not One
Every new roof comes with two separate warranties, and confusing them costs homeowners money:
- Manufacturer's warranty — covers defects in the shingle or material itself. From GAF, Owens Corning, CertainTeed, or the metal/flat membrane maker. Typically 25 years to lifetime depending on the product tier.
- Workmanship warranty — from your contractor, covers installation errors. Typically 2 to 10 years from reputable roofers.
Here is the part most homeowners miss: most roof failures are installation failures — bad nailing, reused flashing, poor ventilation — which fall under the workmanship warranty, not the manufacturer's. A 30-year shingle warranty with a 1-year workmanship warranty is lopsided in the wrong direction.
What Voids a Manufacturer Warranty
- Improper installation — wrong nail count, placement, or depth. This is the number one claim denial reason.
- Inadequate ventilation — manufacturers require it; an overheated attic voids coverage.
- Overlay installation — shingling over old layers usually reduces or voids the warranty.
- Pressure washing — strips granules; explicitly excluded.
- Unapproved modifications — satellite dish mounts, for example, installed without proper flashing.
"Lifetime" Means Less Than You Think
Lifetime shingle warranties are prorated — the payout shrinks every year — and packed with conditions. Read the actual terms, not the brochure headline. The meaningful questions: what is covered in years 1 to 10 (the non-prorated period), and is labor included or just materials?
Enhanced Warranties
Factory-certified contractors can offer enhanced warranties that extend the non-prorated period and sometimes cover workmanship through the manufacturer. They cost more and require certified installation — worth asking about, especially on premium shingle lines.
Get It in Writing
Whatever you are promised — material warranty length, workmanship warranty length, what each covers — get it in the contract. Verbal warranty promises are worth the paper they are printed on. Our quotes spell out both warranties explicitly.