Dormer warranty periods, in plain English
Short answer
A dormer warranty has several layers: the structure (often 6–10 years), the materials (manufacturer terms, often 10–25 years), the leadwork (5–10 years) and the finish (1–2 years). The piece that matters most is whether the warranty is backed by an insurance scheme — that is what survives the company going out of business.
What actually gets a warranty
Quotes often say "10 years warranty" without specifying on what. Ask for the components separately: the structure, the cladding, the frames, the glazing seal, the leadwork, and the interior finish. Each has its own lifespan and its own warranty in practice.
Typical warranty periods
| Component | Typical period | Notes |
|---|---|---|
| Structure | 6–10 years | Often longer with a trade body scheme. |
| Cladding (Keralit/Trespa) | 10–25 years | Manufacturer warranty, separate from the installer. |
| Frames (PVC) | 10 years | Hardware (hinges, locks) often 2 years. |
| Glazing seal | 10 years | Covers seal failure, not glass breakage. |
| Leadwork | 5–10 years | Often the shortest — and the most likely to fail. |
| Interior finish | 1–2 years | Plaster cracking from settlement is excluded after that. |
Company warranty vs insurance-backed warranty
A company warranty is a promise from the firm that installed your dormer. If the firm stops trading, the promise stops with it. An insurance-backed warranty — typically through a trade body — is paid out by an insurer or a guarantee fund. That is the protection that matters in year seven, not year one.