“It’s all guaranteed, mate.” We hear this phrase a lot when homeowners tell us about quotes they have received. It sounds reassuring — until you ask what “guaranteed” actually means, and the answer turns out to be nothing you could ever rely on.
Roofing guarantees are not all the same, and the differences matter enormously if something goes wrong. Here is what the terms mean, what to look for, and what to get in writing.
The three types of roofing guarantee
1. The workmanship guarantee. This is the roofer’s own promise: if our workmanship fails within a certain period, we will come back and put it right. It is the most common type of guarantee and, frankly, the most variable. A workmanship guarantee is only as good as the company behind it. From an established firm that has been trading for decades, it carries real weight. From a one-man outfit with a mobile number and no address, it is worth very little — because if the roofer disappears, so does the guarantee.
Typical workmanship guarantees run from 5 to 15 years depending on the work. A repair might carry 2–5 years; a full re-roof more. Be wary of anyone offering a “lifetime guarantee” on workmanship — no company can promise that meaningfully, and the phrase is often a sales tactic rather than a real commitment.
2. The manufacturer’s warranty. This covers the materials, not the labour. If the tiles, membrane, or flat-roofing system itself fails due to a manufacturing defect, the manufacturer replaces or compensates for the faulty product. These warranties can run 10–30 years on quality products.
The catch: manufacturer warranties almost always require the product to have been installed correctly, to specification, by a competent installer — sometimes an approved one. If a cowboy installs a premium membrane badly, the manufacturer will quite reasonably say the failure is an installation issue, not a product defect. This is why the installer’s own guarantee matters just as much as the product warranty.
3. The insurance-backed guarantee (IBG). This is the gold standard. An insurance-backed guarantee means that if the roofing company ceases trading, an insurer steps in to honour the workmanship guarantee. It removes the single biggest weakness of a standard workmanship guarantee: the risk that the company will not be around in ten years.
IBGs are usually arranged through trade bodies or specialist providers, and they add a modest cost to the job — which is why not every roofer offers them. On a major investment like a full roof installation in London, an IBG is well worth asking about. It typically lasts 10 years and covers the cost of putting defective workmanship right, up to a set limit.
What a proper guarantee should say in writing
Whatever type of guarantee you are offered, get the details on paper before work starts. A proper guarantee document should state:
- What is covered — workmanship, materials, or both, and any specific exclusions
- How long it lasts — the start date and the end date, not just “ten years”
- What voids it — for example, unauthorised alterations, or failure to maintain gutters and clear debris
- How to claim — who you contact, and what the process is
- Whether it is transferable — useful if you sell the house; a transferable guarantee is a genuine selling point
If a roofer cannot or will not put these details in writing, you do not have a guarantee — you have a hope. This is one of the cowboy roofer warning signs we always tell homeowners to watch for.
Common guarantee misunderstandings
“The guarantee covers everything.” It does not. Guarantees cover defects in workmanship and materials. They do not cover storm damage, lack of maintenance, or someone else walking on your flat roof in stilettos. Normal wear, extreme weather, and third-party damage are standard exclusions.
“A long guarantee means a better job.” Not necessarily. A 20-year workmanship guarantee from a company incorporated last year is less reassuring than a 10-year guarantee from a firm trading since 1982. The company’s history is part of the guarantee’s value.
“I don’t need the paperwork; I trust them.” Even with the most trustworthy roofer, get it in writing. Memories fade, staff change, and if you sell the house, the new owners will want to see the documents. Paperwork protects good roofers as well as good customers.
What to ask before you commit
Add these to your list of questions to ask a roofer: What guarantee do I get, exactly? Is it your own workmanship guarantee or insurance-backed? Can I see the terms in writing before I agree? Is it transferable if I sell?
The answers will tell you a great deal about the firm. A professional roofer answers these questions plainly and produces the paperwork without fuss. Evasion, vagueness, or irritation are answers in themselves.
Our approach
Every job we do comes with fully guaranteed workmanship, in writing, as standard — the terms are set out clearly before we start, and our frequently asked questions cover how our guarantees work. We have been family-run in Camden since 1982, which means our guarantees have always been backed by a company that is still here to honour them. If you are comparing quotes, ask each roofer what their guarantee actually says — then ask us for a free quote and compare.