When a roofer says the work is guaranteed, it is worth knowing which of three things they mean. A workmanship guarantee covers how the work was done. A manufacturer's warranty covers the product. Public liability insurance covers damage caused while working. They are separate, they cover different failures, and only one of them is usually written down without being asked for.
Workmanship guarantees
This is the contractor's own undertaking that the installation was done correctly, and it is what covers you if a detail was formed badly and leaks. Its value depends entirely on the firm still trading and still standing behind it, which is a good reason to use an established local business with a fixed address rather than a number on a van.
What matters is that the length and the scope are written on the quotation, not mentioned in conversation.
Manufacturer warranties
Product warranties come from the material manufacturer and cover the product failing in itself, a membrane delaminating, a tile failing prematurely. They generally require the product to have been installed to the manufacturer's specification, which is another argument for keeping the paperwork that says what was used.
A manufacturer's warranty does not cover poor installation, and installation is what most flat roof failures come down to.
Insurance is not a guarantee
Public liability insurance covers injury or damage caused by the works, a scaffold pole through a conservatory, a tile through a car windscreen. It has nothing to do with whether the roof leaks afterwards. Both matter; they are simply not the same thing.
- Ask to see the insurance certificate, not just be told it exists
- Check the policy is current at the time of the works
- Confirm who is responsible for the scaffold and its insurance
- Keep a copy with your quotation and invoice
Keeping the paperwork useful
Store the written quotation, the final invoice, the guarantee terms and any manufacturer documentation together, along with the photographs of the concealed work. It costs nothing, it settles arguments, and it is exactly the bundle a buyer's surveyor will ask about if you sell the property.
Common questions
What guarantee do you provide?
Workmanship guarantees and full insurance are part of how we work, and the specific terms for your job are set out on the written quotation before you commit to anything.
Does a guarantee cover storm damage?
No. A workmanship guarantee covers defective installation. Damage from a subsequent severe weather event is an insurance matter.
Is an insurance-backed guarantee necessary?
It protects you if the contractor ceases trading. Whether it is worth the cost depends on the size of the job, it makes more sense on a full re-roof than on a flashing repair.
Can I see your insurance certificate?
Yes, ask and we will provide it. Any contractor reluctant to show it should be a concern.