Most bad roofing jobs begin the same way: someone you did not contact tells you there is something wrong with a roof you cannot see from the ground. The second most common way they begin is a quote with no line for safe access, which is either an understatement of the price or a plan to work off ladders. Both are checkable before you agree to anything.
The cowboy roofer's first move is the doorstep
Which? puts the doorstep approach first on its list of rogue trader red flags: "a so-called professional arriving at your doorstep without prior contact". In roofing the pattern is well documented. Trading Standards have issued repeated warnings about cold callers offering roof cleaning, following complaints of damaged roofs and poor work.
The pitch works because you cannot check the claim. A stranger reports a slipped slate or cracked mortar, offers to sort it while the ladder is on the van, and you are agreeing to work you had no reason to think you needed. Roof cleaning is often cosmetic anyway. Moss on a sound, well-pitched roof is not an emergency, and it is never something to buy because someone knocked.
It is also unlawful. Persistent unwanted solicitation, and ignoring a request to leave or not return to your home, are banned outright under the current unfair commercial practices rules. The answer on how to spot a dodgy builder sets out that regime and the CMA's new power to fine directly.
How people get ripped off
Money leaves before the work does. Which?'s second red flag is traders who demand a large deposit before they have started, or who offer a discount for paying in cash. Citizens Advice is blunter: avoid traders who only accept cash or want everything upfront, push the deposit down as far as you can, and do not agree to more than 25%.
That 25% is guidance, not law. No UK statute caps deposits at any figure. But the reasoning holds: both the FMB and TrustMark frame the legitimate upfront payment as a contribution towards materials, not a payment for labour that has not happened yet. A roofer who wants half the job in advance is asking you to fund the business's cash flow and carry its risk.
Cash itself is not a red flag, and the separate answer on paying a roofer in cash sets out why the usual scare version of this is wrong. The part that belongs here is the practical consequence the NFRC points to: contractors offering cash or VAT-free deals are not easily tracked down when something goes wrong. The tell is never the discount. It is whether the price is conditional on there being no invoice.
Verify rather than trust
Trust is the wrong frame, because the checks are cheap and the trade is unlicensed. Anyone may legally call themselves a roofer in the UK, so the job title carries no information at all.
Insurance is where verification matters most and is done worst. Certificates are trivially forged. Two checks mean something: confirm the insurer is authorised on the FCA Financial Services Register, and ask the roofer to have the broker email you confirmation or send the policy schedule rather than the certificate alone. Check that the named party is the exact company you are contracting with and that the dates span your whole project. A legitimate contractor arranges this without fuss, and a refusal is itself the answer.
No safe access on a full re-roof is a red flag
The Work at Height Regulations 2005 require work at height to be properly planned, supervised and carried out by competent people using suitable equipment. They do not name scaffolding, and they do not have to. A tower or a powered access platform can satisfy them, and brief low-risk work may need neither. What a full re-roof needs is days of working across the whole covering with materials moving up and down, and safe access of some kind is not optional for that.
Scaffolding is the usual answer on a terrace, which is why a quote that quietly leaves it out is worth challenging. Either the price is understated and the cost is coming later, or someone intends to do the job off ladders. Neither is a good start.
Scaffolding also generates paperwork you can ask to see. Scaffolds must be inspected after installation and before first use, then at intervals of no more than seven days. The handover certificate and the inspection records are documents a compliant contractor has to hand and a cowboy does not.
If you have already agreed to something
A contract forms more easily than most people expect: signing, verbally accepting a quote, fixing a start date, paying a deposit, or telling someone to proceed. But a contract agreed in your home is an off-premises contract, and the cancellation period runs for 14 days after the day it was entered into. Where the trader never gave you written cancellation information, that right can extend to 12 months and 14 days, and failing to give it is a criminal offence carrying an unlimited fine.
Work started during the cooling-off period only counts against you if you requested it in writing. If it began without that written request, or without proper cancellation information, you can cancel and owe nothing for it.
None of these checks help once the scaffold is down, so do them before you sign.