How to Choose a Roofer in London and Hertfordshire: What to Ask Before You Book

Most people call a roofer when something has already gone wrong. That creates urgency, and urgency is exactly the condition that allows poor contractors to operate. This guide is for people at the research stage — those who want to understand how to separate the good from the bad before a problem becomes an emergency.

These checks apply whether you are in Watford, Harrow, Ruislip, Pinner, Hertfordshire or anywhere else in the area. The fundamentals are the same.

Check They Are Registered on a Vetted Platform

Checkatrade and TrustATrader are the two most relevant vetted trade platforms for roofing in the UK. Both require contractors to submit to checks — insurance, identity, qualifications — before they can list. Both carry verified reviews from real customers against real completed jobs.

The key word is verified. A Google review can be posted by anyone. A Checkatrade or TrustATrader review is matched against a job record, which makes it meaningfully harder to fake. This does not make the platforms infallible, but it makes them a significantly more reliable signal than unverified reviews on other platforms.

When you look at a contractor's profile, look at the total number of reviews, not just the average score. A score of 9.8 from eight reviews is a different quality of evidence from a score of 9.5 from 120 reviews. Read the detail in the reviews, particularly what customers say about communication, tidiness and how the contractor handled any problems that arose.

Ask for Proof of Insurance Before Anyone Climbs a Ladder

Public liability insurance protects you if the contractor damages your property, a neighbour's property or causes injury while working on your premises. Without it, any damage or accident becomes your problem to resolve.

Ask for a copy of the insurance certificate, not just a verbal confirmation. Check the level of cover. For a standard residential roofing job, a minimum of £1 million public liability is standard, though reputable firms carry more. Imbrex Roofing carries £5 million. Any contractor who cannot or will not produce a certificate should not be working on your roof.

Get Multiple Quotes, Written and Fixed-Price

Get at least three quotes for any significant roofing job. Not because you should automatically take the cheapest — you should not — but because the process of getting multiple quotes forces you to ask the same questions of multiple contractors and gives you a basis for comparison.

Every quote should be in writing, should itemise what is included and should state a fixed price. Watch for wording like "plus any additional materials required" or "subject to what we find" in a quote. These are legitimate in limited circumstances — if the deck condition is unknown, for example — but they should be clearly explained, not buried in the small print.

If one quote is significantly lower than the others, ask why. In most cases, the difference comes down to materials. A roofer quoting a standard felt re-roof will quote less than one quoting fibreglass. If both are quoting the same specification and the prices are dramatically different, something is missing from the lower quote.

Red Flags to Walk Away From

These are not subtle signs. They are clear indicators that the contractor should not be engaged.

They ask for a large deposit before starting. They cannot produce proof of insurance when asked. They knock on your door uninvited claiming to have noticed a problem with your roof while passing. They pressure you to make a decision today. They refuse to provide a written quote. They want to be paid in cash only.

Any single one of these should be enough to end the conversation. Legitimate roofing contractors do not operate this way.

Questions About Choosing a Roofer We Get Asked Regularly

Is a roofer who knocks on my door ever legitimate?

Occasionally, but treat any unsolicited approach with significant scepticism. If someone tells you they noticed damage to your roof while driving past, ask for a written report and then get an independent inspection from a vetted contractor before agreeing to anything.

Do I need a specialist roofer for chimney work?

Not necessarily a specialist, but you do need someone who has carried out chimney repairs before and can demonstrate that. Chimney flashings, lead work and repointing require knowledge of materials and technique. Ask specifically about chimney experience when you enquire.

Should I use a local roofer or does it not matter?

Local is generally better for trades work, for the simple reason that a local contractor has more reputational skin in the game. They live and work in the area, their reviews are visible to their neighbours and they are easier to follow up with if something needs remedying after the job.

What should I do if a roofing job goes wrong?

Contact the contractor in writing, describe the problem clearly and ask them to rectify it within a reasonable timeframe. If they are registered with Checkatrade or TrustATrader, both platforms have dispute processes. Keep records of all communications. Do not withhold payment for other elements of the job in response — address the specific problem specifically.

Why does Imbrex not require a deposit?

Because we do not need one. We have the working capital to start jobs without asking customers to take on the risk of advance payment. We think it is the right way to operate — you should not have to pay for work until it has been done to your satisfaction.

Imbrex Roofing is registered on Checkatrade and TrustATrader with verified reviews, carries £5 million public liability insurance and has a strict no-deposit policy. We cover West London, Watford, Harrow, Ruislip, Pinner, Rickmansworth, Bushey and the wider Hertfordshire area. If you want a free inspection and a written quote with no obligation, call 0800 474 8347 or get in touch via the contact page.