A roofer knocked on my door saying my roof needs work: what should I do?

A stranger who tells you your roof is in a bad way has a reason to say so: they want the job. That does not mean you have no problem, but it does mean their word is not evidence. You owe them no answer on the day.

Be polite and short. "Thank you, I will arrange my own roofer" is enough. Do not say that you will think about it, because that invites a second visit. Do not let anyone onto the roof, a ladder or the loft, and do not hand over a deposit, a card or a key.

Callers often turn up after a gale, when a damaged roof is believable. They may say they noticed a slipped tile while passing, or that they have materials left from a job down the road. Neither of those is a reason to act. A roofer with a genuine concern can leave a card, and you can ring later if you decide to.

Once the caller has gone, check the claim. Have a look at your own roof, from the ground only, with binoculars if you have a pair. You are looking for tiles or slates that have slipped or gone, a ridge that looks uneven, lead that has lifted at the chimney, and gutters that are overflowing or sagging.

Inside, look at the loft with a torch for chinks of light coming through the roof, damp patches on the timbers, or staining on the ceilings below. Photograph whatever you find, with the date on each picture. Do not climb a ladder onto the roof yourself.

If you find nothing, you have your answer. If you find something, you now know what to ask a proper roofer to look at, and you have photographs of your own to hold up against anything you are told. A genuine fault can wait the day or two it takes to find a roofer you have checked, and a leak can be stopped temporarily in the meantime.

A real survey comes with evidence. Ask the roofer you choose to go over the roof and show you pictures of each problem, then say whether it needs repairing, a temporary patch or a new covering, and why. Then ask for the price as one written total.

Do the checks before you invite anyone. Our answer on finding a good roofer explains how, and it is worth reading before any money changes hands.

Be sceptical of anything that sounds too good. A story that your roof qualifies for a free government replacement is one. No national scheme funds a replacement roof, as our answer on roof grants explains. Be wary also of a price given from the pavement, of anyone who will only take cash, and of a caller who will not give a business address and a landline or mobile you can ring back.

You may have said yes before you thought it through. The law gives you time to change your mind. Under the Consumer Contracts Regulations 2013, an agreement signed off the trader's premises, such as in your own home, can be cancelled for 14 days after the day it was made, with no explanation needed. The trader must reimburse all payments you have made.

The trader has to tell you about this right. If nobody told you, the window can stay open for as long as 12 months after it would otherwise have ended.

One exception matters here. If you yourself invited the trader round for an urgent repair, the cancellation right does not apply to that visit. A caller who came unasked does not fall within it. Our answer on cancelling a roofing contract explains the rules, including what happens if you asked for work to start inside the 14 days.

If you believe a caller was misleading or aggressive, write down what happened while you remember it: the date, the time, what was said, any name or number on a vehicle or a leaflet. Keep any paperwork you were given, and photograph the roof as it is now.

Citizens Advice runs a consumer service that gives advice to individuals, and your local council can tell you where to report the visit. If you paid by card or bank transfer, contact your bank straight away, because speed matters.

Tell a neighbour, especially an older one, that a caller has been round. A caller may well try the next door as well. A roof that really does need work should be seen to by a roofer you picked, with the faults shown to you in photographs and a written quote in your hand. You can ask JJ Roofing Bognor Regis for a written quote after a survey, and the home page lists the roofing work we do.