Water leaks from neighbours are a very common problem, but it’s not always easy to establish precisely where they are coming from and who is responsible for organising and paying for the resulting repair work. According to Direct Line Home insurance, it happens a massive 800,000 times a year! Even a simple leak can cause extensive damage to walls, carpets, tiles and even built-in furniture that can’t be moved out of the way, such as kitchens and wardrobes. The average repair bill is, apparently, £858.

Leaks are a particular problem in flats, with the perpetrator often unaware they are causing a problem and tenants often slow at reporting them. So, what should you do if you spot some water coming into your flat from the one above? The longer a leak goes on, the more the damage it does, so speed is of the essence. The first and most obvious thing to do is place a bucket under the drips and move anything out of the way that might get damaged, including carpets. One excellent tip is that if a lot of water is coming through a ceiling, you can make a small hole in it, controlling its flow and preventing the water building up on the other side of the plasterwork. Once that’s done, go and bang on the neighbour’s door .

If you can’t get hold of them, a plumber should be able to turn off the water supply either to the offending property or for the entire building. In really extreme cases, in England and Wales, you can call the police and get them to force entry in order ‘to prevent serious damage to the property.' Under no circumstances should you break into the neighbour’s property yourself.

When you (or a plumber) get access to the offending property, spotting the source of the leak can sometimes be a serious challenge because not only do flats often have complex networks of old pipework, water can also travel quite long distances through the building’s structure before making an appearance.

Even so, you should start by looking directly above where the water is entering your flat. The most common causes to look out for are; washing machines and dishwashers (especially their connector hoses), baths and showers (pay particular attention to sealants and tile grout), radiators (check the joints between the pipes and the radiator) and any new plumbing work.

Once you’ve found the source of the leak, repairs can begin. There will be an excess, but the costs of the repairs should be covered under buildings insurance, which in the case of a block of flats is usually dealt with by the management. The advice is that you should contact your insurance company (or managing agent, if renting) to report the leak as soon as possible and they will, typically, send out an assessor. It may also be worth taking some photos to document the damage.

If the leak was a minor one and you are planning on dealing with it yourself, first make sure the plaster hasn't blown. It’s very common, but there may be no obvious signs that it’s happened. What you need to do is tap it, as blown plaster will sound and feel more 'hollow' than solid areas. Any loose bits you find should then be hacked off and patch repaired. If, however, it’s still in good condition, you should then let any damp patches dry out for as long as possible – anything up to four weeks - although you can hire a dehumidifier to speed up the process. When the walls are bone dry, you can use an oil based stain blocking paint to cover any discolouration. Be aware if there is even the smallest amount of residual damp, you will seal it in, which, as you can imagine, will just make things worse. 24 hours after applying the stain blocker, you can then paint over it with ordinary emulsion paint to match the existing.