Leaning Tower of PisaBoris Roessler/DPA/Press Association Images

It's not just hosepipe bans that we have to fear as a result of the current dry spell. There's another, much more serious, threat to homeowners in dry parts of the country.

So with the Met Office predicting another dry month in those areas already suffering from low rainfall, we examine this threat to your home.

Subsidence

The danger in question is subsidence. According to the Royal Institution of Chartered Surveyors (RICS), there are more than 30,000 subsidence claims annually, at a cost of over £150 million.
A report in the Daily Mail quoted Steve Foulsham, of the British Insurance Brokers' Association, who said: 'With the drought conditions at the moment we expect to see more claims."

How it works

The problem surfaces in dry weather, as the ground dries up and shrinks. This is a particular problem with clay, which tends to hold a lot of moisture. In dry weather a great deal of the water will evaporate. In addition, trees will suck water from the soil as they are denied rain.


When that moisture goes, the clay shrinks considerably and the earth your house is built on will sink. As a result, the house will start to sink too. This doesn't happen uniformly throughout the house, so parts of it will sink and will open large cracks in the walls and floors. Over time, if these aren't dealt with effectively, it will damage the structural integrity of your home and it could eventually collapse.

What can you look for?

It's vital to catch subsidence early by watching out for the warning signs. Most commonly you will see cracks in brickwork, render, plaster or even stonework. If you have wallpapered your rooms, you may see bulges in the paper. Commonly with subsidence, these cracks will appear around doors and windows. They will typically be wider at the top than the bottom, and will tend to run diagonally.

However, there are lots of reasons why these cracks may appear, so don't panic. If it is less than 3mm wide, then often this is just the general movement that all houses experience.

Likewise, a common sign is where doors and windows start to stick, as the joinery distorts. Again, this can be because of a leak or a faulty door, so it's not necessarily the end of the world. It is, however, essential to be on your guard.

What can you do?
Subsidence can be cured. If it is minor, and the movement has stopped, your insurer may simply suggest you fix the cracks and install markers to monitor whether the problem gets any worse.

However, if it is more serious, the work can be disruptive and extensive. The best solution is often underpinning, which means digging under your foundations and pouring concrete in - or even driving steel piles in. If you are in a terrace, neighbouring properties may need supports too. It means the work can cost more than £50,000.

However, on the plus side, according to RICS, only around 10% of properties suffering from subsidence end up needing underpinning.

Will you be insured?

Home insurance does usually cover repairs to subsidence. However, it tends to have a large excess, so you will need to lay out your own money. It's worth checking what your excess is, as some can be as high as £2,500.

What are the implications?

If you have subsidence, even if you never make an insurance claim, then home insurance for that property will rocket. And it doesn't even have to happen to you to affect your cover. If your neighbourhood is prone to the problem, then premiums will go up across the board.

The process of curing the problem can take months or even years of work and monitoring. According to RICS, two years isn't uncommon. If you want to sell in this time, it will be obvious to buyers, and you will struggle.

If the subsidence is ongoing, then their survey should spot it, they will then struggle to get insurance, which will have a knock-on impact on their ability to get a mortgage. It's not impossible to sell a property with problems, but you will need specialist insurers and you can expect a major hit to the price.

After the problem is cured, there's no legal reason why you should volunteer the information. However, if the buyer specifically asks about subsidence, then you will need to be honest.

Top ten postcodes for subsidence, from Direct Line


• N4
• NW5
• W10
• N19
• NW6
• SE24
• SE23
• SE22
• SE15
• NW11

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