How to spot the signs of subsidence

24 May 2012

During droughts millions of homes could be at risk of subsidence. Find out what it is, how to spot it and what you can do about it.

Houses built on clay soil are particularly susceptible when sub-soils dry out and start to crack, causing the ground beneath the house to sink. Older houses built with shallow foundations are most vulnerable and trees also draw moisture from the ground, causing it to shift.

Signs of subsidence

The first obvious signs of subsidence are cracks appearing; usually diagonal, wider at the top and often near windows and doors. All buildings expand and contract to a degree and not all cracks indicate subsidence. Newly built properties and extensions often crack as they ‘settle’ and fine cracks frequently appear on a recently plastered wall as it dries out.

Watch the cracks

If you think that your home is at risk of subsidence, keep an eye on old and new cracks – especially those that suddenly appear, are wider than a 10 pence coin and go through brickwork or stone. If you’re concerned, it's advisable to contact a surveyor.


In the worst cases, your property may have to be underpinned – often a complex, lengthy and disruptive process. Not only that but buying or selling a house with a history of subsidence and underpinning becomes more problematic when it comes to getting insurance cover.

Meanwhile, regular home maintenance is important, particularly if your house is built on clay. Leaks from drains and pipes will saturate the ground causing ‘heave’ or wash away the soil so keep gutters and drains clear and fix any leaks.

Looking after your home during a drought

In the garden

Trees close to the house will take moisture from the soil. If your home’s at risk, you may need to prune or even remove mature trees and certainly consider where you plant new ones. If in doubt, get in touch with a tree specialist or surveyor.

Help retain moisture in the garden by planting less thirsty plants like lavender and buddleia that thrive in hot, dry conditions.

Mulch, bark chips and gravel help prevent evaporation.

Think twice about increasing patios, decking and paved areas in the garden that actually prevent water getting into the soil.

Catch rain water in butts and buckets and use household ‘grey water’ from the bath, washing up, boiling vegetables and so forth for watering the garden.


A short shower instead of a bath could save up to 400 litres of water a week.

9 litres of water a minute goes straight down the plug when taps are left on while brushing teeth or shaving.

A dripping tap can waste as much as 90 litres a week.

Get mean and dirty – save the laundry and washing up until there’s enough for a full load.

A water saving device in the loo cistern can save three litres a flush.

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The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.