Signs of subsidence
We define subsidence as the ‘downward movement of the ground beneath the buildings that is not a result of settlement’.
Our Buildings Insurance covers you against loss or damage caused by subsidence(please note we don't provide cover if your property has been affected by subsidence in the last 15 years). You can see precisely what’s offered in our Home Insurance Gold and Silver Policy booklet.
What are the signs of subsidence?
It’s not unusual to spot cracks in the walls of your home and, for the most part, they’re nothing to worry about and can just be filled in and repaired. These cracks usually result from settlement, especially in newer houses, as the building moves slightly under its own weight in the years after it’s built.
On the other hand, cracks that may be signs of subsidence tend to be diagonal, often appearing in plaster and brickwork around door frames and windows after long periods of hot weather. These cracks will usually be wider at the top than bottom and at least 3mm wide.
You should also look out for doors and windows that are sticking and don’t seem to fit in their frames, as well as ripples in wallpaper that can’t be put down to damp.
What are the causes of subsidence?
Subsidence is the result of the foundations of a building sinking in unstable soil.
The causes of subsidence include:
- trees and shrubs near your home drawing water from the soil, leading it to shrink and crack as it dries out, causing your foundations to sink
- leaks from drains softening the soil under your home
- your house being built over old excavations, or mines, which are unstable.
How can you fix damage caused by house subsidence?
The simplest fixes for subsidence are usually to catch it early and stop it going any further. That can be done by pruning or removing any trees which lie at the root of the problem and by repairing broken drains. Seek professional advice before removing/pruning any trees.
In more serious situations, the building may need to be strengthened by underpinning its foundations, which may involve installing support beams or adding a new layer of concrete. This can be expensive and may also be an indicator to insurers that your home is at risk of further subsidence, which could lead to higher premiums.
Are there any ways to reduce the risk of subsidence?
In addition to keeping an eye out for any signs of subsidence, there are also ways to minimise the risk and potentially save yourself a lot of stress in the future:
- Make sure you plant any new trees or shrubs at least as far away from your house as the height they should reach when mature. In most cases this will be between five and ten metres away.
- Choose the trees you plant carefully. Broad leaf varieties tend to be responsible for the most damage, and you should avoid planting pyracantha, rose shrubs and wisteria close to the house.
- Control your trees’ growth by having them pruned professionally and regularly.
- If you want to remove a tree, make sure you get professional advice first, as uprooting an old tree could cause exactly the kind of damage you’re trying to avoid.
- Keep up with regular maintenance of pipes and drainage systems to make sure there are no breaks or leaks.
- If you’re thinking of buying a house and have any suspicion of subsidence, commission a RICS Home Buyer’s Report and/or a RICS Building Survey.
Always be cautious when undertaking any task that you’re not fully familiar with as you could injure yourself or those around you, seek professional help where required.
What’s the difference between subsidence, settlement and heave?
Cracks due to settlement are quite common in newer houses and are a sign of the house settling into position, and not associated with subsidence. The cracks won’t usually get worse with time and are not wider at the top than the bottom, which is often a distinctive sign of cracks resulting from subsidence.
Heave, however, can be a serious problem and is almost the direct opposite of subsidence, in that it’s the result of ground beneath a building becoming saturated with water, making the soil expand. This causes the foundations to move upwards and often sideways, causing wide cracks to appear in walls.
Can I get subsidence insurance?
Most Home Insurance policies will cover you for subsidence, as well as heave and landslip. You should check your policy to see the details of exactly what is and isn't covered.