A Guide to Subsidence

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The word subsidence can fill many of us with dread. This however does not need to be the case when we understand what it is and how it can be prevented. We have put together some ideas on how to prevent subsidence and what to do if you spot signs of it in your home.

What is subsidence?

Subsidence describes a process where the ground under a property collapses or sinks lower, taking some of the building’s foundations with it. This puts strain on the property structure, causing cracks to appear.

Damage related to subsidence can be severe and costly to monitor and repair, which makes it a scenario homeowners and insurers alike are understandably wary of.

What causes subsidence?

  • Clay soil can shrink, crack and shift during both hot or wet weather, making the ground unstable and potentially causing foundations to sink.
  • Trees and shrubs can also be a factor, particularly if they’re close to your foundations. Some species absorb a lot more water, making the soil more unstable.
  • Uneven foundations caused by water can make the property unstable.
  • Vibrations or excavations.
  • Leaking or damaged drains.

Signs that I could have subsidence at my property

Firstly, it’s important not to jump to the conclusion that your home is subsiding, as not all cracks are a sure-fire sign. Most are simply caused by the natural movement of the property as it ages.

Signs of subsidence include:

  • ‘Stepped’ cracks, or cracks which appear to run diagonally, and are wider at the top than the bottom
  • Cracks which are thicker than a 10p coin
  • Cracks which can been seen both internally and externally
  • Wallpaper crinkling at wall/ceiling joins
  • Cracks where an extension joins the house
  • Cracks around doors and windows
  • Doors and windows sticking where frames have warped

If you suspect you have a case of subsidence, contact your insurer who can arrange for a structural engineer to visit your property and confirm it. If it is subsidence, there may be an extended period of monitoring to determine the cause. In severe cases, the property may need to be structurally reinforced by ‘underpinning’ – a process which supports the foundations.

What can I do to prevent my home from subsiding?

Some areas of the country are unfortunately at more of an innate risk of subsidence than others due to variations in soil type, but there are plenty of actions you can take to either reduce the risk, or catch it early on.

To cut down the risks of subsidence you can;

  • Check the condition of the property regularly for any signs of subsidence.
  • Avoid planting trees or shrubs too close to your property or outbuildings.
  • If a mature tree is already positioned too close to your property, seek advice from a surveyor or tree expert about how best to manage it and whether it should be removed.
  • Regularly prune trees and shrubs to help reduce how much water is absorbed.
  • Carry out regular maintenance of drains and pipes. You should check for blocked or leaking drains, clear the gutters of leaves and dirt regularly and check pipes to ensure there are no damaging splits.

What can I do if I’ve had subsidence?

Unfortunately, if your home has suffered subsidence, it can be difficult to guarantee that it will not reoccur, and you may find it more challenging to get cover. Most reputable insurers will still provide quotes, but you may find that these contain higher excesses or exclusions relating to subsidence.

Ensure you retain records of any monitoring or surveys which have taken place that explain the suspected cause of the movement and any remedial action which was taken. The more information you can provide when requesting a quotation, the better, as it will allow insurers to consider your case in more detail.

Most importantly remember you are in good hands! Our knowledgeable Client Account Handlers are available if you have any worries or concerns about subsidence and will advise accordingly.


Lumley's Top Tips for Subsidence:

  • Routinely check your property for large diagonal cracks both inside and outside.
  • Check floors, are they bending? Are doors starting to jam?
  • Specifically check areas where new extensions join the original house
  • Try and avoid planting trees within 10 metres of the main building
  • Cut back existing trees
  • Check guttering, pipework and drainage to make sure they are all working correctly and replace any that need work.