How to spot the tell-tale signs of subsidence

Subsidence is no small matter. In fact, it is arguably the most serious issue a property can suffer from, as it not only impacts the structural integrity of the building but will substantially affect its resale value. Spotting the signs of subsidence early on will make a big difference, as it can allow swift action to be taken to stop the issue from getting out of control. But even if the subsidence has progressed quite far, there are methods that are successful at treating it. Plus, precautionary steps can be implemented to prevent it from coming back later on.

Subsidence defined

Subsidence involves the ground underneath a property sinking. When the ground lowers, the foundations of the property can become misaligned. The worst kind of subsidence involves the ground underneath the property sinking at varying rates.

It is worth distinguishing between subsidence and settlement. The Financial Ombudsman Service defines subsidence as the ‘downward movement of the site on which a building stands – where the soil beneath the building’s foundations is unstable’. Whereas, settlement is defined as “downward movement as a result of the soil being compressed by the weight of the building within ten years of construction”.  The distinction is important as insurers will normally not cover settlement.

Risk factors

The risk of subsidence will depend on a variety of environmental, geological and construction-related factors including:

  • Clay soil, which can shrink and crack in hot and dry weather
  • Certain trees and shrubs can dry out soil, leading to more risk of subsidence
  • Older homes with shallow foundations
  • Leaking drains – can potentially soften the soil, making it become compacted under the property
  • Local mining or fracking

How to spot the signs of subsidence

Cracks caused by subsidence will be relatively thick – and a rule of thumb is that subsidence causes cracks that are diagonal, wider at the top and over 3mm in thickness. These cracks will be visible both inside and outside the property and are usually found close to doors and windows. Subsidence can also extend to below the damp course. It is worth noting that if your home is new, or freshly plastered, it is normal for small cracks to develop. This is a result of the plaster drying and the building settling.

Further signs of subsidence can include doors and windows becoming stiff as frames begin to warp, and wallpaper crinkles at wall and ceiling joins. The latter can also be a result of condensation or damp, so it is worth ruling these issues out.

Prevention

Often subsidence is outside your control, but you can mitigate against the risk by:

  • not planting trees or shrubs too close to your home
  • catching rainwater in water butts to water the garden
  • ensuring that your gutters, pipes and plumbing are all regularly checked and maintained

If you think your property may be suffering from subsidence it is vital that you contact a structural engineer as soon as possible to inspect the property.