Subsidence in buildings

If Homes Under the Hammer has taught us anything – aside from the fact avocado bathroom suites will never make a comeback – it’s that subsidence can spell bad news for homeowners.

If you’ve ever filled out a home insurance application you’ll probably be familiar with the term, but unless you’ve lived in a home which suffers from this problem you may not understand what it means.

This guide is packed with all the information you need to make sure you’re making the best choice when buying a new home and covers everything you need to know if the home you own shows signs of subsiding.

What is subsidence?

Simply put, a house that’s subsiding is sinking into the ground. Homes built on clay are more likely to suffer from subsidence than those built on other types of soil.

Subsidence can occur when the ground below the house shrinks or swells due to the weather – during wet weather the ground expands due to the moisture but then contracts during the dry summer months.

So, as much as we may crave a long hot summer, it’s certainly not ideal for homes built on clay.

What causes subsidence?

Aside from the heavy winter rain followed by a summer dry spell there are a few other situations which could cause your home to subside.

Common causes include leaking drains and tree roots.

A leaky drain can wash away the soil under your home or make the ground so saturated that the foundations give way causing it to subside. It’s important to keep your drains clear of debris and in good working order.

And although your lush, green garden may be the talk of the street, the roots from those beautiful trees and large shrubs have to go somewhere. If that ‘somewhere’ happens to be under your home, you may have a problem.

Roots grow longer as they search for moisture, and bigger trees like willows and elms are noted as being among those most likely to cause subsidence if planted too close to your home.

In some cases, where your home is built can cause a problem too. Areas that have been mined in the past can result in unstable foundations or, even worse, structural damage to your home.

The thought of your home sinking into the ground may sound like something pretty noticeable and hard to miss but it’s unlikely to be that dramatic. If you’re looking for signs of subsidence then you need to be on the lookout for distinctive cracks in your walls.

Though many homes may sport a crack or two – which probably first appeared as the house was settling – the cracks which show up as your home is subsiding are quite distinctive.

Cracks from subsidence can:

Appear and spread rapidly compared to regular cracks
Occur both inside and outside the property
Look narrower at one end than the other and run diagonally across the wall
Be found around doors and windows

Other telltale signs include:

Doors and windows start to jam as you try to open/close them as they’ll be out of alignment
Wallpaper crinkling at the wall/ceiling joins (though this could be hiding behind any coving)
Cracks where any extension joins the property