POSTED 27 September 2018 General

Subsidence - What are the Signs and Procedures?

What is subsidence? 

Subsidence occurs when a house subsides, meaning it is sinking into the ground past its original foundation. Subsidence, therefore, can be a very serious issue that not only affects the structural integrity of a property but also its resale value. 

However, if you think your home is subsiding, do not panic. There are measures you can take to help arrest the issue and even the most severe cases of subsidence can be resolved.

What causes subsidence?

Subsidence is caused when moisture levels in the ground change. This can result in the ground sinking or collapsing. When this happens under a building part of the foundations can be taken with it, placing a strain on the building and resulting in damage, wherein cracks can begin to form.

There are a number of key risk factors:

  • If your home is built on clay soil
  • Drought-prone areas
  • Leaking drains and water mains
  • Local mining activity
  • Trees and shrubs close to the foundations of your home

signs of subsidence 

Signs of subsidence 

If you think you might be at risk of subsidence, keep an eye out for possible signs, because the sooner you spot it, the better chance you have to rectify it quickly. Look for:

  • Cracks in the walls, ceilings and outside brickwork.
  • The cracks will be thicker than a 10p coin (more than 3mm), travel diagonally and be wider at the top than the bottom. They are visible internally and externally and found close to doors and windows.
  • Wallpaper crinkling at wall or ceiling joins not caused by damp.
  • Doors and windows sticking as frames warp.

Procedures

If you have noticed any of the above tell-tale signs in your property, the first thing to do is to call your home insurance provider. They will be able to arrange a full survey to ascertain whether or not it is a genuine case of subsidence or if it’s something less serious.

In the most severe instances of subsidence, underpinning may be required. This type of repair work usually halts subsidence, preventing further movement of the foundations.

However, this is a lengthy and potentially very expensive procedure – costing upwards of £5,000 depending on the size of the house and the extent of the damage. Because of this, underpinning is generally only recommended as an absolute last resort.

Luckily, only around 10% of properties suffering from subsidence require underpinning, and there are a number of other possible solutions that can help a homeowner to counter its effects.

How to avoid the risk of subsidence 

The following actions can help to minimise the effect that subsidence has on a property.

  • If you have plants or shrubs near your property, try to prune them regularly. This can help to reduce the amount of water the foliage absorbs from the ground. If you want to remove the plants, it’s vital to seek expert advice first.
  • To avoid leaks, ensure that all pipes, plumbing and guttering are well maintained.
  • You can reduce the amount of water that enters the ground by placing barrels or butts in your garden to collect rain.