How to Spot Signs of Subsidence

What is subsidence?

Subsidence is an issue that often concerns property owners - and for good reason: It can be difficult to spot and costly to fix. In this article, we look at what subsidence is, how to spot it and how insurance may help to ease your concerns.

Subsidence is the downward rotational movement of the ground, which can cause structural damage to a building.

Is my house at risk of subsidence?

Properties built on a clay-rich soil and those with shallow foundations and near to vegetation are most at risk from subsidence damage.

As seen in 2018, when summer was marked by 12 weeks of little to no rain, subsidence can become a wider problem following a long period of hot, dry weather.

Oak, Willow, Hawthorn and Sycamore trees can compound the issue as they require a lot of water and adapt to a drought by spreading their roots into new areas where they wouldn’t ordinarily grow.

What causes subsidence to houses?

Subsidence in a property can be caused by a number of things. Some of the main causes of subsidence include:

  • Tree or vegetation roots disturbing the ground and foundations beneath the home
  • Clay soils increase the risk of subsidence as they shrink and swell depending on the water content (this is usually exacerbated by trees or vegetation)
  • Leaking drains could cause the ground surrounding the foundations to soften or wash away

What are the tell-tale signs of subsidence?

It is not always possible to spot the earlier stages of subsidence, but there are a few key signs of structural movement to look out for, including: 

  • Large cracks in a wall, usually around a door or window frame, which are wider at the top than they are at the bottom. These cracks are usually more than 3mm wide.
  • Doors and windows sticking
  • Sloping floors - this is common in older properties
  • If you have an extension, look for cracks where the extension meets the main part of the house.

What should I do if my house shows signs of subsidence?

Signs of subsidence should not be taken lightly. Should you spot signs of subsidence, it is important to seek expert advice and contact your insurer.

Only an expert will be able to provide suitable advice and the appropriate course of action, which may include underpinning (stabilising the foundations), removing any vegetation or trees, or in some instances demolishing and rebuilding (this is common with garages or extensions).

What can I do to reduce the chances of subsidence?

Unfortunately, there is only so much you can do to reduce the chances of subsidence - particularly if your home is in a subsidence-prone area. However, there are a number of preventative measures you can take to ensure that you are not contributing to the problem:

  • Avoid planting trees too close to your home. This is particularly important if you live in area of clay soils. As a general rule of thumb, tree heights should not exceed distances from the property, but consult an arborist for guidance
  • If your house is already surrounded by large trees, consult a tree surgeon to find out what action you can safely take without causing further damage to your home. Sometimes, removing a tree or plant can cause further damage.
  • Make sure that your guttering is well-maintained so as to avoid leaks, which could cause the ground to soften.

What is the difference between settlement and subsidence?

This is a question that home owners commonly ask. In contrast to subsidence, settlement is a natural part of the building process and is something you may experience if you move into a new or relatively new building. As the ground becomes compacted with the extra weight, small shifts occur as everything settles in. Builders will often return to a new property a few months after is has been finished to check and repair the minor cracks that can appear as a result of settlement.

What do I need to know about subsidence insurance coverage?

As a specialist insurance provider, Towergate aims to cover circumstances just like these and provide cover even if your property has a history of damage caused by ground movement. If you’ve been turned away elsewhere, speak to Towergate - we may be able to help. 

In order to insure a property with a history of subsidence, we will need full details of: the cause; when subsidence occurred; the repairs that have been done; and copies of any surveys that have been carried out. If the occurrence was over five years ago, we may also ask to for a more recent structural engineer's report.

Subsidence insurance from Towergate

For more information, visit our dedicated subsidence insurance page or call us on 0344 892 1750 to speak to a specialist adviser.