Subsidence – for any property owner it is likely to be a dreaded diagnosis. For good reason, too. When subsidence affects a building the cost of putting it right may prove very expensive, not to mention the time and disruption involved in the remedial works. Plus, finding subsidence cover in the future can be challenging.

With loss or damage on this scale, of course, your thoughts are likely to turn to subsidence insurance as a means of protecting your investment in the property. The problem with that solution, however, is that some property insurers simply refuse to cover the perils of subsidence and even when they do, may charge a significantly higher premium for properties in areas of known risk or past incidences of subsidence.

The specialists

Subsidence cover, therefore, is commonly regarded as a non-standard form of protection, provided by specialist insurance providers – such as those of us here at GSI Insurance, where we have made it our particular business to find appropriate cover for properties at risk of subsidence.

Each property is different, of course, so the risk of subsidence is likely to vary from one building to another – even within the same street. A case by case approach, therefore, is typically needed to secure the appropriate cover for any particular property. This is an approach which the specialist insurance provider is generally well suited to offer.

The heart of the problem

Although the risk of subsidence may be at the heart of your difficulties in securing suitable insurance cover, the problem caused by this kind of damage to the foundations of a building are by no means straight forward or the reasons always the same.

Subsidence refers to the shrinkage and collapse of the ground bearing the foundations of the property, but the reasons for its appearance may differ from one property to another. Any of the following, for instance, may contribute to subsidence:

• past mining industry activity;

• leaking or collapsed drains;

• the shrinkage of clay soils in times of drought;

• the erosion of chalky, sandy or gravelly soil during heavy rain; and

• disturbance of the foundations from the spreading roots of trees and large shrubs.

What is more, there is rarely any definitive opinion on the way of tackling and mitigating the risks posed by such developments.

With respect to trees growing close to the property, for example, conventional wisdom has been to remove them completely, roots and all. More recent studies – by groups such as The Subsidence Forum – however, suggest that there are ways of balancing the need to protect buildings from the threat of tree roots undermining foundations and the equally important need to maintain a green and pleasant environment in which trees and other large shrubs have a central role to play.

As the Forum points out, it is by no means clear which trees – even those growing close to buildings – are likely to cause problems of subsidence. Uprooting apparently offending trees may also make problems worse because of the large crater likely to be left behind once the roots have been removed. A more widely accepted practice these days, therefore, may be to keep trees close to your home well pruned, so that excessive leaf growth does not lead to the tree taking up too much moisture from the soil in which it is growing.

Check out our Guide to Subsidence cover for more information.