Subsidence: How To Spot & Treat It

The Causes And Signs Of Subsidence
Treating Subsidence

Subsidence is movement in a building's foundations that is caused by one of several reasons. If you have or suspect your property has subsidence, don't be overly alarmed - in most cases, subsidence can be rectified.

By Gordon Miller

How Is Subsidence Caused?

There are several ways that subsidence usually occurs, most of which are beyond your control:

* In areas with a high concentration of clay soils prolonged periods of dry spells cause the water table to drop and movement occurs.
* Where trees and bushes have grown under the foundations and unsettled the building, especially in clay soils. Find out about your rights when cutting trees in our feature.
* Where a water leakage from a broken drainpipe or mains pipe washes soil away from the foundations. Find out more in our feature about broken or leaking drains.
* In areas with soil that has a high sand or gravel content, or sometimes chalk.
* In areas where there has been previous mining activity. Find out more in our feature on subsidence caused by mines.

What Are The Signs Of Subsidence?

There are several signs that may be indicative of subsidence. Look out for new cracks more than 3mm wide in the exterior brickwork, or the widening of existing cracks. Inside the house, keep an eye out for cracks in the plasterwork, and any 'rippling' effects in wallpaper that isn't caused by damp. If you notice any doors or windows beginning to stick it could be a sign of subsidence. But don't panic, wooden doors and floors may expand and contract slightly with the changing seasonal temperatures.

What Should I Do If I Think My House Has Subsidence?

Check your buildings' insurance. If you have a mortgage on your home you will almost certainly be insured for subsidence. Under the terms of your cover the mortgage lender will arrange for a chartered surveyor to inspect your property. If you do not have buildings' insurance, you will need to contact a chartered surveyor to independently assess the property. In certain extreme cases a structural engineer may be required to assess the level of the damage and propose a schedule of works to rectify the problem.