What to do about subsidence?
Updated: Feb 16, 2021
We have all heard nightmare stories about subsidence. Fortunately, it is a problem only affects a minority of people. However, it is worth being prepared.
Putting subsidence into perspective
Subsidence is mainly a problem in areas with clay soil – notably south of an imaginary line between Bristol and Hull.
The main areas affected are London and the South East, but even in this part of the country, only one in 50 houses has suffered subsidence problems over the last 30 years.
Most home insurance policies will cover the damage resulting from subsidence. You can reduce the risk to your property by knowing what to look out for and taking some simple preventative measures.
What is subsidence?
Subsidence is caused when a building’s foundations sink because the soil is unstable. Contributory factors are clay soil, vegetation that draws water from the soil, and leaking drains. ‘Heave’, on the other hand, is when the ground swells because of increased moisture, causing the foundations to rise.
What are the warning signs of subsidence?
The first obvious signs are cracks, but most houses suffer cracking, so don’t be alarmed by every crack that appears. The damage is usually cosmetic and can be repaired with grout or sealant. Many cracks result from settlement, when a building moves under its own weight in its first few years. These are usually nothing to worry about.
However, watch out for small, usually diagonal cracks suddenly appearing in plasterwork around doors and windows or between different parts of the property, especially after long periods of dry weather. They are normally at least 1mm wide and are usually wider at the top than at the bottom.
If you are at all worried, contact your buildings insurer straight away. If you are in the process of buying a home and suspect subsidence, commission a Home Buyer's Report.