The idea of your home having subsidence is pretty scary, and dry spells make it even more likely. The good news, though, is that it won’t necessarily be as difficult to remedy as you might think.
Subsidence is the shrinking and lowering of the earth that your home is built on, which results in the foundations moving and cracks appearing in the building. It’s more of a problem with certain types of soil and with period properties, as they often have shallow foundations.
There are several causes of subsidence, but one of the most common is trees. Tree roots can cause movement by growing under the foundations, but even if they’re not that invasive, the roots extract moisture from the soil, causing the ground to contract. Consumer group Which? estimates that around 70% of subsidence is caused by tree roots, which is why you may want to think twice before planting a tree near your home or buying somewhere with a sizeable tree close to it. Pruning or removing the tree is often the solution, but it can make the problem worse.
Clay soil is another common cause of subsidence. It usually holds a lot of water, but when the water table drops during dry weather, the clay starts to shrink. Hidden mine shafts or bell mines, culverts and pipework, or sandy or gravelly soil can also cause subsidence. Defective drains also mean that leaking water can wash away unstable soil from around a building’s foundations.
If you think your home is suffering from subsidence, tell your buildings insurer, as they should get an expert to check it out.