Much of south and west Essex, including Brentwood, Billericay, Epping and Loughton, sits on London Clay. Clay soils hold water and change volume as they wet and dry, which can affect the walls of the homes built on them.
How clay soils move
In dry summers, clay loses moisture and shrinks. In wet winters it takes water back up and swells. Mature trees and large shrubs close to a house draw moisture from the soil, making the effect more pronounced.
Not every crack is subsidence
Small cracks are common in many homes and are often caused by normal settlement, thermal movement or plaster shrinkage. Some patterns need closer attention:
- Stepped cracks through brickwork near corners or openings can indicate ground movement
- Horizontal cracks repeating every few courses often point to corroding cavity wall ties
- Cracks above windows and doors may mean a failed or missing lintel
- Cracks that open and close with the seasons suggest movement in the ground
When to get advice
Cracks wider than a few millimetres, cracks that are getting bigger, doors and windows that start sticking, or cracks appearing on both the inside and outside of a wall are all worth having inspected. Suspected subsidence should be reported to your buildings insurer.
Repairs
Where the cause has been dealt with or the movement has stabilised, cracked masonry can be repaired with helical bars bonded into the mortar joints to stitch the wall back together, followed by repointing to match.
Damp on clay soils
Clay’s poor drainage also keeps ground floors and cellars under moisture pressure, so damp and cracking often appear together.
We survey homes across south-west Essex. See cracked wall and wall tie repair in Essex and damp proofing in Essex.
