Can tree roots cause subsidence?
If you have large trees near your home, you might wonder if they are a threat to your property. The short answer is absolutely yes. Tree roots are one of the most common causes of subsidence in the UK, particularly in areas with clay soils.
At Geobear, we believe in being "uncertainty killers." Understanding how your garden impacts your foundations is the first step toward protecting your home.
How tree roots cause subsidence
It is a common myth that tree roots physically "push" against foundations to cause damage. In reality, the process is much more indirect and related to the moisture in the ground.
- Moisture extraction: Tree roots extract large volumes of water from the soil to grow.
- Clay soil shrinkage: When roots pull moisture out of clay soil, the soil dries out and shrinks in volume.
- Ground movement: As the soil shrinks, the ground beneath your foundations drops.
- Structural cracking: Because this movement is rarely even, it causes "differential settlement," leading to the classic diagonal cracks seen in subsidence.
The seasonal pattern of damage
Subsidence caused by trees often follows a cyclical pattern that adds stress to your home’s structure.
- Dry summers: Damage is typically worse during hot, dry summers when trees have a high demand for water and the soil is already parched.
- Wet winters: In the winter, the clay can rehydrate and swell, causing the ground to rise slightly.
- Cyclical stress: This constant movement—shrinking in summer and swelling in winter—creates ongoing stress that can weaken your home's structure over time.
Identifying high-risk trees
Not all trees are equal when it comes to foundation risk. Some species are much more aggressive than others.
- Problematic species: Oak, Willow, Poplar, Ash, and Elm are known for having high water demands and expansive root systems.
- Aggressive growth: Fast-growing species with aggressive root systems pose the greatest threat.
- Proximity: A good rule of thumb is that any tree planted within 1.5 times its mature height of a building could potentially cause a subsidence issue.
Our promise to you
We know how important your home and your garden are to you. Our Geobear solution is designed to tackle these issues head-on without the need for invasive digging or removing the charm of your property. We provide a custom-engineered treatment plan to improve the bearing capacity of your soil and give you back total confidence in your home's foundations.
