Subsidence is a relatively common issue in the UK, affecting tens of thousands of homeowners and business owners each year. According to data from the Association of British Insurers, UK subsidence cases in 2022 numbered around 23,000, which was roughly the same as the number recorded in 2018.
The problem can be particularly prevalent in areas with certain soil types or where historical activities have impacted the ground. Subsidence poses significant risks and can lead to severe structural issues and financial burdens. It’s an issue we’re well-versed in here at Vxcel Piling. We specialise in mini piling, which is widely recognised as an effective technique for tackling the risks posed by subsidence. So, let’s start by examining those in a little more detail.
What is subsidence and why is it dangerous?
Subsidence occurs when the ground beneath a building or other structure starts to sink or settle. This can be a gradual process, or it can happen suddenly, and it often results in visible damage such as cracks in walls, uneven floors, and misaligned doors and windows. The phenomenon typically arises when the ground support becomes inadequate for the weight of the structures above it.
It’s just as dangerous as it sounds. As the ground shifts, it can compromise the stability of buildings, leading to potential safety hazards. Structural damage may not only affect the appearance of a property but can also compromise its structural integrity, making it unsafe to inhabit. What’s more, subsidence can decrease property values and incur significant repair costs, making it a major concern for homeowners and property developers alike.
The five biggest factors causing subsidence
Subsidence can be caused by a variety of factors, some of which are more common than others. We’ve listed some of the top potential causes of subsidence here, ordered in roughly descending order.
1 – Water drainage issues
Poor water management is a leading cause of subsidence, especially for homeowners. Inadequate drainage can lead to the erosion of soil around the foundations or excessive saturation, both of which destabilise the ground. Water pooling near building foundations or poor drainage systems can exacerbate soil movement, resulting in subsidence.
2 – Natural ground movement
Certain soil types, especially clay, are prone to natural ground movement. Clay soils can shrink when dry and swell when wet, leading to fluctuations in ground level. This cyclical movement can cause gradual subsidence as the ground beneath a building shifts.
3 – Tree roots
Large trees with extensive root systems can contribute to subsidence by extracting moisture from the soil. In clay soils, this can cause the ground to shrink and lead to subsidence. The impact of tree roots on soil moisture levels can create uneven ground, affecting the stability of structures.
4 – Construction and excavation
Any number of construction or excavation activities can disturb the soil and affect its stability. For example, carelessly excavating or removing large amounts of soil can compromise the support beneath a building. Similarly, poorly designed or executed foundations can also exacerbate subsidence issues by failing to adequately support the weight of the structure.
5 – Mining activities
This is a much less common one, but still sometimes relevant to people who live in areas with a history of coal or chalk extraction. Mining is known to create voids or cavities underground. Over time, these voids may collapse, causing the ground above to sink. Although less common than other causes, mining-related subsidence can be severe, particularly in regions with extensive historical mining activity.
How can mini piling help?
As we’ve touched on above, mini piling is an effective technique for addressing and mitigating the effects of subsidence. This method involves installing small-diameter piles into the ground to provide additional support to a structure’s foundation. Mini piles are particularly useful in challenging conditions where traditional piling methods may be impractical.
Installing mini piles allows access to deeper, more stable soil layers or bedrock, providing a solid foundation for the structure above. This approach helps counteract the effects of subsidence by redistributing the load and preventing further ground movement. Mini piling can also be combined with other stabilisation techniques, such as underpinning or ground improvement methods, to ensure long-term stability and prevent future subsidence issues.
Mini piling also offers minimal disruption during installation, making it a practical choice for properties with limited access or in built-up areas. Its versatility and effectiveness make it a valuable solution for addressing existing subsidence problems and reinforcing structures to prevent future issues.
If you suspect that you’re dealing with a case of subsidence at one of your own properties, don’t hesitate to act decisively – it can be a very unpredictable (and destructive!) problem to have to deal with!
As highly experienced mini piling contractors here at Vxcel, we have well over a decade of delivering exceptional results – encompassing domestic projects, commercial properties, and industrial warehouses. To find out what we’ve achieved for previous customers, feel free to take a look through our case studies!
