What Are the Top 6 Causes of Subsidence in the UK?

There are multiple reasons for the high number of British homes experiencing subsidence, from tree roots and soil type to inadequate development sites and extreme weather conditions as a result of climate change. In this article, we’ll be explaining what subsidence is, but we’ll also be going through what the top six causes of subsidence are in the UK. Here’s everything you need to know about subsidence in Britain and why the numbers are on the up.

What is subsidence?

Subsidence refers to the sinking of a building, property or structure into the ground. There are multiple reasons for this, which we will get into in a moment. Properties that subside can, eventually, be rendered uninhabitable, in the most severe cases. But there are things that can be done in the early stages to rectify the problem in a way that is simple, effective and with long-lasting results – underpinning. 

Underpinning restores the ground to its full stability and strength, giving the structure that sits on top of solid ground to sit on for decades to come. If you’re concerned about subsidence affecting your home, make sure you’re looking for some of the most common, early signs, before the situation gets out of hand. Signs of subsidence include:

• Cracks in walls, floors and ceilings
• Cracks in exterior walls, running in a zig-zag pattern, along mortar lines
• Sinking or sloping floors and ceilings
• Doors and windows that cannot be opened
• Doors and windows that cannot be closed
• The property noticeably leans to one side
• An extension is moving away from the rest of the house

What are the top 6 causes of subsidence in the UK?

There are multiple reasons as to why a property, whether it be commercial or domestic, succumbs to subsidence in the UK. While weather conditions aren’t the same around the world, we’re going to be focusing solely on the top six causes of subsidence in the UK alone, including soil type, tree roots, leaking gutters, considerable rainfall and more. Here are the most common causes of subsidence in Britain:

1. Soil type

The type of soil your property sits on plays a huge role in whether or not subsidence will become an issue. Clay soil is incredibly prone to quick expansion and contraction, with increased rainfall and the quick temperature rise and drop not helping the situation. Clay soil will retain water, therefore swelling. The hot weather will then cause the shrinkage. This extensive soil movement will also result in the movement of the structure that sits on top of it. This is what can cause cracking in external and internal walls, as well as the jamming of doors and windows.

2. Trees planted too close to buildings & structures

Trees are always on the lookout for water and moisture from the soil. If a tree or large shrub is planted too close to your house, then the roots will find moisture from anywhere, and that includes water from underneath your house. Tree roots can grow to twice their height, often spanning the entire footprint of the house, depending on the species of tree you have. This poses the same problem as the expansion and contraction of clay soil. The trees will extract the moisture from the soil, therefore causing movement underneath. 

If the soil shifts, then so do the foundations and, eventually, your house will succumb to the same fate. To avoid this, make sure you remove any large trees that are close to your home and refrain from planting any trees or large shrubs or bushes too close to your home. If you do want to plant them, plant them as far away from your house (and anybody elses’) as possible. The last thing you want to do is start to affect anyone else’s property, whether commercial or domestic.

3. Leaking drain pipes & gutters

Drain pipes and gutters that leak around your property can cause subsidence, even if your property isn’t built on clay soil. This is because the leaking pipes and gutters are presenting the foundations with moisture where there wasn’t any before. Also, it can cause a concentrated buildup of moisture, which isn’t the case should it rain or snow, for instance. 

This concentrated water pooling can cause one part of the foundations to shift, therefore causing subsidence. In severe cases, the property could end up leaning to one side – the side with the concreted buildup of water. 

Make sure you go around your property and fix any gutters that might be leaking, sweep away excess water and ask a professional to come and check your drain pipes for breaks, cracks and leaks for good measure. If they are broken or leaking, then make sure you have those drainpipes repaired as soon as possible.

4. Poor quality or old foundations

Thin foundations, or foundations made from a poor concrete mix, can cause subsidence. Just as foundations in an inadequate condition can cause subsidence, so can old foundations. This is normally because they’re thinner than foundations built for houses today. Additionally, it can come down to simple wear and corrosion over time. You can have an extensive house survey done, especially if the property is extremely large or considerably old, that will tell you whether or not the foundations are failing. If they are, there’s a simple fix by way of stabilisation, otherwise known as underpinning. Choose Geobear for innovative underpinning techniques that are non-disruptive, mess-free and provide results that will last a lifetime.

5. Properties being built on old mining sites

Historic mining sites can wreak havoc on property foundations. This is because the ground has been significantly weakened. As such, it’s even less likely to be able to comfortably withstand the weight of foundations and the house that sits on it. When buying a home, you can have a Coal Mining Search if it’s something that particularly worries you, or if you’d just like some additional peace of mind. Not much can be done here, other than specialist underpinning to strengthen the ground underneath.

6. Extreme changes in weather conditions

Climate change has played a part in subsidence in recent years. This is mainly because of the quick transition from extensive rainfall and freezing temperatures to hot, dry weather. This doesn’t help when it comes to soil movement, mainly because of soil expansion and compaction. Again, there’s not much you can do here, other than future-proof your property. You can future-proof it by having it underpinned in preparation for continued climate change issues. Read one of our latest blog posts about how to prepare your property for climate change.

Geobear is pleased to provide domestic and commercial customers with sterling subsidence solutions, including the resin injection method. The resin is injected into the ground and pushes through into the gaps and voids, expanding as it goes. The resin then hardens, thus restoring full strength and stability to the ground once again. If you would like further information, get in touch with a member of our friendly professional team today – we can also offer full subsidence investigations and surveys for your peace of mind.