Soil Types: Which Ones Are More Prone to Subsidence?

l typesThere are many different soil types across the UK, from clay and chalk to sand and peat. But did you know that some of them are more prone to subsidence than others? In this article, we’ll be taking you through some of the most common soil types in the UK, together with their characteristics and how likely they are to cause subsidence. Let’s delve deeper into the different types of soil that your property could be sitting on:

What is subsidence?

Subsidence occurs when a property, whether it be commercial or domestic, begins to sink into the ground. This often happens as a result of failing foundations. Foundations can become unstable and weak for a number of reasons, such as: clay soil, tree roots, leaking drain pipes and broken guttering, to name just a few things. If you’re worried about subsidence and your home, then there are certain signs you should look out for, including:

• 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

If you notice any of the above signs, then you should call a professional underpinning firm, such as us here at Geobear. We can carry out a subsidence assessment for you, looking meticulously for anything that indicates subsidence. We will then provide you with the conclusions together with our recommendations moving forward to make sure the subsidence is rectified and your property is restored to full strength and stability. 

What are the different types of soils?

There are many different types of soil that exist in both domestic and commercial settings. Generally, people are unaware of the soil type their house is built on, unless they have had major gardening or landscaping work done. With varying soil types existing across the country, they each have different characteristics, including water retention and drainage, which can play a huge role in subsidence. Let’s take a closer look at the different types of soil that you can come across in the UK:

Soil types: explained

• Clay – also known as heavy soils, clay soils a fertile, but they hold a high proportion of water. It drains extremely slowly and it takes a long time for the clay soil to warm up and dry out as the spring season begins
• Sandy – mostly sand and a tiny bit of clay make up sandy soil. Sandy soils are referred to as light soils and are easy to work with. They’re often free-draining and warm up quicker than clay soils do when spring rolls around. Sandy soils also tend to be more acidic 
• Silt – made up of different particles, silt soil is fertile and it drains well. But it can hold more moisture than sandy soils. Silt soil is easily compacted
• Loams – loam soil is made up of a mixture of soils, including clay, sand and silt. It’s well-drained, fertile and easy to work with. Typically, loam soil is either predominantly clay or predominantly sandy, depending on where it’s located
• Peat – made up of organic matter, peat soils are fertile and retain moisture. However, peat soil is rarely found in domestic gardens, and more so in farmer’s fields or other agricultural settings
• Chalky or lime-rich – composed of calcium carbonate, these are alkaline soils, typically. It can be either light or heavy but it’s a touch soil type to identify, as it can be mixed with other soil types nearby

Which soils are most likely to cause subsidence?

You might have already made your conclusions based on the information we gave you above. However, just in case you’re still unsure about which types of soil are more prone to subsidence, we’re going to be detailing them below for you. Much of it comes down to moisture retention and expansion, and as such, the following soils are more likely to cause subsidence than other soil types:

Soil types & subsidence

• Clay soil – this is often associated with subsidence. Clay soil is problematic in this sense because of how considerable its shrinkage and swelling are. When it becomes wet, it expands, and when it dries out, it contracts. This extensive movement can cause the structure that sits on top to move along with it, therefore weakening the structure
• Silt soil – this soil type can cause subsidence because of how easily and considerably it can compact. This is especially the case when heavy objects or structures are placed on top, such as the foundations for a house, and the weight of the property itself. While it’s not as subsidence-prone as its clay counterpart, it can still cause issues in the long term
• Peat soils – despite not being found in domestic settings, and is more often found in agricultural fields or wastelands, they can cause a subsidence issue when it comes to commercial buildings or new-build properties, where any land is earmarked for development. Peat soil can retain moisture, thus causing expansion. Much like clay soil, this causes movement of the ground. This can transition through to the movement of the building on top

Geobear is pleased to offer domestic and commercial clients expert underpinning and subsidence solutions that will last a lifetime. With non-disruptive technology used in the form of the resin injection method, you can always count on us to supply specialist, effective subsidence solutions and subsidence surveys. If you would like further information, get in touch with a member of our friendly, professional team today – we’re always pleased to hear from you.