A Guide to Subsidence: Telltale Signs and How to Deal With It

Your property’s foundations may be out of sight, but if you start to experience signs of subsidence, they certainly won’t be out of mind. There are some terms and phrases that fill property owners with a sense of panic – and subsidence is often at the top of the list. Subsidence can cause a multitude of issues and can affect the interior and exterior of homes and buildings. In the worst-case scenario, subsidence can affect the structural integrity of a building, leading to cracked walls and even collapse.

Even minor cases of subsidence can reduce the value of your home significantly. If you’re planning to sell up in the future, subsidence could make potential buyers think twice. Alternatively, if you’re planning to buy a property with the early signs of subsidence, you may find it difficult to convince mortgage lenders to offer you a loan.

Learning to recognise the telltale signs of subsidence early on could help to mitigate some of the long-term effects of the issue. While there’s no simple treatment, seeking professional advice as soon as possible is the best step you can take.

What is subsidence?

All buildings require sturdy foundations to remain structurally sound, and this relies on the ground beneath them staying in place. Unfortunately, this doesn’t always happen. If the ground beneath a building starts to sink, you may be dealing with subsidence.

When the ground beneath a building starts to move, the sinking foundations put undue pressure on the building itself. Common signs of subsidence include large cracks in walls and ceilings which can form as a result of this pressure. It’s important to note that cracks in the walls, floor or ceiling aren’t always a sign of subsidence, though they may still indicate that there’s an issue with your foundations.

There are many reasons why the ground beneath a building can start to move but it’s often due to changes in the weather. As the moisture levels in soil increase and deplete, the ground shrinks and expands. If the weather changes dramatically throughout the year, weaker plots of land may become susceptible to subsidence.

The development of subsidence isn’t typically a quick process. In fact, it can happen over many years. During this time, building foundations can become misaligned and houses may start to look slanted, although this is the worst-case scenario. It’s highly unlikely that you’ll notice your house moving unless the issue is very severe.

What causes subsidence?

There are lots of different factors that contribute to the development of subsidence. Unfortunately, it’s difficult to predict or prevent this issue from happening. This is especially true for older houses with older foundations, as the ground underneath them may not have been inspected for decades.

Nevertheless, there are some factors that are likely to accelerate the development of subsidence, which can help property developers avoid particular areas that may be prone to foundational issues.

Some of the most common causes of subsidence include the following:

• Weather changes – As temperatures fluctuate, moisture levels in soil increase and decrease. If this happens quickly, the soil supporting buildings can expand and shrink. Eventually, it will dry out and crack.

This is especially common if the soil has a high clay content, as clay can be vulnerable under hot temperatures. Clay soil is more common in some parts of the UK, such as the Cotswolds and throughout Manchester, so houses in these areas may be more susceptible to subsidence.

• Droughts – Droughts can also leave your home vulnerable to subsidence. A lack of rainfall can dry out the soil underneath a property and cause it to shrink. Over time, the soil becomes too weak to support the foundations.

• Floods – On the other end of the spectrum, floods and periods of heavy rainfall can also accelerate the development of subsidence. As the water washes the soil away, it becomes too soft to support heavy loads and slowly starts to sink.

• Trees – Trees growing too close to buildings is another cause of subsidence. Large tree roots often tunnel through the soil towards building foundations and cause problems by drinking water from the ground. This depletes moisture levels and speeds up the process of soil shrinking.

What are the signs of subsidence?

Acting quickly is vital to taking care of subsidence. Some treatments can take years to work effectively, so recognising and flagging up potential issues is key to nipping subsidence in the bud.

It’s worth noting that many of the telltale signs of subsidence could also be a symptom of something less serious – so try not to panic! A structural engineer will be able to identify the root cause and offer advice regarding your next steps.

Nevertheless, you should be able to recognise the signs of a potential subsidence issue. These include:

• Cracks in the walls, floor and ceiling: This is the most obvious sign of subsidence. Cracks form if there’s too much pressure on the foundations of a building and can develop slowly over time. It’s worth noting that cracks can also appear as a result of other structural issues, some of which are less serious than subsidence. However, if the cracks are wider than 2mm, they may be indicative of subsidence.

• Damaged wallpaper: If the wallpaper in your home has started to ripple, it could be linked to a subsidence problem. Again, it’s more likely that your wallpaper has become damaged as a result of damp-related issues. However, if you can rule out damp, foundational problems may be the culprit.

• Stuck doors and windows: Finding it difficult to open your doors or windows? This could be a sign that your house has subsidence. It’s not uncommon for door and window frames to warp as the foundations of a house sink and more pressure is exerted on the building.

If you think you’re dealing with a subsidence problem, you should act immediately to give your home the best possible chance of remaining structurally sound. Seeking help as soon as you’ve spotted the signs of a foundation issue will ultimately help you save time and money in the long run.

What do I do if I’ve noticed the signs of subsidence?

If you think you’ve spotted the telltale signs of subsidence, it’s time to call a structural engineer. They’ll be able to confirm whether or not the issue is serious and will be able to advise you on the most appropriate course of remedial action. The proposed treatment will depend on the cause and severity of the subsidence.

For example, if the issue has been caused by tree roots growing too close to the foundations of your building, cutting the trees back may resolve the issue. This may not be effective if the problem has been left untreated for too long, but if the subsidence isn’t too severe, tree felling or removal could be the cheapest remedial solution.

Sometimes, opting for permanent solutions like underpinning is the safest and most effective way to deal with structural instability. Underpinning is often needed in circumstances with high levels of sinkage. In cases where there’s been a lot of soil movement, the pressure upon foundations can become too much for the building to handle. If left untreated, sinking floors and collapsed walls could become a reality.

What is underpinning and how does it work? Well, underpinning is the process of strengthening the foundations of a structure with mini piles. These help the weaker foundations bear the load of the building to prevent further damage to its foundations. Underpinning is a highly effective technique that can mitigate some of the more worrying effects of subsidence.

If you need underpinning services for your home or commercial building, make sure you choose highly-skilled professionals, such as the team at Belowground Ltd, to take care of the project.

Belowground Ltd: Piling and underpinning experts in the South of England and Wales

Don’t deal with the stress of foundation issues alone. As specialists in piling and underpinning services, we at Belowground Ltd are well-equipped to handle your requirements safely, efficiently and professionally. Whether you need underpinning services for subsidence in your home or foundation design solutions for a commercial build, look no further than our team of experts.

With offices in London, Bristol and Exeter, we’re on hand to service clients throughout the South of England and Wales. When you work with us at Belowground Ltd, professionalism and efficiency come as standard. We have over 25 years of experience in piling and underpinning and have worked on projects of all sizes. No job is too big or too small for us!

To learn more about our foundation services or for a free, no-obligation quote, contact us today. We look forward to working with you.