What Are The Signs of Subsidence (And Why You Shouldn’t Ignore Them)

Knowledge is power when it comes to subsidence. If you know the signs to look out for, it will enable you to identify any issues early which will save you time and money in the long run.

So, what are the signs of subsidence?

The main signs of subsidence are:

• Large cracks in walls
• Doors and windows sticking and/or becoming misaligned
• Sinking and/or sloping floors
• Wallpaper creasing or rippling at joins with no signs of damp
• Extension cracking or moving away from main property
• Noticeable leaning of a house

In this article we look at the main signs of subsidence and how to spot them. Secondly, the causes to look out for which may mean your property is at high risk of subsidence. And finally, what to do if you suspect your home may be subsiding.

The key takeaway here is don’t bury your head in the sand if you spot any of the potential signs. Otherwise, it can become difficult to sell a house with subsidence if you let the problems get worse over time…

If you do have subsidence, you can still sell your house. Hit the button below to use our free interactive quiz and get property sale recommendations tailored to you and your situation.

What are the main signs of subsidence?

Subsidence occurs when the ground beneath a property begins to sink downwards. The most common causes of subsidence are nearby trees, water leaks and clay shrinkage.

Subsidence can ultimately compromise the structural integrity of your home. It can be expensive and time consuming to fix if left untreated.

With this in mind, it’s important to be aware of the signs of subsidence so you can spot them early and find a resolution before the problems develop.

Let’s look at each of the main signs of subsidence in more detail below…

1. Large cracks in walls

One of the most noticeable signs of subsidence is large cracks appearing in the walls of your home.

Subsidence cracks have some recognisable characteristics, which make them easier to distinguish from other cracks in your home.

Take a look at our handy “subsidence crack checklist” to help you spot signs of subsidence early.

Subsidence crack checklist

Subsidence cracks tend to be...

Wider at the top and slimmer at the bottom.

Usually more than 3mm wide (thicker than a 10p coin).

Diagonal in shape.

Usually found close to doorframes and windows.

Visible both internally and externally.

If any one or more of the above characteristics are present, you should contact your insurer immediately.

The exception to the above rules is any cracking to a building that could be over the root system of a large tree.

Tim Kenny, a residential building surveyor at Tim Kenny Surveying commented in the RICS Building Surveying Journal that “any cracking to a building that is likely to be over the root system of a large tree should give cause for concern”.

If your home has any cracks which are located near to a large tree in your, or your neighbour’s garden, this should be investigated. Contact your insurer immediately. They will arrange for a qualified structural engineer to visit your house and provide a diagnosis.

Not all cracks mean subsidence

It is important to remember that not all cracks mean subsidence.

Cracks can also appear in your home for a number of reasons, including:

• Settlement cracks that appear in a new home. Settlement is the natural downward movement of new homes in the first 10 years of its life. It happens when the soil below is evenly compressed by the weight of the building. It’s common to see some minor cracks appearing in the first few years of a new build’s life before the house has stabilised.
• Hairline cracks that appear on an annual basis. Seasonal hairline cracks can appear in your home. The changing temperature and moisture levels cause the materials of the property to expand and contract. Any cracks that increase in width gradually over time should be investigated though.
• Cracks in new plaster. Cracks appearing in newly plastered walls will often be down to shrinkage. This happens when the fresh plaster has dried too quickly. So maybe don’t plaster during a heatwave or turn the central heating on to speed up the drying process!
• Vibrations from traffic. Cracks can form in your home if you live near a particularly busy or fast road. The vibrations from the volume or speed of the traffic directly outside your house is likely to be the cause of a crack rather than subsidence.
• Lintel failure. Supporting lintels over doors and windows can fail, causing cracks to appear above door frames and windows. The cracks that appear are often diagonal and so can be easily mistaken for subsidence.

Most minor hairline cracks cause aesthetic problems only and are unlikely to indicate a significant structural issue such as subsidence. If you’re in doubt, make sure to contact your insurer who will send out a professional structural engineer to diagnose the problem.

2. Doors and windows sticking

You may have noticed that your doors and windows have started sticking or swinging open on their own accord. Rather than calling ghostbusters, you should get in contact with your insurer. It could be a sign that your house is suffering from subsidence.

The structural instability causes the window frames and doorframes to warp. This means that doors and windows become misaligned and difficult to operate. Look out for cracks or gaps that may also appear around your windows and doorframes.

3. Sinking floors

Sinking or sloping floors can indicate that the ground beneath your property is collapsing.

If any gaps start to appear beneath your skirting boards, act immediately and contact your insurer to discuss next steps.

Sloping floors are commonly found in older properties. They may only indicate past movement, rather than an ongoing subsidence problem. If you are thinking of purchasing a property with sloping floors, ensure you obtain a report from a structural engineer to put your mind at rest.

4. Wallpaper creasing with no signs of damp

If you notice your wallpaper creasing or rippling where the wall meets the ceiling, it could be a sign of subsidence. The most likely cause is damp, but if there are no signs of damp then consider whether subsidence could be the culprit.

The same thing can happen with tiled walls. Look out for cracks appearing in grout or gaps appearing between tiles.

5. Extension moving away from home

Another tell-tale sign of subsidence is your extension moving away from your home or cracks appearing where the extension meets the house.

Properties built in the Victorian and Edwardian eras tend to have simple shallow foundations. Newer extensions will have deeper foundations to comply with the Building Regulations introduced from the mid-1960s onwards.

Both parts of the property will usually be built with different materials too. The extension will be built with more rigid materials, whereas older properties tend to be built with more flexible materials.

When there’s a lack of consistency in foundation depth and materials used, the two parts of the home can move at different rates and therefore cause damage and cracking. This is especially true when the home is built on cohesive soils.

Related: 3 Ways To Tell If Your Dream House Has Subsidence (My Top Tips)

6. Noticeable leaning of the property

The last sign of subsidence is when a house is noticeably leaning.

However, this doesn’t always mean that subsidence is an ongoing problem. The subsidence issue could be historic, meaning the building has now stabilised and may not have moved in years.

If you are thinking of purchasing a property and think one or more of the walls look noticeably wonky, make sure to get a structural engineer out to the property to take a look. They will be able to tell you if the subsidence is ongoing or historic and nothing to worry about.

Remember though that purchasing a house with historic subsidence may make it harder to sell in the future and/or obtain insurance. Read more about subsidence and insurance here.

Is my property at high risk of subsidence?

Although it isn’t possible to accurately predict what houses will suffer from subsidence, there are certain factors that may mean your property is at high risk of subsidence.

Being aware of what can cause subsidence will mean you are better equipped to spot early signs. The earlier subsidence is spotted, the easier it is to fix. Remember, subsidence won’t go away on its own so don’t ignore the warning signs.

Your property may be at a higher risk of subsidence if any one or more of the following apply:

• Property built on cohesive soils (such as clay and silt). Cohesive soils can absorb large quantities of water and so will swell and shrink depending on the moisture content of the soil. In prolonged dry spells of weather, the soil can shrink to such a level that will cause the foundations underneath your home to shift. Cohesive soils are most common in the South East of England, particularly Greater London.
• Trees close to your property. Trees disturb the ground beneath your home’s foundations by drawing up significant volumes of water from the soil, especially during periods of drought. Thirsty trees such as oak, willow, ash, poplar, plane and sycamore trees that are planted closer than the recommended “safe distance” to your home can mean your property is at a greater risk of subsidence.
• Property located in mining areas. Mining can cause subsidence when the earth beneath or surrounding your home’s foundations has been weakened by the collapse of underground mines or from historic mining works.
• Older properties with extensions. When there is a lack of consistency in foundation depth, the two parts of the home can move at different rates and therefore cause damage and cracking.
• Property with poorly maintained pipes, drains and gutters. Water leaks can wash away fine particles in the soil underneath the foundations of your home if it’s built on non-cohesive soil (such as sand and gravel). If your home is built on cohesive soil, water leaks can saturate the soil. Foundations can either give way and subside or rise, causing another type of ground movement called heave.

You can read more about the 6 most common causes of subsidence and how to reduce the risk here.

What is the first thing I should do if I spot signs of subsidence in my home?

If you spot signs of subsidence, make sure you inform your insurer as soon as possible. It’s best to be proactive when it comes to subsidence. Problems left untreated can result in more extreme, time consuming and expensive repairs.

Your insurer will arrange for a professional structural engineer (typically one registered with The Institution of Structural Engineers) to visit your property and accurately diagnose the issue.

You should expect to pay around £700-£1,000 for a professional structural survey. The cost will be covered by your insurance, but in reality your excess for a subsidence claim is likely to be about the same amount. This means that (in most cases) you should expect to foot the bill.

Once the final report has been filed, most insurers will then arrange the repairs with their approved contractors – and ultimately cover the cost of them.

Related: Top 12 Subsidence FAQs Answered (Can You Prevent It, Signs, Claims etc).

Is subsidence expensive and time consuming to fix?

Subsidence can be expensive and time consuming to fix, but every case is different.

Although the average cost to repair subsidence is around £6,000-£14,000, most (but not all) insurers will cover the cost. This will leave you with just an excess to pay of around £1,000.

However, costs can be drastically higher for more severe cases of subsidence, sometimes reaching as high as £50,000. Unfortunately, not all insurance policies will cover subsidence either. This is why it’s so important to be aware of the signs so you can spot subsidence early before the bills start to rack up!

The building work needed to fix subsidence can take as little as two days, or as long as 6 weeks. This will depend on the size of the area affected, plus the extent and severity of the problem.

However, a subsidence issue can take over a year to resolve when you factor in the time waiting on structural reports, gathering building quotes and negotiating with your insurance company.

Related: Read my articles on "How long does it take to fix subsidence?" and "Is subsidence going to be expensive to fix?" to find out more.

Will I be able to sell a home with subsidence?

It is possible to sell a property with subsidence, but it can be trickier and more time consuming than selling a problem-free property.

I designed this short quiz to help you determine your best way forward if you want to sell the property.

Remember you have to declare subsidence to prospective buyers, even if it is historic.

For many people, your best option will be selling by auction. Auction can offer a faster and more certain sale, and potentially get you a better selling price. If you think this could be a good option for you, read “My Guide To Finding The Best Auction House In The UK” here.

Over the last few years, I have spoken with and helped many dozens of people with both ongoing and historic subsidence issues of different severities and causes. If you would like to read more about how I can help you, take a look at my Auction Case Study: Finding out your property has subsidence…when you’re 9,000 miles away.