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

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.

Subsidence can be a very serious problem for homeowners if left untreated. Subsidence can dramatically impact the market value of your home and make it difficult to sell in the future. That’s why it is so important to understand the signs to look out for, causes and processes to follow so you can act fast.

In this article, we answer twelve of the most frequently asked questions on the topic of subsidence.

This article should equip you with the knowledge to identify any issues early, understand who to turn to if you suspect you have subsidence and ultimately save you stress, time and money in the long run.

If your property has subsidence and you're considering selling it, the short quiz I've designed could be a big help. Hit the red button below to get started, and get recommendations and next-steps tailored to your property and priorities.

1. What is subsidence damage?

Subsidence is a type of ground movement and occurs when the ground beneath a building begins to sink downwards. Walls and floors can shift and crack as the foundations of the property are no longer supported by the ground beneath.

Subsidence puts your home at serious risk of structural problems if left untreated. The most common causes of subsidence are nearby trees, water leaks and clay shrinkage.

2. How do you know if a crack is subsidence?

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

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

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.

3. Can you prevent subsidence?

Whilst you cannot prevent certain causes of subsidence, there are things you can do to reduce the risk of subsidence.

Do not plant trees or shrubs near to the property.
Regularly prune trees and large shrubs with the advice and guidance of a tree surgeon.
Regularly maintain external drainage and clear debris from gutters.
Act fast if you spot or suspect a leak.
When adding extensions, ensure the work is carried out by a reputable professional who will consider the soil type and foundation depths of the original property.

4. How serious is subsidence?

Subsidence can be a serious problem for homeowners and should not be ignored. Left untreated, subsidence can render a house uninhabitable, unmortgageable and uninsurable.

Subsidence can dramatically impact the market value of your home and make it difficult to sell in the future. Subsidence can also be expensive and time-consuming to fix if it isn’t caught early.

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. Subsidence won’t go away on its own, so don’t ignore the warning signs!

5. What are the first signs of subsidence?

The first sign of subsidence is usually the appearance of large cracks (wider than 3mm) appearing in the walls of your home or near an extension. Subsidence cracks are quite distinctive from other cracks and usually appear suddenly, especially after long periods of dry weather.

Other signs of subsidence include doors and windows sticking, and wallpaper creasing or rippling at joins with no signs of damp.

It’s not always possible to detect the first stages of subsidence, but it’s important to be aware of the signs so you can identify any issues early which will save you time and money in the long run.

6. What to do if I think I have subsidence?

If you spot signs of subsidence, the first thing you should do is 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 to visit your property and accurately diagnose the issue.

If you're thinking of selling your house, subsidence doesn't have to stop that... Check out this free quiz we've designed for you to learn more:

7. Is subsidence damage covered by my insurance policy?

Subsidence is covered by most home insurance policies, provided your property has not had problems with subsidence in the past.

A good home insurance policy should cover you for:

Cost of repairs for any damage caused by subsidence up to the sum insured under the policy.
Alternative accommodation when the remedial works are being carried out, if it means the property is uninhabitable.
Damage to surrounding structures, for example your patio, where the damage occurred at the same time and by the same cause as the damage to the property.

You should read your policy wording to ensure subsidence is not excluded from your current home insurance policy.

Related: I answer more insurance FAQs in my article Subsidence & Insurance: FAQs, Common Exclusions & Top Tips.

8. What is the subsidence excess?

The subsidence excess is the amount of money you must pay when making an insurance claim for subsidence. This is usually a pre-agreed amount set out in your home policy schedule.

The Association of British Insurers state that “most policies will have an excess of around £1,000 for a subsidence claim”.

9. How long does a subsidence claim take to resolve?

Most subsidence claims take between six months to two years to resolve, but it depends on the cause of the subsidence and the treatment required. Your insurer should provide you with an estimate of the claim duration at the outset.

Claims can drag on when further investigations are required to monitor the rate and patterns of structural movements before the repair works can commence. Monitoring periods can be as long as a year or more in some cases.

10. Will subsidence devalue my house?

As a very general rule, subsidence problems can cut the value of a property by around 20%. Serious defects can devalue your property by as much as 30%.

Historic subsidence will still have an effect on the value of your home, even when the problems are fully solved.

If you're struggling to sell your house because of a current (or historic) subsidence issue, try this free quiz we've designed for you:

11. How will my subsidence claim be dealt with?

Once you’ve notified your insurer, they will arrange for a structural engineer to visit your property to investigate the cause and extent of the damage.

If the structural engineer can easily establish the cause of the damage and the movement of your home has stopped, repairs will usually be carried out straight away.

Where the subsidence is potentially ongoing and the damage is severe, the structural engineer may need to carry out further investigations to determine a long-term solution. This may include a period of monitoring (which can be as long as 12 months or more) to establish the cause and confirm that your home is stable before repairs start.

The cause of the subsidence will then be fixed, and any damage caused by the subsidence identified as part of your claim will be repaired. Your insurers should fund the cost of the repairs.

12. How long can you leave subsidence?

You should contact your insurer as soon as possible if you suspect your property has suffered from subsidence damage. The sooner you contact your insurer, the quicker, less invasive and cheaper the treatment plan should be.

If you don’t think the cracks in your home have been caused by subsidence, it is still a good idea to keep an eye on them. You can monitor minor cracks in your home by marking the width and the end of the crack with a pencil, along with the date. You can also take photographs to document any changes to the cracks.

If the cracks don’t close, or continue to open beyond widths of 5mm, there’s a long-term problem and you should immediately contact your insurer.

By Matthew Cooper, Co-Founder of Home Selling Expert

I'm an experienced property insider, trusted media commentator, and the Founder of Home Selling Expert and YesHomebuyers.com. I've bought and sold almost 150 properties worth nearly £17m, and my advice articles (like this one!) have been viewed more than 1million times.

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