Subsidence terrifies homeowners, and for good reason. The idea of your home slowly tipping into the ground is frightening enough, but the financial implications can be horrific too; from the often very high cost of sorting out the structural problems subsidence causes, to the potentially reduced market value of your home.
So it’s vital to have the right home insurance in place to cover you for subsidence and its effects. If you couldn’t afford to put the problem right without the financial help insurance provides, you run the risk of ending up with a home that’s unsellable, and even condemned.
And if you have a mortgage you would almost certainly be in breach of the terms if you hadn’t arranged home insurance which includes cover for subsidence. Even if you do have home cover for subsidence, your claim limits might not be set high enough.
This guide should help you understand subsidence better and ensure your home cover is sufficient to protect you against its affects.
What is subsidence?
In simple terms, subsidence is what happens when a building’s foundations move in line with the ground the building sits on, and the property’s structure then drops lower into the ground as a consequence.
Subsidence can cause a lot of damage to a building, creating serious structural problems which are difficult to correct. The first signs of it are usually large cracks appearing in stone work and plaster.
The movement can occur due to greater than normal changes in the moisture content of soil; for a variety of reasons the soil dries out too much, making the ground shift by an unusual amount. Areas with clay soil tend to suffer the most from incidents of subsidence.
Subsidence can also happen due to mines being present, the wrong sort of ground being built on and the impact of large trees and bushes.
How subsidence differs from ‘settlement’ and ‘land heave’
‘Settlement’ is the normal adjustment of ground which has had a large amount of weight placed on it, and it doesn’t pose a serious threat to buildings.
Subsidence is often confused with what’s known as ‘land heave’. Land heave takes place due to an excess of water which causes the earth in the ground to expand and ‘heave’ the property upwards and outwards (as opposed to downwards with subsidence).
Why does subsidence occur?
The downward movement of a property can occur for a number of reasons. The main factors include:
- Dry weather – Due to a long, dry spell of weather the water table may drop, or water is simply sucked out of the soil by evaporation, leaving soil extremely dry and unstable.
- Tree and bush damage – The roots of large trees and bushes can cause soil to shift and be displaced, as well as dry out, causing ground movement powerful enough to shift a house.
- The house was built on inappropriate ground– It may be poor planning, bad architecture or ill-informed council officials that leads to a home being built on ground where it shouldn’t have been. Ground which is too sandy, for example, or where there are cave systems not far below the surface.
- Clay soil – Clay soil tends to dry out the quickest of all the types of soil homes are built on.
- Mining and cave systems – Mine shafts and cave systems can lead to large soil movements around them. Houses were sometimes built over or near them in the past, and occasionally still are today.
- Structural damage – Structural damage can be caused by trees and bushes, as well as by certain weeds, such as the infamous Japanese Knotweed.
- Underground water leaks – Water leaking underground can wash away soil, causing movement on, or closer to, the surface. Such leaks might be caused by a mains leak or drains leaking.
- Other properties changing in an area – If your neighbour has their basement dug out, for example, or a swimming pool put in their garden, it can affect the earth to such an extent that it causes subsidence in your home.
How to spot subsidence
Don’t always panic if you see a crack! The first thing to remember is that most cracks the you see around a home are quite normal as nearly all properties experience some natural shrinkage or swell caused by different temperatures and moisture levels as the seasons change.
Although any cracks appearing may not be caused by subsidence, they’re perhaps a timely reminder to check your home insurance and the level of buildings cover you have (see further on in the guide under ‘Check your cover levels’).
However, depending on the nature of what’s happening, it may unfortunately be that it’s caused by subsidence.
Signs that cracks and other problems are being caused by subsidence include:
- Cracks in plasterwork – New or expanding cracks in plasterwork, especially those thicker than a 50 pence piece at one end.
- Cracks in outside brickwork – New or expanding cracks in brickwork on the outside of your property, especially those that are wider at one end than the other.
- Walls not straight – Simply by looking at wall, or using a plumb line, you should be able to tell if it’s straight or not.
- Doors and windows sticking – Doors and windows starting to stick for no apparent reason, could indicate excessive movement in a home’s structure.
- Wallpaper ripping – Wall paper might tear, but it isn’t caused by damp.
- Sinking house – This sign is a bit of a no brainer!
Check your cover levels
Many homes are under-insured for the potential effects of subsidence as people keep the same level of cover year after year without taking into account the increase in the costs of re-building a home and effect of inflation. If you haven’t had a proper estimation as to the level of cover your home needs, subsidence can cause such serious structural issues that the cost of repair work could exceed the sum your property is insured for.
If you’re uncertain, you should check with your insurer what the total sum insured for your home is; these days, most standard policies set a fixed amount, £500,000 being common, but it’s still your responsibility to check. Then compare this with re-building valuations from local builders or surveyors to see if it’s around the right level.
Why is subsidence bad?
Subsidence can have a serious effect on a home’s value as well as the lives of those who live in it. Depending on its severity, it can mean that:
A house is sinking and needs under-pinning work, or other remedial work.
The property becomes so unsafe that no one can, or is allowed to, live in it.
The problems caused are very expensive to put right.
You could see a hefty increase in your annual insurance premium or, worse still, be refused insurance cover.
What to do if you think your home is suffering from subsidence
If you’re worried, it’s better to be safe than sorry, and if you’re lucky, the subsidence will stop and not re-occur, leading to your home only needing some simple re-pointing work.
However, your insurer needs to know if you see any signs of subsidence immediately, as it could suggest problems lie in store in the future and your home’s ‘risk’ profile could change. Here’s what you need to do:
- Contact your insurer immediately – Do this either by phone or email, or both. It may be a requirement of your policy that you report subsidence within a certain time period of first recognising any symptoms, and a delay could negate any claim you need to make. It could also catch the problem early, hopefully minimising the disruption as much as possible.
- What your insurer will do– In all likelihood, your insurer will then send out an investigator, or claims assessor, who will be an expert on subsidence. They’ll assess the problem and any damage, and decide on what needs to be done, arranging the necessary repairs.
- If the cause is uncertain – If it’s not clear what’s causing the symptoms, the assessor may decide to monitor the problem over a number of months rather than have any work carried out immediately.
- A note on the excess – The policy excess is usually higher for subsidence claims. Be aware this is often £1,000, when the policy excess for other more standard claims might be as little as £50 (see below under ‘Issues that can arise with subsidence cover and claims’)
Getting Home Insurance after making a subsidence claim
Once you’ve made a claim for subsidence, especially if it’s a large claim, it can be hard switching to cover providers as other insurers are often wary of taking on a property that’s experienced major subsidence problems. Whether you manage to move providers or not, it’s highly likely your premiums are going to go up.
Whatever you do, always be honest about having made previous subsidence claims. If you’re not, you could see future claims rejected, as well as potentially facing prosecution.
If your home has a long history of subsidence, you may need to seek out specialist cover offered by insurers which take into account the particular circumstances of a building.
If you have any structural work done, keep records (e.g. structural engineer reports) as this will be needed if you change insurers.
Issues that can arise with subsidence cover and claims
As subsidence can be a difficult problem to diagnose and rectify, and as costs to insurers are generally higher, insurers often treat claims for it somewhat differently.
Here are a number of common issues and exclusions to be aware of:
- Greater excess for subsidence – Claims for subsidence are generally much higher than for other more standard claims. Insurers usually therefore stipulate that the first part of any claim which the insured pays, called the ‘excess’, is higher for such claims. The excess on many policies for subsidence is typically £1,000.
- Exclusions for outbuildings – Many home insurance policies only cover the ‘main residence’ (i.e. the main building) for subsidence, and not outbuildings and other areas such as garages, barns, patios and terraces. Or they will only cover them if the main residence is also affected.
- Decreases in market value – Most policies exclude compensation for the decrease in the market value of a home that can occur after it’s had subsidence. A history of subsidence can, naturally, put off potential buyers, but to insurers this isn’t part of the original issue of rectifying the problems caused, so they exclude it as a potential reason for a claim.