Would you consider buying a property where there was risk of structural damage? The answer is probably a categoric “no”, which is why many homeowners have sleepless nights over subsidence – particularly if they are looking to sell their house fast.
But even though subsidence can be a serious problem, it doesn’t need to be a complete turn-off. In most cases, subsidence is manageable and doesn’t necessarily mean the property will be unsafe to live in. Take a read of our guide to subsidence to answer the all-important questions, such as “what is subsidence?” and “how much does subsidence devalue a property?”
Our Guide to Subsidence:
- What is subsidence?
- What causes subsidence?
- How to check for subsidence in a property?
- How to fix subsidence?
- How much does it cost to fix subsidence?
- How much does subsidence devalue a property?
In short, subsidence is…
The movement of a surface, causing the ground underneath the foundations of a building to sink and become unstable.
Read on in our guide to subsidence to find out more about what causes subsidence and how to treat it effectively.
Subsidence tends to occur when the ground below a property loses moisture and shrinks, causing the ground to move below your property.
More often than not, the most common cause of subsidence is due to trees and shrubs absorbing high volumes of water from the soil surrounding your property. In fact, according to Which?, tree root damage is estimated to be the cause of 70% of all subsidence cases.
These are the most common reasons for subsidence:
- The shrinking of soil beneath a property
- Previous mining activity on the site
- Ground vibrations
Soil shrinkage is the most common reason for subsidence to occur. It can be caused by a number of factors, such as water leaking into the soil under the property, which can wash away soil from the foundations – this is most prevalent with soils with a high sand or gravel content.
Clay soils, in particular, are prone to shrinking. As the soil shrinks, it pulls the property’s foundations which can result in structural movement. Clay soil shrinkage can also occur after a spell of dry weather.
It is important to keep your eyes peeled for any signs of subsidence on both the inside and outside of a property, that should ring alarm bells if you spot them. As with anything, the sooner it is identified and diagnosed, the easier it will be to rectify – and often for a fraction of the price.
How to spot signs of subsidence?
- Cracks in the walls, ceilings and/or outside brickwork
- Expanding of existing cracks
- Cracks appearing after a long phase of dry weather
- Rippling of wallpaper (that isn’t caused by damp)
- Sticking of doors and windows
If you notice any of these main signs of subsidence, it is advisable to seek professional advice from a Chartered Surveyor as soon as you possibly can. Read on in this guide to subsidence to find out how to treat the problem efficiently and effectively.
There are three main ways to treat subsidence in your property, and the most appropriate treatment option will be entirely dependent on the cause of your property’s subsidence and how severe the problem is.
Subsidence treatment options include:
- The cutting back or removal of trees/bushes
- Repairing damaged drains and pipes
- Underpinning the foundations
Bear in mind, depending on the treatment, fixing subsidence can sometimes be a lengthy process and last up to 12 months.
Of all treatment options, underpinning is often most associated with subsidence. Despite this, according to the Royal Institution of Chartered Surveyors (RICS), only 10% of properties will actually require underpinning. In fact, the Institute of Structural Engineers advises that you should attempt every other possible solution before opting to underpin your home because it is expensive and requires major repair work.
Underpinning – most expensive option – can cost anywhere between £5,000 and £50,000, depending on the size of your property and the extent of the damage already caused.
- Tree removal
The removal of a tree can provide a quick and much cheaper solution to the problem. The cost of tree removal will depend entirely on the size of tree, but you should expect to pay a tree surgeon somewhere in the region of £120 per hour. For a large tree, which may take 2 to 3 days to remove completely, a sensible price would be around £3,000 + VAT.
In rare cases, removing a tree can lead to the opposite of subsidence, known as “heave”. This is where the ground beneath a property swells up with excessive moisture caused by the absence of a tree that used to keep the moisture levels low. If this happens, an arboriculturist (tree specialist) will be able to provide expert advice.
If leaky pipework is the cause, a CCTV drain survey can determine if this is the issue, and where the work may be needed. The average cost of a drain survey is around £90 but can be anywhere between £45 and £160 – it’s worth bearing in mind that the exact price may vary depending on your area and how severe the problem is.
Depending on the severity of your subsidence issue and if considered reasonable by your insurance, the costs may be covered by your building insurance. Therefore, it is advisable to get in touch with your insurer if you are concerned about subsidence in your property, or you would like to check if you are covered.
If the costs are not covered by your insurance and you simply cannot afford to carry out the effective treatment needed, you may wish to sell your property and move to a new home via a quick sale company. These companies can give you cash for your home quickly, ensuring the problem is taken off of your hands immediately.
As mentioned earlier in this guide to subsidence, there are many negative connotations surrounding subsidence, such as buyers believing that the house is unsafe or unmortgageable. But you’ll be pleased to know that this is not entirely true and, in most cases,, subsidence it is successfully treated.
If a property is under some kind of treatment plan and caught early, there is no reason why the property cannot become structurally sound again and be restored to its former glory.
That being said, subsidence can still devalue a property. In
instances where houses do get sold with subsidence, it can cause a property to
sell for around 80% of its market value.
Feature image credit: Francesco Scatena / Shutterstock