Subsidence: everything you need to know

You thought your home was your perfect partner. The bright rooms, the convenient location, the interesting view. But in time, like any relationship, a few cracks started to appear. They were small and barely noticeable at first, but now they’re getting bigger and you’re wondering if your home really is quite so perfect after all, and if you might have a bit of a problem on your hands.

Stay calm – you might not need to break up with your home just yet. Cracked walls are fairly common in the UK, particularly in older properties. They could be a sign of subsidence, or nothing to worry about, but cracked walls are fixable.

Subsidence means that the ground beneath a building is moving or sinking downwards, with the potential to pull the foundations down too.

While the idea of dealing with it may sound daunting, if caught early enough subsidence can be managed with little intrusion.

Here’s what you need to know about subsidence and whether it’s covered by your home insurance.

There are two main causes of subsidence. In most cases the moisture in the clay below the foundations is taken by trees causing the ground to shrink. This is made worse by heatwaves of prolonged hot weather. In other cases, leaking drains or pipes soften the soil causing movement of the foundation.

Diagonal cracks on the inside and outside of your property extending to ground level are the most common sign that you might be dealing with subsidence. If you’ve spotted cracks like these, get in touch with your home insurer.

Cracks may simply be the result of wear and tear – as properties get older, it’s normal for them to move and settle over the years.

Caught early enough and subsidence can be managed, often with little disruption.

Even when underpinning is required (the process used to strengthen a building's foundations), traditional concrete underpinning – where the depth of the foundations is increased by digging down and filling the spaces with concrete, essentially creating a new set of foundations – isn’t always necessary.

Resin injections are a much less invasive form of underpinning. The technique involves injecting resin into the foundations through small incisions made in the ground which then expands and compresses the soil, at the same time filling in any spaces.

The likelihood is that you won’t need to decide between either, because correcting drainage issues and removing trees are more common solutions.

Needless to say, it’s best to wait for an expert to investigate the issue, cause and likely solution rather than trying to fix it yourself, as you could ultimately do more harm than good.

Fixing subsidence has the potential to get expensive, so it’s a good idea to have insurance in place. Most home insurance policies will cover a claim for subsidence. Subsidence claims are subject to a minimum excess of £1,000, although this may be higher under certain circumstances. There are some key exclusions:

• if there is damage to any part of the buildings (e.g. a boundary wall or patio) unless we accept a claim for damage to the Home that happened at the same time, by the same cause
• if you knew when this policy started that any part of the buildings had already been damaged by subsidence, heave, or landslip unless you told us about it, and we accepted it
• damage caused by settlement, or by shrinkage or expansion of parts of the buildings

At Aviva, we appoint a specialist company to manage subsidence insurance claims, from the initial investigations to the final repairs. They’ll establish the cause of damage, determine whether the damage is covered by your insurance, arrange investigations, and assess and approve repairs.

They’ll usually want to know the rough date the suspected subsidence appeared, along with photographs of any damage. If you’ve got an extension, conservatory or carried out building work, hold on to any documents relating to it, as they may want to see that too.

If it does turn out to be subsidence, your insurance may cover the costs for it to be fixed, along with the cost of repairing the damage caused by subsidence. Conditions, limits and exclusions apply. Pre-existing damage, or damage not caused by subsidence, probably won’t be covered.

If you do see signs of subsidence, get in touch with your insurer asap. Getting the claims process underway early is critical, as it could result in the need for less intrusive work further down the line.

If you’re an Aviva customer, the fastest way to do this is by tapping into MyAviva.

Most subsidence claims take between one and two years to resolve, but if the cause of the damage is outside your control, for example a local authority tree, the claim can take much longer.

The claims process will look something like this:

Investigate

There’ll be a survey of your property to investigate the cause of the damage.

Mitigate

The cause of the subsidence will be fixed.

Monitor

Sometimes a property will be monitored to check a building is stable before repairs start, or to establish if a particular tree is causing a problem.

Repair

Your insurers will fund the cost of repairing damage caused by subsidence identified as part of your claim.

So while subsidence is unlikely to be a welcome change in your relationship with your home, by understanding the signs, causes and having insurance in place, you can get back on with living happily ever after.