Subsidence and its impact on home insurance

Subsidence is one of the most serious issues that can happen to your home, but many of us don't know what it is or what to look out for.

Below, we explain everything from what subsidence is and what causes it to the signs and whether your insurance covers you.

What is subsidence?

Simply put, subsidence is when the ground below your home sinks. It puts your home at serious risk of damage as the foundations can become misaligned, causing your walls and floors to move and become unbalanced.

Subsidence is often mistaken with the following: 

• Heave – the ground under your home to shift upwards
• Landslip or landslide – the ground under your home moves down a slope or is washed away
• Settlement – the downward movement of a property caused by the building’s weight

What causes subsidence?

Subsidence can be caused by a few different issues:

• Weather – subsidence can occur when the ground below your house shrinks or swells due to the weather.
• Leaky drains – can wash away the soil under your home or make the ground so saturated that the foundations give way causing it to subside. 
• Roots – if planted too close to your home they can grow longer as they search for moisture and go under your home.

In some cases, where your home is built can cause a problem too. Areas that have been mined in the past can result in unstable foundations or, even worse, structural damage to your home.

Also, homes built on clay are more likely to suffer from subsidence than those built on other types of soil.

How to spot signs of subsidence

Firstly, check for distinctive cracked walls, not the small cracks that probably first appeared as the house was settling.

Cracks from subsidence can:

• Appear and spread rapidly compared to regular cracks
• Occur both inside and outside the property
• Look narrower at one end than the other and run diagonally across the wall
• Be found around doors and windows

Other signs include:

• Doors and windows unable to open or close due to misalignment
• Wallpaper crinkling at the wall/ceiling joins (this may be behind any coving)
• Cracks where any extension joins the property

Reducing the risk of subsidence

Avoid planting trees or shrubs within six metres of your home.

For mature trees or shrubs, make sure they’re carefully managed and regularly pruned. For larger trees you could ask a tree surgeon how best to look after your foliage.

The Association of British Insurers (ABI) also provide information on safe distances to plant different types of trees. Your insurer may only ask about trees more than 10 metres tall within five metres of your house.

Also regularly check for unfamiliar cracks and keep your guttering and drains unblocked.

I think my home is subsiding, what can I do?

If you suspect your home is subsiding and your home insurance covers subsidence, call your insurer who can advise the best course of action.

You may only need a surveyor to monitor your home for a period, rather than invasive action. If the damage is more obvious the foundations may need to be investigated and soil samples may be taken.

Minor cracked walls which don't affect the structural integrity of your home can often just be filled in and painted over. Serious cracks that impact the structure may need to be re-pointed and repaired with metal fixings.

Your home may need to be underpinned, which is when an additional solid foundation is laid below ground level to add strength.

In some rare cases where the cracks are deemed severe, major reconstruction and some rebuilding may need to take place.

Can I claim for subsidence on my home insurance?

This depends on your insurer so check their terms and conditions before accepting the policy.

Pay particular attention to the subsidence excess. Many insurers apply a higher excess for damage caused by subsidence which varies and can be high if your home has previously been affected.

You must declare whether your home is already subsiding or has previously to avoid your claim being rejected.

If you have home insurance with us, you’re covered for loss or damage caused by subsidence but NOT if due to the following:

• Settlement, consolidation (soil changing in volume because of a change in pressure), shrinkage or ground being compacted 
• Thermal movement (expansion and contraction caused by heat and cold)
• The action chemicals have on or with any materials forming part of the buildings
• Coastal or river erosion
• Demolition or structural changes or repairs to your home

Find out more about what Admiral Home Insurance covers.