What is subsidence?

Key points:

• Subsidence happens when the foundations under your home start sinking

• It can cause structural damage to your property, starting with cracks in the walls

• Certain trees are more likely than others to cause subsidence

• Catching subsidence early is the best way to reduce its impact

Subsidence or heave could cause lasting and costly damage to your property, so it pays to take the right preventative measures and have insurance in place.

John Lewis Money defines subsidence as “sudden and/or unexpected downward movement of the ground beneath the buildings other than by settlement.” But what exactly does this mean, and how do you know if your home insurance covers you?

What causes subsidence?

Subsidence occurs when the foundations under your home begin to sink, causing structural damage to the property. There are a number of things that can cause subsidence, including:

• Nearby trees absorbing moisture from the soil

• Leaking drains washing away your foundations

• Your home being built on unstable terrain (eg clay soil)

What is ground heave?

Ground heave is the opposite of subsidence but can cause similar structural problems. Heave occurs when soil becomes saturated with water, causing the ground to swell and the foundations of your home to move upwards or sideways.

What is landslip?

Landslip is when there has been sudden and unexpected downward movement of sloping ground.

How to spot subsidence

The first and most noticeable signs of subsidence are cracks on the inside and outside of your home. These are caused by movement under the building and can get progressively worse in periods of dry weather. Other signs of subsidence include:

• Expanding cracks in the interior walls, ceilings and outside brickwork

• Appearance of cracks, worsening in dry weather

• Torn or rippling wallpaper that isn’t caused by damp

• Sticking doors and windows

Structural damage caused by subsidence can be dangerous. It can also make it difficult to sell your home and invalidate your insurance if you fail to act on the warning signs and seek advice from a surveyor.

How to prevent subsidence damaging your property

Here is the standard approach for preventing long-term damage:

• Don't plant trees or large shrubs close to your home

• Control the growth of nearby trees

• Keep gutters and drainage systems clear from leaves and debris

• Carry out regular maintenance checks, keeping an eye out for emerging cracks

• Monitor your water usage, as unusually high readings can indicate that there is an escape of water on your property somewhere

Which types of trees can cause subsidence?

Ash, willow, elm, poplar and oak trees are all known for causing subsidence issues as they soak up a great deal of water. If you have concerns about trees close to your property causing subsidence, it is best to seek advice from a qualified arboriculturalist or tree specialist

How to fix subsidence

Catching subsidence early is the best way to reduce its impact. Finding the source of the subsidence early can often lead to reduced costs and avoid the need for significant structural repairs.

What to do if you find subsidence after getting home insurance

According to the ABI subsidence claim handling agreement, if you discover subsidence damage within eight weeks of switching insurance providers, your previous insurer is responsible for your cover. Between eight weeks and a year, the cost is shared between your previous and current insurers.

Does John Lewis offer subsidence insurance?

John Lewis Money Buildings Insurance offers protection against subsidence as standard towards repairing damage caused to your home. Alternative accommodation will also be arranged if you are unable to stay in your home during agreed repairs.

Terms, policy limits and exclusions apply.*

How can I get a home insurance quote with John Lewis Money?

You can get a quote for home insurance with John Lewis Money to cover your home and your belongings. Not only are our Gold, Silver and Specialist home insurance policies five-star rated by Defaqto, but our different levels of cover can be tailored to suit your property. Plus, our Specialist Home Insurance, brought to you by Covea Insurance, is specifically designed for high-value contents & homes, or unique homes.

This article is for promotional or information purposes only. You must not rely on it as advice. 

*The policy does not cover subsidence, heave, or landslip damage to drives, walls, patios, paved terraces, footpaths, tennis courts, fixtures, fittings, permanently wire fixed alarm systems, fences, and gates, plus statues, pergolas, gazebos, garden ponds, swimming pools, and fountains that are permanently fixed into the ground belonging to your home. External lighting, surveillance equipment, fixed solar heating systems, fixed wind turbines, air- and ground-source heat pumps, electric vehicle charging points. Permanently fixed recreational toys and brick-built barbecues. Permanently fixed hot tubs or Jacuzzis. Unless the main residence is also damaged by the same cause, at the same time. There is no cover for loss or damage caused by subsidence, heave or landslip to solid floors unless the foundations of the outside walls of your home are damaged by the same cause, at the same time. 

There is no cover for loss or damage caused by: 

• Structures bedding down or settlement of newly made-up ground

• Coast or riverbanks being worn away

• Demolition, alteration or repair to your home

• Poor or faulty design, workmanship, or materials

• Sulphate reacting with any materials from which any part of your buildings is constructed 

There is no cover for any loss or damage that is covered under an alternative warranty, agreement, guarantee or insurance policy. For example, National House Building Council (NHBC).