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Cracks in walls

All you need to know about cracks in walls

published: 12 February 2021
Read time: 5 minutes

Most houses will have cracks in their walls at some point. In some cases, you'll only need to redecorate, but certain situations may need more work and possibly a buildings insurance claim…

What causes cracks in the walls of my house?

Most houses will end up with a crack in the wall at some point. Most of the time you’ll just need to redecorate, but some cracks may be more serious and require foundation repair.

Some of the causes of cracks in walls include:

  • Wear and tear: Over time, your home is likely to experience wear and tear and minor settling. These cracks usually appear above doors and windows and is caused by movement over time – the ground beneath your foundation can shift over time with changes in weather

  • Moisture: New builds’ lumber contains a lot of moisture which takes time to dry out. As it dries, it can move slightly which can cause small cracks in walls. These are often nothing to worry about – you should generally wait for the wood to dry completely before trying to fix anything

  • A leak: If the cracks in your walls are discoloured (brown or yellow stains), the problem may be caused by water damage. Moisture getting into your home’s walls causes the drywall to soften which can lead to cracking

  • Foundation damage: If you’re seeing large cracks (above 25mm), this may be a sign that your house’s foundation is damaged – so you may need to call a professional for help

crack in wall

Do cracks mean subsidence?

Not all cracks in walls will be as a result of subsidence. Often, cracks which are known as ‘hairline’ cracks aren’t a major issue and may be caused by ‘blown plaster’ – when the plaster has lost contact with the wall. You can check for this by ‘knocking’ on the plaster – if there’s blown plaster, there’ll be a hollow sound.

If you think your property has subsidence, it’s best to contact your home insurance provider as soon as possible. Most standard buildings insurance will cover damage to your home because of subsidence, as long as your property hasn’t had subsidence before. This should take off the financial strain of needing to pay for repairs yourself, as these can be expensive.

How can I tell if the types of cracks in my house are a problem?

When it comes to cracks in walls, they can vary depending on their severity. Wall cracks can vary in length, direction and width, and larger cracks (with a width larger than 15mm) are a potential problem and should be looked at by a structural engineer.

Working out if cracks in your walls are a problem will depend on the type of crack:

  1. Minor: Hairline cracks are less than 1mm wide, and can be easily fixed by redecorating

  2. Slight: These types of cracks can be fixed with filler and are measured between 1mm and 5mm in width.  If they’re exterior cracks, they may need re-pointing

  3. Moderate: Moderate cracks measuring between 5 and 15mm may need professional building work to repair them

  4. Severe: Cracks that are a sign of structural damage measure up to 25mm wide. They should be looked at and repaired by a professional

  5. Very severe: If the wall crack is above 25mm in width, there’s likely to be serious structural damage. This will need to be repaired, which can include underpinning and rebuilding. If the crack is large and running vertically, this can also be a sign of structural damage

If you’re worried about cracks in your walls, it may be a good idea to contact a building professional or structural engineer who will be able to tell you if the wall cracks are cause of concern.

Are cracks in ceiling different than cracks in walls?

Like wall cracks, ceiling cracks can happen over time and aren’t always something to be concerned over. Cracks in the ceiling work in the same way as wall cracks, and are usually caused by structural damage or settling.

If your ceiling cracks are caused by normal settling, there’s usually nothing to worry about and it’s unlikely that you’ll be covered by your home insurance for this. But if they’re caused by structural damage, they will need repair work.

If you are concerned about cracks in your ceiling, it’s important that you contact your home insurance provider as soon as possible, to see what you’re covered for.

What about cracks in plaster?

Cracks in plaster are usually caused by buildings shifting slightly over time and in most cases are nothing to worry about. Hairline cracks in plasterwork (less than 1mm in width) can be fixed by redecorating and won’t need further repair.

If the plaster cracks are of 5 to 15mm, they may be more serious and need masonry replacement. Often, home insurance won’t cover wear and tear caused normal deterioration that happens as your property ages.

Are cracks in walls covered by buildings insurance?

If your cracks in walls are caused by subsidence, your buildings insurance should cover the cost of repairs. Wall cracks caused by subsidence are usually wider than 3mm, appear on both the inner and outer walls, near to windows or doors and get wider over time. Most standard building insurance policies will cover cracks in walls caused by subsidence, as long as your home hasn’t had subsidence before.

If your cracks in walls aren’t caused by subsidence, it’s unlikely that your buildings insurance will pay for any repairs. Cracks in walls can also be caused by poor workmanship, faulty materials or inadequate foundations, which aren’t usually covered by buildings insurance.

If you notice cracks in your new-build property, this is likely to be ‘settlement’ – where your home naturally settles onto its foundations. This is usually nothing to worry about and is a common occurrence in new properties. If your wall cracks are caused by natural settlement, this will be seen as a maintenance issue, so probably won’t be covered by your buildings insurance.

How can I avoid cracks in walls?

There are ways you can prevent cracks in your walls, these include:

  • Spot the crack early: Keep an eye on your walls and if you notice any changes, act quickly to avoid the crack getting worse

  • Contact professionals: If the crack in the wall is measuring above 5mm, you may need professional work to repair it

  • Keeping on top of maintenance: You should be able to fix smaller cracks yourself (cracks between 1mm and 5mm can be fixed with filler.) Try and keep on top of redecorating where needed, so any cracks in the wall don’t worsen

Can I claim on my home insurance to fix cracks in walls?

Whether you can claim on your home insurance for cracks in walls will depend on the cause of the cracks. If the cracks are caused by subsidence, you should be covered to claim on your buildings insurance – but do bear in mind the excess on subsidence claims is often more than for claims on the rest of your cover. This is because the repair costs for subsidence can be tens of thousands of pounds.

If the cracks in your home are caused by natural settlement, lintel failure or thermal movement, it’s unlikely that you’ll be covered by your home insurance. This is because these causes are considered wear and tear and normal deterioration to a property over time.

Compare home insurance today

If you’re looking for peace of mind when it comes to your home, compare home insurance with MoneySuperMarket. All you need to do is tell us a little about yourself and your home, including when it was built and how much cover you’d like on your policy.

With this information, we’ll put together a list of quotes from a range of providers, so you can compare deals by the monthly and annual cost of the policy, the level of cover you’ll get, and the excess you’ll need to pay to make a claim. Once you’ve found the deal you want, just click through to the provider to complete your purchase.

Like all insurance policies, the cheapest available deal isn’t always the best one. We recommend you aim to balance the cost with the cover you get, so you don’t end up under-insured or overpaying for a policy you don’t need.