Does Home Insurance Cover Cracked Walls and Render?

Buildings insurance covers cracked walls and render when the cracking was caused by an insured event: subsidence, heave, landslip, storm, fire, flood or impact. It does not cover cracking caused by age, weather over time, damp, poor workmanship or lack of maintenance.

What decides a claim is how the crack got there, not how bad it looks. Two identical cracks can produce opposite answers.

At a glance

Covered under: Buildings insurance
Claimable causes: Subsidence, heave, landslip, storm, fire, impact
Not covered: Age, damp, poor workmanship
Subsidence excess: Typically £1,000
New builds: NHBC warranty may apply

Key takeaways

Cause decides everything. Insured event, paid. Gradual deterioration, refused.
Most cracks are not a claim. Thermal movement and settlement are normal and excluded.
Subsidence carries its own excess, usually around £1,000 rather than the £100–250 on the rest of your policy.
A subsidence claim follows the house. You must declare it forever, and it narrows who will insure you afterwards.
Claiming is often the wrong move on anything you could repair for less than the excess.

First, how serious is the crack?

Before insurance comes into it, work out what you are looking at. Surveyors and structural engineers classify cracking to a published standard, BRE Digest 251, which runs from category 0 to category 5 by crack width.

Category	Width	Classed as	What it means
0	Under 0.1mm	Aesthetic	Hairline. Negligible.
1	Up to 1mm	Aesthetic	Fine cracks, usually internal. Normal decoration.
2	Up to 5mm	Aesthetic	Redecoration, possibly some repointing.
3	5–15mm	Serviceability	Affects weathertightness and how doors and windows work.
4	15–25mm	Serviceability	Extensive repair. Structural assessment needed.
5	Over 25mm	Stability	Structural intervention likely.

That three-way grouping is the useful part, and it is the language a surveyor will use with you:

Aesthetic (categories 0–2, up to 5mm): it looks bad, nothing more. Redecoration territory.
Serviceability (3–4): the building still stands but it no longer performs. Rain gets in, doors stick.
Stability (5): the structure itself is the problem.

As a rule of thumb, anything above about 5mm crosses out of cosmetic and is worth a professional opinion. Below that, you are almost certainly looking at movement no insurer will pay for.

Source: BRE Digest 251, Assessment of damage in low-rise buildings (Building Research Establishment, revised 1995).

What the pattern tells you

Width tells you severity. The shape tells you cause, and cause is what the insurer cares about.

Diagonal or stair-step cracks, running through mortar joints and usually wider at the top, near windows and doors: the classic sign of subsidence. This is the one that is potentially claimable.
Vertical cracks at a join between an extension and the original house: settlement where two structures move at different rates. Normal, not claimable.
Fine, map-like crazing across render: the render itself failing with age or having been applied badly. Not claimable.
Horizontal cracks, particularly along a mortar course: can indicate cavity wall tie failure. Serious, but usually treated as deterioration, not an insured event.
Cracks that appear suddenly after a storm, flood or impact: the most straightforward claim you can make, because the cause is dated and obvious.

What is actually covered

Your buildings insurance covers the structure of your home, including external walls and render. A claim succeeds when the damage traces to a peril named in your policy:

Subsidence: the ground beneath the property sinking, usually from clay shrinkage in dry summers, tree roots, or a leaking drain washing soil away.
Heave: the opposite, ground swelling and pushing upward, often after a large tree is removed.
Landslip: ground moving sideways down a slope.
Storm damage: genuinely severe weather, not ordinary wind and rain.
Fire, flood, escape of water and impact (a vehicle, a falling tree).

What is not covered, and why claims get refused

Every standard policy excludes gradual causes. This is where most refusals come from:

Wear and tear. Render has a life. When it reaches the end of it, that is maintenance.
Damp and water ingress over time. Distinct from a sudden escape of water, and almost always excluded.
Poor original workmanship. Render applied too thickly, too fast, or in the wrong weather.
Lack of maintenance. Blocked gutters soaking a wall for years is your responsibility, not the insurer's.
Thermal movement and normal settlement. Buildings expand, contract and settle. Not an event.
Pre-existing damage that was there when the policy started.

Should you actually claim?

This is the part that gets skipped, and it matters more than the coverage question.

The excess is not the one you think. Most policies carry a standard excess of £100–250. Subsidence almost always carries a separate compulsory excess of around £1,000. If the repair costs £1,500, you are claiming for £500 and taking on everything below.

Then there is what a subsidence claim does to the house. Once recorded, you must declare it on every future insurance application, and you must disclose it to a buyer. In practice it means:

A narrower pool of insurers, sometimes only specialist ones
Higher premiums, often permanently
Buyers who struggle to get cover, which affects what your home sells for
Surveyors flagging it on any future mortgage valuation

Insurers also take their time. A subsidence claim typically involves monitoring the crack over months, often a year or more, before anyone agrees what the remedy is. Underpinning, which is what most people fear, is comparatively rare; more claims are resolved by removing a tree or repairing a drain. See what counts as minor subsidence for what that usually involves.

None of that means don't claim. If you have genuine subsidence, you need the insurer involved and the cost is far beyond what you would fund yourself. But for anything marginal, a crack you could have repaired for a few hundred pounds, claiming is usually the more expensive decision once you count the excess, the premium, and the effect on resale.

What to do next

Photograph and date it. If it grows, you want the record. Mark the ends with a pencil line.
Work out the cause. Check gutters, downpipes and drains near the crack first: leaking water is behind a great many "subsidence" cracks and is far cheaper to fix.
Check the tree situation. Large, thirsty trees close to the house on clay soil are the commonest cause of genuine subsidence.
Read your policy schedule, not the summary. Look for the subsidence excess specifically.
Call your insurer before a builder if you think it is subsidence. Doing your own remedial work first can prejudice a claim.
Get a structural engineer, not a damp-proofing or underpinning company, if you want an independent view. The latter sell a solution.

New builds and the NHBC warranty

If your home is under ten years old it is likely covered by an NHBC warranty or a similar scheme, which sits separately from your insurance.

Broadly, the builder is responsible for defects in the first two years, and the warranty covers specified structural problems for the remaining eight. Settlement cracking in a new build is extremely common and usually falls to the builder to make good in that first period, so raise it with them before you approach anyone else.

Frequently asked questions

Does buildings insurance cover cracked render?

Yes, if the cracking was caused by an insured event such as subsidence, storm, fire or impact. Render that has cracked through age, damp or poor application is treated as maintenance and is not covered.

How big does a crack have to be to worry about?

Cracks under about 5mm are usually cosmetic and are rarely a structural concern. Anything wider than 5mm, and particularly anything diagonal that is wider at the top, is worth a professional opinion.

Will claiming for subsidence increase my premium?

Almost certainly, and usually permanently. A recorded subsidence claim must be declared on future applications, narrows the number of insurers who will quote, and has to be disclosed when you sell.

What is the excess on a subsidence claim?

Subsidence normally carries its own compulsory excess of around £1,000, considerably higher than the £100–250 standard excess applied to other claims. Check your policy schedule rather than the summary document.

Does home insurance cover cracks caused by damp?

No. Damage that develops gradually through damp or water ingress is excluded from standard policies. A sudden escape of water, a burst pipe, is a different matter and is usually covered.

Are settlement cracks in a new build covered?

Not by your insurance, because settlement is expected rather than accidental. In the first two years it is normally the builder's responsibility under the NHBC or equivalent warranty.

Should I repair a small crack myself or claim?

If the repair costs less than your excess, repairing it yourself is almost always cheaper: especially where subsidence excess applies. Claiming makes sense when the cause is a genuine insured event and the cost is substantial.

General information only, not advice about your own policy. Cover varies between insurers and the wording in your policy schedule is what counts.