Hot weather sees home insurance claims soar - 7 risks to look out for
As Britain swelters, home insurance claims are also rising with the mercury. From cracked walls to garden fires, insurers are warning homeowners to brace for the hidden dangers of prolonged high temperatures.
Aviva reported a seasonal surge in home-related claims during hotter weather, with July and August 2025 seeing more claims for fires than any other month in the previous year as temperatures soared.
Weather-related subsidence and pest infestations can also cause havoc due to balmy temperatures. And with the UK recently seeing multiple days above 30°C this year many properties could already be feeling the strain.
We’ve rounded up the top heat-related risks every UK homeowner should be aware of this summer, along with practical advice to protect your property and avoid costly insurance claims.
1. Subsidence
Summer heat can dry out clay soils, leading them to shrink and crack, putting strain on foundations and causing subsidence.
Subsidence can affect your home insurance by making it more expensive to cover. Some policies also have a higher excess for subsidence claims.
Signs of subsidence include:
- Cracks that appear suddenly rather than develop over time.
- Wide cracks (usually 3mm or more) that can be seen inside and outside of the house.
- Diagonal cracks that are wider at the top than at the bottom.
If your insurance covers it, have cracks assessed by a surveyor. Subsidence can be fixed, but the sooner you diagnose the problem and act, the easier it is to resolve.
NimbleFins previously reported how to avoid subsidence when planting in your garden
2. Fire
Dry gardens, decking, and compost heaps can ignite spontaneously or from careless barbecues. And the average home insurance claim for fire damage was about £16,000, according to Aviva—a figure that is likely to approach £18,500 for 2026 (due to a ~15% increase driven by record-high construction and labour costs in the UK throughout 2025).
As well as soaring fire claims during the peak summer of 2025, insurer Aviva found claims from lightning - which can spark fires by striking roofs and loft spaces - have also increased over the last five years. September 2024 saw three times as many lightning claims than in any other month that year. While final 2025/2026 monthly breakdowns are still pending, the trend of 'convective' storm damage suggests these peaks are becoming more volatile.
Barbecuing in windy weather can be dangerous as gusts can carry hot embers. Ash can also stay hot for days so leave to cool properly before disposing.
Never leave a bonfire unattended, unplug appliances once charged, dispose of cigarettes carefully, and keep mirrors, bottles, and other reflective items away from direct sunlight, Aviva said.
Hannah Davidson, senior underwriting manager at Aviva, added: “The warm weather, paired with a lack of rain means that once started, a fire can spread very quickly – particularly as the ground is dry. Popular items in gardens, such as wooden fences and sheds, can be flammable, causing flames to spread quickly. A small fire in the garden can also spread to the home, causing significant damage.
“Whether it’s hosting friends for a barbecue, charging devices and tools outside or in the home, or even hanging a mirror outside in your garden for decoration, it’s worth paying close attention to what could become a potential fire hazard. With the average fire claim involving a garden amounting to almost £16,000, it’s worth taking out home insurance if you haven’t already, giving you peace of mind knowing that your home and belongings are protected.”
Read more: What Does Buildings Insurance Cover?
3. Cracks/material deterioration
Roof tiles, asphalt, UPVC, and plastics can warp or crack under intense sun.
Flat roofs, especially those covered in bitumen or asphalt, can blister or soften in high temperatures. That can eventually lead to leaks when the weather changes.
What to do:
- Inspect roofs, driveways, and windows for visible cracks or warping.
- Use blinds or curtains to reduce sun exposure on south-facing windows.
- Consider a professional roof inspection if you spot tiles lifting or shifting.
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4. Paint fading
The sun’s UV rays can bleach and break down paint, plastic, and wood over time. External paintwork can fade or peel, especially on south- and west-facing walls.
UPVC window frames and cladding can also yellow or become brittle. Even wooden garden furniture and fences are vulnerable.
This kind of cosmetic damage doesn’t just affect kerb appeal - it can lead to more serious issues like water ingress if materials become porous or start to crack.
Consider:
- Using UV-protective paint or varnish on outdoor surfaces.
- Repainting or reseal exposed timber every couple of years.
- Keeping an eye on plastic trims, seals and gutters that may degrade in sun.
5. Burglary risk
In the heat, it’s tempting to leave windows, doors, or even garages open to get air flowing. But this can leave your home vulnerable to opportunistic thieves.
UK police forces regularly warn about an increase in burglaries during warm weather, especially in urban areas.
Unlocked garden gates, tools left out, or ladders propped up outside can also help burglars gain access. If a break-in happens while doors or windows are left open, your contents insurance provider may challenge a claim depending on your policy wording.
Ways to protect your property:
- Avoid leaving front or back doors open and unattended.
- Lock away tools and ladders to prevent aiding entry.
- Check your home insurance policy for security requirements.
**Read more: How does a break-in affect home insurance?
6. Pest infestation
Hot weather creates the perfect breeding ground for insects and rodents.
Wasps, ants, and flies multiply fast in summer, and once they find access to your home, they can be hard to get rid of.
Warm lofts and garages can attract nesting insects, while rubbish left in heat can attract rats and foxes.
Infestations can cause damage to wiring, insulation or stored belongings.
What to do:
- Keep bins tightly sealed and cleaned regularly.
- Don’t leave pet food or uncovered leftovers out in the open.
- Seal gaps in walls, windows, and loft spaces to block entry.
- Watch for signs of nests in sheds, lofts, or behind cladding.
7. Pipes
Frozen pipes are usually a concern in winter but summer heat can pose risks too. Prolonged sunshine can cause external plastic pipes or garden hoses to warp or crack.
Pipes laid in expanding or shifting soil may also become misaligned, increasing the risk of leaks.
Some boilers or water tanks may also work harder during extreme heat, especially if people are using more water to keep cool. And if your loft gets excessively hot, expansion of pipework can cause clicking or knocking noises as joints strain.
Consider:
- Checking outdoor taps and exposed pipes for signs of leaks or warping.
- Lagging or UV shielding for pipes in sunny spots.
- Draining hoses when not in use, and store them out of direct sunlight.
If you hear unusual plumbing noises, have a plumber inspect the system.
Does hot weather cause noise in houses?
Yes, hot weather can cause noises in houses, such as cracking, clicking and popping.
Temperature changes can cause materials to expand and contract, such as wooden floors, roof timbers, and pipework.
While generally harmless, consistent loud noises may signal loose fittings needing attention.
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