Summer 2026 is on course to be the UK’s hottest on record, and homeowners may currently be more concerned with keeping their homes cool than checking whether the prolonged heat has caused any damage.

However, repeated exposure to high temperatures and prolonged sunlight can put additional stress on roofing materials, insulation and other parts of the home.

According to roofing and insulation expert Mike Storey of UKFR Roofing & Insulation, there are four signs of heat damage homeowners should look out for following a long, hot summer.

1. Cracked or split roofing materials

One of the clearest signs of prolonged heat exposure can be cracking or splitting in roofing materials.

Repeated heating and cooling causes materials to expand and contract, and over a long period of hot weather this can put additional stress on certain roofing components. Homeowners should check for visible cracks, splits or deterioration, particularly around roof coverings, joints and seals.

Mike said:

“We’ve had a long period of very hot weather this summer, and it’s the repeated exposure that’s important rather than just one particularly hot day.“

“Roofing materials expand when they’re heated by the sun and contract again as temperatures fall overnight. Over time, that movement can put stress on materials, particularly if they’re already starting to deteriorate.“

“If you can see any cracking or splitting on your roof, it’s worth getting it checked rather than assuming it’s just cosmetic.”

2. Blistering or bubbling on a flat roof

Homeowners with flat roofs should be particularly aware of blistering or bubbling on the roof surface following prolonged hot weather.

Flat roofs can absorb significant amounts of solar heat throughout the day, and sustained high temperatures can expose weaknesses in the roof covering. Blisters or bubbles can indicate that the roof surface or layers underneath have been affected.

Mike said:

“If you’ve got a flat roof, take a look at the surface and see if anything has changed over the summer.“

“Blistering, bubbling or areas where the surface looks raised aren’t things I’d ignore. They can be a sign that the roof covering has been affected by prolonged heat, and if water gets into those areas later on, you could end up with a much bigger problem.“

“It’s much better to sort these issues now, while the weather is dry, than wait until the autumn rain arrives.”

3. Deteriorating seals around roof windows, vents or other fittings

Prolonged exposure to strong sunlight and high temperatures can also affect seals and other components around the roof.

Look for cracked, dried-out or deteriorating sealant around roof windows, vents, flashing and other roof penetrations. Once a seal starts to fail, water can find its way into the property when wetter weather returns.

Mike said:

“People tend to think about the roof covering when they’re looking for damage, but some of the smaller components can be just as important.“

“If you’ve noticed cracking or deterioration around a roof window, vent or another fitting, it’s worth getting it looked at before the rain returns. A small problem with a seal can become a much bigger problem if water gets underneath it.”

4. Insulation that has become compressed, moved or deteriorated

The effects of a long, hot summer aren’t always visible from outside the property. If rooms that previously stayed comfortable now become significantly hotter, this could indicate you have an issue with the insulation.

Insulation can deteriorate or become displaced over time, reducing its ability to regulate temperatures inside the home.

Mike said:

“Insulation isn’t something most people think about when they think of summer damage because you can’t normally see it, but it’s an important part of how your home handles extreme temperatures.“

“If you’ve noticed that a particular room has become much hotter this summer than it was in previous years, I’d be looking at the insulation as well as the roof itself.”

For more information, visit UK Flat Roofing.