Subsidence can be extremely costly
The recent heat wave could cause problems for some homeowners whose properties are at risk of subsidence damage, surveyors have warned.
The Royal Institution of Chartered Surveyors (Rics) has warned homeowners to be vigilant and look out for cracks, as hot weather can increase subsidence risks.
Subsidence is caused by changes under ground which cause foundations to shift, of which the first signs are usually cracks in the walls.
But the Association of British Insurers (ABI), an insurance trade body, said people should not panic, and it said it was not expecting an increase in claims this year.
Houses which are most susceptible to subsidence tend to have been built before the 1970s and have shallow foundations.
Homes built during the Edwardian and Victorian eras are said to be at particular risk.
Trees close to houses can also pose a threat as they take water from the soil through their roots and exacerbate any shrinkage caused by hot temperatures.
Rics said cracks over 3 millimetres wide were "serious" and required immediate action - especially if they passed through brickwork or stone.
"In light of the current heat wave we, like the insurance companies, are expecting to see a rise in the incidence of subsidence," said Rics' professional information officer John Sparkes.
The ABI, however, played down the concern.
It said there was little evidence of a link between hot summers and an increase in subsidence claims from homeowners.
Source: Association of British Insurers
A spokesman said: "Don't be alarmed. Cracks can appear for a number of reasons. it doesn't mean you have got severe structural damage."
"It is not something we are concerned about at the minute. We don't anticipate any significant increase in claims and we are certainly not concerned about it."
Cracks do not just appear overnight, she added, and the process can take some months.
If people spot a crack and are worried, however, they should contact their insurance company, she said.