The Royal Institution of Chartered Surveyors (RICS) believe that subsidence, caused by the loss of water from shrinkable subsoil, brought about by a period of high temperatures and low rainfall, is a major threat to houses built with shallow foundations.
This is most commonly seen in the construction of pre-1965 houses and particularly during the Edwardian and Victorian eras, shallow foundations are more susceptible to the problem of heave.
This arises when a hot spell breaks and rain causes the soil to expand.
Roy Ilott, a Rics spokesperson, said: We, like the insurance companies, are expecting to see a rise in the incidence of subsidence.
Cracks over 3mm wide are considered to be serious and require immediate action, especially if they pass through brickwork or stone.
Action to permanently correct subsidence is drastic and involves the deepening of the foundations in a process known as underpinning.
The mere fact that a house has been underpinned can cause problems when the owner comes to sell, unless it has been carried out by a reputable building company.
Ilott said: Finding the cracks and notifying your insurance company can be the easy part rectifying the problem can be very complex, costly and disruptive to the household.
House owners should be prepared for delays as premature action can cause further problems and insurers will usually want to monitor walls for a season to asses a pattern.
On finding a crack, householders should immediately notify their insurance company, or their landlord, and make a claim.
However, the process can become stressful as the claim may well involve many parties the insurer, the owner, the loss adjuster, a building surveyor and the building contractor.
Ilott commented: Our experience is that because it is such a slow process there can appear to be little co-ordination between all the parties and owners often feel they are piggy in the middle.
We would advise them to step back and let the experts get on with the job.
To help you deal with issues associated with subsidence, RICS has produces a free brochure entitles: What to do when the earth moves available from the RICS Contact Centre on 0870 333 1600.