Long dry spell could leave some homes at risk of structural movement

In long dry spells, the ground loses moisture through evaporation and to the roots of trees and large shrubs, which can cause the ground under a building to move.

Cracks can be alarming, but the PCA says they don't necessarily mean subsidence or a serious structural problem. Many buildings move slightly, and hairline cracks can come from seasonal changes or from building materials drying and moving normally.

Signs that may need looking into include diagonal cracks around doors and windows, stepped cracks in outside brickwork, doors or windows that suddenly stick, gaps opening between walls and ceilings, and cracks that seem to be getting wider.

Andrew Devitt, technical manager at the PCA, said: "The long dry periods we've had this year can affect shrinkable clay soils, and in some cases that can cause movement in the building above.

"Finding a crack in your home is understandably worrying, but a crack is a symptom, not a diagnosis. Buildings crack for lots of reasons, and it doesn't automatically mean a property has subsidence.

"What matters is finding the cause before deciding what work, if any, is needed.

"Homeowners who notice large or growing cracks should note where they are and how big they are, take dated photos and keep an eye on any changes.

"They should also check for obvious maintenance problems such as leaking gutters, drains or pipes, and contact their buildings insurer if they think structural movement may be involved."

Investigating suspected movement can involve a structural assessment and crack monitoring, along with checks on the soil, drainage and nearby vegetation.

PCA members in the Structural Repair sector specialise in assessing and fixing structural defects, working with structural engineers, surveyors and insurers where needed.

Depending on the cause and how bad the problem is, repairs can include stitching cracks in masonry, structural reinforcement, replacing wall ties, resin repairs and localised stabilisation.

Bigger foundation work such as underpinning or piling is occasionally needed, but the PCA says it should only be considered after proper investigation and an engineering assessment.

Devitt added: "Modern repair techniques mean many problems can be fixed with targeted repairs instead of major rebuilding.

"Getting the diagnosis right comes first. Once you know why the movement happened, you can plan a repair that fits the problem and protects the property for the future."

Homeowners worried about cracking or structural movement can find specialist Structural Repair members through the Property Care Association. More information on structural repairs is on the PCA's website: https://www.property-care.org/homeowners/advice/structural-repairs