Trees and Subsidence

The extreme hot, dry summers and reasonably dry winters in recent years has caused the insurance industry to see an increase in subsidence in buildings.

Subsidence is the downward movement of the ground supporting the building. Damage occurs because the movement is often uneven, causing cracks in walls, floors and ceilings. The main cause of subsidence
in the UK is the shrinkage in dry weather of clay soils which expand and contract with changes in their moisture content. The escape of water form leaking or damaged drains below the ground can also cause

Research has shown that the majority of subsidence problems involve trees to some degree. Trees more likely to cause problems than other have fine root structures longer than other species, such as poplars,
willows, elms and oaks.

Typical signs of subsidence usually show with the following:

  • Cracks from both inside and outside the property
  • Doors and windows sticking, this suggests distortion of the building

All buildings can suffer minor cracking from other causes such as “settling” when a new building has been built. Drying and shrinkage of building materials – which can be sorted during routine maintenance or redecoration.

How can we avoid issues?

  • Do not plant trees or large shrubs too close to property, including garages and outbuildings.
  • Trees that were planted before a property was built must be kept at a manageable level to ensure the amount of foliage produced is in control. This will help reduce the amount of water it requires and will avoid the tree taking over the area and potentially causing damage to property.
  • Trees that were planted before a property has been built should never be removed as this can cause uplift of the ground or “heave” (upward movement of the ground supporting the building – the opposite of subsidence).
  • Always check before altering or removing a tree whether there is a preservation order. You must obtain appropriate consent before commencing any works.

Try and always ensure you have subsidence cover within your policy. It may be that subsidence cover is excluded for various reasons but if it is included it certainly is worth having included in your policy.