What is Subsidence?


The definition of Subsidence

Subsidence is the cyclical movement both upwards and downward of the foundations on which a building stands:

  • Where the movement is unconnected with the weight of the building.
  • The soil beneath the building’s foundations is unstable.
  • The movement of the ground causes subsidence, not the building pushing into the ground. 

Subsidence in the South East of England is typically caused by the Clay ground swelling (Heave) or sinking (subsidence). This movement is typically caused by moisture entering and leaving the soil. Trees increase the rate of water removed in the summer months as they extract water from the ground. It is for this reason that trees & failed drains may cause difficulties to a building.

What is Heave?

The vertical movement of the ground is known as Heave. Water entering clay will cause the soil to “Swell”. Removing a tree will result in localised heave. Heave is typically slow taking years to occur, because of this buildings have longer to accommodate the movement and crack less.

A quick guide

Buildings move and one should not always run to your insurer.

  • Hairline cracks – decorate is quicker
  • Cracks only wide enough to put your finger nail in decorate over, if they return call Croft in
  • Cracks wider than finger nail call Croft in

What is Settlement?

Settlement is the movement of a building due to the foundations being insufficient for the load. Footings that are too narrow will punch into the ground. Subsidence is the movement of the ground below the footing. Building foundations too narrow and them sinking is not subsidence, forming foundations too shallow on ground affect by yearly weather is subsidence.