Subsidence, heave and landslip

Typically the first sign of subsidence, heave and/or landslip movement to a brittle finish building is diagonal cracking which suddenly appears in brittle finishes such as plaster, brickwork, blockwork especially at weak points around window and door openings.

Subsidence is a volumetric reduction in the sub-soil supporting a building typically caused by one or a combination of shrinkable sub-soil, the abstraction of moisture by vegetation, climatic changes, leaking water supplies or mains, leaking below ground foul and storm drainage, proximity to quarries or mines etc.

Where subsidence movement occurs buildings tend to drop into the void created in the sub-soil resulting in downward and rotational movement. Heave is the reverse of subsidence where the sub-soil volume increases occurring typically as a result of excess water pushing a building upward.

Landslip occurs where a natural or man-made slope fails under the action of gravity due to either a pre-existing deficiency and/or a contributing factor.

It should be noted that not all cracking is due to subsidence, heave and/or landslip. Cracks can occur due to shrinkage, differing thermal properties of differing construction materials, corrosion in metals built into brittle materials and settlement especially in new buildings and extensions.

If your property is affected by subsidence, heave and/or landslip movement or any other insured peril EAR Sheppard can help

  • In completing a limited structural inspection and providing an initial written report on indicative cause
  • In arranging necessary site investigations (to include a geotechnical report, a below ground drain condition survey, a check on the water supply/main, an arboricultural report, etc), reviewing investigation reports and preparing a Report Upon Alleged Subsidence, Heave and/or Landslip confirming cause
  • In specifying and  arranging necessary mitigation works
  • In arranging and  completing periodic crack width and level monitoring of the damaged area and building
  • In designing and  detailing superstructure repair and redecoration schemes and where required stabilization schemes such as underpinning and/or take down and  rebuild
  • In preparing Contract Schedules of Work and obtaining tender quotations
  • In acting as Contract Administrator in the contract arranged with the successful builder and  periodically inspecting work in progress

Buildings insurance policies generally include for the recovery of ‘professional fees’ and one benefit of EAR Sheppard providing engineering services is that we are independent and impartial. The cost of our services (along with any initial inspection/report) would typically be recoverable under a buildings insurance claim subject to any applicable policy excess.