Angell Thompson

Subsidence - Diagnosis, Identification of Cause, Mitigation & Repair

What is Subsidence?
Subsidence is a change in the condition of the ground on which a building is supported. It can result in crack-damage to walls and ceilings, distortion to door and window openings and in extreme circumstances, fractures to pipes and other services.
In London and the South East, this damage most commonly occurs to buildings founded on shrinkable clay sub-soils, during periods of very dry weather. This is normally exacerbated where roots from trees and large shrubs grow beneath foundations, causing the clay to shrink, and the foundations to move. Subsidence can occur due to other factors as well, such as the washing-out of soil by water from a leaking pipe or watercourse.
When Subsidence to a building is suspected, a careful and thorough investigation by an experienced Chartered Structural Engineer or Chartered Building Surveyor is required to diagnose the cause, and accurately identify the area of foundation movement. Once this has been established, a course of action can be decided and the correct remedial action can commence.

Since 1978 our Chartered Structural Engineers and Chartered Building Surveyors have been successfully resolving the problems of subsidence damage to domestic and commercial properties across London and the South East. As a result we have built an unrivalled wealth of experience and a highly regarded reputation in this specialised field. Our directors have had considerable experience as surveying or engineering professionals employed directly within the Loss Adjusting profession and as a result have a full understanding of the many issues relating to insurance cover for subsidence, as well as an in-depth knowledge of the technical aspects of investigation and remedial works. We have been appointed as expert witnesses in a variety of cases and have produced reports for the Insurance Ombudsman.

For over 20 years we have worked with most of the major firms of leading loss adjusters resolving personal and commercial subsidence insurance claims. Nevertheless, our services remain independent and we are able to offer a fully independent opinion on Subsidence causes and remedies either directly to home owners or to Insurance Companies.

Our Service

  • We aim to visit a property as soon as possible after receiving an enquiry, usually within 5 working days, and our experienced engineers and surveyors can often identify the mechanism of movement and provide an opinion on the cause of damage at this initial visit.
  • Site investigations will normally be required to confirm causation and enable us to provide formal recommendation for management of the subsidence problem. We have a panel of experienced site investigators who can carry out this work at short notice. The investigation works will typically involve trial pits, soil and root samples and CCTV drainage investigation.
  • We will then issue a concise, clear 'plain-language' report with recommendations for remedial action. Often a building can be stabilised by removing or managing the main cause of movement, but occasionally there may be a need to strengthen the foundations. Whatever remedial works are necessary, we will design and specify the solution, and implement the appropriate works through our panel of experienced specialist contractors.
  • Sometimes a period of monitoring may be required to confirm that the mitigating action has been successful in stabilising the property. This will be fully explained in our report which will clearly define the period of monitoring required.
  • Once we are satisfied that the building is stable we will then schedule and oversee final repairs and redecoration works.