Angell Thompson
| Consulting Structural Engineers & Surveyors

Subsidence

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 usually where roots from trees and large shrubs grow beneath foundations, extracting even more moisture and causing the clay to shrink, and the foundations to move. Subsidence can occur due to other factors as well, such as the softening or erosion of soil by water from a leaking pipe or drain.

When Subsidence to a building is suspected, a 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.

subsicence surrey

What is Heave?

Heave is also a change in the condition of the ground on which a building is supported, affecting only clay soils. It can produce a similar degree of crack-damage, although the pattern of cracking may be different.

All vegetation takes up moisture from the soil in which it grows, some plants more than others. Where established trees or vegetation have existed for a long period of time, the level of moisture in the surrounding soil remains relatively stable over the long-term (subject only to seasonal fluctuations). If such vegetation is suddenly removed, excess water in the soil is no longer taken-up and clay soils will do the opposite of shrink, they will swell and may ‘push-up’ any structure built upon them. Investigation of this problem involves identifying the soil-type, and also any external factors which have influenced the sub-strata, including the removal of trees and vegetation. A solution then needs to be designed.

Where subsidence is identified (see above), removal of nearby trees is often, but not always, the best course of action – the risk of ‘heave’ is one reason why expert advice should be sought. On clay subsoils in particular, trees and vegetation require considered management.

Our Experience

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.

We have built an unrivalled wealth of experience and a highly-regarded reputation in this specialised field. Our directors employment history includes Loss Adjusting experience and we have a comprehensive 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 difficult claims and have produced independent Reports for the Financial Services Insurance Ombudsman.

Independence

Where the investigation of, and solution to a subsidence problem is concerned, it makes no difference who is funding the cost; our opinion will reflect the structural conditions encountered.

We work with many major, and specialist firms of Loss Adjusters resolving personal and commercial subsidence insurance claims; however, our services remain independent - and we will always provide accurate, thorough, unbiased advice.

Our Service - Subsidence Insurance Claims

  • We aim to visit a property as soon as possible after receiving an enquiry, usually within 5 working days.
  • The mechanism of movement and an opinion on the cause of damage, can often be provided at this initial visit.
  • Site investigations may 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 often involve trial pits, soil and root samples and CCTV drainage investigation.
  • We will issue a concise, plain-language report with recommendations for remedial action.
  • Often, a building can be stabilised by removing or managing the main cause of movement. Occasionally there may be a need to strengthen the foundations.
  • We will design and specify the solution, and implement the works through our panel of experienced contractors.
  • Sometimes a period of monitoring may be required to confirm the action taken has been successful in stabilising the property. This will be fully explained in our report, which will recommend the period of monitoring required.
  • Once we are satisfied that the building is stable we will schedule and oversee final repairs and redecoration works.

▼ Insurers will seek to...

...settle claims in the most economic manner reasonably possible and it is a condition under most policies for the Policyholder to ‘act as if uninsured’ i.e. to take good care of their property, minimise loss and minimise cost in the same way as they would if they were funding repairs themselves, without the benefit of insurance cover.

▼ It is a requirement...

...under most policies that the Policyholder takes responsibility for setting their sums insured adequately. It has been established at law that Insurance Companies cannot be held responsible for knowing the reinstatement value of their customers’ property. They will often offer assistance with this, usually referring Policyholders to the Royal Institution of Chartered Surveyors House Rebuilding Cost Index. You can refer to this by clicking here. You will need to know the m2 area of your house.

▼ Note that...

Your sum-insured should include an amount of c. 10% and 5% extra to cover the cost of professional Architects and Surveyors’ fees, and the cost of complying with Local Authority requirements, respectively. Some insurance policies require you to use the insurance company’s own surveyors and contractors to specify and carry out repairs to your building; check your policy wording. However provided your sum insured is adequate it will usually include the cost of independent professional fees where necessary for reinstating your loss. R.I.C.S House Rebuilding Cost Index

  • We saw Steve last week and both expressed our most grateful and heartfelt thanks to him,
    the contractor and all of his team for the quite wonderful and fantastic job of restoring our home.

    Mr C - Kent

     

  • Your views are always so practical, much appreciated!

    Mr S - Epsom, Surrey

     

  • We are really loving our beautiful new home. We can still hardly believe it.
    Thank you so much Steve, you have been a tower of strength for us over the last year.

    Mr & Mrs T, Maidstone, Kent

  • I would not wish to inflict on any one what we have had to go through over the last 11/12 months
    but all I can say is that you and the building team have been fantastic.

    Mr and Mrs C, Broadstairs, Kent

     

     

  • Many thanks for a job well done

    Mrs M, Weybridge, Surrey

     

  • You cannot begin to understand how good it was for us to meet up with you last week….

    Mr and Mrs P, Caterham, Surrey