- Home
- Subsidence Surveys
What is Subsidence?
Subsidence is a serious problem for homeowners. It affects the very foundation of one’s home, and if what you inhabit is not sitting properly on or in the ground, then the whole thing is a likely candidate for some very expensive repairs.
Subsidence is commonly blamed on expanding and contracting clay soils, but clay is not the only soil type that can expand or contract. Other types of earth can shift as well and there are other geological formations that can move imperceptibility but with great consequence.
Water services: services that supply water can be sources of subsidence when they leak. When a pipe leaks, the water saturates the soil near it. The soil then expands and becomes very soft. This is the way a leak can cause subsidence. There are leaks in water supply services that cause subsidence, but very few people know about them. Because of these leaks, somewhere between 1 and 3.5 millimetres of ground movement (subsidence) can occur per year.
Vegetation: there are other causes of subsidence, such as trees absorbing water from the soil, ground movement from mining, and more. They happen either through natural causes or because of human actions.
Understanding these events and the way they trigger subsidence is really important for diagnosing subsidence itself and for coming up with effective methods to stop it and to repair the damage it has done.
How Much Does a Subsidence Survey Cost?
Property owners should budget around £700 for the average subsidence survey. However, this price can fluctuate quite a bit based on how large and complex the property is and where it is located. If you are experiencing subsidence or think your property may be suffering from it, we highly recommend enlisting a surveyor experienced in this niche for a more definitive diagnosis.
How to Perform a Subsidence Survey
At Canterbury, our panel of experienced subsidence surveyors performs thorough examinations of homes. These cover all the aspects relevant to undetected subsidence issues, including how the surrounding environment impacts the property and whether any defects are found during the general building inspection.
Does Insurance cover Subsidence?
The coverage for subsidence damage in insurance policies varies greatly by insurer and policy specifics. While many home and commercial property insurance plans cover the often substantial costs associated with repairing a building affected by subsidence, it’s imperative to consult the policy language, and if necessary, the Financial Ombudsman website, to determine what your particular plan covers. You don’t want to be surprised by costs associated with repairing your home or commercial building after an event that has potentially harmed its structural integrity.
Reporting on Subsidence in Canterbury, London, Bristol, Birmingham, Manchester, and Cardiff
Concerns about the possible subsidence of a home bring a surveyor into play—almost always from the Royal Institution of Chartered Surveyors, Chartered Institute of Building or Residential Property Surveyors Association. He or she will check for subsidence as part of either a level 2 or level 3 Building Survey.
If risk of subsidence is flagged, a structural engineer may be called in for a more thorough examination. If risk remains a concern, a subsidence report may be commissioned to provide a picture of the possible sources of the problem. In many cases, it involves a walk around the property for the professional assigned to issue the report.
The potential causes of subsidence have been identified in the survey report. The next step is to appraise the risk—what is the chance that the building will move any more than it already has? If the survey recommends remedial action to limit any further movement, what sorts of actions might that involve? A structural engineer should be able to answer these questions.
Detecting subsidence at an early stage can stop it from progressing and causing more serious damage. However, sometimes, it is not easy to spot; we can not always recognise the signs as telling us that the house is sinking.
The most obvious indication is a visible crack appearing in the wall. Another sign is doors and windows sticking due to distorted frames. Then there is the more obvious sign of visible changes in floor or foundation positions or levels. Another sign is rippling wallpaper, not caused by damp.
Factors that Reveal Subsidence
Early identification of subsidence helps to stop further, more serious damage. Signs include:
- cracks in the walls that become wider are found and these are thinner on the bottom
- the frames of doors and windows are now off and are therefore causing them to stick more
- obvious changes in the foundation or floor levels can be noticed.
- rippling wallpaper not from damp (the issue being that the wall behind can no longer stand firm and is moving).
Is it possible for a House to Be Sold if it has Subsidence?
People may find it difficult to sell a home that has history of subsidence, as this could decrease the home’s market value and may not be mortgageable. When a qualified surveyor does a subsidence report, it tells you if any action has been done to rectify the problem, giving buyers confidence in the property.
What do Chartered Surveyors do when resolving disputes with neighbours?
The expertise of Chartered Surveyors is really invaluable when it comes to resolving boundary disputes.
Chartered Surveyors have the skill set necessary to determine where a boundary should be placed, using a wealth of information obtained from not only inspecting the site, but also from studying the historical data and legal documents associated with that site.
Increasingly, these experts are using a combination of professional judgment and modern technology to arrive at the boundary line. When they do arrive at a solution, it’s more common than not for these professionals to issue a boundary agreement. This agreement will facilitate a path to a quick resolution and an amicable neighbourhood.
Combating Subsidence with Underpinning
This technique is employed as a last choice due to the risks involved, because underpinning can also lead to more difficulties if done improperly.
Overlooking subsidence can result in major damage to the building and may make it unsafe. In some cases, underpinning is done by strengthening the foundation by deepening it or widening the bottom or both. The contractors try to reach strong soil beneath the unstable soil to ensure the structure stays stable on strong ground. The foundation is supported by the ground that transfers the structure’s weight to a wider section.
The Benefits and Drawbacks of Underpinning
Thanks to underpinning, different causes of subsidence can be managed such as expanding and contracting clay soil, water from below and factors in nature removing the soil integrity. It is adjustable, so it can meet the requirements of every property.
If the groundwater system is constructed badly, it can promote subside sooner which may lead to more damage. So, you really need to choose a reliable contractor.
