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INTRODUCTION |
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"Nobody wants a subsidence claim. If, somehow, we could wave a magic wand
and make subsidence disappear then not only would insurance companies be
ecstatic...you, the home owner, should be as well. Subsidence blights properties and diminishes equity, so it follows that in everybody's interest to reduce the number of claims and contrary to what most people think that's possible. Virtually all subsidence claims are caused by external influences (trees and leaking drains) inter-reacting with clay soils.. This website has been produced to help you minimise the dangers of these external influences. How to manage trees...how to spot if your drains are leaking. We believe it is possible to reduce the number of subsidence claims ..and if that can be achieved it's good news for everybody." Chris Jordan, Head of Insurance, Subsidence Claims Advisory Bureau. |
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TREES, SUBSIDENCE AND YOUR HOME |
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| "The shrinkage and swelling of clay soils is
the single most common cause of foundations related damage to low-rise
buildings. A high proportion of this damage involves trees". |
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Building Research Establishment. |
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Here is a stark fact! |
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In a recent survey, carried out by the above authority, around 70% of all subsidence claims on shrinkable clay soils were attributed to the removal of water by trees or shrubs close to the property! |
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Clay & climate cause relatively few claims. |
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This relationship between trees and their effect on the ground has been
studied for some time. Trees cause clay soils to to shrink due to the
withdrawal of water by their roots particularly in the summer. The amount
of shrinkage or desiccation will depend on the type of clay soil, the
species and size of a tree and the weather conditions. Broad leaved or deciduous trees have a greater moisture demand than evergreen, coniferous trees. In periods of warm sunny weather the amount of water required by the tree will increase. The amount the ground will shrink will also be affected by the amount of water available and the depth of the foundations of the building. Areas of the country with greater rainfall are less likely to be affected .Shrinkable clays are widely distributed throughout the country, although the most highly shrinkable are found within an area south of a line drawn between Exeter and \Hull. As the driest and hottest conditions are usually in the South East England the greatest risk occur in that area. |
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