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Tree related subsidence – What it is and why it happens

Tree related subsidence is defined as the gradual caving in or sinking of an area of land and can be caused by a range of different factors. These can include:

Have You Got Issues With Tree Related Subsidence?

Trees roots can spread by up to three times the height of the tree which means that, whilst a lot of buildings are not affected by the growth of these roots, those built on shrinkable clay soils and located near to a tree are at significant risk of experiencing subsidence.

tree related subsidence

Clay soil is highly absorbent, allowing it to take in water and expand during wet weather. The soil then dries out in the warmer weather and shrinks, meaning that there is a constant heave and shrink cycle within areas consisting predominantly of a clay soil type. Trees can then exacerbate the shrinkage of clay soil by drawing the water out of the soil, causing the ground underneath buildings to shrink significantly and resulting in movement within the property foundations. This movement then goes on to cause cracks in both external and internal property walls.

When dealing with a tree that is causing subsidence, it is always necessary to consider the risk of soil heave. This can occur as a result of the clay soil returning to its former moisture level and expanding once the tree has been removed, causing any foundations laid over the soil to lift and potentially cause further damage.

In order to cater for this, each individual occurrence of tree subsidence should be considered based upon a variety of factors including the nature of the surrounding ground, the quality of the buildings foundations, the span and depth of the trees roots in comparison to the building and the typical variations in conditions throughout summer and winter. The potential removal of a tree that is causing subsidence should always be considered on a case by case basis and is highly recommended to be carried out by a professional arboriculturist.

Contact Us

At ProHort, our team have over 20 years of arboricultural experience and are experienced in identifying subsidence resulting from the presence of trees. Find out more about our Tree Subsidence Reports service, or why not get in touch for more information?