TREES AND SUBSIDENCE

Subsidence as it affects buildings is usually the result of soil desiccation or drying out. This is normally only a problem where the soil type is shrinkable clay.

Serious subsidence ‘event years’ as they are known arise when there is a shortage of ground water and a subsequent permanent decrease in soil moisture which is not replaced. Settlement of the soil leads to movement and occasionally damage to structures which are subjected to the stress of differential movement under their foundations.

Oak, poplar, willow, eucalyptus, elm and Leyland cypress are all classified as having high water demand, but the majority of other species have moderate demand.

If you think that your property is suffering from subsidence, you should first discuss this with your household insurer, who may be able to give or provide specialist advice.

If trees which are within a Conservation Area or are protected by a Tree Preservation Order are felt to be implicated in a subsidence incident, an application to fell or prune the trees is still necessary. Clearly, there must be both evidence of subsidence and a demonstrable link with the tree(s) before consent will be granted.

The following information must accompany any application for tree work:

In addition, the following technical information is required in order to demonstrate a causal link with the tree:

In relation to the last two points, monitoring should be undertaken to establish movement patterns sufficient to link it to the tree.

The Council will refuse to register any applications for tree work in relation to alleged subsidence events if this information is not present at the time of application.

Please note that the Council is unable to visit prior to receipt of an application or assist with the preparation of technical and other information specified above.