Internal Decay Assessments
Decay is a natural process and does not necessarily mean a tree is unhealthy. However, depending on the extent and type of decay, and its position on the tree it can lead to loss of mechanical strength.
Using tomography, we are able to ‘map’ the decay within a tree. Stress waves travel through sound wood faster than dysfunctional wood and so with sensors around the tree measuring the time it takes an impulse to travel through the wood and reach other sensors we get an impression of the internal condition of a tree.
Detailed analysis of the tomogram enables us to determine the loss of mechanical strength and to quantify the extent of tree work that may be required to reduce the risk of failure.
There are occasionally circumstances where tomography is not suitable, such as assessing the extent of decay in buttress roots. In these situations we use a Resistograph – this is a very fine drill that measures resistance as it travels through the wood, providing information on the internal structure of the tree at the points of drilling.
Usually decayed wood has a lower resistance and so with this information, combined with expert arboricultural knowledge of tree species and the fungi involved, we are able to better understand the likely impact of decay on the structural integrity of the tree.
Analysis of the data enables us to produce a specification of works, if required, to reduce the risk of failure.