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Tree Health - Disease and Decay Detection

Decay detection forms an important part of ensuring tree stock is healthy and therefore safe, with little or no risk of failure.


At CBA Trees we provide the complete decay detection, mapping and analysis service to assist our clients in maintaining a safe and healthy tree stock. Decay investigation is carried out in accordance with industry best practice using the latest diagnostic equipment and techniques and our aim is always to minimise damage to trees when identifying and mapping decay utilising our state-of-the-art equipment, much of which is non-invasive.


The extent of decay is normally examined following a full Visual Tree Assessment and may include one or more of the following techniques:



The surface roots, buttress roots, trunk and main branches are lightly struck with a soft faced hammer (sounding). CBA consultants are trained to recognise changes in pitch where decay or other defects occur. This technique is used as part of the initial assessment, is non-invasive and frequently identifies areas requiring a more thorough and detailed inspection.


Soil Excavation

There is a wide variety of decay inducing fungi that infect trees. These may cause decay in branches, the main stem, structural roots and rootplates of the trees below soil level. Inpection of this latter type of decay requires careful excavation of soil to expose the roots and root plate. CBA consultants are trained and certified to use a high pressure Soil Pick (Air Spade) to quickly remove soil whilst maintaining all but the finest roots. This allows the detailed inspection of the suspected decay.

Sonic Tomography. PICUS 


Suspected decay of the trunk may be investigated by Tomography, a system that measures the speed that sound waves travel through wood. Where decay, cavities or other defects are present sound waves take a longer time to travel through the cross section and this is recorded and analysed by the site computer to produce a tomogram. CBA Trees can provide a complete Tomography service producing full colour tomograms of a trees cross sectional condition together with computer generated vertical 3D images where required. This procedure is virtually non-invasive, providing an effective illustration of wood quality.


Black and Dark Brown= sound wood

Tan=interface between sound and dysfunctional wood tissues

Green=dysfunctional wood tissues probably impregnated by fungal hyphae but unlikely to be a cavity

Purple and Blue =areas where there is likely to be significant decayed and dysfunctional wood

Tomograph image
Resi drill for decay detection

Resistograph (Micro Drill) Investigation


The resistograph is a mirco drill that records the drilling pressure required to push the probe into the wood. Where decay, a cavity or other defect is present there is a significant reduction in drilling resistance. CBA Trees has recently purchased the latest resistograph microdrill (IML Resi PD-400 Microdrill) to assist with decay detection and to assess the internal condition of a tree. It is versatile and can be used to investigate root and root plate decay and defects in main limbs, where the use of tomography is difficult. The resistograph can be safely used from rope access equipment; results are recorded on paper traces and also digitally for incorporation into reports. The digital record may also be used to interpret growth rate and age of trees.

About Us


CBA Trees has many years experience in Arboriculture and Tree Services.

If you're looking for a professional solution to your tree problem then CBA Trees has the expert waiting for your instruction!



Contact Us


CBA Trees

Chesil House

Arrow Close

Boyatt Wood


SO50 4SY


Telephone: 023 8098 6229


ArbExcellence LTD trading as CBA Trees is a company registered in England and Wales with company number 08846713. Registered office: Chesil House, Arrow Close, Boyatt Wood, Hampshire, SO50 4SY  VAT Number: 127662913.


Telephone: 023 8098 6229 


Arboricultural Association



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