Advanced Tree Decay Assessments
An Advanced Tree Decay Assessment is a highly specialised analysis designed to investigate the health of a tree from the inside. Instead, this assessment uses specialist tools including Picus Sonic Tomography, Electric Resistance Tomography and IML PD Resistographs.
The PiCUS Sonic Tomography measures the thickness of the tree walls by measuring the sound velocity, to identify defects including cavities and decay.
The residual wall of a tree trunk with an internal decay cavity theoretically must be one third of radius (70% decay /30% residual wall sound wood). Decay beyond 70% is likely to diminish structural support. There are however many factors that must be considered during the risk assessment process, including tree body language, loadings and target, and determined tree management.
The Electric Resistance Tomography uses an electronic voltage to investigate defects in the tree and identify moisture content across a cross section of timber to confirm the condition of the wood internally. Supporting wood is generally drier than other wood tissue and moisture indicated upon the ERT tomograph within the heart wood can be a cause of concern, possibly identifying decay and or a cavity. Different species present different variables, which must be factored into the analysis also.
PiCUS Sonic Tomography and Electric resistance tomography are used in combination. Colours are generated in each tomograph (SoT and ERT) and are then compared. The ‘matrix table’ of colours identify sound wood, early decayed wood, incipient wood and decay wood.
IML Resistograph confirmation tests are then undertaken internally into the tree wood part / cross section to confirm the accuracy of the tomography data, assisting the arborist in overall tree management.
The PD series resistographs use an invasive scientific drill instrument which measures tree density. As the drill enters the timber it can measure high density sound wood, reduced density incipient wood (early decay) as well as no resistance reading, which indicates decay or hollow cavity. This instrument measures the internal residual wall dimensions of tree trunks and/or branches and provides internal wood condition data to guide the experienced arborist in determining the structural integrity of the defective tree part or tree as a whole.
To book an Advanced Tree Decay Assessment, call us today.
Graham Brooks Arboricultural Tree Services Pty Ltd - a highly skilled arborist with more than 38 years of industry experience.
He is a Professional Member of International Society of Arboriculture (ISA) and a Certified Consultant with Arboriculture Australia.
Graham is insured with public liability to $20m and professional indemnity to $5m.
ABN 57093391407 - ACN 093391407
CALL US NOW ON 0412 281 580