UKTC Archive

RE: Hidden defects

Subject: RE: Hidden defects
From: David Evans
Date: Jul 24 2020 16:07:06
<<The problem with moving strictly to risk is that some very important issues 
are missed.  Municipalities are often interested in inspections including 
details of needed pruning, details of disease & insects, details of trees 
blocking stop signs and street lamps, notes on damage done to soils and roots 

Hi Michael

The question I was exploring with inspections related to their use as a risk 
assessment tool.

I agree with you that the main reasons why trees are looked at by 
Municipalities and other government agencies or large institutions, and the 
tree work generated, are little to do with the risk of branches or trees 
falling.  Are these kinds of audit/inventories defined as inspections though? 
 In the UK, they'd usually be called 'surveys'.  An inspection being a closer 
look at an individual tree; which might be for risk, subsidence, or pests and 
diseases etc and would usually be triggered by a reason to take a closer look.

<<To think that inspections are redundant and that most risk is so low that 
inspections should not be done seems rather narrow sighted.>>

I haven't advocated this though, have I?

If it's the risk from branches and trees falling we're looking to manage, 
then the overall level of risk is what drives the proportionality - how much 
effort you put in to manage it.  We know the overall level of risk is 
extremely low. I suspect the risk from tree failure is so low that Passive 
Assessment would pick up most of the 'red' risks.  Hence the value of the 
Obvious Tree Risk Features Guide, which is what triggered this thread.

This is what VALID's tree risk-benefit assessment structure looks like;

Active Assessment | Basic > Detailed > Advanced
Passive Assessment

That's four levels of assessment to manage the risk, but no inspections.  
Each level of assessment is clearly defined.  It seems to me that an 
inspection isn't clearly defined and it means different things to different 


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