Hazard Tree evaluation

"Strength is to be looked at not just weakness but finding the balance of the 2 is the aim" And that balance is reached only when weakness is looked at in relation to strength, not vice versa. Good questions.

"What are the levels of defect before you start to be concerned then?" When the tree is not responding, and the weakness is advancing, I get very concerned. This response and advance can only be gauged over time. When the tree is actively failing--as in Lonely Lashing Leader June 2014--red flags wave and action is strongly advised. It wasn't so much the 3-6" shell wall on a 9' diameter trunk, it was the crack in the leader.
Read it and then tell me if the specs makes sense. http://www.historictreecare.com/wp-content/uploads/2014/12/DD-LLL-1406.pdf
 
guymayor said:
"Strength is to be looked at not just weakness but finding the balance of the 2 is the aim" And that balance is reached only when weakness is looked at in relation to strength, not vice versa. Good questions.

"What are the levels of defect before you start to be concerned then?" When the tree is not responding, and the weakness is advancing, I get very concerned. This response and advance can only be gauged over time. When the tree is actively failing--as in Lonely Lashing Leader June 2014--red flags wave and action is strongly advised. It wasn't so much the 3-6" shell wall on a 9' diameter trunk, it was the crack in the leader.
Read it and then tell me if the specs makes sense. http://www.historictreecare.com/wp-content/uploads/2014/12/DD-LLL-1406.pdf
Click to expand...

Trees tend to start out as solid wood so if there is a hollow or some other defect isn't a hollow a sign that decay has advanced?

If you start with solid wood and then there's a hole that means decay has happened/ increased. Codit does take time to set in so before it's set it's a problem and once it's set it's all good? Without a microscope how can you be sure codit is at 100% all the way around
 
KevinS said:
Trees tend to start out as solid wood so if there is a hollow or some other defect isn't a hollow a sign that decay has advanced?...
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There are trees that are thousands of years old with hollows and structural imperfections. They have lived with these for a large portion of their lives. Could it be that they are just a natural component of tree biology and not defects by themselves.
 
DSMc said:
There are trees that are thousands of years old with hollows and structural imperfections. They have lived with these for a large portion of their lives. Could it be that they are just a natural component of tree biology and not defects by themselves.
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That may well could be! Hollow plane trees tested way stronger than undecayed plane trees at Biomechanics Week. O and Kevin check this for a great explanation of the process: http://www.isa-arbor.com/education/resources/ISABasicTreeRiskAssessmentForm_Instructions.pdf
 
guymayor said:
That may well could be! Hollow plane trees tested way stronger than undecayed plane trees at Biomechanics Week. O and Kevin check this for a great explanation of the process: http://www.isa-arbor.com/education/resources/ISABasicTreeRiskAssessmentForm_Instructions.pdf
Click to expand...

Guy I've been trying to find and read as many different risk forms as I can. I've seen this one before. Again there is lots about what to look for but little on what to do when you have found it.
 
Hard for everyone to make a call with just a couple of pictures... Im not for cutting down everything with a hollow or defect down, but everyone has seen trees fail at hollows, right...?
 
sherwood7 said:
.... but everyone has seen trees fail at hollows, right...?
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I have cleaned up many trees and limbs that failed at sound wood but I feel it may not be proper to conclude that sound wood was the problem. We all like simple answers but sometimes simple, does not give us the right answer.
 
Ive found codominant stems to be the most common tear point

after that I think the amount of breaks ive seen at sound wood or hollow , are probably about the same

this thread has me regaining much confidence in hollow tree structure !
 
"Again there is lots about what to look for but little on what to do when you have found it." I totally agree. What to do comes from the arborist, listing mitigation options based on conditions, observations, analysis.... Frank Rinn's report on the red oak in Ohio, DD and the Lonely Lashing Leader, is currently under deconstruction. I'll post a link on what he said to do (1 mb limit here). Before that, do you have any questions or comments on that tree?
2200 words, might be ~13-15 minutes to read.
April 2015 will be the Torched Tips, a case in progress, in the subtropics.
 
guymayor said:
"Again there is lots about what to look for but little on what to do when you have found it." I totally agree. What to do comes from the arborist, listing mitigation options based on conditions, observations, analysis.... Frank Rinn's report on the red oak in Ohio, DD and the Lonely Lashing Leader, is currently under deconstruction. I'll post a link on what he said to do (1 mb limit here). Before that, do you have any questions or comments on that tree?
2200 words, might be ~13-15 minutes to read.
April 2015 will be the Torched Tips, a case in progress, in the subtropics.
Click to expand...
Sorry I have a lot on my plate this weekend dealing with car trouble I'll read it thoroughly soon
 
guymayor said:
That may well could be! Hollow plane trees tested way stronger than undecayed plane trees at Biomechanics Week. O and Kevin check this for a great explanation of the process: http://www.isa-arbor.com/education/resources/ISABasicTreeRiskAssessmentForm_Instructions.pdf
Click to expand...
Guy like I said I loo
guymayor said:
"Strength is to be looked at not just weakness but finding the balance of the 2 is the aim" And that balance is reached only when weakness is looked at in relation to strength, not vice versa. Good questions.

"What are the levels of defect before you start to be concerned then?" When the tree is not responding, and the weakness is advancing, I get very concerned. This response and advance can only be gauged over time. When the tree is actively failing--as in Lonely Lashing Leader June 2014--red flags wave and action is strongly advised. It wasn't so much the 3-6" shell wall on a 9' diameter trunk, it was the crack in the leader.
Read it and then tell me if the specs makes sense. http://www.historictreecare.com/wp-content/uploads/2014/12/DD-LLL-1406.pdf
Click to expand...

Strength is to be looked at not just weakness. This is a very fair point. I look around and like you posted hazardous tree forms there is work on cavity size and strength green wood weight lumber strength even green wood strength. But as far as I can see if I'm not wrong the live wood stength charts are usually based off solid trees usually without defect. Any time I've seen defect failures it was in a study group based around defects.

So I don't know if they're a good basis of wood strength around a defect. So the 'swag' studies give us one way to see it and green wood breaking strengths is another but neither is right.

So how do you justify strength especially if its in a tree over 36"?
 
guymayor said:
"Again there is lots about what to look for but little on what to do when you have found it." I totally agree. What to do comes from the arborist, listing mitigation options based on conditions, observations, analysis.... Frank Rinn's report on the red oak in Ohio, DD and the Lonely Lashing Leader, is currently under deconstruction. I'll post a link on what he said to do (1 mb limit here). Before that, do you have any questions or comments on that tree?
2200 words, might be ~13-15 minutes to read.
April 2015 will be the Torched Tips, a case in progress, in the subtropics.
Click to expand...

The DD article was good and load reduction at a split makes good sence. Did he reduce that one section or entrench the whole tree?
You didn't worry about the 3" wall on a 9' tree but what if it was an 1 1/2" wall? That hollow also didn't have a external cavity as a weakness so live wood all the way around helps the strength to
 
"So how do you justify strength especially if its in a tree over 36"?"

Justify what? When you walk up to a standing tree, you know that it has justified its strength by standing up to everything thrown at it so far.
Reduce the load, and it will stand up to more. What else do you need to know?

When you apply formulas based on engineering and pipes, you can't justify their use on trees.
Info received from the tree is much more reliable than numbers derived from a formula.
 
guymayor said:
"So how do you justify strength especially if its in a tree over 36"?"

Justify what? When you walk up to a standing tree, you know that it has justified its strength by standing up to everything thrown at it so far.
Reduce the load, and it will stand up to more. What else do you need to know?

When you apply formulas based on engineering and pipes, you can't justify their use on trees.
Info received from the tree is much more reliable than numbers derived from a formula.
Click to expand...
Cycles to failure.
Every tree I've ever been called out to because of uprooting or something snaps or tears out was normal the day before but today there's a rush because it is making the roof leak or crushed there pool,etc.
Or is cycles to failure nonsense
 
DSMc said:
For trees, yes. Trees fail when load exceeds strength. Decreasing load potential, decreases failure potential.
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Less is more that I get and sorry if I'm a broken record. I've just been trying to wrap my head around the whole ratio of strength loss due to defects vs remaining strength of live wood to have a backing for claiming its OK or not OK or how much reduction is needed.

Let's not get hung up on just cavities. Say a codom tears out in a storm and at 1 spot only left 1/3 of the trunk for 1/2 or more of the crown. It can be saved maybe but what mitigation or strength guide lines do you go by
 
With hazard classifications they go as low, medium, high. Or guy you talked with yellow and red flags. I'm looking for definitions of each class on how to delineate the transition for medium to high or if it were on a 1-10 scale where does 7 belong?
 
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