Hazard Tree Assessment?

[bighugetrees]

Got a job to thin 3 firs that had been topped 35 yrs ago. The topping was done at about 50 feet. Now there are two to three leaders growing from there to a height of about 110 feet. Here is the problem or hazard that I am having trouble with. In the top there is some sort of nest(crow or eagle I don't know, but it is big). On this same leader, about 25 feet from the top, a branch has rubbed about half of the tree away. The branch was growing inward from the second leader on the same tree and with motion the friction has rubbed about 40 percent of the diameter gone. I cut the branch in question out and the two tops moved a little more freely and thinned both tops to lessen the load.

Trunk diameter at this point is about 12 inches below the worn out "notch"( not sure what to call it), leaving only about 6 to 7 inches of sound wood holding up the top. Hate to re-top. The owner loves the trees, but I think the top needs to come out.

Any insight would be a great help. Have some great pictures, but can't download my throwaway camera.

Thank you,

Big Huge Trees

 

[treeclimber165]

Sounds like it might need to be reduced to take some load off the worn spot. Hard to say without seeing it, but I'd probably do some crown reduction on the worn lead. Just be sure to cut back to limbs that are 1/3 the diameter of your cut so the limb can take the terminal role. I'd probably go something like 25% reduction on the lead in question. This should reduce the stress on the worn area for a couple years till it can add diameter and strength.

Be sure to inspect the old topping cuts well for good lead attachment. Sprouts from topping cuts that turn into leads are notoriously weak at the attachment point.

 

[Kevin]

I had one of those today.
Two leaders on a maple and one broke off right where they were joined and came down on the cable.

 

[Acer]

Originally posted by bighugetrees

Trunk diameter at this point is about 12 inches below the worn out "notch"( not sure what to call it), leaving only about 6 to 7 inches of sound wood holding up the top.

This reminds me of some of the work done by Dr Claus Mattheck on the potential hazards of trees. He reckons that healthy trees have a "safety factor" of around 4.5, and the fault you describe would reduce that safety factor to 1 ie. no safety factor at all! Put anothe way, the stresses at the fault would be >4 times the stresses just below that fault. I'd rate that as a hazard myself, but depends on what could be damaged should the top blow out at that point. If there's nothing below, and noone ever walks under there, then there's less of a problem.

Again, I'd be careful to check the point where the original topping cuts were made all those years ago. You can often see plenty of regrowth, but the attachment points may be weak or affected by rot.

Good luck!

 

[bighugetrees]

Thank you for all the positive feed back even though it is hard to say without actually seeing the tree in question.

All the advice will be taken and used.

Thanks again,

Dan

 

[rbtree]

Dan,

sent you an email. call me. I'll come look for free perhaps.

sounds like a Cobra install might be called for.

 

[rbtree]

Acer and others.

I've worked on many topped firs over the years, and removed many. It is amazing how much ability doug firs have to withstand such treatment. More often than not, the decay column will only go down a little ways, with the new tops having grown out mostly u shaped with tons of great reaction wood. Of course this in not alway the case. We do find decay all the way to the ground, but that is pretty rare. sometimes a bit of fungal discoloration which may affect the lumber price we get at the mill.

Cedar can be pretty good compartmentalizers also. But not the biggie we felled Monday. It split into two at 44 feet, v shaped, typical of cedar. Then it had been topped at 70 feet about 12 years ago, about 5-7 inch cuts. A little decay was below those cuts, but we got two 20 foot small logs. The butt had seams, and lot of swell. When we dropped it, it broke. Had tons of decay, top to bottom. But we netted 430 board feet from the 660' gross log, so it still paid $390. So i had to charge the customer another $160, so we could make $800 total, for about 11 manhours plus travel. Not bad, but I had hoped for closer to $1000.

Recently we topped two mature doug fir at 70 and 90 feet respectively, that had been lightning struck. I'll bet the now 70 footer will die, as it has no new growth to speak of. The other may make it for 20 plus years, as it is already growing new tops, but with that 20-22 inch top cut I had to make, I don't hold a lot of hope for long life for it.

 

[Acer]

Originally posted by rbtree
..... But we netted 430 board feet from the 660' gross log, so it still paid $390.

Imagine being able to charge to take the tree down and selling the timber as well! Something I've never been able to do. Normally, access to gardens will be poor, so we end up ringing everything to carryable pieces. One recent job that broke my heart was a cedar removal, with a stem about 20" dia with a good 4-5 m straight and knot free. Cedar used to be used by some cabinet makers, but a half day on the phone established that noone was interested in it. The best offer was a musical instrument maker, who would've taken 1 m or so, for free, providing I delivered it, for nothing. I ended up slabbing it up for firewood and dumping it at my local allotments, where these Jamaican gardeners hang out virtually all the time and burn penty of wood to keep warm in Winter. What a waste!

In the past, we've offered reasonable lengths of timber to companies for free (noone wants to pay) just to be free of the hassle of getting rid ourselves, providing they pick it up from site. Normally, I get a call from the client weeks later asking when I'm going to remove that log from their drive, so I end up having to take it away myself anyway. If I can get rid of waste without having to fork out money, that's the nearest I get to a good deal!

 

[Kevin]

RB,
Nice photo.
What is the reason you guys leave stubs on on your removals?
Are they just used for standing on or hand holds while you work the tree?

Acer,
Not many mills will take urban trees because of all the surprises inside of them.

 

[rbtree]

Hey kevin,

That's not a removal, just a dead top, so Ian was spurless.

Irrelevant to the question, but that top had a large cavity to boot, so Ian only went up it a short ways before we pulled it over, kinda near me in the other tree. i was out on a limb for a better video, but his top brushed a branch of my tree, which kinda discombopolated me, so the vid was poor......but at least I'm still here....