concrete root heave

[ArtB]

Soliciting suggestions for root heave.
The attachment is what is planned, before pouring the concrete cover thought I'd ask you guys. This is an about 50 YO D. Fir, root heaved concrete drive segment (poured in 1992) about 1-1/2 inch, Diamond sawed out heaved section and slot where root was tracked (this root cameto the surface in a 'funny' upward loop, never saw it when sand base for original pour was done). The hardboard is over a 2+ foam spacer over the root, should last for a decade of so. \

Corallary query. The english ivy never climbs this tree, but always need to trim it back from others, any opinions on why this particular tree is immume from ivy climb? (?? maybe DW trims it and has never mentioned it, as it is out the kitchen window <G>)

How do the pro's do this?

 

[Tom Dunlap]

Try to find info on Bio-Barrier, I think that's the name. Its a geo-textile fabric with nodules that have a hormone [I believe] that suppresses roots.

Tom

 

[Guy Meilleur]

I use biobarrier below gravel. I asked folks at the company if they had any data on using it to lessen rootheaving. They said no. I asked them if they thought it would hurt the tree if used horizontal instead of vertical; they said no.

So I use it that way but make no promises.
O and Tom it's not a hormone but an herbicide, trifluralin. That's why I asked them about toxicity.

Your bridging plan looks good from here. what is the ground downhill from the tree, a grass driveway? Whatever it is, it looks compacted. If you improve the rooting environment there, it may lessen root growth under the driveway.

How big was the heaving root? Pruning them is an option, tho I hate to make a big wound that close to the trunk.
Scootch away the gravel and take another pic, whydon'tcha?

 

[ArtB]

Dislike herbicides and don't like to cut a root on purpose unless dozing out a tree, which is why the bridge. The far side of the tree abuts public right of way, and the weenie cable guys ground thru one root on the other side when they installed cable in the early '90's - hope a new root is well wrapped around their cable by now <G>.

Here are a couple of pix, looks to be an 8 inch dia root, didn't like having knocked off a 4 inch square of root bark busting the concrete even. It takes off under the longer slot before going deeper.

 

[Guy Meilleur]

Yeah that is a big root; too bad about the wound but stuff happens when you're removing concrete. hope the cable guys didn't whack too big a root. Even tho that was a while ago, given the crappy rootzone downslope yeah pruning the 8" root may be too much.

Re pruning roots in general, it's kinda like pruning branches; doable in the right dose. You don't like herbicides, then you don't like biobarrier. If that gravel was a porous stone like pumice or www.stalite.com maybe it wouldn't heave as much.

As it is you may get the 10 years you're hoping for; if I had to guess I'd say 6-8.

 

[ArtB]

Thanks, Guy:

I've substituted pieces of a shredded foam matress for the gravel, should have more give than even pumice. Have a bushel full of Mt. Helens pumice from 1980, that stuff doesn't give much - collected the pumice off the road into 32 acres of D fir timber I have that was just outside the blowdown zone, still dont want even try to cut any crotches of alders there, still loaded with ash under the moss, any attempt to cut that means a sharpening and sometimes a new chain.

 

[TheTreeSpyder]

Sometimes i use the root pattern in exposed crowns on big trees, for clues to determine weight bearing/ CG.

If, the raised root is on the loaded axis of the lean, especially tensioned, it will especially try to grow larger, in response to the pulls of the weight, growing stronger as last vestige of the equal and opposite reaction, break more stuff i think. On the tension side this is usally 1 main root i think, on compression side it is more a forking usually, but pushing down,and the tensioned roots seem to grow more up and try to reach more leveraged back on large leans.

If dealing with root problems on this loaded axis and the growth responses there in, i find more problems. i imagine Guy knows more than me about getting roots to grow or feed from a diffrerent region to support tree nutritionally, this is to the needs of the mechancal aspects of it's size, the driveway roots might be most needed depending on the weight bearing, and continue to grow more exagerated because of that.

 

[Guy Meilleur]

Good thoughts Ken, if there was lean evident (or even if not), tension/compression is as much or more of an issue than nutrient uptake. After all, structure is more immediately important than nutrition.

 

[ArtB]

The tree does have a lean to the southeast, the root causing the heave is about 90 deg to that, to the NE, but a good observation, and thanks for the insight. Have felled a good number of pistol grip D fir, and the growth rings on the tension side are always much tighter. I'd agree to cut the root if it were on the SE side.

 

[TheTreeSpyder]

i would still look at it like tent guy wires, and where the air comes from, whips through, twists tree, to assess strains and pulls you are fighting, what course Nature might take. As well as which side the Sun shall call more weight to in the future.

Some other thoughts, really questions:

Roots are chasing air, make more available like ya have for less cracking(?)


Trees have no central stomache, wounding roots etc. on one side can have a tendency to likewise damage top on that side(?)

Mychorhizae-could come to the top for air, and to the sidelawn for food/water maintaining those inputs as well as possible, but that may lead to healthier roots in time; but it would seem, with soft fungi grabbing soil oxygen component and doing a bunch of the processing, roots would come up less for air themselves(?)

 

[Guy Meilleur]

Yes air was the reason i suggested stalite or pumice. Anything else put in the bottom like micros, will allow deep rooting and then one thinks lessen the aggressive growth of surface roots.

 

[M.D. Vaden]

Thats and interesting idea - never seen it done like that before. If expansion joints were put in, the section could be easily broken out and repoured ever 5 years or so, to allow the root to grow - basically forming a new, loose fitting cast every now and then.

I keep thinking people should go with cobble stone so they can pull the stones, recontour with a bit of pourous material, and reset the contour every decade or so.

On the ivy, the only guess I've got, is that there is enough light coming in at some part of the day for it to not head up the tree.