Has anyone tried Oxy-Acetylene to cut (burn through) tree roots.

[Captain Dirty]

Posted here as the most likely place people have gas, torches, and experience.

My son had a 24" diameter poplar tree uprooted close to the stone wall in front of his home. We have taken care of the trunk, branches, and slash and are working at excavating the stump. On the yard side we have gone out far enough to break the roots with the backhoe. On the street side we have dismantled the stone wall and found a 1' diameter root that includes a stone (cobble size). I am afraid that pulling or twisting the root may affect the pavement and want to cut the root at the edge of the town right of way. Even after pressure washing, cutting roots is, in my experience, a very fast way to ruin a chain on a chainsaw, and even a pruning blade in a sawzall dulls quickly.

Has anyone experience using oxygen-acetylene to cut a root of that size? Should one use less oxygen pressure so as not to blow the flame out, or does it cut like steel? My torch is rated for 1/2" steel.

TIA
Captain Dirty

 

[oosik]

Consider this before you burn thru the root. I once burned a large( 32" diameter ) pine stump to get rid of it. It burned/smoldered for the better part of a week. Finally after spending far more time on this than it ever deserved - soaked what was left of the stump and covered it with dirt. A week later wisps of smoke arose out of the ground about forty feet from the stump. One of the roots acted as a very slow burning fuse. It started a hot smoldering fire - forty feet from the stump.

Good excuse - I didn't want to mess around with any more burning stumps anyway. I let Mother Nature take them and they rot away.

 

[bcp]

When I was a kid, I tried to cut a 1x2 with a cutting torch, to see what happened. No luck. Just charred the surface. It would burn for a bit when the heat was removed, then go out.

I might try very closely spaced holes made with the largest carbide tipped concrete drill I could find. That might weaken it enough to break.

Bruce

 

[sandfs]

It will not cut like steel.

 

[Wagtail]

Consider this before you burn thru the root. I once burned a large( 32" diameter ) pine stump to get rid of it. It burned/smoldered for the better part of a week. Finally after spending far more time on this than it ever deserved - soaked what was left of the stump and covered it with dirt. A week later wisps of smoke arose out of the ground about forty feet from the stump. One of the roots acted as a very slow burning fuse. It started a hot smoldering fire - forty feet from the stump.

Good excuse - I didn't want to mess around with any more burning stumps anyway. I let Mother Nature take them and they rot away.

This was my very first thought.

 

[wagne223]

Torch will not work.
I would go at it with a chainsaw knowing it will cost a bar and chain.

 

[Redlands Okie]

Ooisk has posted may first thought. It’s likely to come back on you later as it unexpectedly smolder.

Regular wood saws all blade will work fine. The pruning blades dull quickly in dirt when cutting roots, but work fine on limbs. Try a larger tooth demo blade or other type of wood blade.

If you need to cut the rock try a grinder on it with a diamond tile blade, 20 bucks or so for such a blade at a box store. It will not cut the wood very well and is likely to heat up and warp. If its a large rock then cut what you can and then hit it with a shop hammer or such and the rock will likely break on thru.

 

[airbiscuit]

Might it work to rent a concrete saw (at least for the rock portion)?

 

[k0ua]

To understand why the Ox torch will not be effective you must understand what is going on with the torch and why it cuts steel so well. The next time you use and ox torch get the steel heated up like you normally do than press the ox lever and start your cut. Continue the cut but reach over and turn off the gas supply. The cut will continue as you are "cutting with the oxygen". The hot steel is reacting in a chemical reaction to the oxygen and continuing in a self sustaining burning that is exothermic. In other simpler works the hot steel and the oxygen combine to produce heat and lots of it. The pressure of the ox then blows the molten steel out of the cut.

Your water drenched tree root aint gonna do that. No steel in it to react with the ox. Oh sure it will get hot, and may pop and crack from steam expansion, but it sure aint gonna cut like nice piece of bar stock. You concrete saw will cut it, but slowly, but it shouldn't hurt the concrete saw blade I don't think. Clean it and chainsaw it, knowing it will dull the chain is your best bet.

 

[dragoneggs]

One root... what about an old fashioned axe?