I am installing a sprinkler system in my backyard but a thick tree root is crossing a pipe path. This tree was actually removed last year (cut & stump grinding) and the tree roots are the remaining ones. One easy way is of course to rent a stump grinder but don't want to spend money only for this job. I am wondering if there is any other alternative way. I was thinking of using router bits to cut off the top portion of the roots up to, say 10" so that the pipe can pass. But, I am wondering if there is any other better method.
When I have been in a similar situation (dead roots), this has worked for me:
- Dig around the root with a shovel to remove the bulk of the dirt in the way.
- Use a trowel, your hands, something smaller to remove the rest of the dirt near the root.
- Use a reciprocating saw (aka Sawzall) to cut through the root. This may take some time depending on how green the roots are, but those saws will eventually cut through it. Homeowners are more likely to own a reciprocating saw than a stump grinder, as well. If not, a decent one can be had for under $100 and is useful for a lot of demolition tasks.
You said the tree was removed "last year" so the roots are probably fairly dry by now, so a saw should cut through it easier than if it was just removed.
There are several stump removal products; commonly, potassium nitrate (salt peter) works best, but sodium pyrosulfite also works. Drill 5 or 6 holes in the stump and pour in about 1 lb of salt peter (if it's larger maybe you need more). Pour in water, or let it rain in for about a month. This allows the salt peter to be completely absorbed by the stump and roots... it needs to work all the way though the wood.
Then cover it in kerosene and charcoal briquettes. Light it up and it will burn out completely. When done properly it will burn out the roots and all. takes about 3 to 4 days to finish burning larger stumps.
Edit- Stump grinding usually only removes the surface of the stump. Most of it will probably still be there under the ground. But regardless, you can also drill into the offending root, which from what you describe, sounds like is over 10 inches thick. This will save you quite a bit of digging. It may take a little longer, but a lot less labor. I suppose the decision boils down to urgency. Can it wait a few weeks, or do the sprinklers need to be installed ASAP?