I Was told to use Copper sulfate to STOP large roots from advancing …

I was told to drill into them, and put copper sulfate in the holes and in doing so would kill those specific roots, and enable the tree to survive ( I must confess i like the shade and privacy it offers ) I honestly don’t know what to do to stop worrying about these roots and years down the road.

 https://www.arboristsite.com/threads/i-was-told-to-use-copper-sulfate-to-stop-large-roots-from-advancing-around-foundation.368816/