I am installing a new main sewer line because I am tired of snaking the line twice a year to get rid of roots. Yes, this is more expensive in the medium-term, but the peace of mind will be (I hope) worth it. Now that the new line is exposed, is there anything I can place around it (other than concrete) which will deter roots from bothering the line for at least a moderate amount of time (a decade)?
One plumber told me rock salt works. Another mentioned a crystalline herbicide that Home Depot sells. I do not wish to harm the tree, just keep the nasty little root hairs at bay for a decade or two.
Dimitri