We discovered we have issues with our wastewater lateral and it needs to be replaced. Not to get too into the details but where we expected to find a 4” cast iron lateral that could be cleaned and lined we instead found a 6” terra cotta lateral with multiple issues that mainly stem from extensive root infiltration from the maple tree that was planted about 4 feet away from it.
The photo shows the tree and very close to where the line runs. The plan from our contractor is to dig up either side of the stairs and replace with PVC since lining isn’t possible. The excavation is planned to be only in the mulch beds shown, since the main runs in the grass about three feet away from the end of the bed. The existing terra cotta will be left under the stairs and to the main and lined then connected to the PVC.
Our concern is how close the excavation is to the tree and how it will impact the trees health. Ideally we would use trenchless but that isn’t really an option, and rerouting isn’t really possible due to needing to reuse the existing house and main connections. So what should I be sure our contractor is doing to best protect the tree, and how should we take care of it once everything is complete. We are expecting some die off in the canopy but it’s a really healthy tree so we are hoping that with good care we can save it overall.
Generally per 1" caliper of the tree you want about 1' of clearance if you are going to cut the roots for the health/structural stability of the tree. Also if using a trencher they typically are not going to make a smooth cut of the root.
If possible a root pruning machine should be used or if not feasible, expose the roots and make a clean cut with a reciprocating saw. Then feel free to go to town outside of that cut with the trencher. This will allow the new roots to easily grow out of that cut.
Thanks, they are not using a trencher but rather an excavator so I’m sure it won’t be clean cuts of the larger roots. I’ll have to ask them to cleanly cut what they can as they work. We don’t have the luxury working any further out though since the lateral is where it is.