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.
I’ve seen 3x the drip edge but that’s a pretty similar area. This is under the drip edge so not a great spot.
Im just happy we caught the issue before it was really bad. A little backup in the basement let us find a partially collapsed cast iron house trap (which is what was originally dug up, that’s the pile of dirt in the picture) and a lateral that was so full of roots I’m surprised we didn’t have bigger problems. Luckily our HO policy includes service line coverage so at the end of the day if we can keep the tree it’s really not that bad.
You probably don’t need me to tell you this but it would be a great opportunity to get a backwater valve and install it somewhere you can maintain and test it.
Good luck!
Thanks for the idea, our main is about 3’ lower than the first drain so code at least doesn’t stipulate one on our line. We haven’t really had backup issues and this was fully caused by root encroachment (and related issues like seam separation on the terra cotta and loss of proper drainage angle). The line is at least 55 years old so I’m not concerned with backups after we get a clear run going again with a proper functioning house trap.
I certainly don’t know what I’m talking about with respect to your local collections system but backwater valves also protect things like sewer backups caused by downstream clogs (think: farbergs) and backflow when city sewers are being cleaned (more annoying than disastrous). Also for overland flooding.
I’m sure you’ve done research and got good local advice but I wanted to throw that in there for others who may be reading and not know why they are helpful. A nearby city was hit with record rains earlier this week and there were 2000 flooded basements. They weren’t on combined sewers either, the water table was just too high it was getting in the sanitary pipes via cracks and other means.
I do appreciate the viewpoint, and there are areas around us I’d fully consider installing one (both areas with still combined storm/sewer systems and those with challenging topography and less than well maintained systems). Our borough does a great job keeping our system clear and I’ve never talked to anyone around us who has a backup for anything other than a clogged or more commonly collapsed lateral.
It’s a good thing to be thinking of though for others with sewer issues!