Main sewer line roots

adam1885282 · 02-12-2010, 02:27 PM

I searched the archives but didn't find sufficient information, so here's my first post.

My main line had been backing up every few months, then monthly, then weekly, now every day or so. It always clears with a manual snake with no problem. When it was monthly, it wasn't worth doing anything about because it cost me about $20 to buy the snake and about 5-10 minutes to clear the drain. However, it got bad enough that I rented a snake camera. Aside from what follows, the 40-y-o pipes look surprisingly good!

I saw what I am 95% sure are serious roots in two spots. A little detective work allowed me to locate the source of the roots as a couple of bushes I don't care anything about, 2 and 10 feet from the house. The pipe is only a few feet under at this distance. This weekend I'm going to chop down the bushes and dig to the pipe so I can clear the exterior of the pipe. The offending roots should then die and be swept or snaked away. It will also give me a chance to examine the pipe's slope and general condition.

I think there may also be a belly in the pipe. There was standing water where there shouldn't have been but because the camera was under water at the time, I don't know whether the roots were causing the back up or if there's a dip. I think it's a dip.

I really need to think of it as two issues. First, the pipe is useless with roots in it, so those need to go. Second, after the roots are gone I need to consider the "normal" condition of the pipe. The infestation was thick enough I don't think root killer would work, or maybe it will??

Anyway, the digging is just a matter of labor even if it takes me three weekends or I have to hire help. It's not deep enough to be dangerous, but am I wasting my time? Also, since I'm digging close to the house do I need to worry about the foundation? Should I try to shore up the footings if I get that far? It's a concrete slab.

Considering what plumbers in this town charge, I think this would be a $5,000 job. If that's what it takes, fine. I just don't want to pay it if I don't have to. I'd like to at least fully understand the problem. And if I can excavate sufficiently, some professional plumber should be willing to replace the pipe for significantly less.

If anyone has experience in this area, I would greatly appreciate tips, concerns, additional questions, advice. I’ve had the rooter people out and I’ve also had the pipe jetted with a trailered jetter. These roots either weren’t bothered by all that activity, or they’ve grown back.

Thanks!
Adam

Daniel Holzman · 02-12-2010, 04:20 PM

Roots in pipes are a common problem. The problem is made worse when the pipes are near surface, when there are deeply rooted plants or trees near the line, and if the pipe comes in sections that are joined together (i.e. cast iron sewer pipe). You can replace the offending pipe section with seamless plastic pipe, which will resist roots quite well.

PaliBob · 02-12-2010, 09:32 PM

Adam, welcome to the Forum.
Twelve years ago when Pipe Inspection cameras were just getting popular I called a Plumber friend who recently bought a camera to look at the main line of another friend that had a similar problem. The friend had just bought a forty year old house where the clay main line had all been replaced with 4" ABS (plastic) the previous year.

My friend had just moved in with three small children and after three stoppages in two weeks (cleared by Roto-Rooter) he asked me to call my camera guy. While the plumber ran the camera I looked over his shoulder at the monitor.There were NO roots in his line but like your line there was one area (about 10') that was filled with clear water.

When the clay line was replaced with ABS the installer did not pay enough attention to the slope of the trench. So even with NO roots, the line, with heavy use, (3 Kids) was susceptible to blockages. The fix was to dig up the line, grade the trench to a consistent slope, and install new ABS. Two new outside clean-outs were also installed.

Since your line also has a dip, I would recommend replacing the line,
.