Q: I live in the San Leandro, Calif., hills where there is clay soil. Last week, brackish water backed up into my toilets, tub and shower. A plumber came and tried to remove the obstruction, but was unsuccessful. He returned with a camera on a cable and was able to pinpoint the problem. It seems the clay sewer line had shifted with earth movement and tree roots had infiltrated the line.
As a short-term fix, he suggested I install a cleanout where a newer cast iron pipe joins the clay pipe, and that I replace part of the clay pipe where the joint had shifted. He also suggested a new cleanout closer to the street. Because the pipe runs under a concrete walkway it would need to be jackhammered, so the estimate was $3,000.
For the long term, he said I should replace the clay pipe with a single piece of pipe, which he said would last our lifetimes. But this would cost more than $10,000.
What would you do? Is the plumber trying to get extra money from me? I’m thinking at a little over $200 per visit, I can get a lot of sewer line snake jobs before I reach $10,000.
Finally, I read where one could use copper sulfate crystals to control roots, but it’s not environmentally friendly. Rock salt was recommended as safer. Does this work?
A: For the most part, we think the plumber is right on and isn’t trying to rip you off. Sewer line replacement is a big expense, but it’s something you’re going to have to do. Remember that when you sell the house if the problem hasn’t been fixed you’ll have to disclose it to potential buyers. We think you should replace the line and be done with it.
With a big-ticket item such as this, get several bids, ask for and check references, and make sure your contractor is licensed and bonded. We wouldn’t be surprised to see estimates for the job vary by as much as several thousand dollars.
The clay pipe has got to go. A new cleanout or two is not a permanent fix. At best it will delay the necessary replacement of the line. Also, using copper sulfate crystals or rock salt is dicey. Using either may kill the tree attached to the offending roots. Then you not only have to replace the sewer line, but you’ll end up cutting down the tree as well.
Clay sewer pipe has been obsolete for decades. A clay line consists of sections of pipe formed in the shape of a bell at one end. The flat end fits into the bell. Mortar was packed around the joint to hold it in place. Eventually movement of the clay soil breaks these joints and roots intrude.
The next generation of pipe was cast iron with the same bell joint, but this time joined using oiled hemp called oakum and molten lead. This joint was stronger, but still no match for the earth movement inherent in clay soil.
Next came no-hub cast iron joined by rubber couplings and with steel bands. This was better, but root infiltration is still possible.
Today most jurisdictions allow plastic pipe (ABS or PVC). Plastic pipe uses glued joints. Check with the building department so you know what material is allowed.
One option you should look into is trenchless sewer replacement, which we described in a column a couple of years ago.
Basically, a cable is pulled through the pipe and is connected to a bursting head. The head is attached to the new pipe. The bursting head splits the existing pipe and pushes it out of the way as the new pipe is pulled through. The new pipe is the same inside diameter as the old. If required, it’s even possible to increase the size of the pipe.
This method of sewer replacement requires only a hole at each end of the line rather than digging a trench the entire length of the line. For a video of this process, click here.
