Wastewater Woes

August 14, 2011 3:25 PM

Why does the toilet in my basement overflow when I use the dishwasher or take a shower?

Background: older New England colonial (1940s maybe) with no sewage problems for the past year+ I've owned it. There's a toilet in the basement that sits pretty close to the main drainpipe, and lately it's started overflowing whenever I do something that uses lots of water - run the dishwasher, take a shower, probably do a load of laundry though I haven't tried that yet.

Plunging and drain cleaning chemicals had no effect. Flushing the toilet backs it up immediately. I bought a 50' snake and used it on the toilet (if I have an indoor cleanout access point thing, it has to be behind a finished wall somewhere in the basement). I sent the snake in maybe 30 feet before it got stuck; when I pulled it out the bit had moderate amount of unidentifiable grey and stringy black goo on it; not the big huge gross hairball or whatever that I was expecting. Tried it again with the same results.

I don't quite get what's happening here. If the clog is 30' downstream, how come my toilet overflows immediately? Wherever the problem is, how do I fix it?

thanks!

posted by xbonesgt to home & garden (10 answers total)

Sounds like a clog in the main line. The lowest bathroom in my house floods when that happens. You need to call a plumber. Eventually all drains and toilets will overflow.
posted by Linnee at 3:34 PM on August 14, 2011

Yeah this is a clog on the sewer line, probably tree roots. I've rented a machine at a big box store to clean out these lines before with some success, but the commercially available sewer guys seem to have a better success rate since they use a much stronger machine.
posted by Intrepid at 3:57 PM on August 14, 2011 [1 favorite]

Thirding the above comments just for good measure. Had the same problem with backups a couple of years ago, and it turned out to be tree roots, although it could be anything. If you're really into DIY, you can rent a power auger from most any rental place, but my experience is that the time and effort combined with the rental cost makes it better to just call Roto-Rooter or some such. Sooner is better than later, because it won't go away on its own.
posted by Ickster at 4:25 PM on August 14, 2011

Our plumbing was completely stopped up a few weeks ago -- sudsy water was coming up into the kitchen sink when the washer was running. After a local leak detection service sent a video camera through the main pipe all the way to the alley ($150), it was discovered that the tap into the city's sewer line was where the clog was located. The plumber spray-painted a line directly over the clog (called "white-lining") for the city, and the city came out that day and the next to dig down to their pipe and fix the problem ($0).
posted by davcoo at 4:33 PM on August 14, 2011

Seconding davcoo; get it camera'd. Sometimes the city will do this. If the problem's in a city pipe, they fix it, free.
posted by scruss at 4:57 PM on August 14, 2011

Nthing main sewer line problem. This is exactly what happened to us when our main line was clogged with roots. The reason the overflow happens immediately is that your sewer line is draining water super slowly so most of the line is just full up with old water. So, when you add new water to that system, it goes up the toilet since that's the shortest route to relieve the pressure.

Don't do laundry, you'll regret it. You need someone with a pretty heavy-duty motorized snake to make this go away.
posted by troublesome at 6:44 PM on August 14, 2011 [1 favorite]

Older home? You may have a septic tank that needs pumping out.
posted by TedW at 6:45 PM on August 14, 2011

ah rats. Okay, thanks everyone!
posted by xbonesgt at 7:10 PM on August 14, 2011

Agreed, it sounds like your main drain line is clogged. The basement toilet is probably the lowest drain in the house, therefore water will back up there when it can't go down the main drain line.
posted by tckma at 7:08 AM on August 15, 2011

Nthing the "probably tree roots" suggestion. We just dealt with this a few months ago (for our early-1950s house), though in our case at least the backing-up happened outdoors (via the sewer cleanout in the yard). Ended up having to get all the pipes under the front yard replaced as they were completely inundated by roots from the lovely-but-rooty sweetgum tree in the front yard.
posted by aecorwin at 5:34 PM on August 15, 2011