inexplicable repeated backups

[njghost]

9 days ago, when I ran the washing machine, I got an overflow of sewage in the nearby toilet. Major damage. Plumber cleaned trap, which he said was full of paper and excrement. Had all affected areas decontaminated, dried, etc.

5 days later, tried to do laundry and got backup again. (Decontaminated, etc.) Plumber said there was paper, etc. in trap. Thought maybe was a toy or something stuck in the "U". (It was Sunday, so he didn't have his snake or whatever with him.) For past 3 days, I didn't do laundry, but we did use bathrooms normally.

Plumber came today and found the "U" clean: no toys or other objects, and no backup. Line from trap to street is clear. He thinks we're using more (too much) paper, but that makes no sense: This never happened in 25 years, during most of which there were 7 people living here. Now there are only 3!

could it be too little water pressure when toilets flush?
other ideas?
thanks in advance.

[The Builder]

Get your plumber to take up the toilet. You may have a situation that I ran into a while back. If the washing machine line is running into the fitting near the toilet, lets say buy a tee fitting with a side inlet or other fitting, it may be a partial clog near the fitting where they meet or in that area. Once you take up the toilet you can run water into the toilet fitting to see if the water will go down as it should, if not then run the snake into the toilet fitting until the partial clog is clear, and then flush the piping and fitting with water. Me in particular, I like to use the toilet supply line to do that(flex hose). Another thing you could do is have him run water into the washing machine drain pipe to see if the water will go down by itself with ease. If that is the case(and after you have did the above with the toilet) then there could be fragments or other in the drain line that is cathing the washing machine waste and causing the clog. Its a number of things that could be going on, so since your plumber is there he has a bird I veiw. But these are a couple of tips that may assess you in your problem.

[pushkins]

There is no trap in the toilet plumbing line, the toilet itself "is" the trap (to stop gases coming back).
Get yourself a 5 gallon bucket of water and slowly pour it down the toilet, if the toilet doesn't back up then the sewer line from the toilet to the sewer is probably clear.
The simple fact that the washer is causing the nearest toilet to back up suggests that some place after the washer line meets the toilet line there is a blockage.
Easier still would be to remove the toilet and pour the bucket down the 3" line, this way you could get a better idea at how fast the line fills up, if you pour down 2 gallons and it's full then the blockage isn't that far.......5 gallons....it's obviously further down.

[njghost]

Is it possible that the washer itself is not the issue, but just the fact that it puts so much water into the system at once? The plumber said the trap, i.e., the U (right before the water goes out - sorry for my sloppy use of the word) was absolutely clear this morning and, in fact, I'm doing laundry now just fine - the water in the toilet doesn't have the slightest flutter.

The question is why toilet paper, etc. is collecting in the U so much and so quickly - enough to clog it in just a few days.

BTW, the plumber said the side of the U going out of the house was also clean, so does that mean it isn't a backup from the city sewer? or roots, etc. clogging the pipe leading to the city sewer?

[jnaas2]

How old is your house

[njghost]

50 or 52 years. It's a split with 5 half-levels.

[Got Memories]

I had the same problem a few years ago and it turned out that neighborhood kids were taking the top off of the clean-out pipe outside of my house and filling it with rocks.

[The Builder]

Did you have your plumber remove the toilet to see? The toilet indeed has its own trap, but that is not the issue. The fittings that meet up below thw flange should be looked at, if peradventure that may be where the blockade is accurring. A couple of gallons of water won't nessarily work, because it is to little, but again it depends on the situation. A situation I had was similar to this, the toilet would fill up, but also the sink would run slow and the shower would back up. After snaking the shower and plunging the toilet and sink I observed how everthing was connected and clogged/slow draining. So, I pulled up the toilet because I had an idea thats where all the drain connects where, being beneath the toilet, at the fittings. So I added pressurized water by the toilet flex hose, and I let it run for a bit, and sure enough the water started backing up, and not going do fast enough. Then I snaked inside the 4 inch toilet drain and ran the water again inside the drain, and wala, it went straight down. Then I ran the shower and the sink, and could see the water from those fixtures going down the drain. But like I said, your situation may be different, but its worth a try if you don't come up with a solution before that. I had a couple of situations like this, and pulled up the toilet and snaked through the toilet drain and the rest was history.

[LazyPup]

Every fixture has a separate trap and if a trap gets stopped up it can only affect that fixture. If drainage from one fixture appears in another fixture the blockage has to be in a line downstream from both fixtures.

NO reputable plumber would go on a service call for blocked lines without taking a snake.

Bottom line, its time to get a new plumber

[njghost]

synopsis/update:
9/21: I'm doing laundry --> sewage comes up from nearby toilet. plumber cleared trap of toilet paper, etc. confirms line to outside is clear. Plumber says we use too much paper (or our excretory habits have suddently changed).
9/27: First time I tried to do laundry --> sewage flood (smaller this time) comes up from same toilet. plumber comes, clears trap (still says it's too much paper, etc.). It's Sunday, so he came straight from wherever and didn't have snake and other tools with him.
9/30: plumber comes and everything still clear. I do 9 loads of laundry without incident.
10/1 (a.m.): Town checked outside sewer line; found all was clear.
10/1 (p.m.): 2nd floor toilet wouldn't flush. My husband couldn't plunge it out.
10/2: Plumber checked trap before he looked at toilet and it was all clear. Cleared toilet with great effort. Suggested toilet backup probably unrelated, that some object dropped in (it's very close to a very cluttered vanity surface) and stopped it up (it's a very small toilet, so that's a reasonable scenario). H had us run all water sources (every sink, shower, toilet) simultaneously and everything ran fine.
No problems since.
Now: Do I dare try to catch up on laundry?