Plumbing question, where is each thing draining to?

I live in a two-story building on the bottom floor, so I exchange for not climbing stairs, I get to experience plumbing problems from other people.

Most commonly, I get problems with my kitchen sink which backs up and I can find out what my upstairs neighbor has just run down his garbage disposal.

However, I’m now having a problem with my bathroom sink. And what seems to come up through it, is not stuff that he puts down his own bathroom sink, but rather what comes down through his shower/tub.

My shower/tub and toilet are draining normally. But when my neighbor showers, I have to start bailing water out. When I’m gone, I have made a makeshift levee system out of some towels.

So why would my neighbor’s shower be backing up into my sink and where is the water from my shower going most likely?

All of the drains in the building eventually go to the same place. Sinks, tubs, showers, toilets, etc. all drain into the same system of pipes which winds up as one large pipe in the basement connected to the sewer system.

More than likely, there is some blockage in the pipe somewhere that will let normal amounts of water/waste drain through, but will back up with large quantities of water, such as would be used by a shower.

If you are renting, report this to the landlord and tell him he needs to have this fixed. There are definite health/sanitation issues involved.

If you are the owner, then you probably need to have a plumber come and take care of the problem.

There is a plumber due out tomorrow.

So what is happening to what we are flushing down the toilet?

It’s probably going down the drain, just like good little sewage, only more slowly than normal.

Think of pouring liquid into a funnel. If you pour slowly and in small amounts there is no problem, but if you dump a gallon of water in the funnel all at once it will overflow. That’s what is happening in the case of the shower, where there is a lot of water running down the drain in a continuous manner.

Yep. When you have a plumbing question, just ask a FatBaldGuy. (kidding! I’m kidding!!)

Like he says, Sounds like you’ve got a moderate plug in the stack just below your sink. Your toilet and shower would join that stack slightly below where your sink joins, so there’s a possibility of a plug there. As FBG says, if it’s a slow drain, your neighbor’s sink doesn’t trigger the backup, but the large amounts of water from a shower will.

Is it a duplex kind of apartment, or are the units stacked, with identical layouts above each other like more modern buildings? If it’s an old building with unique floor plans, your neighbor’s fixtures may not align directly with yours, i.e. his shower may join the stack that your sink is on, but the toilet goes to a different stack altogether. In a more modern building, the fixtures all join a common stack.

But you’re right, as the lowest tenant, you are closest to the front lines. In other words, when there’s a plug or probelm, you’re the first to know. So actually, your landlord should be happy to hear from you before the problem gets really bad (it’s a good theory anyway)

Somewhere below your apartment, all the vertical stacks are joined together and take a sharp corner to be joined with the stately river of human offal that is searching for a treatment plant, like salmon search for spawning grounds (except sludge flows downstream) this stream is called ‘black water’.

Since your sink also occasionally backs up, it sounds like there may be a slowage in lateral between the building and the City sewer as well. A properly designed system shouldn’t back up except in extreme conditions, like flooding.

The plumber really needs to check out the building lateral also. Older buildings have a tendency for the lateral to slowly become more constrained, until things like toilet paper, feminine products, and Mr. Hanky become stopped, then the whole system goes kerflooey. There’s an episode of Dirty Jobs where they go in to deal with one of these.

I would estimate the building to be about 40 years old. I lived there for 14. Plumbing problems are a recurring thing. This is the first time the bathroom has had a plumbing problem. The kitchen sink/garbage disposal is usually where everything goes bad. Usually on a weekend. When I decide to cook. I hardly put anything down the garbage disposal now. But when I tell my upstairs neighbor that his water is flooding my place, he just says “Who cares?”

I remember that episode. It was indeed a Dirty Job. The phrase he used to describe the mess was “crap bomb”.

Definitely call your landlord, clogged drains aren’t that hard to fix - certainly simpler than dealing with cleanup.

Thanks for the info.

It’s not that I haven’t called. I’ve rented long enough to know that. I was just curious as to what exactly causes the problem and what makes each problem unique.

slight nit-pick, it’s known as “gray water” here. The rest of your post is spot-on.

Carry on.

No, what he describes is indeed “black water”, according to the most common descriptions. (I don’t know of any ‘official’ definitions, really.)

But they are generally described as:
“black water” = water contain human waste (water from toilets).
“Gray water” = used water, but not containing human waste (water from showers, clothes washers, kitchen sinks, etc.
“white water” = unused water, coming into your house from your well or city water main. Also called “clean water”.

Looking at the water in the sink, I would say it is definitely gray.

[Seinfeld episode]

Elaine: Why couldn’t you just wait?
George: I was there! I saw a drain!
Elaine: Since when is a drain a toilet?!
George: It’s all pipes! What’s the difference?!
Elaine: Different pipes go to different places! You’re gonna mix 'em up!
George: I’ll call a plumber right now! <Goes for the phone.>

[/Seinfeld episode]

In all fairness to your neighbor, what should he say?

The neighbor should be saying “I’m so sorry, I’ll try and keep my water usage down until the clog is fixed.”

Okay, I can see that.