Sewer smell in bathroom

10 years ago

Hi there -
I live in a 2nd floor condo with two bathrooms. There has been a persistent sewer smell coming from the master bathroom (which unfortunately has been making the room itself smell...). I've tried the following: replaced the wax seal on the toilet, snaked toilet/shower/sink (no clogs!), poured drain cleaner down shower/sink (let sit then run with hot water for ~10 min), poured bleach down drains (let sit then run with hot water for ~10 min), leave sanitizing/bleach tablet in tank of toilet in case stinky organisms were growing in there, pouring vegetable oil down drains after running hot water to help ensure the p-trap stayed full.

Here's what I really don't understand: when I removed the toilet to replace the wax seal, the smell COMPLETELY went away. As soon as I replaced the toilet, the smell came back gradually. When I did the bleach/hot water routine and topped drains off with oil, the smell went away at first but now it's back stronger than ever PLUS it smells like bleach (even though I ran hot water!). This super strong poop-chemical smell has been amplifying over the past day. I'm at the point now where I've sealed off the door to the bathroom and have the window in the bedroom open with a fan running. It's really noticeable when you first step into the bedroom, and honestly burns a little bit to breathe.

I know that the obvious answer is to get a professional out ASAP, but what I'm looking for is really just any ideas as to what could be causing this odor? Has anything like this happened to you before?

Featured Answer

homebound

10 years ago

This would be unlikely, but maybe there's a break in the drain line somewhere. I am now working on an old house in which a portion of the stack had to be replaced due to a crack in a hub (sanitary tee) that was dripping in the wall. Big mess. Probably not your issue, though.

But first I would tent everything, separately, with plastic. Let it sit for a while, then slowly remove each and put your nose under to see if you can locate the smell underneath. For example, cover the shower drain. Cover the entire toilet. Cover the sink, etc.

I once did this for a bathroom and discovered the stinky smell emanating from the tile & grout itself (I had draped the tile wall with painter's plastic, too.) The smell was due to wet greenboard behind the tile. No kidding.. And it did stink like the sewer.

Another time I did this and it turned out to be the sink drain. After pulling out the pop-up drain, we found it covered in black goop from toothpaste spit, hair, etc. Really gross. After cleaning it up, all was well. Yes, that can smell like sewer smell too, if it's been there a while. Good luck.

BTW, see if you get the smell when you turn on the sink faucet. If there's gunk in the drain (like just above the trap), the smell will come out of the sink overflow and hit you right in the face. We have this occasionally, and I pour a little splash of bleach down the drain and let it sit.

This post was edited by homebound on Wed, Mar 19, 14 at 7:15

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Comments (7)

aidan_m
10 years ago
I think the reason the smell went away when you pulled the toilet was because of "nose blindness"

Strong odors like those from sewer gas are only detectable to the human nose at low concentrations. Over a certain level, the smell is just too much for the olfactory nerve to handle, and the brain turns off the response.
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dmstev
Original Author
10 years ago
First, thanks for the responses! I didn't realize that about smelling sewer gas at certain concentrations, which would explain it. Also tenting each fixture is a really good idea - I *think* I have located the source - the shower drain. I didn't mention in my original post that the shower filled up with sewage about a week ago, then drained on its own. A plumber came out and said whatever was clogging the drain wasn't clogging it anymore since the shower drained on its own and that the general smell probably wasn't related to the shower (?). I noticed yesterday though that the oil I had poured down the drain was now around the edges of the shower tray, indicating to me that at some point the shower had filled again with water (no poop residue, so assuming it had to be just water/grey water), thus pushing the oil out of the drain where ever it was "stuck".

I have no idea why/how this would be happening, but today I'm going apes**t on that drain. Boiling water/drain-o/rootor again etc.
homebound
10 years ago
Oil? I certainly hope not.

For the sake of discussion, let's say you are pouring oil down a sink drain, then seeing it come up from the shower. That means the drains merge and that you probably have a blockage (complete or partial) beyond the shower drain.
homebound
10 years ago
Oil? I certainly hope not.

For the sake of discussion, let's say you are pouring oil down a sink drain, then seeing it come up from the shower. That means the drains merge and that you probably have a blockage (complete or partial) beyond the shower drain.
dmstev
Original Author
10 years ago
Sorry - that wasn't clear - I poured the vegetable oil down the shower drain. It came up from the shower drain later.

From what I've read online this morning (however credible that may be!) it sounds like there IS a blockage somewhere further along the line...if my attempts at clearing out the shower drain don't work I'll have someone come out to look at the main line.
homebound
10 years ago
Ok, but why are you pouring oil down any drain? Not good.