Dear Bucky,
First, what does the smell resemble? Sewer gas does not always smell like sewer gas. Check the traps under your basin and/or tub. If they are leaking they are allowing the odor through the traps; or they simply evacuated themselves. I've had situations where a trap leaked under a basin and the resulting mold under the cabinet smelled like methane. What I would do is clean the entire bathroom and wait a day. Then on my hands and knees, peform a "sniff test" around all suspect areas.
Good luck,
Len
P.S. It could be a mouse. Those little buggers can get into the darndest places. I've actually drilled holes in each stud bay before I found them.

[This message has been edited by Iceman (edited January 24, 2002).]

I'll share 2 experiences:
I had a flying squirrel get into a wall through the attic and die there.
I had a very slow drip under a pedestal sink that was rotting the floor where you couldn't see it. Didn't find it until the smell was noticeable.

Hi Bucky,
Besides what has been mentioned,I've run into odor problems if water stands in ductwork,aluminum stud material,and other metal.Unfortunatly,this odor resembles a dead animal or rotting garbage.Let us know what the outcome is.

[This message has been edited by Matches (edited January 24, 2002).]

Update: AC guy came, could find nothing. I have searched everywhere and found nothing but the funny thing is that the smell is starting to go away. After replacing the beeswax on the toilet, bleach out the ying yang down the drain and toilet (no tub in this room), maybe I hit upon something or maybe the dead "thing" has finished decomposing...??? Thanks for all your thoughts and help. I keep you updated if I actually find something!!!

Bucky

OK, we still have the smell, brought plumber out, $500 later, the smell is still there. One theory is that someone painted over wall paper 2/3 yrs ago and the chemical breakdown is causing the smell. Anyone ever heard of such a thing?

Dear Bucky,
After the e-mails, I'm out of ideas. But for Merlin, Have you ever wondered why, when you left the bathroom, the smell disapears?
Len

We have foul smell as well. Maybe that time of year. Especially by the look from this subject last year.

We too have a foul smell coming from upstairs master bathroom. What we did:
1). We did a thorough cleaning.
2). Discovered area around toilet was soft.
3). Pulled toilet...found water damage extending through both 1/4" and 3/4" subfloors fortunately ceiling was okay--Whew!!
4) We replaced subfloors and wax ring.
5) Still had smell so 3 different plumbers suggested several ideas.
6). Removal of toilet and recheck of flooring, replaced wax rings, poured bleach down sinks, shower, tub, sink overflow, A/C drain tube and the list goes on.
7) $1400 later we are no closer to solving smell problem. Today, we cut through ceiling from the downstairs directly under toilet and that has yeilded no leads either. Anyone want to venture a guess. We will take anything else at this point.
Exhausted,
Steve and Tawnya

If you have a septic system you should check the vent that goes from your septic line through the roof. It should be a 4 inch pipe which vents gases from the lines. Sometimes birds or squirrels will build nests in them trapping the odors which then escape wherever they can inside the house. I use a piece of old pantyhose leg to close up the top of the vent and keep critters out. Seems to work...

I also am experiencing an smell that is predominantly in an under the stairs closet adjacent to bathroom wall which has the bathtub behind. The pipes appear fine and clean but can see under bathtub through wall in the under stair closet. There is soil under the tub and a methane vinegar death-like smell that appears to be coming from it. Noticed after replacing the tiles with ceramic around the tub/shower. Any ideas re some bacteria in that soil and if so how would i disinfect it? i guess i could vapor barrier and drywall it in but probably not the best option. Cannot smell in bathroom it self.

I’m experiencing the same issue. House is 4 years old. This bathroom isn’t used very often, and the smell is coming from underneath the sink. I’ve paid a plumber to come out and tell me that the pipes are clean, no sewer gasses are coming through, no leaks, nothing. He had no idea what was causing the odor. I have taped off the sink drain and overflow as well as the holes in the wall where the plumbing comes through. An hour later, the smell is stronger than ever. And as someone else above has experienced, the severity of the odor comes and goes at random. This bathroom is also next to the master bathroom, and it has zero affect in that bathroom.
Just wondering if anyone figured it out? What’s the cause/solution?

I live in a condo...and the weird odor is coming from a interior bathroom. We have check everything, even mold. what is this order.

I just read this and we are experiencing the same exact thing. Sour nasty smell that is weak and strong other days but always there. I get sick when I go in, chest hurts, throat hurts glands hurt. I’m ready to rip open the bathroom walls. Animal control said it can’t be an animal or it would produce flies, plumber said nothing leaking. Hvac guy says vents clear. I want to cry.

ever heard of the peppermint test

We have the exact same smell in our master bathroom and can’t figure out what it is or where exactly it is coming from - has anyone been able to find a solution??

Oh joy, the same issue here. I hoped for an answer but I guess not. Foul order started a month ago and comes and goes. Toilet is solid, floor does not appear wet. No smell under house or anywhere else in home other than what drifts from bathroom. I have had mice die and smell bad for a time but not this long. Tried vinegar in the toilet tank and smell seemed less for a couple days but it is back.