Mystifying bathroom odor

[sheahasu]

I'm beyond mystified. I'm clueless! I've looked at related threads on this site and can't find an answer. I have a bathroom that has a terrible urine odor. I have removed the old flooring, bleached (repeatedly) the subfloor before putting new vinyl tiles down, replaced the wax ring on the toilet, and checked the vents for blockage (there wasn't any that I could see) and flushed them just in case. The traps are fine (well, I don't know how to check the tub one, but the sinks and toilet seem to be o.k.) All to no avail. The vent issues seems to be related to a sewer smell, which I don't have, but I tried it anyway!

I can't get rid of the smell. I can't seem to figure out where it's even coming from. I have crawled around sniffing the floor, the base of the toilet, the walls, the cabinets, under and inside the cabinets, around the tub, etc. I looked pretty stupid, but I had hoped I'd find something. Nope. There doesn't seem to be a source, it's just there.

The bathroom is on the second floor, above our garage entry into the house. About 6 months after we moved in, one of the kids flushed a toilet bowl brush (NOT a flushable one), and we had some leaking in the pipes in the basement where it appeared to have gotten caught at a connection. However, by the time I finally decided to rip open part of the basement ceiling to see why it was getting wet, the obstruction must have finally pushed through because it hasn't happened since, that we can tell, anyway. That was about 2 years ago. The smell started about 8 or 10 months ago. It's always worse after the shower is used, although I can't pinpoint if it's the actual running of the shower or the humidty it causes. I'm guessing the latter because it seems to be worse now that it is colder out and the showers are getting hotter. It's so bad that the door has to be kept closed and the fan running almost all the time because otherwise the whole hallway starts smelling, too.

If anyone has any new ideas, I'd love to hear them!

[faucetman886]

In your description of what you crawled around and checked I dont see that you have sniffed the toilet bowl itself. I know its a disgusting thing to do but actually the rim under the bowl can build up urea soaked into hard water buildup in the holes around the rim and it can be almost impossible to clean even flushing bleach through the tank (which can permanently damage your tank parts BTW and shouldnt be done much). If the smell is coming from there youre only easy solution may be to replace the toilet itself.
Thats my best guess, it certainly looks like you have exhausted all of the obvious problems other than the actual stud work under the bathroom that may have been supersaturated during the leak. If that is the case you may have to open that wall and paint everything with "Kilz" sealant.