Spots on wall that stink

Hi all

I started noticing these spots on my wall that stink pretty bad (when you put your nose up to it). I’m not sure what to do other than open up the wall to see what’s going on. Has anyone ever seen this before? I’ve searched the internet and couldn’t find anything similar to it.

thanks in adv

Picture with light off to see it better

Not as noticeable with light on
ance

 

What's on the other side of the wall as well as above it?

 

The other side of the wall is a shower stall, but not the plumbing for the shower (thsts in a different wall). Above is the attic. I stuck my head up there and the HVAC air handler is above it, but it’s in perfect working condition- no leaks anywhere and dry as a bone. It’s a real head scratcher....

 

Is the shower surround water tight? no voids in the grout or caulking
Maybe double check the air handler to make sure the pan or drain pipe doesn't leak.

How long ago did these spots appear? Do they vary in size depending on the time of day?
Compared to the rest of the wall do they feel cooler? damp?

 

No water - the wall is water tight. Checked the HVAC again- no issues there.

From what I’m reading- it might be mice that have nested. Strange because I would think that I would hear something.

 

So you have been above it. What is underneath? Do you have a basement or crawl space or is the house a slab on grade? Can you look at anything from below. You know, you can buy a little camera to attach to a phone and poke a small hole and see what's there. Could there be a sewer vent up that wall? How old is the house? How long yave you lived in the house? Anything like it else where in the house? This is curious. Let us know what you find.
Can you describe the odor? Urine? Feces? Like a chicken coop? Could it be nicotine? How long since you painted the wall?

 

I like tightcoat's idea of poking a hole and running a camera.

How do you know the wall in the shower on the other side is watertight?

 

Thanks. We just bought the home and that is a fresh coat of paint. There was some staining on the wall, but we used kilz and it still came through. There is a crawl space underneath and I went under there yesterday. Found a dead mouse.... can’t really tell how long it was dead (or what killed it). I think I’m going to have to open up the wall and replace the drywall at this point.

 

Before I went that far I'd try coating those spots with BIN, paint and then see if it bleeds thru. It could be a contaminate that was painted over.

 

It sounds like you really want to look inside the wall. Do you know what is involved in tearing off the wall and installing and taping and finishing the wall? I'd sure try something less radical to start with. If you don't want to spring for a camera there are also sophisticated stud finders that can spot things like vents and pipes and the like. and marksr is could be right about something that was on the wall prior. There seems to be a pattern to the spots. Use you imagination and think about what could cause such a pattern. But maybe you just want the fun of redoing the wall? Please keep us in the loop about what you find. Is the texture different on the spots from the rest of the wall? The fact that there is an odor still intrigues me. I would like the excuse to get a camera.

 

It looks like you have a ceiling access / dropdown stairs in that hallway,
Try going up to the attic and looking down into the wall cavity.