Bathroom wall wet dirt smell
We have a 4 1/2 year old house with a problem that no one has been able to figure out.
It started about 3 years ago when we began to notice a wet dirt smell in the wall behind
The shower of our bathroom. [There is a small room behind the bathroom so this wall that smells is not an exterior wall. There is a second wall also in the shower that is an exterior wall.] It does not smell all the time, frequently when you use the shower or if it is a windy day or sometimes for no reason. We stopped using the shower for a couple of weeks and the smell was still present, though not as strong. We have had two plumbing contractors come out and do the smoke test of the plumbing system and no leaks. All the plumbing vents were checked and all were in working order. We had a mold inspector out and no evidence of mold. We tore a huge hole in this wall to see if there was anything in it to cause the smell, nothing. We have tried pouring Clorox down the drains, as recommended by our water utility company. We have looked in the attic to see if there is any evidence of a roof leak, and it is bone dry. We are wondering if it might have anything to do with the drainage in the yard next to this bathroom, it is often wet for some reason, either a leak in the sprinklers or poor drainage. Or could it be due to a crack in the foundation? We do not know where to turn to next. Please Help!