Hello, I hope someone may be able to offer some advice. I recently noticed some staining on walls in my flat. I live in a ground floor flat conversion and the wardrobe is built against the original external wall of the house. The staining is around a piece of stud wall which was created to case in the soil vent pipe, which I believe serves the flat upstairs. I created an opening in the wall to have a look, and inside there is clearly dampness and was even fungus growing - this is in line with where the staining is. I'm not where where the moisture is coming from. There is no obvious water running down the pipe, although there is some brown deposit on the join which perhaps could be from a leak? I'm concerned it's coming up through the floor, but not sure if that would happen. Either way, I'm not really sure what to do next or who to contact to fix the issue. I'm reluctant to make the opening bigger at this stage as it's in my bedroom and don't want the smells/spores spreading around. I have attached a few photos, not sure how helpful they are. It's causing me a lot of anxiety so any advice would be gratefully received! Thank you
Most likely a leak from the soil pipe somewhere. As u live on the ground floor though it could also be coming from a floor above, so possibly not even from when you use your facilities.