what are the mysterious stains on wall around my apartment?
Answers:
Moisture and fungus stains.
Other answers:
Sorry about that
Sorry about that
probably leaks of some sort...call your super right away.
mold/ mildew?
Mold. Bad news. Bad for your health.
It's your funk. Clean your apartment at least one a month might help. Oy!
Is your furniture Red? it might be that the color rubbs of on the wall. On the other hand it just might be mold. Just call supper!
get the CSI team around woth one of those cool torches. i bet you $300 every single one of them is semen
Stop hacking people up in your apartments and then the stains won't develop any more!
Sounds like rust stains to me. Maybe pipes in the walls are leaking and bleeding through. Or maybe cheap metal fasteners were used on the drywall and they are rusting. Either way the real problem is probably moisture.
The last guy sounds about right. If your building is concrete, then chances are it is reinforced concrete. This is where metal bars are cast into the slab to ad strength. If these bars are exposed to air and moisture then they will rust. These could be the causes of the patches, but it is very difficult to actually diagnose something like this from a worded description. You need to get a professional to come and have a look. Architect/ Surveyor etc....
A surveyor?
mildew