We live on the first floor of an apartment building, over the parking lot. Apparently there is a leak in the parking lot, and it seems to be coming from our bathroom.
Four years ago, someone did some work for us and told us that the tiles in the bathroom were not done well, they were slapped onto the cement while it was drying and there is no adhesive, and we'd need to fix it at some point. We think this is causing the leak, as the water is getting into the walls. I decided to see if I could do it myself, and I literally picked a tile off of the wall - just came off. (They're not all like that.) I thought I would just lay the adhesive on a flat surface, but this is what it looks like! Lots of holes! Where I live, buildings are made with concrete and stone. Anyone have any clue what this is and what to do about it? thx!