My 100+ y/o rowhouse has an unfinished basement about 4.5′ below ground with a bathroom that must be almost as old (toilet connects to the main, old tub, etc.). The bathroom is adjacent to the back exterior wall of the rowhouse (short side of a ~50×15 rectangle).
I was painting that back wall, and noticed the paint wasn’t covering well in some spots, and a brownish color was coming through – the wall was tan before but there was a small amount of discoloration then. So I started scraping it and a ton of paint and other ‘stuff’ came off very easily – not a lot of brick or mortar, but a load of everything else. Places where it came off were like paper mache to the touch before I scraped, and went down to the exposed brick after.
I am wondering if this is just a load of paint or other wall covering built up over the years, or if I have a serious cause for concern. It’s on the exterior so water makes me nervous, and it only goes up the wall about 3′.
Appreciate any thoughts – thanks.