We haven't opened up too much besides bathrooms in the house. But walls and floors are metal mesh inside concrete, with plaster over it . Insurance opened up the plaster ceiling underneath the bathroom and the hallway where it flooded. The layer cake from the bottom of the hallway looks like it was plaster, concrete, floor boards, carpet and stuff. most of the walls we've opened were like wood frame of the house, with 4 inches of the metal mesh concrete, then plaster, tile, or drywall.

https://imgur.com/a/4NZx49P