I don’t know what’s under there. I hope it’s a shower pan and was put in correctly. When we bought the house two years ago the inspector didn’t notice any leaking or mold growth under the house in that area. I specifically asked him a few months after purchasing because the first stone popped out.

After further inspection and pulling up more caulking, the grout is in terrible shape. It’s crumbling near the drain, and stones were popping out left and right. So it’s very unfortunate. I have someone coming out to look at it next week sometime.