Lead painted floor below current subfloor: can we leave the subfloor when replacing main floor?
I bet that floor squeaks really bad, I would be surprised if it doesn’t when you pull the stone and mortar. The reason the floor is breaking up is from movement.
Yes you can leave the lead paint it will be covered so there is no risk, the stone and mortar flooring , I have never tested that for asbestos because that would be uncommon.
I would remove the floor and sub floor at a minimum possibly even the next layer and redeck using t&amp;g plywood this will be needed if you want to tile to prevent the new floor from doing the same as the current floor.  If putting down vinyl I would still re deck but I hate squeaky floors and am a really big guy.