I've been having some repairs done (started out as DIY, but then realised it was beyond me!). The shower has leaked and damaged the bathroom, so we're ripping out the damaged material ready to replace it. However we're not sure about the floor construction - the original plans have been archived and aren't easily accessible. The management company for the block could only tell me that it's a floating floor with sound insulation in (understandable as there's another flat below), but not what materials have been used. The top layer is chipboard. Under this is what appears to be plasterboard, and under that seems to be rockwool. There's at least one more solid layer but we can't really see what it's made of - and the whole lot appears to be on top of the joists as far as we can see. I've never heard of plasterboard or rockwool being used in a floor (apart from rockwool between the joists, which it doesn't seem like this is). Google only seems to turn up boards with some kind of foam or rubber filling. Can anyone shed any light on what this is likely to be? I'd really rather avoid tearing up any of the undamaged part of the floor to figure out the construction.
Mike