Hi guys. The property in question is a first floor maisonette.The existing bathroom floor tiles have been laid on what seems to be 25mm plywood on suspended floor and this friend of mine wants to do up her bathroom and change the floor tiles. 1) If i lay new floor tiles on existing tiles, would the timber joists be able to support the extra weight?2) Or should i try to remove the existing tiles? 3) Is it possible to remove the existing tiles without damaging the plywood or should i lift up the whole lot? Thank you ever so much for your time and your superb pieces of advice.