If it was done in the 70's, the tiles are probably laid on a screed which makes it (IMO) easier. Just smash the tiles & concrete base to reveal the boards. Don't get me wrong, It's still pretty hard yakka – but it has less potential to damage the floor when removing it.
I think this is what it is since there is a small portion of tiles entering the bathroom that was damaged at some point and i can see screed underneath there. I wasnt sure if this was an attempted repair job on just that small portion, but considering what you mention i think its likely to all be laid like this.
Smashing also sounds better than having to pull out or punch hundreds of little nails hehe
Thanks for the tips…i havent yet taken up any of the tiles so i dont know if there is sheeting underneath, but i do know that much of the work around the house was done by the previous owner (in the 1970's i might add) so who knows what lies beneath?
we are ripping out the kitchen in a week or so, so when i do that ill take up a couple tiles which will be hidden under the cabinets regardless of which flooring option we take.
Daedalus – with the floating floors, the hallway flows into the bedrooms and the kitchen into the lounge which will have carpets. Did you have any issues with steps in the floors between rooms? There is already a small step with the existing tiles, so my concern with adding another layer is that there will be a noticable step between rooms.