We had a twin unit and had the bathroom,hallway and kitchen tiled and it was all stiil solid when we moved four years later
....when its used correctly it's absolutely fine....20/30 years a go cement board was not heard of...yet people still had tiles in there bathrooms and kitchens.....all I'm saying is....
well went to have a look at a lodge builder the other day 18mm water proof chip board floor ha ha wanted to tile the whole floor 80 m2 i asked why have you done this was told thats the way we all build these these are split in two then joined on site .they dont tile the whole floor but want to bring in new finishes and tile the whole floor they had one 60% built and one at the base level we changed the floor build up on this one to the real way of doing it in the modern world should end up leading the field with fully tiled floors with under floor heating .some have the brains to move on and some dont .