i'v been to measure a bathroom floor up today, (16sq/m) so quite big! they're already having some building work carried out on the house so the joiner's already ply'ed the floor. But with 6mm ply which is nailed down every 100mm?? the joiner insists that this is how he prepares all floors prior to tiling and other tilers have never said its unsuitable! but i've told them it needed to be 12mm and screwed down, but i think they're a bit reluctant to take it all back up now! Is ok to go over with 6mm hardibacker boards?
