Ok, so this is an age-old-topic for discussion, and I've read through most of the old posts on this forum, but I'm still interested in people's experience.
My plan is this. I have a large chipboard kitchen floor. The floor has three particular faults - firstly: where two large pieces of flooring join in the center there is a slight ridge (very very slight, I mean about 1.5mm ridge). This spans the length of the room. Secondly: under the fridge-freezer there is another ridge where the floor declines slightly for some reason... and thirdly: when I walk across the room (on the bare floor) there is movement in the floor.
Anyway, I know tiling on less-than-perfect wood floors is a recipe for disappointment, but I'm going to do it anyway. My plan: 12mm exterior grade ply screwed at 200mm centers max in large (2.4m) sheets to minimise joints. Then a PVA seal applied to the ply, followed by 330mm square ceramic floor tiles with a flexible adhesive and grout. I may position the tiles so that they meet over the very slight ridge (instead of having tiles span the ridge) so that any cracking is centered on the flexible grout (or should I do it the otherway around since tiles themselves are less likely to crack... aren't they?).
Any experience of advice appreciated.