tiling over a wood fllor Advice and information on tiling and fixing tiles to a variety of surfaces

[dan007]

Please help i have laid 18mm tongue & groove floring in my shower room & am going to lay wbp ply over the top so i can tile on this i am going to seal this with a mix of sbr bond & cement slurry then tile with floor tiles my questions are what thickness ply do i need (i dont want to raise floor to high was thinking of 6mm ?) & am i sealing it correctly & whaT adhesive do i use & is the grout & adhesive better if i get it in powdered form or ready mixed i have been told so many different things please help many thanks

[welsh brickie]

6mm is ideal screw it down every 150mm to ensure no movement.