help for bathroom and en suite

[jimmyk07]

my sisters asked me to tile her bathroom and ensuite. Im just looking for advice on surface prep. The walls are ok, pretty flat, so im not concerned there, but the floors are floorboards, so can i ask, do i use 12mm ply? also, do i use a sealant on the ply before tiling? and with them being porcelain tiles, do i put anything on them before grouting, so as not to mark them? any advice welcome, many thanks, jimmy

 

[DHTiling]

Hi Jimmy, what condition are the floorboards in... any loose or damaged ones..?

 

[jimmyk07]

hi dave, the floorboards are sound, no loose ones.