I have just removed the old floor tiles from my bathroom., It appears the boards were tiled straight onto rather than using ply or anything else. My question is, can I overboard with 12mm ply or 6mm tile backer board, or is it easier to rip them up & use 25mm ply & tile straight onto that. I have scraped the boards & there is a little residue on some of the boards but not horrendous. BY the way I am using 2ft x2ft porcelain tiles.
Thanks in advance
Thanks in advance