I am in the process of redoing the flooring in one of our bathrooms and putting down ceramic tile. the bathroom is about 80SF . The existing floor was carpet ( terrible idea whoever built the place ) except for the toilet area which was vinyl flooring. Once i started demoing the carpet i realized that the subfloor consisted of plywood (thickness unknown) and then particle board glued and nailed/screwed down ; about 5/8″ thick.
I know tiling over particle board is a horrible idea, but the bathroom area is tight and demoing out the particle board is something i would like to avoid.
I saw in other forums and asking some other ppl the best way to move forward without demoing out the particle board and came up with the following strategy.
Seal particle board with Regard > install 1/4″ cement board over sealed particle board ; screw down only> seal gaps and seams with silicon> tape and apply thin set over seams> apply redgard over seams and maybe screws?> then install tile over cement board ( 1/4″ thick tile)> grout> caulk perimeter with silicon .
please let me know if this will work? or if i need to change the strategy? or if this is over kill? or if I’m missing anything.