Hi, I am building my house and need the real deal advice about what I need to (or don't need to) install underneath the tile. Cement board? Plywood? Membrane? There will be hardwood abutting the tile, and various installers have said I need to raise the tile up so it is the same height as the tile.

I am also having the steamshower tiled and have been told there needs to be waterproofing and cement board backing is this correct?

Thank you so much!!