Marble on bathroom walls

Hi all,

I've got my bathroom down to the bare studs and I'm installing a jacuzzi tub. pump motor access is in the front.

One school of thought says vapor barrier then 1/2" concrete backer board on the walls around the tub/shower before the marble (or porcelain tile) is installed, the other school of thought says vapor barrier then mortar trowled on over an expanded metal mesh prior to the marble tiles.

I plan on using 12x12 tiles of marble or the porcelain, my big question is will they stick to the cement backer board if i opt for that route. Does a person grout with mortar the seams & joints of the concrete backer board? What product is used to secure the tiles to the wall ? Zero grout width?

The jacuzzi tub has a 3/4" flange turned up on 3 sides, it looks as if the inside surface of that flange should be flush with the wall prior to the tiles being installed, so the bottom edge of the tile is inside the tub flange.

Does a person float a thin skin of mortar over the concrete backer board to smooth out any wall imperfections prior to installing the marble tiles?

Who knows, i may contract it out, i just want to make sure its done right and looks first class.

Any help/suggestions/tips will be greatly appreciated. thanks,

Terry

I would put the cement backer on the walls. It just seams this is more stable, I did it in my tub and it works great. Do not try to use green board, use cement backer board. The builder of my house used green board and the grout failed, not once, not twice, but three times. I finally replaced the tile myself and it has been fine for a couple of years. Green board is not very water proof. I put the backerboard up to the flange (not beyond the flange). My thought was, if the calk starts to degrade (which it will) then the backer would act like a wick and suck up moisture causing failure. Make sure you use a good grout and use a sealer. I sealed my grout three times before using the tub. It was a little overkill but I figured after putting all that money and effort into the tile was worth it. I then reapply sealer once year.

Good luck