Where can i install porcelain tile?

Question

Can i install it on a wood subfloor? there is plywood then some plastic tile then a 1/4 inch subfloor that it will lay on top of.

when i install in in a tub surround do i put it straight on the green board? is it ok to install it straight on "drywall mud" or do i have to prime the walls?

Answer 1

You should use 1/4" cement backerboard on top of the tile but it would be better if you removed the tile first. As far as the greenboard goes....get rid of it. It is not good for a tub surround. Install 1/2" cement board instead. If you are putting it on the walls other than the tub area then prime the walls first.

Answer 2

No, you cannot install on a wood sub-floor.  Even the slightest movement will cause it to crack and make the grout unstable.  On the floor, you must first install a concrete impregnated underlay, such as hardi-backer or wonderboard.  Walls do not have to be primed.

I must disagree with the previous answerer... Greenboard is designed for this.