can you tile over marble?
You need to check structural weight loading. marble is already pretty heavy and now you’re putting a porcelain or ceramic layer on top of that. It may cause serious structural sagging or other problems. A rather light consequence would be your grout or tiles cracking, but there are far worse potential consequences.
The marble surface is likely polished or honed and it might have a sealer on it or contaminates from pass use. I would recommend first roughing up the surface of the marble. This will take off any contaminates that could compromise the ability of the tile to bond to it.
You should use a polymer modified thin-set mortar adhesive that meets ANSI A118.4, or better yet ANSI A118.15, to bond the tile to the prepared marble surface. There are flexible thin-set mortars that are recommended for bonding tile over tile too. Make sure the thin-set mortar you use is recommended for this application.
I'm Linda. I don't have marble in my home but I found an article with directions on how to cover marble with tile. I hope this helps you. Wishing you the best!
Tammy,. Is this a floor, or what? Give some better information.