Designing Kitchens and Bathrooms - Marble Floor Tile -Adhesive Mastic or Thinset???

I am about to lay 12x12 marble tile in a bathroom. Is there a difference between using adhesive mastic or thinset?? I want to use thinset so that I can imbed an electric heating mat under the tile.

Thanks.

Mastic is not to be used on floors. There are two colors of thinset, gray and white. White should be used with marble. Do not adhere the marble to wood, just in case you're considering that.

Mastic is not to be used on floors. There are two colors of thinset, gray and white. White should be used with marble. Do not adhere the marble to wood, just in case you're considering that.

Thanks for the fast reply. I was planning to put down hardyboard and then marble tile. Would that work? Also, the marble tile is a greyish-green color. Should I still use the white thinset?

Thanks again.

Now you're getting out of my experience level. I've never installed a green marble, but have been told there are special considerations with it. The various colors in natural stone are created by different minerals in the material. Those different minerals have different characteristics and, green colored marble, or so I've been told, will do some strange things if not installed properly. There are other installers on this site who will know more about this so hang on a bit to see what they have to say. Some of these guys have to actually work to supplement their income from helping folks here. As to the rest of your question, lets let the one talking about the marble deal with that also.

I've installed some green marble in the past but its been a while. I used white thinset and it turned out ok. Ive heard some green marbles will actually warp from the moisture in the thinset, and its suggested that they be set with epoxy mortar.