We are considering having a white marble mosaic installed on our bathroom floor. We are in an older house in Houston and had to prepare our slab (leveling and waterproofing)for hardwood installation in the rest of the house. Our ground here is very moist gumbo clay which holds water. We did interview several professional hardwood floor companies and all 5 companies suggested the same procedure.
I'm wondering if it would be the same for the marble and, if so, what should we use? I don't want any effervescing later. This marble is too expensive.

I know there is a special thin set/ adhesive to use on natural stone. I learned this the hard way. We had a marble backsplash installed in another bath and the contractor bought the standard type adhesive for regular porcelain tile and it ruined my backsplash! Aargh. These darn contractors. He wouldn't make good on the mistake and disappeared of course. I need a marble specialist !