QUESTION

I had 1 inch x 1 inch marble tiles installed on the shower floor and a shelf shower insert. The tiles were shiny before installation. After grout was applied; they are now matte and dull. The installer instructed me to use denatured alcohol to make the floor shiny. Upon research I read not to use denatured alcohol on marble?? Also after water hits the floor, it looks dirty as the floor is drying. (I have not used the shower yet, but noticed this after installed ran the water. Is this to be expected? Also it takes longer than overnight for the floor to dry completely?? Thank you

ANSWER

ANSWER - Denatured alcohol is acidic and can act as a solvent to break down sealers or stains that could be on the stone.  They use oxalic acid in polishing stone because it breaks down the surface as they polish it.

Some natural stones are treated at the stone production facilities with penetrating sealers or stains to enhance the stone.  So some solvents will take away the sheen.   Marble in particular is sensitive to chemicals; particularly those that are acidic as it attacks the calcium carbonate that marble is made of.   So the smudges could be from the solvent or the acid could etch the surface to give it a dull look.  Or make the type of grout used left a latex/polymer haze that can be removed with a latex remover.

Whatever you do test it out first in an inconspicuous spot to make sure it is giving you the results that you want.  You can hire an experienced professional stone restoration company to refinish the stone that in theory should be able to restore it so it is like new.