Black Grout Stains on White Marble
by Lisa Brown
We just installed a black/white (thasos) sp? marble foyer..using back unsanded grout ..the tile company we bought it from didnt tell use to seal the tiles first,,now the black grout has stained the white tiles, leaving them looking grey..we have used everything to clean and not to scratch..but they still look very dirty..help!! ..the marble was expensive and beautiful ..is there anything that will bring them back to the original color?
Unfortunately, there is not a good solution to this problem. Marble stains can most often be removed, but not by typical cleaners or methods as you've found out.
In this case, it's the extent of staining that is most problematic.
And yes, depending on the porosity of the stone sealing tiles before grouting is a good idea to prevent bleeding and staining of the tile by the grout.
Of course, with dense, low-absorbency stones sealing is often unnecessary and most commonly the grout and tile colors are similar enough to eliminate a problem.
Too late now I know, but the water test for sealing
is helpful to gauge the likelihood of encountering this problem.
But when such different colors are involved and the stone is porous enough it can turn into a mini disaster.
Given that these stains are likely "full-thickness" stains they will be difficult to remove.
You will have some
luck following the procedures outlined in the Removing Granite & Marble Stains ebook
I say "some" luck... you can likely get the stains out eventually, but you will definitely have to make repeated applications.
Also, given the square outline shape of the stains and that even in a foyer it's a relatively large area, this will be an ongoing project.
I'd first do a test on one small spot... the worst area and see what kind of results you can get. If you get a noticeable improvement, then you may be in luck... just keep at it.
You're only other viable option is to tear it out and start over.