Marble backsplash that turned grey after installation

[Nurse Nancy]

We had 3" octagonal Alabama white honed marble tiles installed as a kitchen backsplash on August 1,2007. About two hours after the installer finished grouting the tile, the tiles began to turn varying shades of grey. They are still grey two months later and the veining appears as dark smears instead of veining. The installer did use white Versabond thin set and the tile was installed over newly installed dry wall. The tiles have not been sealed to date. Can anyone tell me what happened and what we need to do?

[Topshop]

Was the thinset a pre-mixed adhesive like from Home depot? The pre-mixed stuff is really mastic and contains oils which will do that to light colored stones sometimes. The discoloration usually goes away after time when the adhesive dries.

Some of the other guys on this site may be able to recommend a pultice which may draw out the discoloration.

[cheesedog]

this is common on lighter color stones, but they usually dry out and clear up after a week or two. the fact thats its been just shy of 2 months makes me think that topshop's idea could be very possible. did you feel the surface? does it feel gritty, or is it smooth like it should be. sometimes people dont clean up properly after grouting and it will leave a very light haze when it dries. pretty much every time we do a shower with light stone, there are grey spots from the thinset for a week or two.
what would help a lot is if you can find out exactly what they used to put the splash up.

[Steve Patrick]

Maybe an issue of subfloresence. I've seen what Topshop is talking about when using a general mastic ie: Home Depot. Whew..poulticing vertically, that's going to be interesting.Nancy can you post some pics?

[cheesedog]

i have a trick for poulticing vertically. i guess its not really a trick, since anyone with a brain would think of it. make a plastic square, cover the stain, tape the bottom and sides, put the poultice in, tape the top, then put strips of tape across the face to hold the poultice tight to the stone.

[Steve Patrick]

The "trick" I've used is the super thick papertowels doubled up w / denatured alcohol or whatever chemical already soaked in. Roll'em out as you move along w\ plastic. It seems to keep the poultice more consistent against the vertical surface. Not as much of a mess when removing.

[Huligar]

please make sure it is a plain white paper towel with no dye.

[Steve Patrick]

Yep. Nothing like having a pattern of smiley faces across the surface.

[Topshop]

I like the yellow duckies myself.