White tiles turning grey?

[phylliss]

We have just had our bathroom tiled with 300x600 white ceramic glazed tiles. 2 days later they have all turned a varying shade of grey. The tiler has never seen anything like this before. He used grey adhevise and white grout. The tile shop claims that tiles are not faulty, and that they will turn back to white within 5 days (which they haven't).

Has anybody ever experienced anything like this? Any advice.

[woodsprite]

Sounds to me that components of the adhesive have somehow permeated through the back of the tile and come up under the glazing. I would be a/ checking that the tiler used the appropriate adhesive and b/ asking the tile people WHY the tiles turned grey and by what mystical process they will return to white.
We had a heap of large white tiles put into the new bathrom a few months back - grey adhesive, white grout - and no probs. I suspect dodgy tiles.
Hope you can get it sorted.
Jeff

[mic-d]

Try this test with a spare tile/offcut. Lay it on a moist rag. Wait a couple of days, keeping the rag moist. Compare the test tile with the set tiles and a dry tile. If the test tile is a greyish colour, you're in luck, it's probably just the moisture from the adhesive, if it's stayed white, I think the tile shop might have a problem. You say the tiles are varying shades of grey, is that just random or does it follow the boundaries of the waterproofing? I might expect if it was just from moisture, it might be worse where the w/p is because the moisture has no alternative escape.

CHeers
Michael