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dulling and whitening of limestone tile

Article Number: 1525 | Rating: Unrated | Last Updated: Tue, Jul 1, 2008 at 12:00 AM

Hello, I have a limestone tile (honed) shower, which was installed about 4 years ago. Most of the stones still look excellent and as they did when they were first installed, except for a few that have a white haze that covers almost the entire surface of each tile. I've read about efflorescence, but I'm not sure that is indeed what this is. This discoloration (or dulling/whitening) wasn't there initially, and I've only noticed it in the last year. It only affects 4 tiles, and they are installed in completely separate areas of the shower. It's almost as if the haze is part of the surface too, in that there is no discernable layer of deposits. When I wet the tiles, the color returns to normal. I tried MB-3 and scrubbed them with a soft brush, and it did appear to remove a good deal of the whiteness on one tile but not so much on the others. Do you have any idea what this could be and what, if anything, I can do about it? Any help you could offer would be really appreciated. According to your posts on efflorescence, it appears you recommend ripping out the installation and starting anew. If it is indeed efflorescence, anything I can do to avoid that drastic measure? In other words, I don't got the money! Thanks!

Dear Jason:

“ According to your posts on efflorescence, it appears you recommend ripping out the installation and starting anew. ”

Well, that's pretty drastic, alright! And certainly not the case when there are only 4 tiles involved! J

In the worst case scenario, all it would have to be done is replacing those 4 tiles; but at this stage and going by your report, I'm not so eager to label it as efflorescence. At least not yet.

Why?

For starters, because efflorescence does not happen on only 4 random tiles.

Second, efflorescence is mostly on the surface – not within it as you report.

So then, what could it be? And, most importantly, is there a remedy?

My totally honest answer to both questions is that I don't know for sure.

I would chalk the first question to “one of the mysteries of limestone”…

And if we accept such possibility, then, of course, there's no sure answer to the second question, either.

But – you may cleverly object – why with only 4 tiles and only after 4 years?

Good question indeed. On the other hand, if there were not so many mysteries with limestone… L That is ultimately why I'm not overly baffled by your report.

So this is what I propose:

1. First you check thoroughly the grout lines around those 4 tiles to make sure that the grout is in place and unscathed – which will put to rest once and for all the possibility of efflorescence.

2. If when they're wet they go back to their original color, the application of a good quality stone color-enhancer like MB-6 would give you that “wet-look” (without any sheen – only the darkening) permanently (hopefully…).

3. If that will work, you will send me a thank you note. If not… You will replace those 4 tiles! (Hey, it's only money, right?... J )

May I ask you now to please read and e-sign our Statement of Purpose at: http://www.marblecleaning.org/purpose.htm?

Ciao and good luck,

Maurizio Bertoli

www.marblecleaning.org – The Only Consumers' Portal to the Stone Industry Establishment!