Granite tile and BIG probs with adhesive showing through

deeaa · 07-17-2008, 09:56 PM

Anyone ever seen this before? We used mortar that was recommended for our granite tile backsplash and we now have dark, oil looking stains showing through most of the tiles. Not nice! Is there anything at all that can be done now short of starting all over? We actually started earlier and it began happening so we took the tiles down. We went to Home Depot and showed the guy what happened. He recommended this other stuff. We mixed it up as directed and started using it. About an hour or two later the same discolouration began happening. All that work for nothing!

concretemasonry · 07-17-2008, 10:19 PM

Cheap granite has high absorption.

Project_Pat · 07-18-2008, 12:25 AM

Did you use Versabond thin set on these?

tigerbalm2424 · 07-18-2008, 07:32 AM

Can you post pics? I guess I am just interested to see what this looks like.

ccarlisle · 07-18-2008, 08:57 AM

I am not surprised.

You know there are at least two thousand stones that could be called "granite" according to strict geological definitions and amongst those, only about a handful are real "granites". Most granites we see aren't what you and I would like to think as granite, they're something else that was mined - and then sold as granite.

Basalt is a good example, mined everywhere and sold as granite in big box stores.

What is the name of this stone you bought, where did you buy it, how much a sqft...?

I'd bet you were sold a 'granite' but bought a basalt. Properties quite different. What colour is it?

tlg · 07-30-2008, 01:02 PM

We had this happen when granite was laid for our fireplace. I was really worried. It was the moisture in the adhesive coming through the stone.
It took about a month, but eventually all of the moisture dried out and the dark marks went away. I hope this will be your experience too.

We aimed fans at the marks to speed the process.

concretemasonry · 07-30-2008, 01:44 PM

I don't know about adhesives, but "granite" can absorb much more moisture and water soluable materials than people think. - Just look at some of the newer "granite" buidings a day or two after a good rain. You can still see the moisture patterns.

Dick