'sort of' green marble and thinset [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


View Full Version : 'sort of' green marble and thinset

07-20-2006, 11:09 AM
Gaaah! All set finally to mix the thinset and put down the first tile.. Scan the instructions on the thinset bag and find 'Not for green marble'

My tile is 'sort of' green and for that matter 'sort of' marble.

It's 'sort of' green in being a very light gray/green and 'sort of' marble in the it's got lots of plant and shell fossils and parts - which seems to fit the desciption of limestone (or maybe dolomite) better than marble. In any case, it's clearly not serpentine. I bought the stone at Expo Design Center - Home Depot's fancy sibling - under the name Olive Green marble. It's from Turkey. (And by the way, it's quite different from the showroom sample - but that's another tale of woe altogether.)

I calmed down a little and spent 1/2 hour googling. Found the usual variety of half-applicable info - including 'All green marble tends to curl when exposed to water' and more usefully in this forum's archive John Bridge saying 'All stone that has this tendency is classed as "serpentine."' (good for me, I think) and ' Unfortunately, if it happens, the problem tends to occur about a month after the job has been completed.' (extremely scary)

I'd just go out and buy epoxy mortar, but don't want the trouble and (I'm guessing) expense if I don't need to. I also have about 1/8" of levelling I need to do over the durock on the floor and I believe I've read somewhere that epoxy doesn't work well for this.

In the same thread, John Bridge suggests a skim coat of fast-set thinset as an alternative to back-sealing or epoxy. This sounds doable, but again, if I don't have to.....

Thanks for any advice.


Sponsored Links

07-20-2006, 11:20 AM

Sounds like you've done your homework :king: . I think you have a limestone too and you should be O.K. I've actually set Green Marble with thinset way back before I knew and had no problems..Still I would'nt take a chance if I knew it was a serpentine. The Speed set may be a good safe bet.

I'm not sure how you know for certain what you have...possibly someone hear will. Let's see who we can find that knows.

07-20-2006, 12:24 PM
One test for warpage is to take two of the suspect tiles and place both in a shallow pan (cookie sheet, whatever), one face up and the other face down. Put some water in the pan but only enough to come up the tile 1/4 of the way or so. Let sit for a couple days, remove, dry and check for warpage. This "test" comes from the first edition of Michael Byrne's book on tile. :)

07-20-2006, 01:35 PM
Thanks. That sounds definitive. I'm going to do that.