Flooring

[haincelestial]

I am tiling a shower stall floor.  The shower pan is custom built fiberglass pan that recommends high quality polymer modified thinset.  The thinset at Home Depot all reads "Do not use with resin-backed stone."  The tile is a small basket weave travertine set on a mesh sheet.  I bought omnigrip premixed thinset for the shower walls (porcelain tile) but omnigrip reads "Do not use on shower floors."

What is the best thinset to use for mesh backed sheets of stone for a shower floor?

Thanks! 

[Jay_HD_CHI]

Hey there haincelestial,

Great question!~

With mosiacs becoming more and more popular, mesh-backing is being found on more and more tiles these days. However, not all mesh-backs are made alike and some are made with epoxy based ahesives, some with urethene and others with resin-based. Since there is no clear specification on the tiles, I readed out to our vendor for the travertine mosaics, MS International. I asked them about this Chiaro 2x2 Mosaic because it wasn't clear exactly which tile you were using, but this sounded close. The backing that they use for this tile and most of their travertine tiles is resin-based.

So this poses the question--what to use to ahere it?

First things first, return the Omnigrip to the store if you haven't used it yet. While it's great for adhesion on walls and backsplashes, it should stay out of the shower like you read.

Secondly, you are right in reading that the thinsets will all read, "Do not use to install resin backed
stone..." reason being that the resin sometimes it hard to bond to. Our thinset vendor, Custom Building Products will recommend that you use an Epoxy Bonding Mortar for this job. This is a product that we can special order for you directly from CustomBuildingProducts, and it's called EBM-LITE™ Epoxy Bonding Mortar. It's chemical resistant and gives a very strong bite onto the tiles.

I will say that I personally have never had any trouble with having these tiles bond using either FlexBond or Marble & Granite thinset pefore, and have never had any of our pro installers mention that they don't work or that they specifically need that Epoxy mortar. These are very tough thinsets and will provide you with great adhesion as well, but since it's not "vendor recommended" I can't tell you that this would be the best option, only my personal opinion on the job.

I hope this helps you get your project on the way. Please let me know if I can clarify anything further for you or if you have any other questions!~