Yeah...what that other guy said! You wrote that it's "clear glass tile with a white backing". Is the white backing an epoxy coating? Or is the white backing a mesh that the tiles are glued to? One thing to be careful of with glass is the thinset. If you leave ridges in the thinset, you might get uneven bedding of the tile and you;ll see the thinset ridges through the clear glass tile. I'll apply the thinset (white thinset, not gray) to the walls using the notched edge of the trowel, that will get you a measured amount of thinset on the walls. Then I use the flat side of the trowel to knock the ridges down so the thinset is smooth. Then set your tile in that. You want 100% coverage on the backs of the clear glass tiles. Regarding white versus gray thinset, gray can muddy the color of the clear glass tile. A slight tangent, but a lot of times with clear glass tile I've colored the white thinset with pigments for added effect. Mongo

I'm almost certain this is *not* rectified tile; it just has straight edges rather than uneven/wavy/scalloped edges that many tiles emulating natural stones have. We're getting the tile tomorrow, so I can't show the tiles butted together; I have only one 6x6 sample tile I can offer a picture of: This deserves my better camera and a muted bounce flash, but I only had I my little point-and-shoot handy, which puts too much flash directly on the surface and makes it look shinier than it is -- but hopefully it gives somewhat of an idea. Bill, the floor tile isn't down yet, but he's probably going to start this morning. I thought there was always grout between floor tiles, and just wanted to keep the grout lines from being too wide and dominant, which is why I thought 3/16" for 13x13 tiles is what I've usually seen or read. Is the amount/absence of grout purely aesthetic and to even out minor variations in tile size for non-rectified tile? It has nothing to do with holding the tiles in place at all? Would you recommend butting them together on the floor as well, if the sizes seem to be very uniform? Mongo, the tile is going on the floor and on the walls, floor-to-ceiling, in both dry and wet areas (alcove tub also used as a shower). If we do butt the tiles close together on the wall and/or floor, does he then just squeeze (unsanded) grout in whatever small gap there is between the tiles? Thanks for the quick help! -- Eric

Just to add, I know that Bill, Mongo and anyone with a real clue doesn't care for the Schluter edging, but I did end up using the Dilex EKE for the joint between the shower pan floor and the walls, and no caulk needed there. It is a very low profile profile, and you just grout to the edges, as the thing itself acts as the movement profile. I am hoping it lives up to the claim of maintenance free. I am not completely adept (and DH is definitively NOT) at caulking technique, although my joints in other spots did improve as I went along, I realized that if I wanted a nice clean corner, that was the way for me to go. The really talented folks may not need to use it but I don't count myself among them. I think it looks nicer than any caulk job I could have done, and the "matching" caulk did not live up to a color match- I used TEC, Birch, and the matching caulk was downright GRAY! So, the Dilex actually comes closer!

My primary concern is why are the tiles lifting in the first place? Was the base ever sealed with anything? And you said this is a "concrete pan", is this deck mud over a membrane, or are you going over a slab? There's a membrane somewhere under the "concrete", right? Just asking. The thinset should not be from an old bag that's been laying around for months and months. Old thinset can undergo partial hydration in the bag, weakening the final bond strength. If your thinset is old, go crazy and splurge $15-$30 on a new bag. The thinset should be mixed so it spreads like soft butter; loose enough to spread, but tight enough so that when you do spread it with a notched trowel, the ridges hold and don't flow out and collapse. The idea with using a 1/4" notched trowel is that after the tile compresses the thinset, the 1/4" high ridge is compressed to a 1/8" thick setting bed of thinset, evenly coating the underside of the tile. You want to bed the tiles in the thinset so you compress the thinset ridges down, but you don't want to mash them so hard that you squeeze out all the thinset from between the tile and the substrate. All that said...yes, clean off the old thinset so that there is no loose powder or clumps adhered to the bed. You want it smooth. You can have a residue of old thinset on it, but you want it smooth. If youre using Custom thinset, then as Bill mentioned, use a modified thinset for your next attempt. Either VersaBond (lightly modfied) or FlexBond (highly modfied). My apologies if I'm being too much "Tile 101" on this reply, but even dryset will provide a good bond to a properly prepared base. Mongo