We plan on very tiny joints. Are spacers used for very thin grout lines? Yes. Usually they're small tapered spacers called "marble wedges", as seen in the pic below. but Bill Vincent recommended siliconized latex caulk in another thread. Are there particular brands that perform well? Whatever the brand grout you used, that's the brand of caulking you get, as well, and from the same place, and in the same color as the grout. Just about all grout manufacturers now make their caulkings with antimicrobial agents in them to put a stop to mold and mildew. Do we fill the tub with water before caulking? If it's cast enamel, it's not necessary. If it's plastic or fiberglass, you'd do alot better to make sure the installer supports the "belly" of the tub with mortar or foam. It'll go alot further than filling the tub. The reason for filling the tub is so that excessive movement won't stretch the caulking past its limits. Even a better idea is to limit said movement (which is what you do by supporting the bottom of the tub). Also, I remember a thread mentioning using caulk instead of grout in the "corners," but I am not sure if that means just the bottom corners, or the whole vertical seams where the back and side walls of tile meet. Any place where one wall meets another, or a wall meets a floor (or in this case the tub), it should be caulked.

It is curbless. No linear drane. It's a long shower and the shower head does not point towards the opening. It does meet code and the drain, though not linear is not centered on the shower its offset (due to plumbing constraints) and is closer to the back wall. I wanted to bring the tile out because I am paranoid about dripping showertakers so this gives you enough room to get out and finish drying. It was also an aesthetic decision just because I like the way it looks. Kind of like a rug. I was thinking silicone caulk as well. Thanks for your help!

I have a very similar hex tile on my bathroom floor and a square floor drain,because I have a zero-entry shower pan and I wanted a back up in case of overflow. My floor drain has a tile-able cover and so my contractor ran the hex tiles right up to the edge, tiled the cover. and grouted. Before he finished the bathroom, the grout along the edge had crumbled a bit and he redid it. We leave the cover on at all times, yet the grout has crumbled a bit at the edge again. So... I don't have an answer for you! But I am interested in answers you get! I do love your tile, though.

No way. Did you receive a sample prior to ordering and did it represent what you received when you ordered? We would refuse as well and TileBar needs to step up. Don't back down with them. We would refuse this for multiple reasons, including those stated above but also what looks like very suspect marble quality just based on your photo. Do pay attention to the country of origin when considering tile from an online source. Basically, it cannot be installed to their specifications OR industry standards without taking the sheets apart and hand setting the individual mosaics. Now that's an expensive install!