Don’t put glass on a floor. Unless you want a cut foot bleeding everywhere when something chips it.

I can't imagine how difficult it will be to keep that floor clean.

That seems like it would be very slippery underfoot?

Not any more slippery than polished marble mosaics - even less so because there will be a lot of grout.

As far as keeping it clean, we've had a pebble tile in our current master for 5 years. I was worried about all the grout too, but it hasn't been an issue - even with all the painting and caulking and other dirty work we've been doing the past year. And glass is a heck of a lot easier to clean than stone.

As far as the danger of chipped glass - when my foot is bleeding Sophie can take great pleasure in saying "I told you so." Which I'm sure she will.

Rio - To be fair, I'm so paranoid about slipping that pretty much everything looks like it might be slippery to me - I wouldn't have a polished marble mosaic, either. My ideal shower floor (from a slip perspective) is something with a sandstone-type texture. I suspect it'd be a PITA to clean, though, since the texture would grab dirt.

Luckily I'm not redoing a bathroom any time soon.

I do imagine it will look very nice.

I wouldn't do it.

This is one of those things that REALLY calls for a test run. Can you waste a square or three to test different grouts on?

You want to test colors anyway--test them with different grout types.

I think glass is harder than most stones. I wonder why sanded is okay for stone but not glass?

Thanks - I think sanded is probably the way to go. But you are right about testing the colors. Luckily I have some time before we start the master.

The tile spacing itself determines whether sanded or unsanded. Not the materials used. Big honking swathes of unsanded will shrink and pull away from the tile. It needs sand for body. But sand will scratch glass. Microfines sanded grout for glass tiles.

Mapei FA The FA stands for fine aggregate. Always test first. Mapei CQ would not be used for the same reason as river stones. The following statement is from Mapei.

Can MAPEI Flexcolor CQ be used with pebble mosaics?

No, MAPEI Flexcolor CQ should not
be used with pebble mosaics. MAPEI’s solution for the challenges of
pebble mosaics (wide and narrow grout joints, curing time, cracking) is
Ultracolor Plus FA.

Is there a custom building products grout I can use? Mapei's palette doesn't have a blue. 11 grays, but no blue. At least CBP has an ice blue.

Why is blue grout so hard to find? It seems like all the blues have glitter or something in them, making them astronomically expensive.

Update: We are finally getting ready to tile the floor. Here's my quandry. I found navy blue grout that matches the walls of the bathroom and used that for the bubbles on the wall.

I had planned on using the same blue on the floor, but now I'm second guessing. The floors are unstained concrete and the counters and other horizontal surfaces have gray in them. I'm wondering if a gray grout on the floor might work better.

What do you all think?

I think gray would look better. Love the bubble tiles!

I am about to use the same/ similar iridescent bubble tiles on the floor / niche & bench seats- now researching the proper grout & thinking of glitter grout. Anyone use glitter grout & which one is best?

I sent a longish response earlier - don't know why it didn't post.

We used regular sanded CBP and added glitter to it: Hemway (Silver Holographic) Glitter Grout Tile Additive 100g for Tiles Bathroom Wet Room Kitchen | Easy to use - Add/Mix with Epoxy Resin or Cement Based Grout | Temperature Resistant. It worked great and we still love it after 18 months of heavy use.

In the past we used the Bostik Dimension Diamond Pre-Mixed Glass-Filled Grout. It is expensive and the results were - meh.

If it is the same tile, try to lay it out on the floor beforehand. It is about 1/3 the price of similar tile, but the sheets don't line up well. We ended up having to push in individual bubbles to plug the gaps.

The other thing we learned: Don't cut the bubbles to make the sheets flush against the walls. It looks better to just have the grout fill the gaps.