We have honed/filled travertine 16" tiles in our shower and on the floor throughout the bathroom. We love it. It is smooth and looks beautiful. It shows no discoloration or scum build up so far (only about 1 year). I plan to use it in another bathroom. It was sealed when it was installed. Our 16" tiles weigh a lot, but size and weight is not a problem as long as it is installed by someone who knows what they are doing. Huge tiles have been used on vertical surfaces for many, many years. Travertine and its cousin marble are some of the most common natural stone wall tiles, so I don't know how it "would not be that ideal for walls". I would only worry about travertine and marble for a kitchen counter or a vanity counter. When was the last time you spilled red wine on your wall? - Jim

This is no challenge at all. I've DONE a steam shower (or should say REdone-- the old one was falling apart because the tile guy never waterproofed a thing-- not even the plywood seat) where they DID fabricate the glass ceiling. I'm not sure who did it, if it was just a local custom glass company, or someone who specializes in this kind of thing. If you're really interested, do a search on Point Sebago Resort, and ask to speak to the owner. Or you could ask to speak to their head of maintenence, Ed Bartlett, who is the one that actually contracted me.

I have also thought about the drain and mud packed against the drain threads as a possible failing point. My plan is to carefully cut the dry pack around the diameter of the drain to reveal the snap ring. I will then remove the snap ring, Apply the liquid membrane to the entire shower. The snap ring will clamp/pinch the liquid membrane therefore providing one continuous membrane that will be sealed to the drain. The old shower in the exact location put in by the builder had no membrane, just a fixed drain (no snap ring) and never had any problems. I am not the only one who has done a shower this way i.e the link I posted. Also the red guard is a step above what I took out. They had no membrane, no liquid membrane, and used regular sheet rock. I am taking extra steps beyond what the builder did and I am using better material such as modified thinset and polymer modified grout. I don't see how this will fail. If I use epoxy grout, and or epoxy thin set I have three water proof membranes. First the tile/epoxy grout, next the epoxy thinset and finally a liquid membrane. If water somehow makes it past that it will meet cement board, pressure treated lumber (knee wall/bench), concrete cinder block and finally concrete slab. It is not like this is a wood sub frame. The steps I am taking are way beyond what the builder did in 1993 and again there were no mold issues with the old shower.

If your primary goal is for the front wall to be 100% glass, you can do that and still have the shower head in the middle of that glass wall. Just bring the plumbing up from the floor, or down from the ceiling, along the face of the glass. You can even have the exposed plumbing on the bathroom side of the glass wall, with it running through a hole in the glass so you can then mount the shower head inside the shower space. Do a search for "exposed shower plumbing" and you'll see some examples. You'll probably not see many on glass walls, that's not common. But when it makes sense to have exposed plumbing on a glass wall? Feel free to do it if it's your best option. Another alternative? I've only done this a few times, but since none of your walls work out very well for a shower head, in the past I've dropped the shower head supply pipe down vertically from the ceiling with the shower head at the end of the vertical drop. It allows a shower head in the middle of the shower space, away from the walls. I think your windows would see less water with the shower head on the front glass wall with the head pointing towards the windows than they would with the head between the windows, pointing away from the windows. Windows in a shower? Non-wood windows perform best. But if you're stuck with wood windows, a good proper prep and top coat can help with water resistance. I'll typically use a topical membrane on the shower walls and run the membrane from the wall right on to the window jamb, sealing the membrane to the window jamb with a flexible sealant. Then tile over the membrane. It's a unique space, good luck with your installation.