Not a problem at all as long as the shower was planned for that with the walls and ceiling all waterproofed properly and the ceiling pitched correct for water runoff. While technically not a steam shower you are sealing the shower itself the same as if it were..................

Instruct your contractor to install mechanical ventilation and forget about it.

Ditto Joseph Corlett. The term "drywall" in this context makes me nervous. He should be saying green board. In an enclosed wet room with that shower and tub, I also would have tiled everything including the ceiling. That plus a vent solves any issues.

There is already a vent in the bathroom and it is right outside where the transom would be.

I know that tiling the top and sides of the surround would eliminate the potential issue but I don't think that is a look I want. I like the clean look in the photo. I'm afraid tiling that part of the shower, especially the ceiling, will cheapen the way it looks. It gives it a commercial feel. I could see tiling the inside of the surround in my bathroom's accent color, which is red but I wouldn't want to to tile the ceiling red. And I don't know that I want the walls of the shower to be one color tile, the sides of the surround to be a second color of tile and then the top of the shower to be a third color. Isn't that a bit much?

Pitching the ceiling here is definitely unnecessary. When using a steam shower having condensation dripping on you would be annoying. But while taking a shower you are being doused with water from above and would never notice condensation falling on you from the ceiling.

Why not add a vent outlet to the shower? Which vent are you using? If the Panasonic, they have an option similar to the Fantech where you can have multiple outlets that look like 4" recessed lights. If this option does not work for, then go with your current plan. If something happens with mold, just remediate it.

Personally, I like the whole shower tiled. I see this is many contemporary and modern homes. You can play a lot of tricks with tile, the ceiling could look painted depending on the sheen of the tile used. You could use colored large format glass tile. Take a look at Porcelanosa' catalogue if you have not already for some interesting ideas on how to use their tiles in different ways.

Good luck!

I think you are going to be sorry if you don't tile all the way up and including the ceiling. Even if you add exhaust inside the shower. Why don't you like the look? Maybe you can tile the section that would be drywall in a contrasting tile (white?) to get the same/similar look?

Same as what a couple of other posters wrote. I'd advise putting a fan vent in the shower ceiling and one in the bathroom ceiling. Air can be drawn through both grids by by a single remote fan motor, or you can have two independent fans.

As you isolate the shower space from the bathroom space, it becomes more important to add ventilation inside the shower space itself.

Is that plain drywall on the ceiling of the shower? If so, I wouldn't want that at all.

What you like is the look of the stark contrast? The line of white against the dark tile? Could you get the same concept by using white tile to form the band /on the ceiling?

It's not just the contrast of color I like. It's also the way the surround offsets the shower from the rest of the bathroom. And I like the contrast of the tile against the seamless white. Of course I can use white tile there but I'm afraid I won't like it as much.

In this photo there are walls on three sides of the surround. In my bathroom there will only be tile walls on two sides of the surround and glass on the other two sides. So the surround will look like it is suspended from the ceiling. I'm afraid having tile and grout lines will ruin the effect.

The vent has already been installed so moving it will be a pain. Plus, inside the shower is an LED downlight and a giant rain shower head taking up most of the overhead space. It's going to look awfully cluttered if I put a vent in there too.

There are companies that make an interior cement based plaster (stucco for the inside) that you can use to simulate the look of drywall without the concerns of drywall. I wouldn't install drywall or even greenboard in such an enclosed space personally, even with ventilation but that is me. I would waterproof it and stucco over it.

What about cement board instead of drywall or green board?

Re tile. Usually, people have too many colors and too many borders that don't coordinate well. Bathrooms tend to be chopped up and that makes things worse. I think 3 colors of tile is 1-2 too many. I'm planning a new shower with one tile on all 4 walls and an accent tile on the ceiling.

I think a red ceiling would be fabulous. But then everything else would be the same color. Just my 2 cents.

To quickly revisit this, I decided if I do this I will definitely use tile throughout and no transom. But a vent is practically impossible under the circumstances (please don't try to convince me of ways to make a vent work).

The question I now have is whether or not I am going to have excessive steam build up in the enclosed shower? As I mentioned, it is a large 6' x 4' shower and assume showers are no longer than ten minutes -- usually closer to five minutes. This is not intended to be a steam shower and I don't want to be wading through a fog of mist at the end of my shower. Is it going to be an issue?

Perhaps a stupid question but I've never had a shower that was enclosed from floor to ceiling so I have no idea how fast steam would build up under the circumstances. Thoughts?

"But a vent is practically impossible under the circumstances (please don't try to convince me of ways to make a vent work)."

I won't try to convince you of a thing, but you may find that big fat red tag from inspection quite convincing.

I've said multiple times in the thread that I already have a fan in the bathroom.

In fact I have TWO fans in the bathroom. Just not in the shower. My inspector loves me. Is that what the big fat red tag means?

Thank you! Very helpful!

It sounds like even with a transom I might regret doing this. If you've got a gap between the glass and ceiling and have steam build up I'm guessing it will be pretty bad for me if all I have is a transom which would be smaller than your gap.

I'd like more information about your layout. How high is your ceiling and how much space is there between the top of the glass and your ceiling? How many sides of the shower do you have a gap?

Where I currently reside the shower is 28" x 55" with a nine foot ceiling. The shower walls go up to the ceiling on three sides and on the fourth side where the glass is there is a three foot gap between the ceiling and glass.

I have no problems at all with steam build up here. Three feet is a lot of space for steam to escape but I'm wondering why it's so much worse for you when you have a larger shower?

Sorry to belabor this, but I just want to clarify because your post is a tad ambiguous.

"I have a 3' x 6' shower that doesn't have glass to the ceiling and IT gets pretty steamed up after only a minute or two"

What is "it"? Are you saying the shower gets steamed up or the glass gets steamed up?

I'm more concerned with steam building up in the shower to the point where the air gets foggy in the shower. Less concerned about the glass getting fogged up. The more I think about this the more I think you're talking about the glass because I can't imagine the air inside a shower that large getting that fogged up after a minute or two.

Let me try to help here. I have a 54" x 54" neo angle shower in the master. 2 walls are glass to the ceiling. Eight foot ceiling. The door is about 6-1/2 feet tall. It gets completely steamed up with a normal shower. you cannot see in. There is a vent in the ceiling directly in front of the door and it clears out much of the moisture within 15 minutes.

The ceiling is tiled.

However, there still is moisture left in the shower and we watch out for mildew starting on the sides of the bench and below the shower controls.

We are trying to tell you what will make things easier. If you pick the wrong tile and have a crappy tile setter then perhaps the shower will have a commercial look. Mine doesn't and I will never have mildew spots on the ceiling, nothing condensing up there nor will I have issues with the lighting in the shower.

I'm pushing out my powder room to put in a 4 x 6 roll in shower. The best tile in the scheme is the ceiling tile.

Thank you rococogurl but you seem to be responding to the initial post and not what I have said since. Thanks to the advice I got I decided to put tile everywhere in the shower I don't have glass.

The question I have now is how steamy it will get inside the shower? It doesn't sound like your shower gets steamy enough to bother you while using the shower. Correct? I don't care much if it gets too steamy to see in the shower from the outside.

I'm a little unclear about your mildew comment. Are you saying that you are getting some mildew in those two areas or you're just on the lookout for it in case it happens? After showering do you leave the door open to help clear out the moisture?

It gets steamy in the shower. And enough so you cannot see out. It doesn't bother me but it's substantial.

We often do leave the door open. But that would not be sufficient. We still need the vent to pull out all the moisture and that takes about 15 minutes until the glass clears, even after it's been squeegeed down.

Point about the vent is that it's surprising how long it takes for the shower to dry out. So I watch for mildew as I had it build up on caulk once. I have marble and a bleach pen isn't the best for stone.

Facing the same issue with the new expanded bath. I already have a Panasonic 115 cfm fan in the 6 x 6' powder room which works perfectly. Wasn't sure whether that would be sufficient or whether I needed a second vent near the shower entrance if we're only adding 7 feet to the room. So size is about 6 x 12-1/2 total. Discussed that with the contractor and he advised the second fan -- even though the venting through the garage roof would be quite involved.

Panasonic just came out with a new "Whisper Green" fan that has an on/off sensor plus other bells and whistles & supposed upgrades. Always tricky but not much new in that category. They offered me a chat with someone from the company and I plan to take it and ask them what's really required for extraction in wet locations. Will post when I find out

But right now, I'm planning 2 vents. My contractor is second generation and did our reno 13 years ago. He knows what he's talking about and I usually do what he recommends as he sees his various jobs over the years when he goes back to do more, just as he's coming back to us.

Glad you're tiling the shower ceiling. Smart. Was going to suggest a slab if the tile lines bother you. They can manufacturer any size these days -- I saw amazing onyx look slabs at the tile store the other day and she mentioned the custom sizing (though not anything I can use).

Thanks so much! This is very helpful to me!

I also have two fans in the master bathroom, one is fairly close to the shower door. I'll probably put a transom near the fan to help it suck moisture out but I'm not sure how effective it will be since the transom is a foot below the ceiling and the steam will rise above. Better than nothing I suppose.

I don't want to squeegee a 6x4 shower every day. Or ever really, unless the bathroom itself is being cleaned. You think it's a necessity with my shower design? I can live with water spots and streaks between regular cleanings.

As for the Panasonic fans, read some review and get some advice. Don't believe everything Panasonic claims. They have some fans with built in humidity sensors but based on the reviews I read the sensor does not work at all. I have all my bathroom fans on motion sensors so they turn on automatically and then turn themselves off. Since they are quiet I have nothing to lose by running them more frequently, better than the other option.

Yes - unless you get some of exhaust system to bring air in and out of the enclosed air.

Seriously - it is 'only a shower' so there wouldn't be much steam? ! Look at the bathroom mirror after the shower has been running and now claim that

BTW I doubt the contractor is using or said 'drywall' - that is the only word an uninformed homeowner knows as to what makes up walls.