glass block window in tub shower?

[wkearney99]

We have a bathroom tub/shower with an exterior window. The old setup used a vinyl-clad aluminum double-hung window in a wood frame. Suffice to say the moisture was hell on the wood frame. In replacing it I'm considering using glass block. I'm thinking of installing it such that the interior tiles will form the casing. I'd like to use bull nose tile in from the wall into the window space. I'm planning on making sure there's a slope away from the windows to make sure water doesn't pool at where the glass and tile meet.

Any thoughts or issues I should consider when doing this?

What's the best way to install the block and the backer for the tiles? This is a brick-on-block wall about 10" deep with a slight gap between the brick facing and the block. I'll have to cover that with "something" and figured backer is the right material (properly anchored of course). How do I deal with the edge of the backer and tile where it meets the window blocks?

I'm figuring the grout for blocks will be about the same depth as the 1/2" backers but possibly not quite as deep as the combination of backer, grout and tile. Or should it be? Then there's the question of how to deal with the joint where the tile meets the block?

[Doug Aleshire]

wkearney99,

I have done many conversions from the traditional window to glass block of those with the tub/shower combo. Take a look - FLUSH with ceramic tile inside. This should help and I included the manufactures installation procedures. This should make it easy for you to install.

http://dougaphs.smugmug.com/gallery/229281

http://www.pittsburghcorning.com/includes/specs/mortar12.pdf

http://www.pittsburghcorning.com/includes/specs/kwiknez.pdf

http://www.pittsburghcorning.com/homeowners/ApplicationsDisplay.asp?cat=Bathroom

http://www.hy-lite.com/homeowner/products/

Hope this helps!

[wkearney99]

Nice pictures of what looks like nice work!

How about not installing them flush? How about installing them so that there's a shelf on the inside? I'm assuming that it'll have some degree of slope to prevent pooling while still allow it to hold shampoo bottles (but not soap, there's dush for that) . I'd expect to seal it as thoroughly as possible. Or is this just a tremendously bad idea that should not be tried at all?

Also, the thickness of the wall might be a problem. Given most block appears to be up to 4" thick they wouldn't extend far enough into the rough opening to effectively mate up with exterior brick facing. What then? Build inward with brick on the exterior?

[Doug Aleshire]

wkearney99,

Glad you liked the pictures but I hope it provided some insite to what you are proposing.

Shelf application is fine as long as it is a tapered shelf. Personally, if the existing window is of a large size in height, I avoid any shelf in this location and also that the shelf would not be very deep. One issue is we glass block and you have a brick exterior, you don't really have much of a shelf. Especially if you want to make the exterior look to be similar as the other windows. It would be better placing a shelf where there is less chance of water hitting it. My glass block installs within this area is where I want it to be easily cleanable - wipe down is easy - no edges to contend with. Shelf here can be a problem spot and I don't like call-backs. Maybe consider another location like the corner ceramic shelves on the showerhead end. Trying to do a shelf at the glass block location could and would be a problem. Any leak here is going to damage your walls and backer. I just think the odds are greater here, for a shelf install, to have problems.

On the exterior, it is best, since you have a brick exterior to consider filling the sides/bottom of the new window with brick or cast fillers. Provide a slope on the sill to avoid any problems with rain.

Another way is to use treated 1x stock on the top and sides - make the width of these to meet flush with your exterior brick or just short of flush. Apply aluminum flashing and apply tapered sill and apply flashing to this. You end up with a good looking exterior, no leaks. Use silicone caulk on the exterior.

Hope this helps!

[wkearney99]

I hear what you're saying about clean up and possible leak issues. I'd hope that proper installation and extra effort would help avoid leaks. As for cleaning, well, it's just another part of the shower area and shouldn't be any more or less of a hassle than anything else. Besides, there's a cleaning service in there every 2 weeks...

I'm also planning on 'framing' this area with marble, not just tiles. If not the all four sides then, for certain, just the inset ledge. With an inward slope back into the tub of course. Marble mainly to ease clean up, for one, but also to avoid extra seams.

I'm figuring on using as heavy a thickness of plastic sheeting as is possible behind the backer and leading straight down to the tile flange on the tub. As well as sealant on the surface where the backer is screwed to the studs studs. If (or should I say, when) water gets through any grout cracks or caulk it'll get routed down to the tub flange. I don't think there's much more that could be done to handle it, is there?

As for depth and outside appearance, the wall thickness here is 10.5" and probably another 3/4" to an inch from added backer, thinset and tiles. Using regular 3" block would still leave considerable room on either side. It's going to have to be recessed on one side or the other and doing it outside would make it look strange in comparison to the other windows. But considering it's already glass block it's *already* going to look different. But any added depth would be pushing it. Yes, I could go with the pressure treated and siding flange treatment as that's what the other double-hung windows already use. I'd prefer to avoid the added hassle/effort.

So what you're basically saying is that you'd avoid it first because of cleanup and second because of call-backs from leaks, right? Well, cleaning is cleaning (and I don't have to do it!) and I plan on being excessively picky about sealing it up. That and I'd have nobody to call (blame?) but myself.