Glass Block Window Install
 

Greetings....long time lurker, first time poster.

We're re-orienting a bathroom, and part of that is moving the tub against an exterior wall. There's currently an awning window (36" x 21"), but we're going to remove it and put in glass block (32" x 16") so we still have some natural light source (can't do a skylight/tube). I've searched quite a bit for different install suggestions, specifically when it comes to waterproofing around the frame, and based on all my searching, here's what I'm thinking so far:

-Once the window is removed, use 2x4 to reduce the size of the rough opening.
-Install Hardibacker on the walls and in the opening
-Mud and tape joints, then Redguard
-Install tracks/rails for the glass block, then of course put in the block
-Generously seal with Silicone

We're doing a tile surround that will at least go up to the height of the window...bullnose when we get to the edge of the glass block.

So my question...am I on the right track? What am I forgetting?

Welcome to the forum.

Have you considered a acrylic block window? http://www.hy-lite.com/homeowners/

we have considered those, but we can get a thicker window (that almost matches the depth of the frame) using single block construction. Then there's no sill to deal with. Also, the cost is a bit lower and hopefully it's a bit more insulated.

Your plan will work fine. Be sure to use "glass block mortar" for the install, nothing else. Except if it is the kit thing then 100% silicone is used but it can make a helluva mess of things.:) It will take three or four coats of Redgard to accomplish the waterproofing. My last one I used KERDI Mat for the waterproofing but I have it on hand all the time.

I would set the blocks flush with the wallboard surface so that the window/glass block can be trimmed with bullnose tiles all around thereby framing the window and giving it a finished look at the same time. The outside can be fitted any way it will work but should have a flashing tucked slightly under the glass block. The interior fit is the important one. Once the tile is installed and grouted the bullnose can be caulked to the block using acrylic or siliconized caulk and finished perfectly with a wet sponge. I would never use 100% silicone.