Learning to use glass block

In my quest to get the house a little more heat-efficient, this weekend I attacked the basement "window" by the stairs. When we bought the house, the opening in the foundation by the basement stairs where a window should have been was instead wide open, with a thin piece of foam insulation loosely tacked in place. It was very drafty and I'm sure let a few critters through. Shortly after we closed, I made a thicker, heavier baffle out of styrofoam, fiberglass insulation, and an entire roll of duct tape. It helped, but not much.

This weekend, spurred by the installation of the new front door and a $10 coupon for Lowe's, I finally fixed it up right. I decided to fill the opening with glass block, as it both insulates and will help illuminate the dim stairs.

The whole project actually went pretty smoothly, considering the space wasn't designed, modified, or modifiable for the job. I am lucky that the rough opening had previously been prepared for a window of some sort, so it had good wood all around and was square. However, I only had 16 1/2 vertical inches to work with - and 8x8 blocks. Once I installed the plastic channels all the way around, I dry-fit everything, and it was tight. Tight enough that to get the last pair of 8x8 blocks in, I had to remove one side of the lower channel to slide the block in.

Once the blocks were in, I was left with a roughly 2 inch gap on one end. I stuffed some 2" styrofoam insulation in and sealed around it. It's not the greatest solution to the situation, but it'll keep things draft-free through the winter.

Overall, I'm pretty happy with how the project turned out. The basement stairs definitely have more light, the opening is now sealed against bugs, mice & other small intruders, there's no draft that I can find (and if I did miss anything, I can just re-caulk), and it looks better from the outside to boot. When not used in a "structural" capacity, glass block turns out to be extremely easy to work with, requiring no mortar or other masonry tools; just the channels, spacers and silicone caulk/adhesive. They just look intimidating due to the size & some of the "special" materials. I'm looking forward to doing a future project with them.

Pictures