My basement has some glass block windows, that seem to be improperly (or not-optimally) installed. See picture….
As I understand it, there should has been a perimeter channel attached to framing, and the glass blocks installed into that. As it is, I get a little cold air radiating (possibly leaking from outside) out the top.
I was thinking of using spray foam to cover the top, but I'm not sure how that will affect the gaps between the blocks. I'd like to seal it as best I can, and then possibly use XPS + foam on top.
I wonder if I can cut up a perimeter channel and use some caulk to glue/seal it to the top? I'd have to do it in several pieces (one strip between each set of joists).
Edit – In case it matters, here is the larger view; I might do something a little different where that cold air return duct is.
Best Answer
Buy some anchors and attach them a good few inches up on each side, and across the blocks. Throw some mortar or a generous amount of glass block adhesive on top of the anchor (you can also screw it into the joists). Throw a 2x4 firmly on top of mortar so your gap is equivalent to your other gaps. Then secure the 2x4 (might even think about 2x6 for this installation) to the joists with a few screws on each side. Caulk any corners or gaps.
This will finish your install and keep the air leak issues. As it stands your blocks are kind of dangerous right now. That middle one isn't secured and when these things fall and break... they explode and shards could be in person they explode on. The anchor and top plate will fix this issue and help fix your air issue too. (If you still notice any drafting after caulking I suggest smashing some roxul into the area.