I will replace the window in the garage that is broken, small, and ugly, with glass blocks that will hopefully fit well in the opening. The wall is made of lightweight concrete/hollow concrete, and I am considering whether I could build two layers with glass blocks (provided the material is sufficient), in this way I could make it "align" nicely with the wall on both sides, and reasonably better insulation.
Are there any drawbacks to doing it as I planned?
Are there any drawbacks to doing it as I planned?
Some glass blocks, however, do not withstand our cold winters. All manufacturers I have seen write in fine print that they should not be used as exterior windows in our Nordic climate. Then again, it could be that they just want to disclaim responsibility in case they crack and that they may withstand more than they promise.
But I would definitely have tested your idea.
But I would definitely have tested your idea.
These glass blocks are supposed to be "frost-proof" and I have used them elsewhere in the house without any issues.
It was mostly a question of whether double layers could cause any problems. Read somewhere about the risk of condensation, but I find it hard to see how moisture would find its way in but not out.
It was mostly a question of whether double layers could cause any problems. Read somewhere about the risk of condensation, but I find it hard to see how moisture would find its way in but not out.
A PVC window probably costs less than the glass blocks, and has better energy performance. Halfway into the wall, it will be colder. I can imagine there might be a risk of condensation between the glass blocks. But with your wall construction, it should only be an aesthetic problem.
Interesting aspect.
I haven't even considered the cost since I bought these glass blocks very cheaply "second hand" and if it's enough for two layers, it's because I have some left over from another project.
I don't have an exact idea of how wide the air gap between the two intended layers could be, but could one imagine sealing "outward" with some kind of sealant (acrylic caulk/silicone/marine sealant) to make it "moisture-proof" between the layers? Or is the glass block mortar so "permeable" that it itself lets moisture through the joints? You can also glue the glass blocks, but I have no experience with that and I still have mortar left, so I would prefer to go that route.
Or is the problem likely of such a minor nature that it isn't worth putting a lot of effort into it?
I haven't even considered the cost since I bought these glass blocks very cheaply "second hand" and if it's enough for two layers, it's because I have some left over from another project.
I don't have an exact idea of how wide the air gap between the two intended layers could be, but could one imagine sealing "outward" with some kind of sealant (acrylic caulk/silicone/marine sealant) to make it "moisture-proof" between the layers? Or is the glass block mortar so "permeable" that it itself lets moisture through the joints? You can also glue the glass blocks, but I have no experience with that and I still have mortar left, so I would prefer to go that route.
Or is the problem likely of such a minor nature that it isn't worth putting a lot of effort into it?