I have any number of these left over from the build. I'd like to stick them in my roof between the rafters.... but
I have a dreadful feeling Mr @JSHarris will say ' No you can't ' . I think we've had this conversation before but for the life of me I can't find it.
Wasn't it the small gaps between the blocks that'll prove too hard to seal off?
Please tell me I can use them. It's such a huge waste not to....