For various reasons, there ended up being a gap of just over 3 cm between the newly cast slab in the extension and the old slab. My idea was to insulate the gap with insulating foam (or whatever it's called) to avoid a thermal bridge.
Do you think it's a good idea or is there some other better material to insulate with?
Do you think it's a good idea or is there some other better material to insulate with?