I have tried to get hold of "siporex" or equivalent boards in 75 mm thickness to cover a wall behind the fireplace, if I use minerit, the chimney sweep says I must have several boards with an air gap between them. Therefore, the "light concrete" seems convenient.
I have called around in Gothenburg but no one seems to have them in their catalog even :S
Where can I find them?
Best regards, Torbjörn