Hi. A friend recommended the following make up to acheive a 0.28 u value.
Rendered Blockwork, 100mm Dritherm 32, 100mm (0.16) for the inner leaf. He suggested Toplite but I can only see them in 3.6kn. Because of a lot of steel, I would like to use 7kn but I cant find a block with a matching (to...