I have removed some of the plaster on an external non cavity wall back to the brickwork. Had to do this to remove tiles that were cemented to the wall. Following a building control inspection I have been told that as I have removed over 50% of the plaster I need to insulate the wall to try to achieve a U-value of 0.28 W/m2K.
What thickness thermal board would be required to achieve such a value?
What thickness thermal board would be required to achieve such a value?