You may have seen that I am building a 4.4 x 6.8 workshop. The walls, 2000mt high, will be 4 x 2 filled with 90 PIR & a noggin midway up between 600mm studs. The outside will be 11mm OSB, glued and screwed, and weatherboard. The Inside will probably be 9mm ply. The 45deg pitched roof will be...