i wish i had the cash to do a better job i really do, but the house isnt even ours so i'm reluctant to spend anymore money on the garage than i need to. all i need to do is stop the condensation like i said before i can deal with myself being cold in there and if i have to stick a pet mat or something in the control box for the cnc when its done i can cope with that.

for me now that polystyrene seems to be the best option and going off the price i may even cut strips to go in the deepere parts of the roof before i stick on full sheets over the top, this will reduce the air gap up there and also provide 50mm insulation in places