Has anyone ever used foil based roof insulation. The stuff I have been given is a bit like bubble wrap with a bit of foam and some foil around it (airflex). I know I'm supposed to leave an air gap between the roof and the insulation and also between the insulation and the plasterboard to minimise condensation but will it be enough on its own? Where I live, winters can be -15. Should I be using it in conjunction with rockwool or anything?:confused: :confused: :confused: