I am building a small 6x8 cold room in the northeast corner of my basement. The two outside walls are concrete, the two inside walls are 2x6, insulated with R22 Roxul. The space above, on the main floor of the house, is the kitchen. I am putting R22 Roxul in the ceiling joists of the basement. My question is - should I put the 6 mil vapour barrier in the joists first, then insulate, or should I insulate and then put the vapour barrier. In other words, which side of the insulation does the vapour barrier go?