I need to repair a hole in an attached garage. When I looked in the hole there is yellow insulation but no vapour barrier. the other side of the garage is a bathroom that is very cold . Should there be insulation and then a vapour barrier and finally the drywall?
The vapor barrier goes on the heated side of the insulation, or in your case, the side facing the bathroom. If the garage itself is conditioned space, there may only be a vapor barrier on the exterior walls and the insulation behind the bathroom would be for sound. Note that the craft paper backing on insulation is considered a vapor barrier.