I'm remodeling my bathroom, one wall of which is an exterior wall. I took out all of the old drywall around the tub/shower to replace with cement board. On the exterior wall, the vapor barrier has a few small holes and cuts, and some moisture has obviously intruded to some of the fiberglass insulation behind it. The water intrusion has been pretty minor but I was wondering if I should replace the entire vapor barrier or if I can just use house wrap tape to patch up the holes. If I do replace the entire vapor barrier on that wall, how to I properly secure the barrier behind the heavy cast iron tub that sits up against that wall?