Insulating back of attic-exposed shower
To All, much to our dismay the unseasonably cold weather in TN exposed a weakness in an upstairs bathroom. We came home one night to a rain storm in the kitchen. Turns out the back of the fiberglass shower in the bathroom is completely exposed to the attic. The cold air simply followed the open space under the shower and froze the cold supply pipe. The pipe has been fixed, we're getting estimates to remodel the kitchen but I still need to fix the root cause. I try to be as much of a DIYer as possible. I was think about blocking the cold air using spray polyurethane foam and closing off the back of the shower with a piece of exterior sheet insulation. I was quite surprised that a contractor would've left the shower exposed like that. Any comments/suggestions about my forward?
Thanks in advance, Curtis