I'm currently remodeling my home in Atlanta, GA. The house is 32 years old. I'm basically combining two bedrooms into one large master bedroom, master closet and master bathroom. I'm very confused about whether or not I need a vapor barrier on the exterior OR interior walls for the bathroom. I plan on building a 3 walled tiled shower that will not touch any exterior walls within the bathroom. The bathroom itself will have one exterior wall. My current exterior insulation is the fiberglass paper faced insulation batts between the studs, then some kind of black faced fiber board nailed to the studs, and lastly the exterior cedar siding. I've heard and seen so much about vapor barriers on TV shows such as yours and Holmes on Homes. I was a little confused on the issue after I read the IRC 2009 code requirements. Do I need vapor barriers at all on any of my walls whether exterior or interior for my bathroom, for my "location zone" within the U.S.? Do I need a vapor barrier for the bathroom ceiling which will of course include the shower ceiling (my attic is right above the bathroom ceiling)? Any advice and/or suggestions would be greatly appreciated on this confusing issue.