MOISTURE PROBLEMS: FIVE CASE STUDIES High moisture levels and a wrong-side vapor barrier ruined this year-old home. Note the ice running down the logs. The plywood roof sheathing turned black from moisture. The source: a kitchen fan exhausted in the eaves. Firewood stored in the basement contributed to rotted sheathing and studs. Confused Over Vapor Barriers This New Hampshire house was a year old when I saw it. The main level was log cabin construction but the second-story wall was framed. From the inside out, the upper-story wall consisted of v-groove 1x6 pine boards, unfaced 6-inch fiberglass, 4- mil poly, and vertical T&G plank siding. There was water damage everywhere. Ice ran down the exterior of the logs (see photo, top right). The contractor was obviously confused about the vapor barrier, which he installed on the cold side of the wall, rather than