Denny writes from Moundsville, West Virginia: "I live in West Virginia and we are using R-13 insulation in our wall with a face covering. Should I use a vapor barrier on top of this? How close should I staple the face paper and should it be stapled on the face of the 2 x 4 or on the inside edge?"

Answer: The Kraft paper on our R-13 Fiberglas™ insulation is an adequate residential vapor retarder. If you wish to install a different vapor retarder over it, we recommend the Kraft paper be slashed freely. It is acceptable to either face staple on inset staple the facing in an exterior wall.