We put in rock wool insulation, which is unfaced. We put over it the kraft/asphalt vapor retarder that is for it (stapled it to studs overlapping edges). The debate is to tape the seams or not.
My way of thinking is that the open seams make the vapor retarder pointless if there are large stretches of areas allowing vapor to pass through quickly, hence I vote tape the seams with something like Tyvec tape.
But the husband says that once the sheetrock goes up and slightly presses on the kraft face, it will help seal off the seams, and the little bit that may remain ‘open’ will only help the vapor dispel that much faster.
Anyone have some insight into this?