Owens Corning web site says to use duct tape to repair torn insulation facing. FWIW, after discussion here on NG, I wrote to them and received this reply:
builder tape. We manufacture the following product available at your local building supply.
BILD-R-TAPE (Construction Tape) is a multi-purpose construction tape assembled using an acrylic based, pressure-sensitive adhesive combined with polypropylene film. Bild-R-Tape provides superior sealing, and ease of handling which are the characteristics of a high quality construction tape. Bild-R-Tape exhibits superior bonding to a range building products over a broad temperature ranges. Bild-R-Tape is formulated to resist mildew and mold growth. It is also designed to maintain its adhesive properties under high humidity conditions to provide a long lasting seal or closure.
PRODUCT USES:
Owens Corning's Bild-R-Tape is designed and engineered primarily for seaming and sealing of joints in foam insulation and other sheathing materials, to secure lap edges in house wraps and vapor barriers, and to repair rips and tears in faced insulation, construction films and membranes."
Bob