Available nationwide since January, Zip System R-Sheathing consists of 1/2-inch (R-3) or 1-inch (R-6) polyisocyanurate foam bonded to the inside of Zip System enhanced OSB structural sheathing. The product has a built-in water-resistant barrier (the green facing) and a 180-day guarantee against moisture damage. When used with Zip System tape, it also serves as an air barrier. Cost ranges from $42 to $46 per sheet.
Huber Engineered Woods, 800/933-9220, zipsystem.com.