Unframed barrier walls that needed a Class A fire-rated material, which spray foam could adhere to, and that could span large areas without stretching. Project Solution: Fi-Foil’s FSK Shield™ has two facings - a low-emittance foil layer and a Kraft paper layer. When the foil layer is facing an airspace, it also helps reflect radiant heat. And FSK Shield™ is a Class A fire-rated insulation facing. It was the perfect solution barrier walls, manufac-tured in 54” width rolls, with a coverage of 1,000 square feet. It can be stapled to the nearest framing and spanned over large areas to define the barrier wall between the conditioned and unconditioned spaces (such as porches and garages). Furthermore, with the foil facing outward and the Kraft paper facing inward, the spray foam easily adheres to the Kraft paper surface. In this Cornerstone Custom Construction home, 31-W Insulation sprayed 5-1/2 inches of open cell (0.50 lb) foam to provide an R-value of approxi-mately R-19. 31-W Insulation in Orlando has been using this barrier wall hybrid insulation system for over a year.