What is Foil Scrim Kraft (FSK) Insulation?
Foil Scrim Kraft or FSK insulation is a flame retardant, vapor-barrier, and is one of the most commonly used facings in the insulation industry today. A FSK insulation facing is made of lightweight aluminum foil that is layered against a fiberglass scrim and then paired with a final layer of natural brown kraft paper. This is then all laminated together using a flame-retardant adhesive.
FSK insulation is most commonly utilized with duct wrap, duct board, and mechanical spin-glass boards on the outward-facing, exposed surfaces of HVAC ductwork, but is also used in batts for exterior walls, and ceilings.
What we did with this job
We installed R19 FSK batts insulation on all four exterior walls covering all of the exposed wood surfaces with foil material. We also installed R38 Fiberglass batts insulation in the ceiling that were covered with FSK paper, and taped the seams with an FSK tape totaling just shy of 8,000 square feet of material.