Johns Manville Formaldehyde-Free FSK-25 batts combine the thermal and acoustical performance of fiberglass insulation with a flame-resistant foil-scrim-kraft facing rated 25/50 (Flame Spread 25 or less / Smoke Developed 50 or less). Available in R-values up to R-30, FSK-25 batts are engineered for exposed commercial applications such as metal building roofs, mechanical rooms, and panel deck assemblies where a code-compliant flame-resistant facing is required.
The fiberglass core is bonded with a bio-based binder, is GREENGUARD Gold Certified, and will not off-gas formaldehyde. The FSK facing also functions as a vapor retarder. Extra-wide tabs on Panel Deck variants speed modular roof installation. Inorganic glass fibers resist rot, mildew, and deterioration over the life of the building.