FOSTER VAPOR-SAFE MASTIC is a high solids water based, fire resistive, flexible vapor barrier finish for most types of thermal insulation, including polystyrene foam. Is non-flammable when wet and has a mild latex “paint type” odor. Is ideal for vapor sealing ASJ, FRK, and FSK jackets and board facings at joints, laps and over staple and weld pin punctures. Meets NFPA 90A and 90B 25/50 requirements.

VAPOR-SAFE MASTIC meets requirements for LEED IEQ 4.2 Low-Emitting Materials, Paints and Coatings. VOC: 36 g/l, less water and exempt solvents. Meets the requirements of Military Specification MIL-PRF-19565C, Type II and is listed on the QPD 19565.