Foster® 95-90™ (light consistency) Vapor-Safe® Mastic is a fire resistive, fibrated, water-based, vapor barrier sealant for indoor or outdoor low, medium and high velocity heating and air conditioning ducts. It performs as a tough and flexible adhesive and sealant, forming a durable seal against air leakage when used with reinforcing membrane. Mechanical fasteners of the type and number normally used for duct assemblies are required to provide rigidity to the duct system.

Foster® 95-96™ Vapor-Safe® Mastic is a fire resistive, fibrated, water-based, vapor retardant sealant for indoor or outdoor low, medium and high velocity heating and air conditioning ducts. It performs as a tough and flexible adhesive and sealant, forming a durable seal against air leakage when used with reinforcing membrane. Mechanical fasteners of the type and number normally used for duct assemblies are required to provide rigidity to the duct system.