Foster product Sealfas Coating provides a protective finish for insulation on air conditioning ducts and cold water piping when applied in 2 coats with reinforcing fabric embedded between coats. When relative humidity exceeds 75% for continuous periods, or where the insulated piping or equipment contains chilled water, brine or refrigerant, additional vapour barrier protection is suggested. Sealfas Coating is compatible with polystyrene and polyurethane foam insulations. It may be applied to the joints or edges of fibrous duct liner insulations to seal and prevent air erosion.