749 Vapor-Blok Water Based Elastomeric

749 Vapor-Blok Mastic is a premium quality water-based vapor-barrier coating which effectively prevents water vapor from passing through it. It is designed to prevent the intrusion of water vapor into thermal insulation when applied on surfaces which are colder than ambient temperature. It is compatible with virtually all types of thermal insulation and can also be applied to a variety of other types of substrates as needed. It is a safe, easy-to-apply water-based latex emulsion, but it achieves the type of low perm rating normally associated with solvent-based products.