Abstract: An insulation product includes an elongated batt of fibrous insulation material, and a facing adhered to a major surface of the batt. The facing is a coextruded polymer film of barrier and bonding (and preferably carrier) layers, with the bonding layer having a softening point lower than the softening point of the barrier layer. The bonding layer can include one or more of ethylene N-butyl acrylate, ethylene methyl acrylate, low density polyethylene and ethylene ethyl acrylate. When the facing has been heated to a temperature above the softening point of the bonding layer, but below the softening point of the barrier layer, the facing is adhered to the batt by the attachment of the bonding layer to the fibers in the batt due to the softening of the bonding layer. The heating can be either conduction heating or ultrasonic heating. For ultrasonic heating, the bonding layer is resonant at a different ultrasonic frequency than the barrier layer.