An insulation product includes an elongated batt of fibrous insulation material having a first major face and a first installation end. A facing covers the first major face. The facing includes a mounting flange extending beyond the first installation end of the elongated batt of fibrous insulation material. A method of producing the insulation product includes the steps covering a major face of an elongated batt of fibrous insulation material with a facing and making a cut line through the elongated batt of fibrous insulation material so as to provide the elongated batt of fibrous insulation material with a first installation end and a removable discard strip adjacent the first installation end.