An insulation blanket includes a fibrous insulation layer and a facing material. The fibrous insulation layer has a first major surface and a second major surface and at least one longitudinal cut which extends from the first major surface to the second major surface and forms adjacent layer sections. Each layer section has at least one inner sidewall. At least a first inner sidewall of a first insulation layer section has applied thereto an adhesive for adhering together an adjacent second inner sidewall of a second adjacent layer section. The facing material has separation means which extends substantially along the at least one longitudinal cut. The facing material is disposed on the first major surface of the fibrous insulation layer.