Abstract: A composite panel, has: an insulating subpanel having a bottom face to be secured to a substrate and a top face opposed to the bottom face, the top face and the bottom face delimited by interconnected edges of the insulating subpanel; a polymer membrane adhered to a portion of the top face, the polymer membrane including a flap, the flap extending from a membrane edge of the membrane to a junction between the flap and a remainder of the polymer membrane, the junction being recessed inwardly from an edge of the interconnected edges of the insulating subpanel such that a portion of the top face of the insulating subpanel is free from attachment to the polymer membrane, a length of the flap extending from the membrane edge to the junction being greater than a distance between the edge of the interconnected edges and the junction.

Abstract: A building panel comprising a fiberboard panel providing the structural integrity of the building panel. An insulation layer is laminated to the fiberboard panel, the insulation layer providing a required thermal value to the building panel. A functional layer forms an air barrier, a water barrier and/or a vapor barrier of the building panel. The functional layer is secured to the fiberboard panel on the opposite side of the insulation layer.