An insulating member is disposed between the top of a wall and the underside of a roof to more effectively insulate the structure and prevent condensation fostering growth of mold and mildew occurring along the surfaces of the wall, ceiling and roof. A first surface of the insulating member overlies the top plate of the wall extending inward between the ceiling joists a distance of at least 1.5 feet. A second surface overlies the outside surface of the wall extending downward along the exterior of the wall a distance of at least 0.5 feet. A third surface is shaped to substantially conform to the opposing underside of the roof deck such that the space between the roof deck and the wall top plate is sealed off by the insulating member. Multiple air flow pathways extend through the insulating member providing continuous air flow from soffit area into the attic space.