a drainage arrangement positioned on a rear face of an exterior insulation product the construction market utilizes a large number of exterior insulation products the preferred embodiment of the instant application is described in the context of composite siding by example only it is understood that the instant invention could be applied to any exterior insulation product having a planar surface the drainage arrangement as it is positioned on the otherwise flat rear face of a foam backer is generally referred to as a drainage plane the drainage plane is configured to encourage water from leaks and water from heavy condensation to run down grooves positioned therein the grooves can be of any of a wide variety of configurations and can be laid out in any of a wide variety of patterns the grooves can be positioned in a grid and can be positioned anywhere from vertically to some angle off the vertical the drainage plane of the present invention is particularly beneficial in those cases where a foam board is positioned flat against another component such as an osb panel that would naturally resist the water from freely running down the back of the osb panel with reference to the drawings wherein like items are numbered alike and.