Perm-A-Barrier Detail Membrane is ideal for protecting and sealing critical areas of the building superstructure from the damaging effects of the elements. Perm-A-Barrier Detail Membrane is part of the full Perm-A-Barrier system for commercial applications. By minimizing air and water vapor flow through the building exterior at transition areas, Perm-A-Barrier Detail Membrane seals transition and detail areas to provide a continuous air barrier and Prevents premature deterioration of the building envelope.