Specifically designed for commercial roofing applications involving mechanically attached EPDM, PB6HD is an excellent choice for re-roofing single-ply membranes. The board's install time and ease of use give you the necessary tools for a lower installed cost. And the extruded polystyrene (XPS) foam provides durability and high moisture resistance. PB6HD is available as 4′ x 50′ fanfold bundles.