BLOCKOUT DB DIMPLE BOARD is made from highdensity polyethylene (HDPE) with high compressive strength and resistance to chemicals and plant roots. Its dimpled structure creates an air gap between the wall and the surrounding soil. BLOCKOUT DB DIMPLE BOARD is used for draining the groundwater and protects the underground waterproofing systems from damage caused by soil pressure. It is used as a moisture barrier for concrete. It is placed directly on the soil to provide a clean base surface. It rapidly drains the water near the walls and redirects excess water to drainage channels, particularly in tunnel applications.