500/520 sheet drain is a prefabricated sheet drain consisting of a formed high impact, molded polystyrene core covered with a nonwoven polypropylene filter fabric. The filter fabric is bonded to each dimple and prevents soil particles from entering the flow channels while allowing water to freely enter the drainage core from one side. The collected water flows to designated exits. AMERDRAIN 500/520 is designed for sub-surface, single-side vertical applications requiring high-flow capacity and high compressive strength. AMERDRAIN 500/520 also functions as a protection course to waterproofing membranes. AMERDRAIN 520 provides additional protection for soft waterproofing membranes. The high-strength polymeric film is bonded to the flat side of the drainage core to prevent membrane intrusion into the back of the dimple.