Flexo drain boards are a lightweight, high strength modular Flexo drain boards which is especially designed for sub-surface drainage and waterproofing membrane protection. Flexo drain boards are manufactured from high strength polypropylene. The Flexo drain boards also acts as a protection layer over waterproofing membranes, and also creates a thermal insulation barrier. The open surface design and high internal void volume enables the rapid capture and transport of high water volumes. The Cups designed in the Flexo drain boards can store little water also. The roots of plants and grass can take this water through Capillary action and will help in the growth of these plants.