Dry Wall. Cosella-Dörken’s three-ply Delta Footing Barrier keeps groundwater out of walls by providing a waterproof break between a building’s footing and its foundation. Tough fabric outer layers protect the impermeable plastic membrane during backfilling and bond tightly to the concrete. The product is sold in 82-foot rolls for $74. Cosella-Dörken Products, 888/433-5824. cosella-dorken.com