Delta-MS is a waterproofing treatment that keeps basements dry using air-gap technology. The HDPE membrane has distinctive dimples that function as air pockets, allowing the concrete walls to breath, and allowing any water that may enter to flow freely to the drain tile. Unaffected by freeze/thaw cycles, it is nonpolluting and impervious to soil bacteria or mineralization, and functions even when cut or torn. Cosella Dorken Products Inc. 905-563-3255.