Abstract: An apparatus and method is disclosed for preventing the damage by the rotting of concrete floor decks wooden components commonly used in multi-story buildings and the like and for preventing accumulation of the water and moisture over and beneath the concrete surface. The apparatus includes an anchoring flange; a cavity portion perpendicularly connected to the anchoring flange including in the base thereof at least one perforation suitable for water drainage and a leg portion, extending downwardly from the intersection of the cavity portion and the anchoring flange, for placement against the external side of the building structure that protects the building structure.