US Patent 7543414 Drainage system for use in building construction

A flashing and drainage system for use in cavity wall construction, including a flashing member is sized and shaped to be received within a cavity of the wall and over a base member. The flashing member includes a lower flashing portion and an upper flashing portion. The system includes a water permeable body disposed on the flashing member including a plurality of weep tabs extending on the lower flashing portion and spaced apart to correspond to weep holes formed through the wall and a plurality of porous bodies positioned on the upper flashing portion. The water permeable body has a porosity sufficient to permit water to pass therethrough but substantially insufficient to permit mortar and debris to pass therethrough.