Forming corners and end dams with conventional flashing materials is a complicated, labor-intensive process. This is one reason why corners are often the points at which flashing systems fail. One company has introduced preformed flashing corners and end dams designed to work with linear flashings. The corners and end dams reportedly save time and effort in installation and also improve performance. The preformed corner comes in a standard size to span one course of block. Depending on its installed position, it accommodates both inside and outside corners.