Poor flashing design is the most prominent factor in up to three quarters of all roof failures.
The flashing element is the most vulnerable part of any roof system because it is the point at which the horizontal roof deck and vertical surface join. It is also an intersection of two different materials, such as parapet walls. In addition, flashings are vulnerable because they are applied around all roof penetrations such as skylights, HVAC units, vents, expansion joints and other areas where the membrane is interrupted or terminated.