Understanding Rain Screen Wall Systems
Understanding Rainscreen Wall Systems was created to clarify the key principles and background information for Drained/Back Ventilated or Pressure Equalized Rainscreen wall systems. This should also act as a resource for the General Contractor, Code Official or Building Owner to explain how the design properties of these two systems accomplish water infiltration management and control.
Both systems use some amount of open joinery and generally allow a limited amount of water into the rainscreen cavity area between the cladding and the air/water barrier. Drained/Back Ventilated (D/BV) systems rely on the rainscreen cavity to both drain and dry-out any residual water.
Pressure Equalized Rainscreen systems (PER) also employ a rainscreen cavity, but add compartmentalization to minimize water penetration in areas such as building corners where wind pressures can increase significantly.