A rainscreen design is where a water-resistive barrier (WRB) is installed inboard of the cladding (WSS) as a secondary barrier to prevent water ingress, and a drainage gap is installed between the cladding and WRB to allow drainage of water which penetrates past the cladding and to increase the outward drying ability of the assembly. The use of a rainscreen design can greatly increases an assembly's durability.

This approach is recommended for all wall assemblies, even in locations where not required by code.