The solution to pre-mature building envelope failure has been the rain-screen wall assembly. Fundamental to this assembly is a combination of materials and strategies that provide the “4-D’s”: deflection, drainage, drying, and durability. The exterior skin of a building wall cannot withstand fully 100% of the moisture load imposed by the external environment at all times. As such, attention to deflection is the primary wall strategy using a combination of claddings, flashing, and battens (overlapping materials) to manage as much of the moisture load as possible. Sealant joints that require maintenance and installation perfection such as caulking are avoided for all but cosmetic purposes or details that just cannot be accomplished any other way. Added to this primary wall strategy is creating a cavity behind the wall that provides a back-up or redundant layer that can handle any incidental moisture that is driven through the cladding. This cavity if, compartmentalized correctly, becomes a pressure equalized drainage plane. A cavity where moisture without external wind forces allows incidental moisture to drain behind the cladding and out of the wall at designed drainage flashing. It is also a cavity that also allows for venting/drying to remove water vapour. Finally, all components within this cavity are designed for durability to provide very long term performance unaffected by incidental moisture. Correctly assembled the building structure will never encounter moisture from the external environment.
Nu-Tech has been an industry leader in adopting modern rain-screen technology and has been successfully constructing durable rain-screen walls in the Vancouver area since 1995.