Moisture Management of EIFS Walls— Part 2: Classification of EIFS Systems

When durability of EIFS-clad houses located in some coastal ar eas with high moisture exposure was questioned, the EIFS industry introduced new solutions. Most of the newly developed EIFS products are based on the prem ise that a weather resistant, continuous, exterior skin can be difficult to achieve, let alone maintain, during the service life of a building. These new systems have two identifiable features: (1) EIFS cladding and (2) a multifunctional second-line of de fense to contain and manage water that passed the cladding. Three subsystems and systems, namely, source drained (SD-EIFS), drained screen (DS-EIFS), and vented screen (VS-EIFS), rely on water drainage from the wall assembly. The fourth multifunctional EIFS is primarily based on the storage and drying capabilities of the wall assembly.

Another prerequisite of a functional wall assembly is the presence of an air barrier. Experience indicates that only the redundant wall system with multiple defense mechanisms presents the opportunity for a durable and low-maintenance building envelope.