EIFS (Exterior Insulation & Finish System)
CSI Division 07, Thermal & Moisture Protection
An exterior wall cladding built up from rigid foam insulation board adhered or mechanically attached to the wall, then coated with a reinforced base coat and a textured finish coat, distinct from stucco since EIFS's insulation and finish are a manufactured system rather than a traditional plaster assembly.
Why it matters
Early "barrier" EIFS systems had no drainage plane and trapped any water that got behind the cladding, a problem that caused widespread moisture damage and lawsuits in the 1990s, which is why current EIFS installations require a "drainage" EIFS design with a water-resistive barrier and drainage channel behind the insulation, not the older barrier approach.
On a real project
A contractor installs a drainage EIFS system over a water-resistive barrier with a continuous drainage plane behind the insulation board, so any water that gets past the finish coat drains down and out at the base rather than becoming trapped against the sheathing.
Who this matters most to
A specialty EIFS subcontractor installs the system. A QA/QC Inspector verifies the water-resistive barrier and drainage plane are properly installed before the insulation board covers them.
Where this goes wrong
An installer applies an EIFS system without confirming the required drainage plane is continuous behind the insulation board, leaving a section where the insulation is adhered directly to the sheathing with no drainage path. The trapped moisture isn't discovered until a tenant reports a persistent musty smell near that section of wall years later, and an invasive moisture probe finally traces it back to the missing drainage path, exposing sheathing damage no one suspected from the exterior.