Exterior Insulation and Finish System (EIFS) is a type of exterior wall cladding system providing exterior walls with an insulated finished surface and waterproofing in an integrated composite material system. The cladding system or insulation board is either attached adhesively, mechanically or both to the substrate.
Although often called “synthetic stucco,” EIFS is not stucco. EIFS vendor, Dryvit, coined the term “Outsulation,” which is essentially combining both continuous insulation (ci) and design-flexible aesthetics into a single exterior wall system.
The EIMA, EIFS Industry Member Association, states EIFS typically consists of the following components:
- An optional water-resistive barrier (WRB) that covers the substrate
- A drainage plane between the WRB and the insulation board is most commonly achieved with vertical ribbons of adhesive applied over the WRB
- Insulation board typically made of expanded polystyrene (EPS) which is secured with an adhesive or mechanically to the substrate
- Glass-fiber reinforcing mesh embedded in the base coat
- A water-resistant base coat applied on top of insulation to serve as a weather barrier
- A finish coat typically uses colorfast and crack-resistant acrylic co-polymer technology
