EIFS is typically attached to the outside face of exterior walls with an adhesive (cementitious or acrylic based) or mechanical fasteners. Adhesives are commonly used to attach EIFS to gypsum board, cement board, or concrete substrates. EIFS is attached with mechanical fasteners (specially designed for this application) when installed over sheet-good weather barriers such as are commonly used over wood sheathings. The supporting wall surface should be continuous (not “open framing”) and flat.
The most common type of EIFS used today is the system that includes a drainage cavity, which allows any and all moisture to exit the wall. EIFS with drainage 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 that 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 that is applied on top of the insulation to serve as a weather barrier
• A finish coat that typically uses colorfast and crack-resistant acrylic co-polymer technology.