EIFs

EIFS, or Exterior Insulation and Finish System, is a non-structural exterior wall cladding used on many building facades. It combines thermal insulation with a decorative and protective finish. A typical EIFS assembly includes a weather-resistive barrier attached to the structural substrate, rigid insulation boards, a base coat reinforced with fiberglass mesh, and a polymer-based finish coat. Some systems add a drainage plane or cavity to aid moisture management, and joints and penetrations are sealed with compatible sealants or tapes.

There are two common forms: traditional EIFS (often called thin-coat EIFS) and EIFS with drainage (drainage EIFS). Traditional EIFS relies primarily on the base coat and finish for weather protection, while drainage EIFS includes a designed path for moisture to escape behind the insulation.

Benefits include high thermal resistance, reduced wall thickness compared with masonry, lightweight construction, design versatility in texture and color, and the potential to integrate with air barriers for improved energy efficiency.

Drawbacks include vulnerability to moisture intrusion when detailing around openings and edges is poor, and ongoing maintenance and inspections. EIFS requires skilled installation and compatible substrates, and repairs may involve replacing finish coats or sections of insulation. In the past, moisture-related failures led to increased attention to flashing details and the development of drainage EIFS and updated installation standards.