What are EIFS?

EIFS is an acronym for Exterior Insulation and Finishing Systems. According to the International Building and Residential Codes (IBC/IRC), and ASTM International:

​EIFS are a non-load-bearing exterior wall cladding system that consists of an insulation board attached adhesively or mechanically, or both, to the substrate; an integrally reinforced base coat; and a textured protective finish coat. 

​EIFS with Drainage are modern EIFS systems that incorporate an air/water-resistive barrier and a method to collect and redirect incidental moisture that bypasses the outermost surface. 

EIFS with Drainage typically consist of the following components and materials:

1. An air/water-resistive barrier (AWRB) applied over the substrate
2. A drainage plane between the AWRB and the insulation board
3. Continuous Insulation (CI) board
4. Glass fiber reinforcing mesh embedded in the base coat
5. A finish that is applied over the reinforced base coat and provides the final appearance​

• ​EIFS with Drainage provide architects with a great deal of design flexibility to achieve an energy-efficient building envelope that resists both air and moisture infiltration as well as protection against wind, rain and impact, in extreme weather events.
• EIFS with Drainage offer easy detailing and greater Continuous Insulation (CI) thickness, which is often impractical with other wall claddings.
• With EIFS with Drainage, the CI is located on the building exterior rather than in interior spaces, which provides generally a simpler and more efficient means to install and achieve CI. EIFS with Drainage are the predominant EIFS system in use today.

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Achieving a High-Performance Building Enclosure

​As the focus of building design and construction progressively shifts toward sustainability and energy efficiency, architects, codes and standards, and building product manufacturers are placing more importance on the building enclosure’s performance. The building enclosure is comprised of many individual building components that function together to control temperature, humidity, airflow, and moisture, resulting in a more comfortable building for occupants. High-performance enclosures can also withstand the forces of extreme weather events, making buildings more resilient. In addition, they lower operating costs because they are more energy efficient, and reduce life cycle costs by being more durable and requiring lower maintenance. A high-performance building enclosure, such as one clad with EIFS with Drainage, provides protection against the elements and is a means to protect the health and well-being of occupants.

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The Importance of Continuous Insulation (CI) and the Thermal Bridging Envelope

The performance of the thermal envelope depends on insulation materials and R-values; how insulation effectiveness can be affected by thermal bridging; thermal properties of the roof, walls, windows and doors; and the airtightness of the enclosure, among other factors. 
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​According to the International Energy Conservation Code (IECC) and ASHRAE 90.1, CI is insulation that is continuous across all structural members without thermal bridges other than fasteners and service openings. Under some conditions and compliance paths in the IECC and ASHRAE 90.1, CI is required for above grade exterior walls. CI, such as what is used in EIFS with Drainage systems, provides the highest levels of thermal efficiency in above-grade exterior walls because, unlike typical insulation installed between structural wall framing members, it provides uninterrupted thermal insulation.