Design Considerations for Higher Performing EIFS.
Moisture performance of EIFS is misunderstood and it continues to be a subject of much consternation.   While the evolution from face-sealed barriers to drainage systems shows promise, acceptance by commercial markets has been slow and only marginally effective in delivering reliable results. Further confusion stems from insufficient design criteria for EIFS assemblies that incorporate cavity insulation with low-permeability interior vapor retarders. Energy mandates present even greater challenges for EIFS design, which must strike a balance between thermal performance and the often conflicting objectives for moisture control.
This presentation explores the tumultuous history of EIFS in context with prevailing perceptions of moisture performance.  Case studies are integrated with discussions on building code compliance, industry standards, and advanced research. An overview of failure tolerances for conventional EIFS assemblies will highlight important considerations for:  1) drainage design; 2) insulation thickness & placement; 3) use of interior vapor retarders; 4) air barrier continuity; and 5) building pressurization.
Presenter
M. Steven Doggett, Ph.D., LEED AP |  Principal Scientist |  Built Environments, Inc. | Phone: 651-439-9396 | Email: sdoggett@built-environments.com
Dr. Doggett is the Founder & CEO of Built Environments, Inc., an architectural & building science consulting firm located in Stillwater, Minnesota. He consults with architects, contractors, developers, building owners, and government agencies on building enclosure performance. Dr. Doggett’s expertise combines advance building modeling with extensive field and design experience to help multi-stakeholders achieve resilient, high-performing buildings. He has served as the principal investigator and senior project manager on hundreds of projects involving all markets and all building types. Dr. Doggett currently chairs the Minnesota chapter of the Building Enclosure Council.
Resources
- Open EIFS: A Resilient 100 Year Wall
- The Hygrothermal Performance of Exterior Wall Systems: Key Points of the Oak Ridge National Laboratory NET Facilities Research Project
- The Hygrothermal Performance of the NET Exterior Insulation Walls: Phase I
- The Hygrothermal Performance of the NET Exterior Insulation Walls: Phase II
- EIMA: Exterior Wall Cladding Performance Study
- NRC CNRC: Pressure Equalization in Rainscreen Wall Systems
- Commercial EIFS Design 101 (Minnesota Lath & Plaster Bureau)
- EIFS Best Practice Guide (Canada Mortgage and Housing Association)
- EIFS Standards