Infiltration of All-Wood Façade Construction Techniques
Research Team:
Mark Fretz
Dale Northcutt
Jason Stenson
Davis Whalen
Project Duration:
2024-2026
2024-2026
Facilities:
Emmerson Lab
Emmerson Lab
Introduction/Background
Significant research has investigated how wood products, and mass timber in particular, can be used in large structures. Recent work has also suggested that there are significant carbon advantages in doing so, from both an operational and embodied carbon perspective (the researchers highlight Mishra, et al. (2022)). In support of this evidence, this study is part of an ongoing exploration of how to use mass timber products in additional building applications, such as in innovative enclosure designs.
Research Methods
A custom air pressurization chamber was built in the Emmerson Lab to host an 8’x8’ mass timber wall sample that included one of three different joint geometries with a combination of sealant, no sealant, air and water resistive barrier. Samples were pressurized and air infiltration for the joint type was quantified and compared across configurations.
Key Findings
Overall, the main takeaway from these tests was that air infiltration rates were very low for all tested samples. MPP samples performed generally better than CLT samples, and sealed joints performed better than unsealed ones. However, all the tested conditions displayed levels of air leakage far below stringent building airtightness requirements such as the Passive House Standard.
Future Work
The results of this work have informed the enclosure design of the MPP house prototype and the next phase of work will be to conduct in-situ whole building air infiltration testing on the upcoming second MPP house prototype constructed outside of the Emmerson Lab.
Publications & Presentations (and/or Relevant Resources)
Journal article in development
Fretz, M. (2025, November 4). Infiltration of All-Wood Facade Construction Techniques. 2025 Mass Timber Research & Design Innovation Symposium, Corvallis, OR. https://www.youtube.com/watch?v=9IHjK9owyRU
Mass Timber Infiltration. (2025, February 18). Institute for Health in the Built Environment. https://buildhealth.uoregon.edu/projects/mass-timber-infiltration/
Funding Acknowledgements
Started with a WIG grant – performed infiltration testing on all wood building
TDI ARS
They also acknowledge Emmerson Lab staff, Logan Banks, Hillary Johnson, and Ellie Thacker