Infiltration of All-Wood Façade Construction Techniques

Exploring the Future of Sustainable Building with Mass Timber Technologies

In the quest for more sustainable urban development, mass timber construction has emerged as a vital innovation, offering the potential to dramatically reduce carbon emissions in the built environment. Recent advancements in North America have highlighted the effectiveness of mass timber in creating taller, more fire-resistant buildings that address both environmental concerns and market needs. However, the journey towards greener construction doesn’t stop at structural design.

At the University of Oregon’s Energy Studies in Buildings Lab, our researchers are pioneering the next frontier in mass timber applications—focusing on building envelopes that encompass a significant portion of construction materials. Unlike the extensive research conducted on mass timber structures over the past decades, the performance of Cross-Laminated Timber (CLT) and Mass Plywood Panels (MPP) in building envelopes remains less explored. This gap in knowledge suggests a tremendous opportunity to optimize these systems for better environmental performance and aesthetic integration.

Field Study Insights from Portland, Oregon

A recent field study conducted on an all-wood mass timber building in Portland utilized advanced techniques like calibrated blower door tests and infrared imaging to identify infiltration pathways at the joints of exterior wall CLT panels. While the panels showed expected resistance to infiltration, the connections between them revealed preliminary inconsistencies that could not be fully analyzed due to the limitations of field testing.

Research Directions for Enhanced Building Performance

To address these challenges, our lab has identified key research questions that could lead to significant improvements in mass timber building envelope performance:

1. Can simple adjustments to the assembly of these systems enhance airtightness?
2. How does the natural air pathway behavior in CLT compare to that in MPP?
3. Does post-milling dimensional change affect joint tolerance and infiltration?
4. What roles do weather-resistive barriers (WRB) and joint sealants play in controlling infiltration?
5. Which joint profiles (butt, lap, spline) offer superior performance?

By exploring these questions through controlled lab testing, we aim to refine the design of mass timber envelopes, ensuring they are not only structurally sound and fire-resistant but also optimized for energy efficiency and visual appeal. This research is crucial as we move towards a future where mid-rise buildings made from mass timber could significantly decrease embodied carbon emissions, aligning with global decarbonization goals.

Join Us in Redefining Urban Architecture

As cities around the world strive to decarbonize the built environment, the role of innovative construction technologies like mass timber becomes increasingly important. Through collaborative research and development, we are not only addressing the technical challenges of today but also paving the way for the resilient, sustainable, and aesthetically pleasing cities of tomorrow.