Abstract: The objective of this project is to design, build, deploy, instrument, monitor and publicize a demonstration modular unit made from cross-laminated timber (CLT) using low-grade Ponderosa pine (PP). The demonstration unit will highlight the viability of large-volume production of modular units that can be used in low- and mid-rise structures.

Project Duration: 2019-2021

Research Team: Mariapaola Riggio and Lech Muszynski – Department of Wood Science and Engineering, College of Forestry, Oregon State University

Graduate Research Assistants: Sujit Bhandari, Sina Jahedi

International exchange student-collaborators and undergraduate interns: Benjamin Blengino, ESB, Nantes, France; Benjamin Strasser, SFH Salzburg/Kuchl, Austria; Zhixin Luo, University of Oregon, Department of Architecture.

Design Advisory Group: Katerra, Rothoblaas, Anderson Construction

Research Advisory Group: Rothoblaas, Vaagen Timbers, SMT Research, Oregon Forest Research Institute (OFRI), TDI

Facilities: A.A. "Red" Emmerson Advanced Wood Products Lab

Standards: National Design Specifications (NDS), International Building Code (IBC), ASCE 7



Restoration programs in Pacific NW generate a large volume of underutilized PP logs. If a substantial volume of these logs can be used in high-value product, such as CLT, the revenue might to some degree offset high costs associated with the restoration operations. This research builds upon a 2017 Wood Innovation project led by Dr. Muszynski and Dr. Riggio aimed at defining a custom lay-up of CLT from low-value PP that meets the standards (as defined by ANSI/APA PRG 320). This research is aimed at building a major demonstration project so that the public perception towards low-value PP logs could be changed.

Research Details:

The project has two major activities:

  1.    Modular Unit Design: Modular units with focus on easy assembly and disassembly to be designed using low-grade PP CLT. The structure is designed using innovative connection that is easy and quick to assemble and disassemble.
  2.    Modular Unit Demo: The designed unit will be demonstrated in two phases: a single module demo and a full-scale model serving as a “living lab”. Moisture content and moisture induced movement of the panels will be monitored during this phase.

Results + Resources:

Designs of modules assembled with innovative connectors are developed based on 8 foot (2.4 meters) and 12 foot (3.6 meters) wide panels. Based on preliminary numerical results, CLT made from low-grade Ponderosa pine has been found to be adequate for low-rise applications. These results will be presented at the Mass Timber Conference 2020, Forest Product Society International Conference 2020 and World Conference on Timber Engineering 2020.

Future Work:

Future works include:

-        Testing of innovative connector with PP CLT

-        Fabrication and construction of a single module

-        Fabrication and construction of a full-scale model