Mad River Mass Timber (MRMT), based in Humboldt County, has become California’s first producer of dowel-laminated mass timber (DLT), using research developed at the UC Berkeley Wood Lab under the guidance of Assistant Professor Paul Mayencourt. This new venture aims to improve forest health, reduce wildfire risks, and help provide more affordable housing, while also advancing the goal of decarbonizing construction.
DLT panels are made from a range of wood species, including small-diameter or fire-damaged trees such as red fir, hemlock, and Ponderosa pine—wood that typically goes unused in traditional construction. These panels are constructed using wooden dowels instead of chemical adhesives, making them fully recyclable and helping sequester carbon for the lifespan of a building.
“It’s essential that we reimagine how we build,” said Mayencourt. He noted that mass timber is a renewable resource that can store carbon and reduce dependence on concrete and steel—materials linked to significant global greenhouse gas emissions. A recent study published in Building and Environment found that mass timber buildings could lower global warming potential by an estimated 39–51% compared to reinforced concrete buildings and 28–34% compared to those made with structural steel. Another study found the average embodied energy of mass timber buildings is 23% higher than reinforced concrete alternatives.
Previously, builders in California had to source mass timber from out-of-state suppliers in Washington or Canada. Transporting these materials over long distances increased their environmental footprint. MRMT’s local production now provides a lower-carbon option for California’s construction sector.
George Schmidbauer, MRMT President and fifth-generation sawmill operator, explained his motivation: “When I learned about mass timber in college, I knew it was something I wanted to pursue. The market was gaining momentum and there was increasing demand for locally sourced materials to address California’s wildfire and forest health issues.”
Schmidbauer discovered that traditional cross-laminated timber (CLT) production required significant investment and modification to local sawmills due to incompatibility with much of California’s lumber supply. After visiting UC Berkeley Wood Lab and seeing Mayencourt’s work with DLT fabrication on a smaller scale, he recognized its potential for efficient low-carbon construction without high costs.
The collaboration between academia and industry included weekly calls between Schmidbauer and Mayencourt as they worked together on scaling up DLT production. “Initially, I acted in a consulting capacity, working to help develop the DLT process,” said Mayencourt.
To achieve commercial-scale output, MRMT built its own DLT manufacturing equipment using standard components. The company now produces prefabricated floors, roofs, walls, and beams suitable for various types of construction projects.
Sourcing wood from national forests and tribal lands through forest health initiatives allows MRMT to remove biomass that would otherwise fuel wildfires—a process which can offset some costs associated with wildfire mitigation by turning waste into valuable products. “With DLT, we can put lower-value wood into panels and engineer around that species’ reduced structural capacity,” said Schmidbauer.
Mayencourt’s team is collaborating with Schmidbauer on prefabricated DLT kits designed for rapid assembly of affordable multifamily housing units—a move intended both to address housing needs across the state and support rural economies by creating jobs where the timber is harvested.
“The entire process is optimized for local economic and environmental benefit,” said Schmidbauer.
“Seeing MRMT scale up the manufacture of DLT is exciting,” added Mayencourt. “With one relatively low-tech innovation, we can tackle forest health, wildfire risk, the housing crisis, and struggling rural economies. We can start to fulfill our commitment to reduce greenhouse gas emissions for the future of our planet.”
