Mad River Mass Timber (MRMT) has become California’s first producer of dowel-laminated timber (DLT), using research from the UC Berkeley Wood Lab led by Assistant Professor Paul Mayencourt. This development marks a shift in how California sources and manufactures mass timber, with potential benefits for forest management, wildfire risk reduction, and affordable housing.
The DLT panels produced by MRMT differ from traditional lumber as they can utilize a variety of wood species, including smaller or damaged trees like red fir, hemlock, and Ponderosa pine that are typically not used in construction. The process also repurposes fire-damaged timber, providing commercial value to materials previously considered waste.
Assistant Professor Paul Mayencourt said, “It’s essential that we reimagine how we build.” He noted that mass timber is a renewable resource that stores carbon within building structures, helping to lower atmospheric carbon levels over time. DLT uses wooden dowels instead of chemical adhesives, making it recyclable.
Until recently, builders in California relied on mass timber imported from other states or Canada. This practice added transportation emissions that reduced the environmental benefits of mass timber construction. By sourcing and producing DLT locally, MRMT aims to support California’s transition to low-carbon building methods.
A study published in Building and Environment reported that buildings made with mass timber have an estimated 39–51% lower global warming potential compared to reinforced concrete buildings and 28–34% lower than those built with structural steel. However, another study found that the average embodied energy of mass timber buildings is 23% higher than concrete alternatives.
George Schmidbauer, president of MRMT and a fifth-generation sawmill operator, explained his motivation: “The market was gaining momentum and there was increasing demand for locally sourced materials to address California’s wildfire and forest health issues.” He also highlighted the economic barriers posed by traditional cross-laminated timber (CLT) production facilities. After consulting with Mayencourt at UC Berkeley Wood Lab about small-scale DLT fabrication experiments, Schmidbauer identified DLT as the most viable solution for efficient production using local resources.
With support from the Joint Institute for Wood Products Innovation grant and collaboration between academia and industry experts like Mayencourt and research associate Jitske Swagemakers, MRMT designed its own DLT manufacturing equipment. The company now produces prefabricated floors, roofs, walls, and beams for various types of construction projects.
Sourcing wood for DLT panels involves removing biomass from forests through restoration projects on national forests and tribal lands. This helps reduce wildfire fuel loads while turning forest management into an economically sustainable activity. Schmidbauer stated: “With DLT, we can put lower-value wood into panels and engineer around that species’ reduced structural capacity. This means we can connect forest restoration and wildfire mitigation to the low-carbon construction economy in more ways than previously possible.”
MRMT is also developing prefabricated DLT kits aimed at accelerating affordable multifamily housing construction—a collaboration drawing on Schmidbauer’s experience in housing development and Mayencourt’s architectural expertise. As these projects expand, MRMT expects to create jobs in Humboldt County where the raw material is harvested and processed.
Schmidbauer commented: “The entire process is optimized for local economic and environmental benefit.” Mayencourt added: “Seeing MRMT scale up the manufacture of DLT is exciting… 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.”
