California has a wildfire problem and an affordable housing problem, and UC Berkeley Wood Lab co-director Paul Mayencourt hopes his work advancing an underused material can help address both. It's called mechanically laminated timber (MLT), a relatively inexpensive and accessible way of creating wood panels that's been more widely adopted in modern Europe than in the United States. In this short video, part of our ongoing video series Born at UC Berkeley, learn about the innovation from our host, Angela Zhang (class of '26).
Mayencourt, an assistant professor of cooperative extension at the College of Environmental Design and Rausser College of Natural Resources, teaches both students and local lumber business owners about engineering wood products. His efforts to expand awareness of MLT have been paying off: He recently partnered with a Humboldt County company, Mad River Mass Timber, and helped it become the first in the nation to commercially produce dowel-laminated timber, a type of MLT.
California's forests, Mayencourt said, have an overabundance of wood, and this overgrowth makes wildfires more severe. To reduce such fires, the California Wildfire and Forest Resilience Task Force has set a goal of "treating" - lowering wildfire risk through expanded forest thinning, prescribed burns and strategic replanting - 1.25 million acres per year, an area roughly the size of Delaware. But California's forestry industry has dwindled, so the state is short on infrastructure to process excess wood.
MLT can make use of salvaged wood and otherwise unusable small-diameter trees as well as sustainably harvested timber. Because the material is made without adhesives or heavy and expensive equipment, it can be produced at smaller scales and with startup costs as low as $1,000 for equipment. One type of MLT, nail-laminated timber, consists of stacked pieces of wood nailed together. Another, dowel-laminated timber, is easier to recycle because it's made entirely of wood. Dowels are placed in drilled holes, and the moisture of the surrounding wood causes the dowels to expand, holding the panel together.
Courtesy Paul Mayencourt
MLT is environmentally friendly in other ways, too. The production of concrete and steel, the materials that dominate commercial construction today, is responsible for 11%-15% of global greenhouse gas emissions. But a 2024 study found that buildings made of engineered wood lowered the structures' global warming potential by around 46% and 31% compared with those made of reinforced concrete and steel, respectively.
In recent years, California laws have evolved to allow buildings up to 18 stories to be constructed using MLT and similar wood materials, a change that could help local economies and the environment. Mayencourt and his collaborators have also designed affordable housing using MLT, including barracks for the same hotshot firefighter crews who combat wildfires.
Mayencourt regularly holds trainings to educate private individuals and businesses about MLT. At a visit to the Wood Lab, George Schmidbauer, the Mad River Mass Timber president and fifth-generation lumberman, spotted a panel of dowel-laminated timber leaning against a wall and asked about it. Mayencourt consulted on a process to produce the material at scale, using wood from California, and created a design guide for how to use the material in construction in accordance with the state's building code. In June, the company shared plans to hire 30 more employees for a new, larger facility. Mayencourt hopes this accessible construction innovation will continue to spread in California and beyond, advancing rural economies, forest health and a greener planet.
