By Mary James

Mass timber lies squarely in the midst of a solution set for multiple issues that California and other states across the country face: the need for housing supply that can be produced efficiently, the drive to lower the embodied carbon of construction materials, and better management of our forests to reduce the risk of wildfires. Indeed, a 2024 study comparing the global warming impacts of constructing 8-, 12-, and 18-story buildings with a variety of materials concluded that mass timber buildings resulted in an 81–94% lower global warming potential (GWP) than concrete buildings and a 76–91% lower GWP than steel buildings. A downside of mass timber is that it can be hard to source in the United States without paying a heavy price in transportation costs and the related carbon emissions.

Now, a California company, Mad River Mass Timber (MRMT), is changing the supply picture with the recent opening of its dowel-laminated timber (DLT) production facility. DLT is essentially dimensional lumber pressed together and secured in place by wooden dowels to form prefabricated floor, wall, and roof panels. The use of dowels eliminates the need for adhesives used in such other mass timber products as cross-laminated timber (CLT), enabling DLT panels to be fully recyclable.

Schmidbauer, who comes from four generations of forest harvesters and sawmill operators, had worked previously in affordable housing development in California. MRMT is a vertically integrated company; the lumber used as the source material for the DLT comes from North Fork Lumber Company, owned by the Schmidbauer Group. He sees mass timber production as a process with multiple co-benefits, including contributing to responsible forest management practices. According to Schmidbauer, California has thrown billions of dollars a year at forest treatments in order to mitigate wildfire risk. “Those forest management outcomes create more healthy forests and can create wildfire mitigation with certain treatment types,” he explains, adding, “The problem is those treatment types on their own are really expensive to do.”

DLT panels can be produced using 2x4 lumber from a large variety of timber species, so its production adds economic value to many forest management practices that involve harvesting small-diameter trees throughout diverse forest landscapes. While clearing out biomass is an important part of wildfire mitigation treatments, it rarely has enough market value to pay its way out of the forest to biomass utilization facilities, he notes. “But if you can pull the highest value out of the merchantable timber with products like DLT, that added value to the project helps subsidize the transportation of low-value biomass out of the forest as well,” he says.

Schmidbauer had considered producing CLT panels but soon realized that, in addition to requiring adhesives and much more expensive production equipment, it would not be the best match for California’s forest treatment objectives. “Most CLT isn’t made from truly small-diameter timber because you need a log big enough to pull 2x6 lumber from,” he points out. “That gets, I think, lost in all the nuances of the industry.” When compared to CLT production, DLT also opens the possibilities of using a greater variety of tree species because CLT’s adhesive bonding requirements favor single-species lumber whereas DLT does not.

After doing more research into the product, Schmidbauer realized DLT also offered several structural and architectural advantages over CLT. Its efficient fiber orientation allows it to span further than CLT panels in the primary direction.

RMI Senior Associate Auri Bukauskas notes that DLT panels are all oriented in a single direction, which is efficient where only one-way spans are needed. Meanwhile, CLT typically supports two-way spanning (plate action). DLT also has superior fire performance and the ability to integrate acoustic performance into the exposed surface of the mass timber panel through surface profiling.

Together, these characteristics provide significant value to mass timber projects, from both sustainable and financial standpoints.

“Each mass timber product has its place in the market, but I expect DLT’s market share to grow in the coming years as the AEC community learns more about its benefits,” Schmidbauer says.

MRMT’s first project is for a custom building in Washington state designed by Anderson Anderson Architecture, which was founded by brothers Mark and Peter Anderson and is currently based in San Francisco. The firm has extensive experience designing with prefabricated modular and panelized building systems, and they have long been advocates of mass timber construction. In addition to using CLT and now DLT, they have also used nail laminated timber.

Peter Anderson explains that part of the attraction to DLT was its novelty. While they wanted the opportunity to experiment with a new material, they also felt compelled to try DLT because it could further democratize timber. Anderson notes that there continue to be large financial barriers to entry associated with the manufacture and use of CLT. They were also attracted to DLT because it highlights the unique features of the wood, whereas CLT tends to be more uniform.

"Its appearance is expressive of the wood pieces it's made out of," Anderson says. It allows for a more rustic look, while celebrating the wood.

The Washington project defies easy categorization beyond one word: ambitious. Built on land owned by the Anderson family and 10,000 square feet, the building will include a workshop and office space for the firm, as well as two residential units. One of those units will be occupied by a family member, while the other will be a rental. Most notably, it will be constructed using DLT floor, wall, and roof systems.

“It's a really beautiful project,” enthuses Schmidbauer, “and as soon as the weather allows, we'll start putting the panels up on site and get some good pictures,” Schmidbauer says.

Although Schmidbauer is very excited about this project, his longer-term goal is to address California’s housing supply and forest health crises. Toward that end MRMT just released an RFP to assemble a multidisciplinary team to develop a prefabricated structural approach for multifamily housing that leverages locally sourced wood products. The firm is looking for teams that include an architect, structural engineer, and developer with an aligned pilot project.

“The goal isn’t a one-off concept. The goal is a deployable kit-of-parts and structural system that can be replicated across multiple sites and building types,” says Schmidbauer. The selected team is expected to use the funding to advance design development for a pilot project and validate cost, schedule, and permitting assumptions. For further information, reach out to MRMT at [email protected] with questions and a short summary of a proposed team and pilot project.