F
or centuries, people have sought ways to make wood and timber products resistant to fires and other threats.
In 1820, French scientist Joseph Gay-Lussac first developed a means to treat wood with borax and ammonium phosphates to make it resistant to fire. By 1898, wood treated with fire-retardants was written into New York City’s building code.
Over a century later, as our world experiences a growing number of extreme weather events and increasingly heightened risks of wildfires, the demand to mitigate these hazards and the damage they cause has risen as well.
CURRENT NEEDS
“The Lāhainā wildfires intensified an already growing demand for fire-resistant wood products,” says Brian Brokaw, a buyer for HPM Building Supply. “Fire-retardant-treated lumber has become increasingly popular as it combines wood’s versatility with enhanced safety features. We’re seeing greater adoption of treated wood, fiber cement siding and non-combustible cladding materials across both residential and commercial projects. This shift reflects both stricter building codes and heightened awareness of wildfire risks in vulnerable areas.”
HPM’s selection of fire-resistant materials includes lumber, as well as doors, drywall, sheathing and decking, says Brokaw. “These products provide varying levels of protection, from basic flame-spread resistance to high-temperature resistance, with some products like our fire-resistant doors rated to withstand flames for up to 90 minutes.”
HPM’s selection of fire-resistant materials includes lumber, as well as doors, drywall, sheathing and decking, says Brokaw. “These products provide varying levels of protection, from basic flame-spread resistance to high-temperature resistance, with some products like our fire-resistant doors rated to withstand flames for up to 90 minutes.”
But as is often the case with the most desirable products, there may be challenges in trying to acquire them for a project, including higher costs or limited availability, which may affect a project’s bottom line as well as the decision-making process.
“While standard building materials are generally more affordable and readily available, they lack these specialized fire-resistant properties,” says Brokaw.
Additionally, he says, many of HPM’s wood and timber offerings are sustainable, reflecting growing desires for environmentally responsible building products and practices. “The demand for sustainable wood products has grown significantly, driven by environmental awareness throughout the construction industry. Builders and developers increasingly prioritize materials with low carbon footprints,” a trend further motivated by green building certifications such as LEED and WELL.
“Our lumber comes from mills certified by the Sustainable Forest Initiative (SFI), which ensures responsible forest management practices,” adds Brokaw. “SFI certification requires organizations to protect water quality, wetlands and riparian zones while actively managing habitat and biodiversity impacts.”
A NOVEL OPTION
Mass timber is another wood product that, while hardly new, is new to Hawai‘i.
Architecture and engineering firm Hawaii Off Grid recently announced a partnership with the nonprofit WoodWorks-Wood Products Council to use mass timber in the construction of a home on Kaua‘i — Hawai‘i’s first residence built using mass timber products — as well as in the construction of several homes in Lāhainā.
Mass timber was developed in Austria in the 1990s and brought to North America in the 2000s, but has its origins in glue-laminated timber (glulam), which can be traced as far back as the early 1900s.
Modern mass timber products — such as cross-laminated timber — are growing in popularity because they are highly resistant to fire, are sustainable and allow for shorter construction times.
“Mass timber is a category of engineered wood products featuring large structural members made by laminating smaller wood pieces,” explains WoodWorks Regional Director Kate Carrigg. “Mass timber elements arrive onsite custom-cut and often pre-installed with hardware, reducing erection time and the need for skilled labor, enabling smaller crews to complete more projects efficiently.”
“The prefabricated aspect of [mass timber] is huge because the idea is that construction goes really quickly,” says Austin Pollard, Hawaii Off Grid project manager and lead designer. “So everything comes in packages that are kind of preorganized so that … they can be kind of assembled really quickly onsite, and they kind of come together like a kit of parts.
“So … the speed of construction is what we’re relying on here,” he says.
With an urgent need for homes in Lāhainā and elsewhere in Hawai‘i, wide adoption of mass timber may be a much-needed game-changer.
“We need lots of options in the toolbox because we’ve got 4,000 houses to build just in Lāhainā, 10,000 houses around Maui, and we usually build about 150 to 200 houses a year,” says Hawaii Off Grid Principal Architect David Sellers.
TESTED FOR RESILIENCY
While the need for rapid construction is top-of-mind for Hawai‘i overall, so is the desire for structures that can withstand wildfires. Mass timber’s design makes it highly resistant to fire, especially when compared to other wood products and frame systems.
“[Mass timber] is a lot more fire-resistant than typical stick frame just because of how dense it is. … It takes a lot longer to burn. It chars instead of burns through,” says Pollard. “[W]hen it chars, it kind of seals the wood and protects it. So that’s kind of how it got approved through the IBC as a fire-rated building material.”
Not only is mass timber fire-resistant, but Carrigg explains that mass timber has undergone strict testing requirements as required by the United States, being rated for its performance in everything from fires to high winds to earthquakes. The U.S. Department of Defense has even conducted successful testing of mass timber for use in blast-resistant construction.
“When designed and detailed appropriately, mass timber structures are capable of achieving high levels of resilience in many different applications and environments,” Carrigg says.
THE GREEN FACTOR
Additionally, mass timber, as a wood product, is by nature renewable, producing fewer greenhouse emissions than other traditionally used materials.
“Wood has many attributes that make it well-suited to sustainable design,” says Carrigg. “Wood products have low embodied carbon compared to other building materials, which indicates fewer greenhouse gas emissions, and they continue to store carbon absorbed by the trees while they are growing. Wood is also natural and renewable. It can contribute to energy efficiency and biophilic design, and is durable, adaptable and re-useable.”
“Sustainability is a big thing for [Hawaii Off Grid],” says Sellers. “So the ability to store more carbon in the building than we release when we construct the building is huge.”
Widespread adoption of mass timber products has been slow, and Hawaii Off Grid anticipates challenges as project teams adjust to how the product will affect a project’s workflow. Because mass timber is a prefabricated product, there will need to be more upfront coordination between the designer and prefabricator, who normally isn’t involved in the early stages of a project and will affect when and how the drawings are generated.
Aside from the logistical challenges, Hawai‘i has been slow to adopt mass timber due in large part to now-resolved questions about termite treatment.
“All structural material, wood material in Hawai‘i has to be treated with a high board treatment, a borate treatment for termites,” says Sellers. “… We’re used to treating, say, glulam beams, but we’ve never treated a 4-foot-wide by 40-foot-long chunk.”
With an updated treatment and testing process developed and now in place, Sellers is hopeful the use of mass timber products will see faster growth in Hawai‘i.
GOING MAINSTREAM
Currently, no suppliers in Hawai‘i offer mass timber products. HPM’s Brokaw notes that “[w]hile we don’t currently offer mass timber, we continue to evaluate its potential for the Hawai‘i market,” keeping the door open for the Hawai‘i-based supplier and manufacturer to add mass timber to its offerings at some point.
“Mass timber is fast becoming mainstream,” says Carrigg, but advises that challenges still remain, citing the steep learning curve that designers and contractors may face for new products and processes. “This is especially true when transitioning from more traditional site-built systems to prefabricated building systems or when switching from concrete and steel to a biological material — wood,” she says.
But Carrigg, whose purview includes Oregon, Idaho and Hawai‘i, remains optimistic about the continued growth and adoption of mass timber in Hawai‘i.
“As the demand for mass timber grows in Hawai‘i, we hope to see more advancements in manufacturing and fabrication both on the mainland and on the islands that help to increase efficiencies for Hawai‘i’s unique environment and shipping considerations.
“Mass timber has proven to be a sustainable solution for the rapid production of housing and other much-needed infrastructure in markets all around the world and continues to drive and inspire new innovations in construction.”
