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LVL’s strength and durability make it ideal for prefabricated housing construction. Its ability to store carbon and minimize environmental impact also makes it the perfect sustainable alternative to other materials. However, there are challenges to solve before its widespread adoption in the construction sector.
Despite substantial investment, greenhouse gas emissions from the construction sector continue to break records. The industry is not on track to achieve decarbonization by 2050, and the gap between actual emissions and stated goals is widening. Using laminated veneer lumber (LVL) and other engineered wood products in residential construction – the largest segment of the overall sector – is seen as one way to improve its sustainability.
Hidden strengths beneath the veneer
LVL was invented in the 1940s but has only begun increasing in popularity in prefabricated housing construction in the past few decades. It is a composite made by peeling thin layers from softwood trees and laminating the veneer sheets in the same direction. Water-insoluble glue holds the veneers together.
“When you make a composite, you disperse the defects,” says Peggi Clouston, a wood mechanics and timber engineering professor at the University of Massachusetts Amherst. “By taking a large piece of wood, breaking it down into veneers, and putting the veneers back together again, you limit the effect a knot can have to one layer only.”
Unlike the dimensional lumber used in traditional timber frame houses, LVL is produced in large billets that can be cut to specific sizes depending on the desired purpose.
Jason Chiu, the managing director of the University of British Columbia’s Center for Advanced Wood Processing, says, “Engineered wood is uniform, and the strength can be predicted.”
LVL is twice as strong as structural steel in terms of its strength-to-weight ratio, meaning it provides the same strength at half the weight. “Engineered wood can replace concrete and steel in certain applications,” adds Chiu. Once coated with waterproof phenol formaldehyde resin adhesive, LVL can last for more than a century as long as it is properly maintained.
Wooden building blocks of choice
Prefabricated homes, the components of which are manufactured in a factory and then installed on-site, are becoming increasingly popular in Europe and North America. Traditionally, these homes are made with masonry, dimensional lumber, or steel frames. However, LVL is increasingly used as the material of choice for floor and roof-supporting beams.
“LVL provides excellent opportunities for prefabricated house manufacturers because of its high mechanical properties, rigid form, and high tolerance values,” says Mickael Trauss, the product manager for LVL at Stora Enso.
“Using intelligent structural design, a housing complex can be manufactured and assembled with LVL sustainably with fewer truck deliveries, reduced construction waste, and increased build efficiency for lower cost compared to conventional materials,” he adds.
Munkaila Musah, an assistant professor of advanced building technologies at the University of Massachusetts Amherst, says LVL also provides aesthetic and design benefits for prefabricated homes.
“These are engineered products, and they are made to have certain competitive advantages,” he says. “Because of its dimensional stability [the ability not to shrink or swell when exposed to moisture], you can use LVL to span long distances without support. LVL gives you strength that you don’t get from nonstructural composites.”
As a result, Musah says the material is well suited to building increasingly popular open-As a result, Musah says the material is well suited to building increasingly popular open-concept homes, where entire floor plans are uninterrupted by support beams or walls.
“People don’t want columns and walls separating the kitchen from other rooms, so LVL is often the choice material,” he says. “It can also be aesthetically pleasing, which is unique about wood-related products.”
Constructing carbon clout
While its strength and aesthetics make LVL an appealing material in prefabricated housing construction, supporter of engineered wood argue that its environmental benefits set it apart.
The manufacturing process of engineered wood is far less energy-intensive than concrete or steel production. Furthermore, carbon comprises about half of LVL’s mass. Once treated, that carbon is sequestered as long as the material remains intact.
“Trees capture CO2 when they grow in the forest and safely store it as carbon when used in buildings, making this one of the most efficient ways to reduce the carbon footprint of the building sector immediately,” says Trauss.
Musah agrees, arguing that embodied carbon is as vital as operational carbon when considering the climate impact of construction. “If we want to reduce our carbon contribution, especially in the built environment, which is one of the biggest emitters, we have to talk about materials like LVL,” he says.
Aside from emissions, Clouston adds that engineered wood production also has far fewer negative environmental impacts. “There’s not a lot of talk about pollution to the environment, which is minimal when you turn trees into wood products,” she says. “By comparison, turning iron ore into steel pollutes the air and water and causes eutrophication.”
Lumbering away from LVL stigma
According to the International Market Analysis Research and Consulting Group, the LVL market is projected to grow to USD 6.7 billion by 2032, a 24 percent increase compared to 2023. However, there are still many challenges to the widespread adoption of LVL and other engineered wood products.
“Despite timber being the oldest construction material, it is somehow new,” says Ewa Ostrowska, the senior engineer for Metsä Wood UK. “There is still this stigma that timber is not a long-term material.”
While she has seen a marked improvement in knowledge of engineered wood products over the past two decades, Ostrowska believes there needs to be more formal training in undergraduate engineering and architectural degrees.
This is compounded by software limitations, with engineered wood product specifications not included in the most popular architectural and engineering software. While some exist, she believes it has yet to spread widely across the industry. It is also incumbent on the industry to better educate policymakers, constructors, and the public about the benefits of building with engineered wood.
“The most important thing is education and explaining to everyone how to use LVL,” she says. “It’s economical, stores carbon, is sustainable and doesn’t use much energy. There is still a lot of work to do to push the boundaries so that people understand how to build with LVL.”
Watch video: Engineered Timber Is Redefining Innovation in Architecture | Jim Heverin x Raute
