Building the future with timber as strong as steel

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Graeme Black, CEO of Australian forestry firm Lignor, is holding up a cutting board to show me. It is striped, with layers of dark wood shifting to light wood and back to dark.


Relevant Sustainable Development Goals


“It’s made of seven-year-old eucalyptus,” he explains.

“At Lignor, we have managed to create a cross-laminated stranded timber product, using eucalyptus, that can replace 70-year-old tropical hardwood products in construction. This cutting board is made from some of the off-cuts.”

Building materials alone, primarily cement and steel, account for 10% of manmade carbon emissions, according to the International Energy Association.

Demand shows no signs of slowing, as cities and the global population continue to grow.

Greater use of wood – especially for structural components such as panels, posts and beams – could help reduce the industry’s contribution to greenhouse gases.

Unlike cement and steel, timber locks up carbon, at least for the lifetime of a building.

Eucalyptus for example, one of the world’s fastest growing trees, are transforming carbon atoms into wood as they sprout up, while becoming economically useful quickly too.

Eucalyptus trees are also plentiful, found in about 20 million hectares of plantations around the world, mainly as a source of pulp for the paper industry.

Black and his team hope this ready-made resource can take on a new role in construction.

Eucalyptus with the strength of steel

The secret lies in how the wood is prepared. Stranding helps unlock a wood’s tensile strength by breaking logs down into fiber before pressing these strands into thin panels.

Layering these panels at right angles to each other – cross-lamination – strengthens the wood even further. While cross-laminated timber is light, it has strength that compares to steel.

Stranding and cross-lamination are not new, but Lignor is the first to make stranding work for eucalyptus trees, while pioneering cross-lamination for other stranded woods, promising a cheaper, stronger product.

With stranding, Black and his team can turn up to 80% of raw hardwood into a mass timber product. This compares with up to 60% for traditional cross-laminated timber, which is made using a saw, losing more high-grade wood in the process.

Stranding also promises to make cross-laminated wood more durable by coating each strand with protective resins that guard against fire, insects and fungal infections. Without stranding, these can only be applied to a panel’s surface.

Strand mat forming prior to Pressing into a panel
Strands extracted from a log about to be compressed into a panel (image: Lignor)

Certification and mass production

Lignor has patents for a portfolio of wood products in Australia and the US, as well as trademarks that also cover the EU.

Next up is getting its cross-laminated stranded timber certified as a building material. The company hopes that will happen in the US by early February, opening up markets that use US design codes while giving the green light to mass production.

“There are markets like Japan, Korea and elsewhere around the world that are interested in the product, once it’s been certified for construction in the USA,” says Lignor’s technical director Peter Burton.

A US$25 million plant, sourcing US hardwood, could take around 18 months to build – potentially partly funded by strategic investors as well as Lignor – with product sales to follow in 2023.

Longer-term, Lignor plans to ramp up large-scale manufacturing by licensing its IP for engineered wood to partners around the world, although cross-laminated stranded timber is the main focus for now. “Getting the first plant up and running in any new technology is always the hardest,” Black remarks.

It hasn’t all been plain sailing.

Bad actors in Lignor’s supply chain had replicated the techniques used to cross-laminate eucalyptus to produce an inferior product more cheaply.

Fortunately, Lignor’s new stranding process is harder to replicate with US and Australian patents that apply to all woods. Lignor has since reworked its supply chain to manage this risk.

A resurgence for wooden buildings

New ways to make wood safer and stronger are helping promote timber’s credentials among developers and architects, with some high-profile projects grabbing headlines around the world.

Engineered wood can match steel for fire resistance, and is less prone to temperature changes than cement.

The world’s tallest wooden building, an 18-story residential and commercial timber tower called Mjøstårnet, opened its doors to the public in Norway last year.

In Singapore meanwhile, a 40,000 square-meter six-story complex being built for Nanyang Technological University could become Asia’s largest wooden building when it is finished, potentially this year.

Timber-frame buildings are still the exception, however. Cement and steel usually win out as the cheaper option, especially in markets with low labor costs.

Regulatory clarity on using timber in construction also varies by market, adding uncertainty when pricing projects, although government incentives and decrees have encouraged uptake in some countries.

As a result, mass timber products have been most popular in Europe and North America so far.

New forms of cross-laminated timber, including Lignor’s product, could broaden that footprint, especially with more affordable options.

“Timber construction is one of the major pillars of a well-managed sustainable economy,” notes Hans Woldring, principal natural resources and agriculture specialist at the Asian Development Bank.

“Alternative protein sources and vertical and urban farming free up agricultural land that can be used for timber production,” he suggests, pointing out that around 65% of agricultural land is used for rearing and feeding livestock.

Building exterior
Timber at work: Singapore’s Block 81, originally envisioned with a full-steel design, uses wood for the building frames and roof (image: Venturer)

Efficiency, productivity and safety

Mass timber products offer other benefits, including increased productivity and faster construction times, as large wooden components are prefabricated off-site.

Assembling these timber components in advance, combined with wood’s lighter weight, also make building sites safer and quieter by reducing the need for deep foundations and heavy machinery.

The biggest driver of change, however, could be the importance that private and public organizations attach to sustainability – something that could tip the balance towards more wood and less cement and steel.

While local governments are often on board, especially in public housing, more large companies are also thinking beyond short-term economics when commissioning buildings, notes Kevin Hill, CEO of Venturer Timberwork, a Singapore-based building contractor.

Venturer already does a lot of work with high-end hotels that are keen to promote their commitment to sustainability. Now, other sectors are showing a sharper interest as well.

“A lot of the drivers and changes are coming from these big organizations, and that goes into designers’ and developers’ requirements,” Hill says.

“A culture of change management is more important than overcoming any engineering challenges, or perceived engineering challenges, about using timber on a bigger scale.”

 

GO DEEPER

Why timber buildings are catching on (JLL)
A path to net zero carbon emissions for building and construction (World Green Building Council)
How buildings contribute to climate change (Curbed)

 

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Sarah Lewis

Sarah Lewis

Director, Marketing & Communications, AVPN

Graeme Black

Graeme Black

CEO & Executive Director, Lignor

Kevin Hill

Kevin Hill

CEO, Venturer

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