Are structural timber products experiencing a renaissance?

Since its inception, engineered timber has been a popular choice for civil infrastructure projects. Several technological advances in the 21st century have allowed the use of multiple wood species and residues to make engineered wood components, and it can also help remedy supply issues.

But if supply of traditional timber is high, many in the wood processing industry believe solid timber is still up to the task as a structural solution.

Bruce Larsen, general manager of Northpine, subscribes to this belief. A mainstay in the Auckland and Northland timber industry for over two decades, Northpine specialises in small batches of specialist structural timber products marketed as Northbeam – and with a steady supply of quality Northland radiata pine, the company consistently delivers good volumes of this high-spec pine.

“The radiata that grows in Northland is stronger, stiffer and denser than almost anywhere else in the country,” says Bruce. “Due to the warmer northern climate, our trees tend to grow faster – which is beneficial in itself – but the climate also provides for timber with stronger characteristics.

“This allows us to do certain things, like cutting larger dimension products closer to the core of the tree, while retaining the good structural properties.”

Strength, stiffness and density make this species of pine excellent for Northpine’s flagship product, the Northbeam SG8/SG10 Solid Timber for civil infrastructure. Ideal for civil, commercial and residential projects, the beams and square posts are produced in lengths up to 7.2m – improving span capacity by up to 30%.

“SG10 especially is suitable for structures benefiting from a larger span – and this means you can use wider spaces between bearers, which in turn means fewer foundation piles due to the wider span between beams,” says Bruce. “The strength of SG10 means you can use less timber to do the same job.”

Northpine is able to make these SG10 – as well as SG12 – products simply through the quality of the radiata pine it uses, and the processes it has refined over the years at the company’s Waipu mill. Bruce says it’s especially gratifying when Northpine’s products are pushed to their potential – like when they were used for the Mangōnui Waterfront redevelopment, which included a new boardwalk and wharf.

“We used huge 350x150 timber beams for that project specified into SG8, which reduced vibration and other structural issues in the walkway,” says Bruce. “That’s an unusually large size – normally you’d be looking at using a laminate-type product. But it indicates how we’re using this raw material to push the limits.

“It’s a combination of high-quality timber as well as the age of the pine – more mature wood is stronger than younger wood. For jobs like the Mangōnui Waterfront boardwalk and wharf, we had to go and scout the larger, better trees in order to maximise the potential of this Northland radiata pine.”

Northpine’s work in this field is strongly aligned with the aim recently announced by the Ministry of Primary Industries (MPI) to “make better use of our forestry resources by processing more wood onshore, producing more high-value wood products, and using residues to grow the forest-based bioeconomy”.

The Ministry also wants to increase the amount of wood used in construction by 25% by 2030.

“The only way that’s going to happen is if we put more priority on using wood as a construction material,” says Bruce. “Of course there’s big opportunities for engineered wood products – but also solid wood products like our own, particularly in structural components where you want to have a natural timber look.

“If you want that look as well as high quality timber, we’re here and ready to produce.”

Learn more about Northpine and its services.