Douglas-fir Processing Opportunities: Douglas-fir Strategy
By Tony Desmond, November 2020.
Download SWP-T113 (pdf)
Douglas-fir, as the second most widely grown exotic species in New Zealand, has an important role in New Zealand forestry and all wood consuming industries. Its greatest asset lies in its structural properties and these have been put to good use in New Zealand over many decades. This study investigates and evaluates some of the more attractive options for bringing Douglas-fir to the market.
Douglas-fir has advantages over the most widely planted exotic species in New Zealand, Pinus radiata, in its physical properties of stability, stiffness, natural durability, and strength to weight ratio. In qualities such as machinability, brittleness on nailing - both products of the large difference between early-wood and late-wood densities - and time to maturity it is less attractive than P. radiata.
In reaction to leaky home experiences in the late 20th century, the New Zealand building code was changed to eliminate the use of any untreated softwoods in normal construction. However, in 2011 D-fir’s natural resistance to wetting and associated decay mechanisms was again recognised byan amendment to the building code allowing its use in indoor areas, but in the meantime kiln dried and treated radiata had moved in to occupy the niche that Douglas-fir had enjoyed. In most cases now Douglas-fir is graded the same way as radiata and marketed alongside it where, perhaps its stiffness advantages are not leveraged as effectively as they could be.
Of the options available for the use of Douglas-fir logs the least-cost lowest-risk option is that of exporting whole logs. Douglas-fir logs command a premium over radiata logs in the markets they are traded.
Sawmilling and marketing structural wood alongside radiata requires a lot of capital and must bear a higher log cost driven by log export prices. On the face of it, sawmilling Douglas-fir has little economic attraction unless the product goes into specialty markets or has value added by further processing.
Opportunities to add value by further processing already exist in the form of engineered wood products including glue laminated products, mass timber products like cross-laminated timber, and developing technology like optimised engineered lumber (OELTM) products. All these processes are capable of differentiating Douglas-fir by making use of its inherent strengths.
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