How a waste management services company is recycling timber waste from construction and demolition projects to support the circular economy.
According to Blue Environment’s National Waste Report, the construction and demolition sector produced the equivalent of one tonne of waste for every person in Australia and accounted for about 44 per cent of our total waste, in 2021-22.
As the recycling of materials such as concrete, bricks and glass is well established, about 80 per cent of construction and demolition materials are recovered and reused. Meanwhile, engineered timber was left in landfill – until now.
Waste management services company reDirect Recycling has received an exemption to recycle timber into particle board, following an 18 month trial which saved more than 2000 tonnes of engineered timber from landfill.
“The adhesives in engineered timber products led the EPA to say, in the past, that there were limited beneficial reuse opportunities for the products and thus permission to recycle it was not granted,” reDirect Recycling CEO Aaron Hudson explained.
“But we were able to do multiple stack emission tests in our Oberon facility to prove that when we heat up the engineered timber, flake it, feed it and manufacture it back into particleboard and structural flooring, it doesn’t cause any environmental impacts.”
Hudson said that the two products, CUSTOMpine and STRUCTAflor, had about a 25 per cent recycled component before the trial; now, it’s closer to 60 per cent and the product can be recycled back into itself.
“There is a massive demand for it, and it will continue because governments are putting in their procurement guidelines that there needs to be a certain percentage of recycled content in the products they use in government buildings,” he said.
The products are made by reDirect Recycling’s sister company Australian Panels.
Victor Bendevski, Manager of Environment and Regulatory Compliance at Australian Panels, said this was the first large-scale recycled particle board project of which he was aware.
He said that laminated veneer lumber is a problem for the industry because the glues prevent it being used in mulch products, so it ends up in landfill.
“The glues don’t pose any significant issues for us because we chop it up and turn it back into a product,” Bendevski said. “There is no risk of leachate or ground contamination.”
The process begins when contracted waste companies Bingo and Central Waste extract the material from mixed waste streams at resource recovery facilities around NSW, aggregate it and process it to a 300 mm minus material.
After this is delivered to reDirect, the process focuses on removing contamination, particularly that of copper chrome arsenate impregnated in wood products and any other foreign materials such as steel.
The material is then shredded to between 50-100mm, scanned again for metals and aluminium, washed and optically sorted for plastic contamination.
“With the exception of plastic, all the foreign materials we take out are also recycled,” Bendevski said.
After the washing, the timber is flaked, dried, screened and air graded to separate the particle sizes. Then it’s off to the glueing section to be made into particle board.
“We built a new particle board plant in 2019, and from the outset we always anticipated using recycled materials for the input,” Bendevski explained.
Reaching 100 per cent recycled inputs is still a long way off though.
“We need to maintain the structural integrity of the product, making sure it is fit for purpose. Until then, the rest of the input comes from plantation forests.”
Even though the company is creating its own input materials, Bendevski says it’s not a money-saving exercise at the moment.
“There’s the extra transportation, and processing these materials is much harder on machines,” he said. “But it’s the right thing to do and it helps us to be competitive. Australia exports a lot of chip, so we need to stay competitive and not pay the export rates.”
Australian Panels has long been recycling other non-engineered timbers in a closed-loop manufacturing process, which also uses waste water from the chip process to create steam for energy. The engineered timber recycling process adds to the company’s commitment to sustainability.
But it’s not just the reduction in landfill that makes this breakthrough important. It is estimated that the building industry accounts for half of all virgin material used globally. Being able to recycle engineered timber back into buildings, and have it again recycled when no longer needed, is in line with circular economy goals.
According to a report from the Australian Housing and Urban Research Institute, the circular economy calls for “a closed loop of building design and materials for sustainable housing that involves low-emission, re-used or recyclable and durable building materials”.
Keeping engineered timber in the loop is a strong step forward towards this goal.