hardwood CLT

Hardwood CLT: An Australian Innovation

Foreword by Ian Thompson, Editor

Hardwood CLT is relatively unheard of because of the challenges of drying hardwoods compared to wider grained softwoods. This video unveils the sustainable benefits of using hardwood CLT for more than paper, it’s a significant evolution in the Australian forestry industry.

This video hosted by WoodSolutions Australia dives into the potential of plantation hardwood, a material traditionally used for pulp, to be harnessed for something much more innovative. The discussion pivots around the concept of engineered wood, particularly cross laminated timber or CLT, and the feasibility of using hardwood, instead of the customary softwood, to create it.

The advantages of using hardwood are numerous; it’s denser, stronger, and typically more durable than softwood. This could translate into buildings that are robust and longer-lasting. Additionally, hardwoods can offer more variety in grain patterns and colors, allowing for greater aesthetic diversity in construction.

The video features insights from industry experts on the benefits of this shift and the potential it holds for the industry. It also spotlights how a company in Tasmania has managed to produce certified hardwood CLT, a significant breakthrough in the field.

So, if you’re interested in the future of forestry and construction, this is a quick look at the benefits and possibilities of using hardwood CLT for our building projects.

Australian Innovation: Hardwood CLT Unveiled

Video Transcript

So it’s fair to say there’s something massive happening behind the scenes in the world of forestry right at the moment. We are on the cusp of developing a new product which could change the way we look at plantation hardwood forever. Plantation hardwood in the southern climes of the country, there’s plenty of it.

Traditionally, Australian plantation hardwoods have been grown for pulp. The trees get chopped, sent away to Japan or China, and made into paper, which has been, and still is, a vital part of the forestry industry in Australia. It’s been specifically grown for the pulp sector. So that’s what the the the tree breeding is about, and uh, that’s what we’ve grown it for. So it was particularly grown for that market.

So we haven’t explored until more recent times what else we can do with that product, and that’s certainly been a focus of the industry in more recent years. But what if these trees, which for decades have been regarded as a low value, albeit a very important part of the industry because the world needs paper, but what if they could be used for something much higher in value than just pulp? What if they could be used to construct the buildings of tomorrow?

Engineered wood or mass timber building systems are nothing new in Australia. There are various examples of this, from plywood to laminated beams. And one of the most exciting engineered wood products is cross laminated timber, or CLT. CLT is cross laminated timber. So essentially, you have a piece of timber in one direction, perpendicular, and then as many layers as you have.

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“Cross laminated timber is a is this beautiful alternative to stick construction because when we use a board or a stick, it has to meet certain criteria for its performance. So based on its knots, or how many knots are in it, um, what what it’s, its grain direction is, so that it’s it, we know that it’ll last the test of time. When we create CLT, we can use low quality timber. We’re taking a lesser quality material and making beautiful strong buildings out of it.”

All the CLT which has been created to date and used to build some pretty substantial buildings, and even houses in this country, has been softwood CLT. But now, that could be about to change thanks to research and science.

“The rolling shear is one of the challenges in the CLT panel. So when we apply the load on the CLT panel like this, we might have some failure like this, which we call rolling shear. So the layers are rolling on top of each other.”

The reason hardwood hasn’t been used yet to create CLT is because there’s challenges in grading and particularly in drying it. “If you take a kitchen sponge, for example, when you dry it, it kind of shrivels up and twists and bows. But then when you wet it again, it springs back to life. Eucalypts are a lot like that.

They’re full of water, and when they dry, they crumple, and they create all these stresses. And then when you, through different drying regimes, pump them up with steam, or you recondition the timber so that it takes its original form, or their part of it, you you take all that, all that tension, all that’s compressed wood, and you blow it back up. That’s what creates kind of all these uh checkings and tears. So drying this material is one of the hardest things.”

A company in Tasmania, Cusp Building Solutions, has cracked the code, so to speak, and now can make certified hardwood CLT using the resource that’s already on the ground. This is exciting news for forest managers such as Forico, who manage almost 100,000 hectares of hardwood plantation in Tasmania alone. “It’s an established ready-to-go resource.

The challenge is it’s grown for a pot wood market, so the resource is what’s standing, but it is there. And what they’re proposing enables them to use that that would resource, essentially to put it into a higher higher value and a very different product. That’s a really exciting thing for the industry to to not have to rely on that that export market to such a high extent.”

Architects and designers are also excited about what the future could hold. “Being able to use sustainable hardwood plantation timber grown right here in Australia to build with ticks a lot of boxes. Number one, they’re using sort of accredited materials, and so it so it’s plantation grown.

The idea that you know labor is now 60 of a building cost, so if you can substantially get into that as a way of making things more economical and use timber factory produced timber engineered timber, that is the way that i see this whole state going in a very very productive way going forward.

I see far more engineered timbers, you know, you can build whole houses in a factory, purpose made, that sort of idea of making them quickly, bringing them to site directing them. That is going to help the supply of timber and structures going forward, you know building a wood has got to be the ecologically best way of doing things.”

“We are looking at utilizing that material locally now. So because there’s so much of it, up to three million cubic metres of this chip is being produced each year. So if we can take a a small proportion of that, or all of it if we can, and build buildings locally to meet this housing crisis and the demand of construction materials, what a beautiful story for now.”

It’s a matter of watch this space. The code may have been cracked. It’s now up to industry to scale up, which is going to take time and money. But it’s fair to say we’re on the right track to get more from our hardwood plantations. They really are the ultimate renewable.

CLT House – With No Drywall And A Cork Shower!

How It’s Made: Cross Laminated Timber (CLT)

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