Too much cheap softwood and not enough hardwood? THE solution's ingenious... give mother nature a helping hand. Peter Kernan explains a revolutionary new alchemy that turns softwood hard
A decade ago, the New Zealand Forestry Research Institute looked at its productive timber plantations, and took fright. Long before then, the country had chopped down its once-extensive forests of kauri hardwood trees to supply the masts, keels and hulls that made Britain Mistress of the Seas. In their place it had planted softwood varieties – so successfully that the problem was not a lack of timber, but a surfeit. There might have been only five mature kauri trees left in the whole country, but it had softwood coming out of its ears and prices were falling accordingly.

Replacing the softwood plantations with hardwood was not on. Wood is the slowest-growing crop in the world, and while some softwood species need just 20 years to mature, hardwoods can take anything between 40 and 100 years, which makes the economics unworkable. And in any case, with the charge of environmentalism up the political agenda, New Zealand had by then made a conscious decision not to harvest hardwood any more.

Instead, like some guild of medieval alchemists searching for the philosopher's stone, the institute set about creating a technology that would transform low-value softwood into high-value hardwood. Astonishingly enough, its research was successful. It took the institute's scientists six years to perfect a starch-based formulation, called Indurite, which makes softwood as dense and tough as hardwood and endows it with the same performance properties.

Opportunity knocked
The institute, well aware that its strengths lay in R&D rather than commercialisation, sold the technology to a New Zealand sawmill, which in its turn subsequently sold it on.

And that's where serial entrepreneur Tony Pettley enters the story. An industrial chemist by trade, Pettley offers hope to everyone who hasn't made a million by their forties. The 54-year-old, laid-back Australian was safely on the corporate payroll until 15 years ago. "I drifted into being an entrepreneur, really," he says. "It just sort of happened." Since then, he's set up several businesses and sold them on.

In 2000, having flogged off his latest venture, a service that disposed of chemical waste safely and recovered solvents and fuels, Pettley was looking for a new opportunity. Networking religiously at the tennis club, he heard that Indurite was for sale. Along with his business partner, he bought it. Why?

"Because the timber industry is changing," he says. "There's great pressure on native hardwoods to produce high-performance timber economically. Indurite fills the gap, creating sustainable solidwood from softwood."

I’m not a rabid environmentalist BUT I am a pragmatist. Why go into an unsustainable business?

Tony Pettley

The sustainability angle is a clear differentiator for Indurite in markets like flooring and doors, where hundreds of suppliers compete, but is it also a matter of principle for Pettley? "I'm not a rabid environmentalist," he says, "but I am a pragmatist. It would be folly to contemplate going into a business that was not environmentally sustainable." And Indurite does have impressive organic credentials. Apparently you can safely drink the formulation.

Pettley set up Indurite plc in the UK six months ago, to exploit the huge UK market for hardwood – a market that ranges from pencils to flooring and doors. The grand strategy is to create demand by targeting the general consumer, with Pettley making money from licensing the Indurite process to sawmills and selling them quantities of formulation to produce sustainable solidwood. Sawmills can create Indurite timber without investing in new equipment (see What is Indurite?).

Indurite allows sawmills to clean up their act. A lot of timber, softwood in particular, is heavily dosed with toxic preservatives, fungicides and fire-retardants that contaminate mills and their soils. Sustainability, however, is probably a hotter topic for architects than sawmills, which show more interest in Indurite's dimensional stability - its resistance to twisting and warping.

What's in it for construction managers? Price and performance. Because Indurite fills with hard cellulose the voids in timber that give the wood fibres the room to buckle and break, it is less likely to bend or bow, which makes building and fitting doors and floors easier. And while Indurite timber can't compete on price with the very cheapest hardwoods such as Asian oak (which come with so many knots and gnarls that wastage can double the rough-sawn cost), it is far cheaper than cherry, walnut and teak.

Unlike hardwoods, Indurite presents no problems of supply. If you can't get hold of the hardwood doors or boards specified for your project, Indurite's ready availability offers a good alternative when you have to despecify.

Indurite also glues together well and edges are not so rough as with softwood. "It's smoother than hardwoods and has fewer knots," says Shyam Nath, director of floor fitter R&S Wood Flooring. "It's a lot easier on our sawblades." Nath rates Indurite's dimensional stability as better than ash, beech and maple, but inferior to oak and tropical woods.

What is Indurite?

As a tree grows, so its wood fibres twist and turn. In dense hardwood, the fibres are so closely packed together that such deviation is difficult. In less dense wood, the spaces between the cellulose molecules are bigger, allowing the fibres to twist more. Indurite fills the voids between fibres with corn-based starch. This by-product of the food industry is a form of cellulose that hardens to leave the fibres with nowhere to move. Kiln-drying at a sawmill evaporates the water in the voids of timber, leaving pockets of air. Pressure-treating the timber with the Indurite formulation in the mill’s vacuum chamber forces the starch into the air pockets. The wood then goes back to the kiln, where the heat causes the cellulose in the starch to matt itself tightly together into a dense solid. Varying the quantity of formulation determines the final density of the Indurite wood. An irreversible process, Indurite increases the density, and thus the hardness, of softwood from around 400kg/m3 to whatever is required; 650kg/m3 is typical for flooring – it’s harder than most hardwoods and is fire-rated. This greater and more evenly distributed mass means that Indurite, like hardwood, doesn’t easily warp, crack or bow. By selecting the grain of the softwood feedstock and adding colour along with the formulation, it is even possible to mimic hardwood species. The colour penetrates through the timber and doesn’t fade as fast as that of hardwood. Indurite markets solid wood floors under the Maro brand name, and is negotiating with manufacturers to create a range of internal doors. There isn’t much point in using Indurite timber for window frames or external doors because it would need painting: you’d get the same performance from painted softwood, which is always going to be cheaper. And although Indurite is hard, it’s still wood and can misbehave. Subject it to a temperature of 60 degrees C and it will twist; soak it and it will warp.

Source

Construction Manager