My shortlist (0 item)

    Mushrooms emerging in construction realm as insulation

    Warren McLaren

    To get off on the right foot, it’s not really mushrooms we are interested in. More their maze-like roots, known as Mycelium. Mushrooms are merely the fruit of such roots, like the visible tip of a much larger, submerged iceberg.

    And no small iceberg, either.

    By some definitions Australia’s own Great Barrier Reef is considered the world’s largest living organism. If you’re measuring such things by area the top of your list might be the mycelium of the Armillaria solidipes or ‘honey mushroom’ of Oregon’s Blue Mountains. It covers close to 10sqkm.

    This vast unseen mycelium is where all the action is happening. Often a metre underground.

    Think about that for a moment. This stuff grows in the absence of light. There, of itself, is a huge environmental bonus. Less energy required in the production phase.

    The beauty of Mycelium is that it can be harnessed.

    Multi-award winning Paul Stamets is an American mycologist (a fungi botanist), who could reasonably be considered the pioneer of modern uses for mushroom roots. This former logger, and author of Mycelium Running: How Mushrooms Can Help Save the World, has developed not only prototype medicinal applications from fungi, such as small pox, HIV and malaria treatments, but also a multitude of other innovative uses.

    For example, using oyster myclelia his ‘myco-remediation’ was able to turn diesel fuel contaminated soil into nontoxic material suitable for landscaping. In just two months the atmospheric pollutants known as polycyclic aromatic hydrocarbons (PAHs) went from 10 thousand parts per million to less than 200.

    Paul Stamets mushroom enzymes had effectively converted hydrocarbons into carbohydrates. They do this by secreting enzymes and acids that break down lignin and cellulose, which in turn are formed from long chains of carbon and hydrogen. These are the same chains inherent in the structure of petroleum products, which is, of course, millennium-old plant matter.

    Importantly for the building industry, Stamets has also harnessed the power of a fungi which is entomopathogenic, that is it can kill insects. In particular carpenter ants, fire ants, and wait for it, termites. Yes, Stamets applied for a patent on a non-sporing mycelium that attracts termites. After they eat it, the tiny mushroom roots continue growing inside the insects, to the point where they die and become mummified. Ever better, mushrooms then sprout through their bodies and emit spores that repel other nasties. As Stamets puts it, “You have a near-permanent solution for re-invasion of termites.”

    Exciting as Paul Stamets’ work may be, his is not the only game in town.

    Eben Bayer and Gavin McIntyre were mechanical engineering students at Rensselaer Polytechnic Institute, a private research University in New York, when they developed the ideas that now form the basis of their business: Ecovative Design. The start-up cut its teeth conjuring up biodegradable packaging manufactured from mycelium.

    First launched in 2009, after picking up a bunch of awards and lucrative seed funding, Ecovative’s mushroom foam packaging starts with a low cost, locally sourced feedstock, such as rice hulls or corn stalks. Once cleaned this agricultural waste product is inoculated with mycelium. The mushroom roots spread out quickly, essentially eating, or metabolising, plant lignin, a substance that animals and humans can’t digest. Any substrate that isn’t munched simply becomes like the aggregate in concrete, with mycelium binding or gluing it all together in one unified composite.

    Mushroom insulation from Ecovative.

    Remember Oregon’s 10sqkm of mycelium mentioned above? It is estimated that has been forming its mass for between 2,000 and 8,000 years. Fortunately, Ecovative have been able to scale that timeframe down a fraction. Its mushroom foam completes its growth in just five days. Then it is bunged in a heating chamber to stop the growth process.

    Even though there are a few industrial processes to help it along the way, Ecovative reckon its mushroom materials use 80 per cent less energy to produce that expanded polystyrene (EPS), or what we commonly refer to as styrofoam. Yet it costs the same, whilst enjoying equal performance characteristics. As evident by the fact that Dell use it to ship its computer servers in, just as Puma despatch surfboards in the stuff.

    But packaging has been but a gateway product. Look out building industry! The spider web-like tentacles of mycelium are coming your way.

    As of November 2013 at the Greenbuild Expo in the USA, Ecovative announced a raft of construction materials they say, “will be market ready in the next 12-24 months.”

    First cab off the ranks might be a product they once called Greensulate, but which now goes by the name of Ecovative Mushroom Material. It’s an insulation foam produced in much the same manner as its packaging. Except in this case, a building’s walls provide the mould. The mycelium allows the insulation to be grown in-situ bonding between the inner and outer walls with sufficient strength to negate the need for studs or noggins, thus reducing the thermal bridging affect.

    An insulation that practically grows itself – in the dark, and inside – is made from cheap agri-waste, is fire retardant, has high insulation value, yet at the end of its useful life, is completely compostable.

    Sounds rather fanciful, but then nature is rather adept at miracles.

    Acoustic tiles. Image: Ecovative

    Ecovative’s co-founder Eben Bayer, who grew up on a farm, likes to quote Arthur C. Clarke, doyen of science fiction, who wrote, “Any sufficiently advanced technology is indistinguishable from magic.”

    Eben uses another ‘living system’ to articulate why he thinks it is possible to find uncommon beauty in common things. A chicken takes starch and water and creates an egg, every day. If we can take that small marvel as commonplace, one day we should also accept mushroom materials as mainstream.

    Hence Ecovative’s intended roll out of a family of built environment products, including a formaldehyde-free, tree-free alternative to fibreboard, dubbed Myco Board; Mushroom Insulated Sheathing: continuous insulation suitable for retrofits or new construction; as well as structural insulated panels (SIPs), and acoustic tiles.

    ​Myco Board. Image: Ecovative

    Obviously the company sees great potential for mycelium production in the construction industry. Gavin McIntyre, Ecovative’s other co-founder hints at why their work is generating so much interest. He cites research by the US Environmental Protection Agency (EPA) which found that by volume expanded foam products and materials occupied 20 per cent of United States landfills. Ultimately mushroom materials are entirely compostable. They make soil. Not waste.

    Not surprisingly, the Cradle to Cradle Products Innovation Institute, an endeavour of renowned architect William McDonough has awarded Ecovative Mushroom Material their prestigious Certified Gold score.

    Eben Bayer believes their technology sits at the intersection of biology and hard core engineering.

    Philip Ross might add art to that equation. Adding to the qualities already espoused by Ecovative, this amateur mycologist and inventive artist, reckons that dried mycelium is also mould and water resistant, traps more heat than fibreglass insulation, all the while being stronger, by weight, than concrete.

    Ross is cited as having, “destroyed many a metal file and saw blade” whilst shaping the 400 or so mushroom bricks from which he erected a small arch-style structure as an art exhibit. By some estimates a strand of mycelium can hold up to 30,000 times its own weight. Yet this strength comes virtue of a manufacturing process that produces a mere one tenth the carbon emissions of traditional petrochemical manufacturing.

    It might be hard to conceive of mushroom building materials. But who thought Australia would have one million solar rooftops, that the once banned urban rainwater tank would become almost mandatory, or that councils would approve houses made from bales of straw?

    Back to Top