One of the people excited about NSW's newly legal industrial hemp crops is researcher Klara Marosszeky. She has been developing a commercial viable hemp building material, and will now be able to source her raw materials locally rather than trucking them all the way across the country.
A project of Klara's has been hemp concrete. Mixing hemp hurds (the pithy core of the stem) with a lime-based binder, plus water and a little sand, sets off a chemical reaction akin to petrification. The fibre becomes a mineral and sets like cement and can be moulded into robust building blocks. These are fire-retardant, pest proof and light, while still having the ability to 'breath'- allowing the passage of moisture vapour.This is, strictly speaking, not new technology. Three years ago we mentioned that Ireland was revising the process. (They even wrote book on it: Building With Hemp.) The Irish were, in turn, picking up on work that had been done in France, where many stone-like buildings, including century old bridges, have used this remarkable material. And some time ago we noted a British brewer who had used hemcrete, as some call it, to construct their massive distribution centre. And just this month, American Lime Technology (AMT) announced they were now the exclusive North American distributor of Hemcrete construction materials.
But back to Klara Marosszeky, who has been pursuing her Australian variant of the process with the University of New South Wales since 2003. "We've developed the material for blocks, sprayed walls, panels and in-fill." She said, adding "You can grow enough hemp for a house on one hectare in four months." Part of her research has been in making the product 'commercially competitive', "because I realised there was no point in having a sustainable product that cost an awful lot to build with."
See also: TreeHugger Eco-tip: Hemp.