The New South Wales hemp fibre industry was commercialised with the passing of the NSW Hemp Industry Act in 2008.
In the 10 years preceding that, individual licensed researchers including the Australian Hemp Masonry Company’s Managing Director, Klara Marosszeky conducted agronomic trials to prove the crop’s viability.
Klara’s commitment to working closely with the farming sector began with field trials in 1999 growing European seed varieties in Wollombi in the NSW Hunter Valley, and continues with ongoing research partnerships, such as in Ashford, related to fibre farming and processing.
The company’s research into development of an Australian hemp lime construction material commenced at the Australian Centre for Construction Innovation at UNSW in 2000 and included research into making composite materials from various forms of processed hemp and a variety of Binder materials to identify solutions that would significantly minimise the embodied energy of the building material.
The only criticism of hemp building materials is that the Binders used are based on various forms of lime, all of which have a footprint because they are super-heated. The research at UNSW sought to identify a better balance. We lowered the input of limes, compared to other marketed products while retaining sufficient strength and maintaining the material’s other performance characteristics i.e. breathability and excellent thermal and acoustic performance.
The company’s research included investigating multiple applications for hemp including suitable mixes for blocks and panels and while there is now a demand for both of these products, initial builds have focussed on the most sustainable application of hemp lime, which is in building monolithic structures in which the frame is embedded between forms, providing an airtight building fabric and thermal mass.
As well as being a building method that can easily be adopted for volume house building and commercial construction, this building method offers an affordable option for low income groups and Owner Builders willing to be involved in installing their own hemp walls. It’s also suitable for retrofits and for restoring older buildings particularly where there are issues with damp because the vapour-permeable material mitigates the humidity .
While all natural building materials perform much better than petro-chemical based walling materials with respect to life cycle analysis, hemp construction materials have the added appeal of being able to create a very modern sharp edged finish where that’s the aesthetic you’re after.