Posted by: Shayne Korithoski
Bio-material development is catching on everywhere—Europe has been at the forefront of research for the last 25 years and North America is finally starting to catch up. Here in Canada, there is now a keen interest in an industrial hemp fibre industry. It has been legal for Canadians to grow hemp since 1998, but the focus was previously only on food development. Over $8 million dollars worth of hemp food products were exported from Canada in 2009 alone.
Hemp’s potential as a building material has been gaining more attention in the last 3 years–advancing in France, particularly, and more recently in Ireland and England as well. However, the technique of using hemp and lime in buildings is centuries old. Hemp bio-masonry materials are produced from using hemp shiv (the woody core of the plant) and a mineral binder such as natural lime. Hemp buildings have been shown to be highly insulative, fire and mold resistant, extremely durable and carbon neutral. As a fibre, hemp is superior to other agricultural crops in terms of biomass; comparing it to wheat, for example, we find hemp yields triple the amount of fibre per hectare (and sequesters 22 tonnes of carbon dioxide per hectare as well).
Many green building experts predict that–due to continuing decline of worldwide timber quality and availability, as well as the increasing costs of labour and energy–prefab and SIP (Structural Insulated Panel) construction will become increasingly popular and cost-effective over the next 10 years. At the same time, a campaign to develop healthy materials for the green building industry is gathering steam. Currently, most SIP products contain styrene and/or spray-foam. Yet styrene (along with formaldehyde) was recently added to the U.S. Department of Health and Human Services (HHS) “Report on Carcinogens” earlier this year. Disocyanate chemicals used in spray-foam insulation are also being investigated for toxicity by both the U.S. EPA and health agencies in Europe, with the potential outcome being a ban or restriction on them. Bio-materials can be developed using non-toxic binders, but unfortunately not all manufacturers are choosing them. It is quite common to come across board and/or sheeting products that were produced using flax or hemp and subsequently combined with a binder containing formaldehyde. These developments underscore the need for new products that are free of these chemicals. There is also a push from both the U.S. & Canada Green Building Councils and the Cascadia Green Building Council for “nutrition-fact” type labels on building materials themselves. Recently the Cradle to Cradle system, Pharos Lens and the Declare label have been created to bring more transparency to the building industry. The use of such labels will no doubt lead to a greater demand for more non-toxic, locally made materials and systems, especially within the LEED and Living Building Challenge programs.
The old economy largely abandoned local manufacturing in favour of exporting jobs overseas because of cheap labour and cheap oil; now those jobs are starting to come back. But not enough attention has been given in the past to looking at where the materials are coming from and how they are made. The case of imported toxic drywall in 2008 is a perfect example of how something tragic can happen when the manufacturing is sub-contracted out and the company marketing & distributing the product does not oversee what is going into it—most houses made with the hydrogen-sulfide contaminated drywall had to be demolished. This was a real shame and we cannot afford to have it happen again. By relocalizing manufacturing, we can have greater control over quality and can ensure the production of non-toxic, healthy building materials. An added bonus will be the creation of many meaningful green jobs. The bio-material industry is perfectly positioned to help bring this new paradigm into fruition. When we keep industries local, carbon emissions are reduced, local farmers are assured demand for their fibre crops, and local economies start to emerge.
Stay tuned as we develop our new hemp bio-masonry SIP product; we will keep you posted with updates, here on our blog.