If one scratches the surface of most of the environmental claims made by manufacturers of green building products, chances are high that any particular material offers only a modest reduction in environmental impacts and can often come with high impacts when the product’s full life cycle is taken into account. In general, I tend to dismiss grand claims such as the one made in the title of this article.
While clay plaster probably won’t save the world, I do believe that it has a remarkable potential to dramatically lower the environmental impact of our buildings while simultaneously helping to achieve very high levels of energy efficiency in a way that is unique among our material palette for the sheathing of walls.
Rice cultivation is common throughout most of Japan. Subsequently, rice straw is locally and plentifully available. Historically, rice straw was a valuable commodity in pre-industrial Japan. Rice straw was used in agricultural and architectural applications and was also used in the production of daily goods. For example, rice straw provided bedding for livestock, thatch roofing for buildings, and flooring for homes in the form of tatami mats. In pre-industrial Japan, rice straw was also used to create sandals, snow boots, raincoats and other commonly used items.
Following on from Tom Woolley’s article in the last issue of TLS, I thought some practical tips on building with hemp-lime would be a natural progression (if you’ll forgive the pun). My business partner William Stanwix and I run a company called Hemp-LimeConstruct,which has been building commercially with hempcrete in the UK for 6 years now, both in new-build (from small extensions, of domestic houses to large community buildings) and in the restoration and retro-fit of traditional and historic buildings. We have learned a great deal along the way, and now provide consultancy and training services to others wishing to use hempcrete; self-builders, construction industry contractors and architects alike.
Traditional Japanese earthen floors are called Tataki. The pronunciation is similar to the Japanese verb to pound, tataku, as these floors are pounded similar to traditional earthen floors in many other countries throughout the world. However, the word Tataki is written in Chinese characters as 三和土, meaning literally “three and earth” or “three harmony earth”, which reflects the fact that Japanese Tataki floors consist of three ingredients, earth, lime and bittern, a byprod the creation of a traditional earthen floor in Northern Japan as conducted by Keisuke Noda-san of Noda Plaster Works.