{"id":49819,"date":"2018-02-05T07:29:09","date_gmt":"2018-02-05T06:29:09","guid":{"rendered":"https:\/\/renewable-carbon.eu\/news\/?p=49819"},"modified":"2018-02-01T13:12:05","modified_gmt":"2018-02-01T12:12:05","slug":"the-many-faces-of-hemp","status":"publish","type":"post","link":"https:\/\/renewable-carbon.eu\/news\/the-many-faces-of-hemp\/","title":{"rendered":"The many faces of hemp"},"content":{"rendered":"
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Photo credits: Esteban Lopez<\/figcaption><\/figure>\n

A relatively recent interest in hemp as a building material responds to a global trend that encourages the development of bio-based products and the reduction of carbon emissions. But its use dates back to many centuries ago.<\/strong><\/p>\n

In China, in 200 BCE, hemp was mixed with lime and tung oil, and used as caulk for\u00a0junk ships<\/a>, classic ancient Chinese sailing vessels. It is no surprise these hemp vessels, which sailed by the early Middle Ages, are still in wide use. The\u00a0permeability of the hemp material\u00a0that controls moisture similarly to existing wooden elements, makes it ideal for the shipping industry.<\/p>\n

In\u00a0France, we can find another example of\u00a0its early use in construction in the 6th century. Hemp mortar was discovered in\u00a0Merovingian bridges<\/a>\u00a0where the crop was used to reinforce abutments.\u00a0The first construction using hempcrete (hemp and lime composite) wrapped around a timber frame was built in 1989 in the same country.<\/p>\n

Nowadays, France is\u00a0Europe\u2019s biggest producer of industrial hemp, and\u00a0first in the world in hemp-seed production\u00a0accounting for 59 percent of the global total.<\/p>\n

The plant can be grown locally and harvested with minimum input in a matter of months. French\u00a0Cavac Biomat\u00e9riaux\u00a0cultivates hemp and flax. The plantations are located close to its manufacturing site, reducing the company\u2019s carbon footprint. The industrial production of hemp, flax fibres, and shiv, undergo a process of defibering and burling after which they are packed and delivered to the site. \u201cWe are a complete hemp chain from the field to the site,\u201d says Valentin Colson, Service R&D of Cavac, which is also member of the European project\u00a0ISOBIO<\/a>\u00a0focusing on eco-materials for low-carbon construction.<\/p>\n

The company produces\u00a0bio-based flexible and rigid insulation panels\u00a0for the construction industry. \u201cOne important point is that the panel is vapour permeable.\u00a0It is hydrophobic, which means that water has difficulty to penetrate the panel,\u201d explains Colson, offers an\u00a0excellent long-term mechanical stability,\u00a0and can also be used to seal and improve the air tightness of the building.<\/p>\n

Even though the\u00a0hemp used in construction is fire resistant,\u00a0researchers continue to look for better eco-friendly alternatives.\u00a0\u201cWe are working on the fire-proofing of the new panel and try to find an eco-friendly solution to fireproof it,\u201d\u00a0says Colson.<\/p>\n

In the UK, it was illegal to grow hemp between 1929 and 1993, because the plant belongs to the cannabis family. Other places such as Australia, New Zealand, Canada, and the US banned the cultivation of hemp for nearly 70 years due to its connection with marijuana. However, only 0.3 percent of THC (Tetrahydrocannabinol), the principal psychoactive ingredient in marijuana, is present in the strain of plant grown for hemcrete. All the bans are lifted now.<\/p>\n

In the US,\u00a0hempcrete imported from Europe was used for the first time in 2000\u00a0in the\u00a0exterior <\/a>of a home\u00a0built for\u00a0spiritual leader and Sioux elder Ernest Afraid of the Bear<\/a>\u00a0on the\u00a0Pine Ridge Reservation<\/a> in an attempt to offer the Sioux a return to a self-sustainable and independent life in balance with Mother Earth. However,\u00a0the construction of a permitted hemp home did not begin until 2010.<\/p>\n

In that year,\u00a0former Asheville mayor Russ Martin and his wife Karon Korp<\/a>\u00a0built the first permitted hemp home in Asheville, North Carolina. Back then, they consulted with environmental designer\u00a0Anthony Brenner<\/a>, who brought\u00a0the idea of building with hemp to the couple who was looking for a sustainable, energy-efficient home.\u00a0After the success with Martin-Korp\u2019s hemp house, Brenner was consulted on many other hemp homes.<\/p>\n

Hempcrete panels are used as insulating infill of walls, roof, and under-floor offering great thermal and acoustic performance.\u00a0Concerns in long-term performance\u00a0of the plant in construction such as biological degradation, infestation, moisture, structural degradation, or fire\u00a0\u201care solved with the presence of hydrated lime,\u201d\u00a0says Brenner. Among the many benefits of building with hemp, he highlights\u00a0\u201ccarbon-negative, non-toxic, fire-resistant, and mold-resistant.\u201d\u00a0It provides natural insulation, and it makes for a healthy and safe building site. When a building is demolished, the\u00a0hempcrete can be recycled and reused\u00a0in a new building.<\/p>\n

In the US, \u201cmany states are passing legislation to grow hemp now, which will make it more cost effective. The cost was the biggest hurdle,\u201d says Brenner. This was because before the Agricultural Act signed by former US President Barack Obama in 2014 all the hemp was imported from Europe, mostly from France and the UK.<\/p>\n","protected":false},"excerpt":{"rendered":"

A relatively recent interest in hemp as a building material responds to a global trend that encourages the development of bio-based products and the reduction of carbon emissions. But its use dates back to many centuries ago. In China, in 200 BCE, hemp was mixed with lime and tung oil, and used as caulk for\u00a0junk […]<\/p>\n","protected":false},"author":59,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_seopress_robots_primary_cat":"","nova_meta_subtitle":"","footnotes":""},"categories":[5572],"tags":[12430,11877],"supplier":[12280],"class_list":["post-49819","post","type-post","status-publish","format-standard","hentry","category-bio-based","tag-buildingmaterial","tag-naturalfibres","supplier-cavac-biomateriaux"],"_links":{"self":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/49819","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/users\/59"}],"replies":[{"embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/comments?post=49819"}],"version-history":[{"count":0,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/posts\/49819\/revisions"}],"wp:attachment":[{"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/media?parent=49819"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/categories?post=49819"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/tags?post=49819"},{"taxonomy":"supplier","embeddable":true,"href":"https:\/\/renewable-carbon.eu\/news\/wp-json\/wp\/v2\/supplier?post=49819"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}