Date: February 06, 2019
“Hempcrete or Hemplime is bio-composite material, a mixture of hemp hurds (shives) and lime (possibly including natural hydraulic lime, sand, pozzolans) used as a material for construction and insulation. It is marketed under names like Hempcrete, Canobiote, Canosmose, and Isochanvre. Hempcrete is easier to work with than traditional lime mixes and acts as an insulator and moisture regulator. It lacks the brittleness of concrete and consequently does not need expansion joints. The result is a lightweight insulating material ideal for most climates as it combines insulation and thermal mass.
Hempcrete has been used in France since the early 1990’s to construct non-weight bearing insulating infill walls, as hempcrete does not have the requisite strength for constructing foundation and is instead supported by the frame. France continues to be an avid user of hempcrete; it is growing in popularity annually.
Like other plant products, hemp absorbs CO2 from the atmosphere as it grows, retaining the carbon and releasing the oxygen. Theoretically 165 kg of carbon can be absorbed and locked up by 1 m3 of hempcrete wall during manufacture.
The typical compressive strength is around 1 MPa, around 1/20 that of residential grade concrete. It is a low density material and resistant to crack under movement thus making it highly suitable for use in earthquake-prone areas. Hempcrete walls must be used together with a frame of another material that supports the vertical load in building construction, as hempcrete’s density is 15% that of traditional concrete.
Limecrete, Ltd. (UK) reports a fire resistance rating of 1 hour per British/EU standards.
In the United States, permits are needed for the use of hemp in building.”
Presentation “Industrial Hemp: The Future of Green Building”
And, excerpts from John Patterson’s Tiny Houses Workshop
Can You Build a House With Hemp? – National Geographic:
“Growing industrial hemp was illegal in the United States after 1970 because the industrial plant and marijuana were considered to be the same, when in fact they are different varieties of Cannabis. In recent years, some states have changed their laws, allowing farmers to start growing industrial hemp, which is used in everything from clothing to nutritional products to building materials. Oregon grower Cliff Thomason says growing and processing hemp was stymied because it was illegal, but now a knowledge base for best uses can grow, along with the plants. View a hemp home constructed using hempcrete, a building material that advocates claim is mold resistant, breathable, and eco-friendly.”
A Stunning Small Home Made From Hemp:
“Hemp is a building material like no other. It has incredible thermal properties, is environmentally friendly, rat and insect proof, fire and earthquake resistant and is an affordable way to build. Plus, the end result looks amazing!
After loosing her father to mesothelioma (a cancer caused through exposure to asbestos), Tiffany studied building biology, and together with her husband Michael, set about finding healthy ways of constructing a non-toxic small home for their young family.
The result is the Skyfarm. An amazing small home made from hempcrete, together with lots of salvaged and reclaimed materials. Be sure to watch the full video to find out how it was constructed, and all about the incredible building material that is hemp!
Check out the Balanced Earth Website for more information on building with hemp:
Introduction to Natural Hempcrete Construction Methods:
“This webinar is designed to introduce participants to the materials and techniques required to use hempcrete as a building insulation material. Based on the book, Essential Hempcrete Construction, we will examine the material properties and specifications for hemp and for a variety of binders, and look at sourcing options for these materials. Mix ratios, forming systems and material placement will also be covered, including the use of hempcrete as sub-slab, wall and roof insulation. We’ll also cover the material costs and labour inputs for using hempcrete, as well as the equipment required to mix and place. Finishes for hempcrete walls will also be covered. Finally, the webinar will examine the building science implications of using hempcrete, including thermal performance, moisture performance and air-tightness.
– Understand the basic material composition of hempcrete, and learn how to source the materials.
Continuing Education Units (CEUS)
Chris Magwood is obsessed with making the best, most energy efficient, carbon sequestering, beautiful and inspiring buildings without wrecking the whole darn planet in the attempt.
Chris has authored numerous books on sustainable building, including Essential Hempcrete Construction (2016), Making Better Buildings (2014) and More Straw Bale Building (2005) He is co-editor of the Sustainable Building Essentials series from New Society Publishers, and is a past editor of The Last Straw Journal, an international quarterly of straw bale and natural building. He has contributed articles to numerous publications on topics related to sustainable building and maintains a blog entitled “Thoughts on Building.”
Chris is an active speaker and workshop instructor in Canada and internationally.
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