When inner stalks of the hemp plant are ground into fine chirps, then mixed with lime and water, a durable, flexible, fire-resistant material is formed. This is basically how hempcrete – a renewable building material – is made.
While hempcrete sounds like a new phenomenon, it has been in use for centuries in some parts of the world. For instance, about 2000 years ago, ancient Gauls used hempcrete-like materials to build bridges and homes. It has also been a popular building material in India and China, and it’s now quickly gaining traction in Europe and North America.
Moving into the future, how is hempcrete a sustainable building material? What are some of its benefits?
Brief History of Hempcrete
Developed in France in the late 1980s to replace worn-out wattle and daub in the medieval timber-framed houses, hempcrete is a construction material made from shiv (the inner woody core of hemp plant), lime binder, and water.
The lime has high silica content which allows it to bind properly with the hemp hurd. The mixture is 6-8 times lighter than concrete, safer, and suitable for all building projects. Despite being in use for years and associated with lots of environmental, hempcrete is still not popular in the U.S., especially after hemp was banned back in the 1930s.
This eco-friendly building material is excellent as insulation infills between or around structural framing. It’s often applied as floor and roof insulation, external and internal wall insulation, as well as retrofit infill panels.
How Hempcrete Is a Renewable Building Material
Consider the following benefits of using hempcrete as a green building material:
1. Reusable
Unlike concrete, the quasi ductile properties of hempcrete allow it to be reusable without affecting its structural properties. This means that you can use hempcrete over and over, saving you a lot of money in the long run. Additionally, when done at a large scale, hempcrete can significantly reduce the pressure on the earth’s natural resources.
2. Great Carbon Sequestration
Construction is responsible for about 39% of carbon emissions, creating an urgent need for carbon-neutral construction materials.
Hemp fields have a high carbon dioxide absorption rate, making hempcrete a sustainable building material than concrete. Building with hempcrete gets us closer to achieving a sustainable eco-friendly future.
3. Sustainable Harvesting of Hemp
Growing on every continent except Antarctica, the hemp plant is resilient, taking not more than four months before its ready for harvesting. With a strong ability to outcompete weeds, hemp grows extremely fast with little water, fertilizers, and pesticides.
As a result, it’s a more reliable and sustainable building material compared to other plant products used in construction such as wood.
4. Absorb of Moisture and Carbon Dioxide
Thanks to its porous nature, hempcrete absorbs and releases moisture, controlling indoor humidity levels. At high relative humidity, hempcrete absorbs moisture and releases it when the humidity drops. Appropriate humidity levels will also prevent the growth of mold.
Hempcrete can also absorb carbon dioxide. Over time, your hempcrete house can significantly reduce your carbon footprint for a greener future.
Other Benefits of Hempcrete
Besides being a renewable building material, hempcrete comes with a range of other benefits, including:
Safe and Easy to Work With
Unlike typical concrete, which is heavy, toxic, and caustic, hempcrete is light, non-toxic, and easy to carry along. This reduces the risk of injuries at construction sites. Hempcrete homes are also more family-friendly as the material doesn’t release toxic substances over time – concrete contains alkaline compounds such as calcium oxide that’s corrosive to the human skin.
Mold and Pest Resistant
Mold and pests can easily compromise the structural integrity of your home, especially if it’s made from wood. Fortunately, the high pH levels of hempcrete make it a natural repellent for mold growth and pests. With a hempcrete home, you don’t have to introduce toxic substances in your home to eliminate mold and termites.
Fire Resistant
Hempcrete can provide fire resistance for up to two hours. However, this will depend on the type of finish and thickness of the composite used.
Sound Insulation
When used on walls or interior partitions, hempcrete traps and dampens sound waves thanks to its relatively porous nature. This guarantees you the much-needed peace, especially in noisy neighborhoods.
Suitable for All Climates
Due to the excellent thermal abilities of hempcrete, cooling and heating costs are significantly reduced. It diffuses heat during the summer to prevent overheating and retains the heat during the winter. Additionally, thanks to its moisture-absorbing ability, hempcrete is perfect for regions with high humidity.
Does Hempcrete Have Shortcomings?
Being relatively new in the U.S., it may prove difficult to find a reliable hempcrete supplier. The few available experts may charge more for their services due to high demand. You may also incur additional costs if you were to hire a hempcrete builder. Additionally, you may need permits from the local authorities to use hempcrete.
With the benefits put into consideration, these challenges are worth enduring. Additionally, with the recent legalization of hemp cultivation, you can expect more hemp products (including hempcrete) in the market. As a result, hempcrete manufacture and application will be seamless.
Learn More About Hempcrete
The benefits and need for hempcrete can’t be ignored. It’ll help you cut down on your carbon footprint and generally promote a more natural, healthier living.
For all your hempcrete-related questions, feel free to contact us for more information.