CannaConstruction: From Field To Foundation
I always like seeing non-recreational use cases for the cannabis plant because I feel that they help give the plant legitimacy in front of naysayers. One of the best use cases for it is in construction and it has been used this way for multiple millennia. In this post I will be going over developments in the construction world that involve cannabis.
First on this list, and the most interesting in my opinion, is hemp-based rebar. Researchers from Rensselaer Polytechnic Institute (US) say they have developed a hemp‐based rebar reinforcing technology for cement construction. Rebar is used to construct skeletal frameworks in conventional cement buildings to provide tensile strength, which concrete lacks. More specifically, the material in question is a “hemp-based natural fiber-reinforced thermoplastic”. The hemp rebar is made through a pultrusion process in which the fibres are pulled together with thermoplastics into a heated die and melted to form a solid bar. The team’s studies have found that the material is comparable in strength to steel rebar, can eliminate problems with corrosion, and can help drastically cut down on greenhouse gas emissions. The team believes that it can last three times as long as steel rebar in salty environments, which is typically 40 to 50 years. Unfortunately, since it is a very new development, and is apparently still awaiting peer review as of March 15th 2022, it isn’t available for purchase anywhere. But yeah, welcome to the future.
Second on the list is hempcrete. Hempcrete, which is also called hemp concrete and hemp lime, is a bio-composite made of the inner woody core of the cannabis plant mixed with a lime-based binder and can be traced back to 2000 years ago when it was used by the ancient Gauls to build bridges and homes. Hemp has also been a popular building material in Japan, China, India, and more recently in Europe (hempcrete in its modern form was developed in France in the 1980s). In the US, the use of hempcrete has been limited, especially after hemp was banned in the 1930s. However, it’s slowly gaining traction as a result of the 2018 Farm Bill. Combine it with the hemp rebar mentioned above, and your project will be indestructible (maybe).
Next up is HempWood. HempWood is made via a patented process that utilizes bio-mimicry to transform hemp fibers and protein (soy) based bonding agents into a viable substitute for anything solid oak can be used for, including flooring, cabinetry, joinery, paneling, and decking. No added formaldehyde. All hemp growth and material production is conducted in the US and the hemp is grown using sustainable methods, which helps eliminate deforestation. HempWood is the first pressed hemp building material available for purchase in the US, ever.
Then there’s hemp coreboard. Coreboard is manufactured by a US company called Sunstrand, founded in 2014, and is meant to be a sustainable replacement for particle board and other board materials in many applications, including cabinetry. Hemp is light-weight, durable and strong, making it a perfect fit for applications where particle board is generally used. In addition, it’s easy to work with and reduces manufacturing and shipping costs because of its lower weight. It also has the added benefit of being manufactured without formaldehyde and VOCs, unlike particle board and plywood. Of important note, however, is the fact that the hemp boards currently being manufactured by Sunstrand are not structural, though the potential is there for the future.
Last but certainly not least, we have hemp insulation. Hemp insulation, also called batt, is manufactured (also by Sunstrand) using hemp wool. Hemp wool is made with wood and strong fibers obtained from the hemp plant. Hemp insulation contains approximately 92% biomaterial and around 8% polyester fibers. Fire treatment and non-toxic bonding agents constitute the remaining composite to make it compliant with Class A fire requirements.
In the future, I hope someone can use the information in this list to build a cost effective and robust HempHome.