With the legalization of hemp, new opportunities arise for sustainability-focused contractors. Hemp could be poised to disrupt the industry of conventional building materials.
In 2018, the Trump Administration passed the latest iteration of the Farm Bill, effectively removing hemp from the federal List of Controlled Substances. With the stipulation that it cannot contain more than 0.3% THC, hemp turned from a stigmatized shrub into a blossoming cash crop.
Two U.S. companies, one in Idaho and the other in Kentucky, have stepped up the challenge. Using American hemp farmers and factories based in the U.S., Hempitecture and HempWood are championing the future of sustainability in building materials.
How Is Hemp Being Used in Construction?
While hemp has been used as a building material in Europe for more than 30 years, it’s only beginning to gain ground in the U.S.
American entrepreneurs are turning hemp fibers into wood, concrete, and insulation. There are no limits on the scope of this growing green industry. Manufacturers intend to deliver materials to residential, commercial, and industrial builders.
Greg Wilson, the founder of HempWood, has developed a wood-substitute that is 20% denser than oak and grown 100 times faster.
“[HempWood] utilizes bio-mimicry to transform hemp fibers and protein-based bonding agents into a viable substitute for anything solid oak can be used for,” Wilson states on his website.
Wilson, who opened the first HempWood factory in Murray, Kentucky in the fall of last year, claims HempWood can replace any timber function. HempWood can even be cut, sanded, and stained. With a special focus on replacing hardwoods for flooring, cabinets, and furniture, Wilson plans to oust deforestation using the versatility of hemp.
Hempcrete, on the other hand, has its limitations when compared to its conventional predecessor. Best used for insulation, hempcrete blocks need to be used with a load-bearing timber frame.
However, hemp insulation is still a viable alternative to concrete and fiberglass. Made by mixing hemp shivs with lime and water, hempcrete is breathable, non-toxic, and eco-friendly. In fact, hemp insulation has the same R-value as fiberglass at around 3.7 per inch. Naturally, insect-repellant hemp fiber absorbs moisture, reducing mold and deterring termites.
Hempitecture, an Idaho-based construction firm, has already helped construct three buildings using hempcrete, with impressive results.
Hemp, Health & Safety
Hemp homes could mean better, safer air for the occupants. By eliminating the number of toxins in the air due to concrete dust and harmful binding agents, hemp enthusiasts hope to have residents breathing easier.
Hemp takes no pesticides to grow and uses minimal fertilizer. In manufacturing, HempWood uses a soy-based binding agent instead of synthetic chemical binders.
Hempitecture’s HempWool insulation is made of 100% natural raw materials. That’s 92% hemp fiber and 8% polyester.
As for the environment? Hemp actually absorbs carbon dioxide. From growing to manufacturing, Hempitecture and HempWood make a point to be zero waste and carbon negative.
Could Hemp Building Materials Disrupt the Industry?
As Wilson puts it, “…A more sustainable way of living is no longer a luxury, but a requirement.”
With a close eye on the climate, both political and environmental, Wilson believes disruption is imminent.
However, more research needs to be done. For example, there is no standard for hemp building materials, making it difficult to regulate and certify.
And in its current state, hemp building materials may be prohibitively expensive for the average American.
Russ Martin, former mayor of Asheville, North Carolina, built his 3,400 square foot home partly using imported hemp-based materials in 2009. The cost? $133 per square foot, compared to the average $84 per square foot in the same year.
Wilson is currently striving to keep HempWood competitively priced with hardwoods like oak, stating that softwoods like pine and poplar are out of reach.