By Benjie Cooper
IG: @nuglifenews
It was once a mandatory crop for some American farmers, but the formerly banned hemp plant is now beginning to experience new life in the United States. On February 7, 2014, Barack Obama signed the Agricultural Act of 2014 which included language that acknowledged a distinction between industrial hemp and THC-rich varieties of the cannabis plant. The law authorized institutions of higher learning and state agriculture departments to conduct research and begin pilot programs in states that legalized hemp cultivation. More than thirty states have approved laws under the Farm Bill since its passing and removed barriers from its production. Farming is allowed in sixteen of those states, which grants cultivators more rights than the 2014 bill does.
While banned in the U.S. for many years, many other countries around the world cultivate hemp as they’ve been doing for a long time. China sits at the top of the list producing 44,000 tons of hemp annually, and France is the leader in hemp-seed production, generating 59% of the crop’s worldwide total. Though the importation of hemp products has been allowed in the United States, the reality of domestic cultivation brings the possibility of much more widespread use in the country and a wealth of innovative new applications.
Among the many uses of the hemp plant is an inexpensive building material known as hempcrete. Hempcrete is a bio-composite material made from a combination of inner hemp hurd fibers, a small amount of cement, and lime as a binder. While the name implies that it’s a type of concrete, it doesn’t actually serve the same purpose. Hempcrete is not a structural material per se, but it can offer significant benefits when it’s part of a building’s construction. You won’t find any sidewalks made out of it, as it’s only 15% as dense as concrete, but you might find it on the inside of a wall.
After the steel or wood framing of a building is complete, the lightweight hempcrete can be used as an infill, molded into blocks, or cast around the frame using forms. Insulation, termite-proofing, humidity and temperature control, and fire resistance are some of the benefits of using hempcrete in construction as opposed to some of the more conventional building materials.
When the walls of a structure contain hempcrete insulation, the temperature and humidity inside are regulated naturally by the breathable waterproof material. In some cases, it eliminates the need for air heating and cooling systems entirely. Because hempcrete helps control the humidity, it creates an environment that is very resistant to mold and fungus growth.
Carbon dioxide plays a significant role in the structural integrity of the hempcrete. Because lime is in the mixture, it will slowly harden over time as it absorbs CO2 from the atmosphere. As a result, unlike other building materials that can deteriorate as they age, hempcrete will get stronger the older it gets. Combined with the fact that hemp draws carbon dioxide from the air when it’s growing, hempcrete is considered to have a carbon-negative footprint.
Hempcrete walls are not inflammable, but they do have a high resistance to fire. When exposed to hot enough temperatures, hempcrete will char and disintegrate, but it will not create flames or spread a fire. This feature can help protect the frame of a structure from fire damage when a hempcrete barrier is shielding it. If termite-resistant hemp fiberboard is also part of a building’s construction as opposed to wood, a structure’s flammability can significantly decrease while increasing its strength and durability.
As we see the beginning of hemp’s return to widespread cultivation in the United States, the opportunities for new applications are sure to abound. Hempcrete is only one of the technologies that can benefit from the reemergence of hemp onto the American farmland. There are already houses that have hempcrete in their walls, and there is no shortage of cannabis products to fill them, but expect to see an increase in sturdy, eco-friendly hemp and hemp-based building materials make their way into the scene in the coming years as the United States rejoins the rest of the hemp-producing world.
