We get many comments on social media every time we publish an article on Hempcrete. Some are ironic, but most of them ask what would happen if it caught fire. This is a valid question because there is still much confusion over the differences between hemp and marijuana, which both come from the same species of plant ( Cannabis Sativa). While marijuana does have psychoactive effects, tetrahydrocannabinol, (THC) is mainly found in the flower, hemp-based building materials are made from the stem which contains low amounts of THC. The building will not be destroyed by a fire, as the title suggests. These materials are resistant to fire and dissipate flames. They also maintain structural integrity and don’t emit harmful smoke.
It is an old practice to use hemp in civil construction. Numerous studies have demonstrated how beneficial this plant can prove to be for the industry’s future. It has a low carbon footprint. This means that it absorbs less carbon than it produces. At the end of its useful lives, it can be returned to nature and degrade naturally. Concrete mixers mix hemp, powdered limestone, water, and other ingredients to form a thick paste. This is then petrified by chemical reactions and makes a light, but durable block. The mix can be laid as non-structural blocks or sprayed to create wall structures. Hempcrete is resistant to mold and has excellent thermoacoustic qualities.
Hemp-based materials perform well in fire, contrary to what you might think. Specific rules are followed to determine the properties of each material. For example, the ASTM E84-19B results for hemp concrete in the United States showed remarkable performance. They were able to achieve top ratings for “flame spread”, and “smoke product” ratings.
A fire test was conducted in Australia to simulate wildfires and embers. There is also the possibility of fuel accumulating at the base. This is especially worrying in Australia where large forest fires are a common occurrence. The 200 mm thick concrete walls of hemp were not damaged by the 600 mm flame that was placed directly against them for 60 minutes.
Similar results were also confirmed in the collection of hemp concrete experiments. It was found that hemp concrete acts as a barrier between fire and building structures. Hemp concrete is non-flammable and doesn’t allow flames or heat to escape. The study’s author stated that “currently available data suggest that hemp concrete can be used in applications that require 60-minute fire resistant, and that it is easily possible to increase this to 90- or 120 minute fire resistance by modifying the specification.”
All precautions must be taken when dealing with forces of nature such as fire to protect lives and preserve resources. Many researchers are now focusing their attention on this subject and studying the behavior of different materials in a fire. Hemp-based materials are fire resistant enough to allow residents to evacuate quickly, and reduce the spread of the fire as well as the chance of inhaling smoke from the fire. It will therefore be difficult to burn a wall made of hempcrete. However, it will not cause any psychoactive effects. Despite jokes, hemp remains a highly stigmatized material in many nations. However, it must be addressed. The many uses of hemp in various industries have the potential to replace polluting substances that are harmful to our environment. They may even be the catalysts for a shift in civil construction.