Hemp-based building materials have the ability to transform agricultural activities and the construction industry. Environmental awareness and corporate responsibility are major themes in the business world today. This is why more and more people are interested in using natural building materials that are renewable, sustainable and eco-friendly. Hempcrete, which is a bio-composite product made from lime, water, cement and hemp, is an ideal building material for specific construction purposes.
Global warming, climate change, resource depletion and carbon footprints are serious environmental problems that continue to worsen throughout the world. The construction industry and engineering experts are searching for sustainable development solutions that will meet present needs without compromising the safety and security of future generations. Sustainable building material are any materials that are produced or harvested that have zero negative impacts during the life cycle and disposal process. Wood, steel and concrete are excellent materials, but they all require large amounts of energy for extraction, processing, manufacturing and transportation. Each of these stages contributes to higher levels of embodied energy, which refers to waste and redundancies. Popular sustainable building materials include straw bales, rammed earth and hempcrete.
What is Hempcrete?
Hemp is a fast growing plant that comes with naturally stretchy and strong fibers that grow inside the core stem. When this core is chopped up into tiny pieces, it can be mixed with lime, water and a little cement to create hempcrete. This is a low-density material that offers excellent thermal, insulation and humidity regulation benefits. Hempcrete has lower density and thermal conductivity as well as better acoustic insulation properties than regular concrete. Because it has low elasticity and compressive strength, it cannot be used as a direct load bearing material. However, it makes an excellent fill material in timber stud walls. When it is used as insulation in structural frames, lime plaster is added for weatherproofing purposes. Fire resistance tests reveal that hempcrete is impervious to continual contact with blowtorches.
Construction companies use hempcrete materials to strengthen timber stud walls by minimizing weak axis buckling and providing continuous elastic support. While high-density hempcrete can bear a limited load, but it is more expensive to produce. Low-density hempcrete requires less binder during the manufacturing process, so it is more economical and suitable for structural infill material. However, more research is needed to understand how hempcrete with different density can increase buckling strength and act as load bearing materials. Building codes and the associated engineering equations for calculating the compressive strength of timber are outdated. Traditional resistance against change is slowly happening through news articles and research by organizations like the American Society of Mechanical Engineers.
Positive Environmental Impacts
Environmentally conscious building designers can now create buildings that’s support healthy indoor and outdoor environments. The ideal natural building materials will require limited energy to produce, harvest and renew. This will lower the carbon and pollution footprints of the building during and after construction. Hempcrete has a high thermal resistance, or an R-value, of approximately 2.4 per inch. This is higher than straw bale construction and various earth and straw construction mixes. It is close to conventional cellulose or fiberglass insulation products. Higher R-values increase the material’s insulating power. Hempcrete offers adjustable thickness because it can be manipulated to meet the thermal requirements of different climates and buildings. It’s high density produces low air infiltration, which reduces HVAC energy waste. Hempcrete is a hygroscopic material, which means that it can absorb and release water in response to changing humidity levels.
Hempcrete promises excellent construction and environmental benefits. Readers can learn more about the benefits of hempcrete from this insightful Tedx Talk.