- Hempcrete, a biocomposite material made from hemp, lime, and water, is fire-resistant and eco-friendly.
- Hemp block walls maintained structural integrity for two hours during fire tests, making them ideal for fire-prone areas.
- Hempcrete is sustainable, carbon-negative, and provides excellent insulation and humidity regulation.
- Despite past stigma, hemp is gaining recognition as a viable and versatile building material.
- Hempcrete offers a low-tech, sustainable solution for building fire-resistant homes in wildfire-prone regions.
As wildfires continue to devastate communities, particularly in regions like California, families are left searching for ways to rebuild safer, more resilient homes. While high-tech solutions like AI-powered fire prediction systems and water-dropping drones are gaining attention, sometimes the answer lies in simpler, low-tech approaches rooted in sustainable building practices.
Enter hemp blocks, also known as hempcrete—a fire-resistant, eco-friendly construction material that could revolutionize how we build in fire-prone areas.
What Is Hempcrete?
Hempcrete, or hemplime, is a biocomposite material made from a mixture of hemp hurds (the woody core of the hemp plant), lime, and water. It’s used for construction and insulation and is marketed under various names, including Hempcrete, Canobiote, Canosmose, Isochanvre, and IsoHemp. Unlike traditional concrete, hempcrete is lightweight, breathable, and sustainable, making it an attractive alternative for eco-conscious builders.
Hempcrete’s Fire-Resistant Properties
A recent study published in the Journal of Building Engineering examined the fire behavior and structural performance of hemp-based materials, including raw hemp shives, hemp blocks, and non-load-bearing hemp block walls. The findings are promising for those looking to build fire-resistant homes.
Researchers conducted a series of tests, including cone calorimeter, bomb calorimeter, standard furnace, heat-transfer rating inducing system (H-TRIS), and small-scale elevated temperature material tests. The results showed that hemp blocks do not catch fire when exposed to open flames.
Instead, they smolder slowly, producing minimal smoke. Even more impressive, walls made of hemp blocks maintained their structural integrity for two hours during fire tests—a critical factor in preventing building collapse during a fire.
While raw hemp shives exhibited ignition and a relatively high heat release rate (HRR), hemp blocks showed no flaming ignition and an HRR significantly lower than that of shives. The blocks charred under extreme heat, but their structural capacity remained intact up to 200°C. At 300°C, the material’s strength diminished, but the overall performance was still remarkable.
The study concluded that hemp block walls are highly fire-resistant, with plastered walls likely to perform even better. This makes hempcrete an excellent choice for building in fire-prone areas.
Why Hempcrete Is a Game-Changer
Hempcrete’s fire-resistant properties are just one of its many benefits. As a sustainable material, it has a low environmental impact. Hemp is one of the fastest-growing plants on Earth, requiring minimal water and no pesticides. It also absorbs large amounts of carbon dioxide during its growth, making it a carbon-negative building material.
Additionally, hempcrete is breathable, regulating humidity and improving indoor air quality. It’s also lightweight, reducing the load on building foundations, and provides excellent insulation, keeping homes warm in winter and cool in summer.
Overcoming the Stigma Around Hemp
Despite its many advantages, hemp has faced regulatory hurdles due to its association with cannabis. While industrial hemp contains only trace amounts of THC (the psychoactive compound in cannabis), it has taken years for nations to recognize its potential as a viable building material. Today, however, hemp is gaining acceptance as a sustainable and versatile resource for construction, textiles, and more.
A Sustainable Solution for Fire-Prone Areas
For families rebuilding after wildfires, hempcrete offers a way to construct homes that are not only fire-resistant but also environmentally friendly. Its ability to withstand extreme heat, combined with its sustainability and insulation properties, makes it an ideal choice for disaster-proofing homes.
As the world grapples with the increasing frequency and intensity of wildfires, solutions like hempcrete remind us that sometimes, the best innovations are rooted in nature and tradition. By embracing sustainable building practices, we can create safer, more resilient communities for the future.
Companies producing hemp blocks:
Hemp and Block
Colorado. The company offers made-in-USA hempcrete, hemp blocks, pre-cast hemp-lime products, and hempcrete binder, sourcing materials domestically to support the American economy.
HempBLOCK USA
Exclusive distributor of BIOSYS and MULTICHANVRE blocks, re-branded as HempBLOCK, providing innovative hemp blocks for construction.
HempStone
Builds with and supplies natural high-performance building materials, including HempLime (hempcrete), to create healthy buildings and retrofit structures.
International Hemp Building Association
Hemp Building Company
Provides hemplime insulation services, natural building materials, and training workshops in the United States.
Americhanvre
A full-service hemp building material installer dedicated to promoting hemp-based building materials at the forefront of green building.
