While obstacles still stand in the way of the general use of hempcrete in construction, the building material is here to stay. We already know how to make it, and are exploring its potential throughout the building industry. Wide-spread use is still a ways away as tests get done for its durability and stability. But, that doesn’t mean the recipe for creating hempcrete isn’t out there.
Wet mixing hempcrete
Wet mixing is when you add water to a dry set of ingredients to create the final product. When you make cement, you add it to water along with sand and coarse aggregate. When creating hempcrete, you add water to the shredded stems of hemp plants. A lime mineral-based binder rounds out the ingredients. It transforms the plant into a concrete-like substance.
Once all the ingredients combine, a chemical reaction known as hydration occurs. This is when the concrete hardens and gains strength. The same occurs with hempcrete. It’s the water that stimulates the reaction between the other materials in the mixture. It becomes a workable paste until hardened into its final product.
Both concrete and hempcrete rely on this process to create dependable building materials. The difference is that concrete has a long-standing reputation. Hempcrete is still new to the game.
Not the same solid hemp
One obstacle for creating hempcrete is its final, hardened state. Unlike concrete, when hempcrete hardens, it’s not a complete solid. This is because a void space appears between the strands of hemp stems. The lime binder holds the strands together, but it’s not a complete merging of materials, so hempcrete is technically softer than concrete.
This isn’t to say hempcrete is weak. It’s just different. And, to adjust to that, the strength of the materials used in hempcrete aren’t the same. The particular part of the hemp plant, the woody stem, used in the mixture is some of the plant’s hardest material. Lime, which serves as the binder, is a trusted component of building materials, used for thousands of years. Together, they can work in the right setting.
These factors, along with the inconsistencies between hempcrete makers, makes it harder to align it with local building codes. Since it’s also new, hempcrete is harder to make in the quantities builders might need. Developing a stronger binder could change the game, but that advancement is still underway.
Insulation for now
For now, builders are exploring hempcrete’s potential within a variety of insulation materials. The argument for the product is that it’s environmentally-friendly. Hempcrete comes from a renewable source — hemp. Using the often unwanted stems means manufacturers can capitalize on the whole plant as well. Less waste is ecological, even when talking about plants.
As builders turn to construction options that can help lower their energy costs, the demand for insulation increases. Hempcrete could prove useful. The material can resist humid conditions and is naturally antimicrobial and antifungal. This means a lower risk of mold and mildew within the walls.
Hempcrete is also certified as fireproof. It recently passed one of the most rigorous requirements for any building material. The downside to hempcrete as an insulation material though is it may need 12 inches of wall. Other types of insulation only need about 4-5 inches of insulation, meaning hempcrete can eat away at a building’s square footage.
Hempcrete on the horizon
Whether it becomes a sustainable building block for our homes and offices down the road, hempcrete already has a lot going for it. As consumers shift to wanting materials that are eco-friendly, durable, and dependable, this could get a leg up in the construction industry. A lot may still need to happen, but hemp’s potential in this particular area is definitely one to watch.
You can stay up-to-date on hemp’s latest developments through the extensive resource bank at Arbor Vita8. We put our industry expertise into everything we do. We’re on top of hemp’s trends to properly advise both farmers and manufacturers on where to take their hemp next. To learn more, contact us today.