National Hemp Month Spotlight: Hemp in Buildings and Construction Materials
By Jace Pohlman, Law Clerk
Jul 14, 2021
As part of National Hemp Month, we're highlighting beneficial ways to use hemp and hemp products in our daily lives. This post will focus on using hemp in buildings and construction, opening the door to stronger structures, unique designs, and an overall positive impact on the environment.
Two parts of the hemp plant are primarily used for construction purposes—the fibers from the skin of the hemp stalk and small pieces of the hemp stalk, called hurds. Given hemp's ability to grow in different climates and regions, there is a lot of untapped potential in using this crop as a building material.
Hemp fibers are typically used for products like building insulation due to the hollow build and strength of the material. Additional benefits include more efficient moisture handling when compared to traditional materials, and nontoxicity, which safeguards installers and homeowners from harmful chemicals and volatile organic compounds.
Hempcrete and Hurds
Hurds are small pieces of hemp stalk and can absorb and transfer water vapor extremely quickly. Hempcrete is precisely what it sounds like—hemp-based concrete! Hempcrete is made by mixing the hurds with other materials, such as clay or sand.
Hempcrete is used as a building material in four typical ways: casting, sprayed, block/bricks, and panels.
Casting is a low-tech approach and consists of manually casting hempcrete around a timber framework or structure.
The sprayed technique is similar to casting but lowers the water content within the hempcrete mixture.
Blocks are similar to the typical concrete blocks or bricks used in common structures but provide additional insulation.
Panels use both hempcrete and hemp fibers and provide a quick-fix installation system for numerous building types. Panels can be made offsite, then transported to the building site and installed quickly.
Impacts of Hemp Building Materials
There are many benefits to using hemp-based building products and techniques, including:
Hemp can help reduce the energy used to heat and cool buildings because of its strong insulation capabilities.
Hemp building products release less moisture into the air, which can help prevent mold accumulation due to water absorption.
Hempcrete becomes more fire-resistant as it ages. If burned, it does not produce the flames or gases that typically accompany the burning of conventional building materials.
Using hemp in building materials will help us all on our path to becoming carbon neutral. When the hemp plant is in the growth cycle, it absorbs carbon from the air (and may even clean contaminated soils). And as demand rises for hemp construction materials, more hemp will be cultivated around the world. It's a win-win!