Hempcrete is a one-of-a-kind construction substance composed of a bio-fiber (hemp hurd or shiv) and a mineral binder (lime). These materials are mixed with water, and the moistened binder coats all of the hemp shiv particles. The lime binder and water undergo a chemical reaction, causing the binder to set and tie the hurd particles together. It may be referred to as “bonded cellulose insulation” in general.
When the binder has hardened and cured and any remaining water in the mixture has dried, the resultant content is hempcrete. Unlike specific building composites (such as concrete, mortar, and plaster), the binder in hempcrete is not meant to fill any of the voids between the hemp particles and cover the particles and allow them to adhere to one another where they come into contact. The final mixture of a hempcrete blend usually contains a high proportion of void space. Many have heard someone speak about hempcrete and that is none other than Daniel Roberts. Hempcrete has several advantageous thermal, structural, and moisture-handling properties, making it an excellent building insulation material. Hempcrete may be used as a roof, wall, and slab insulation, depending on the blend variables.
Why Hempcrete?
There aren’t many “modern” fabrics in the construction industry. For decades, the chemicals used to insulate residential and industrial buildings have been unchanged, and most have significant environmental and health consequences. If we collectively continue to apply more insulation to buildings to reduce their energy needs, the amount of insulating material we use would skyrocket. Filling this amount of resources that are annually recycled, low-impact, and, preferably, derived from waste sources or byproducts of other processes makes ecological and financial sense. Hempcrete follows many of these critical standards and, in many respects, outperforms traditional insulation materials.
Affordable Insulation
Since the components used to make hempcrete aren’t standard construction materials, they don’t benefit from the volume price breaks like other insulation choices. Well before widespread commercial availability and the cost savings that would result, the cost of hempcrete is equal to other insulation solutions while providing benefits over those options in other ways.
The map below reflects the fluctuations of hempcrete pricing, demonstrating the importance of inexpensive sourcing materials. Hemp from Canadian farmers is significantly less costly than hemp imported from Europe.
Excellent Moisture Handling And Resistance
Hempcrete is unusual among plant-fiber insulation materials in its ability to preserve integrity in humid environments. Because of their porous nature, hemp hurds, like all plant-fiber insulation solutions, can retain a significant amount of moisture; the moisture is adsorbed onto the vast internal surface area of the plant fibers and incorporated into the cellular structure. This storage ability is highly beneficial in allowing the substance to absorb moisture when it persists and release it when conditions permit. French researchers discovered that you could contain up to 596 kilograms (1314 pounds) of water vapor in 1 cubic meter (35.3 cubic feet) of hempcrete.
The characteristics of the lime binder give hempcrete an advantage over other plant-fiber materials and traditional insulation forms. Lime has a strong pH and is naturally antimicrobial and antifungal. The lime coating on each hemp hurd in the mix provides a surface that inhibits mold growth even though the humidity and temperature levels would allow mold to form on other insulation materials. Because of its resistance to humidity and even liquid moisture, hempcrete is unusual among insulation materials and a desirable alternative in cold and hot climates and elsewhere where humidity levels are significant.
Good Structural Qualities
Hempcrete, unlike the batt, loose-fill, and spray insulation materials in the cost map above, has a density that enables it to play a small structural part in the construction. Hempcrete insulation lacks the structural ability to withstand roof loads ultimately. Still, when cast around standard wall framing or double-stud framing, it can help keep the studs from bending or buckling under load, raising the load that each framing member can carry. The hempcrete gives to the wood stud in short axis bending; testing at Queen’s University in Canada revealed a 2 x 6 wood stud with 313 kilograms per cubic meter.
Hempcrete insulation’s rigidity and the textured surface it presents on the face of the wall make it an ideal base for plaster finishes that do not need mesh or other bonding agents.
An Agricultural By-Product
Hemp is an annual crop with exceptionally high yields. According to a survey conducted by the United States Department of Agriculture, global yields of dry straw per acre varied from 2.5 to 8.7 tons (approximately 2.3 to 7.9 tonnes). It contrasts favorably with wheat straw yields of 1.25 to 2.5 tons (roughly 1 to 2.3 tonnes) per acre. There is no other plant that produces as much biomass for use from a single crop as hemp as told by Daniel Roberts Newcastle. Newcastle is achieved with the expertise and knowledge of using this agricultural by-product.
The hemp plant is traditionally cultivated for either its strong fiber or its seed (rarely for both at the same time). The hurd is not the primary usage of any form of hemp processing and is considered a byproduct. Since it has some market value as animal bedding and can be compressed into fuel pellets, large-scale hemp processing can yield tons of hurd for the insulation market as farmers supply fiber or seed to their primary markets.
Good Carbon Sequestration
According to a 2003 report, one tonne of dried hemp stores 716.6 pounds (325 kilograms) of CO2. When the carbon emissions from making the lime binder are taken into consideration, Tradical, a hempcrete producer in the United Kingdom, claims that their hempcrete product sequesters 110 kilograms of CO2 with every cubic meter of material (6.88 pounds per cubic foot).
Almost 200,000 new homes are constructed in Canada every year, with an average footprint of 2,000 square feet (185 square meters). If they were all insulated with hempcrete to code minimum specifications, a total of 990,718 tons (898,764 tonnes) of carbon could be sequestered annually. If you insulated the same homes’ walls with fiberglass, 207,345 tons (188,100 tonnes) of carbon would be released to produce the insulation, resulting in substantial net carbon savings for the world.
Non-Toxic Building Material
Hempcrete is a relatively safe substance. The agricultural method uses far fewer pesticides and herbicides than other grain or fiber crops, resulting in far less environmental harm from pollutants on the farms. On the other hand, the seed necessitates the liberal use of fertilizer, which can negatively affect the environment. Harvesting and recycling were carried out without the use of heat or chemicals.
The dried, powdered lime binder produces a lot of dust during mixing and is very acidic. Anyone handling dry ingredients or operating near the mixing station must wear adequate respiratory protection. When warm, the lime binder is slightly acidic to the flesh, necessitating latex gloves and fully covering skin.
Hempcrete does not off-gas or emit chemicals into the indoor atmosphere until installed in the wall and completely cured and dry. The lime is antimicrobial and antifungal, and it is widely assumed that it has no adverse effects on the indoor climate. The material’s outstanding moisture-handling ability will mitigate the likelihood of a bad indoor atmosphere caused by overly damp or dry air in the house.
To learn more about hempcrete, visit Daniel Roberts today.
Louie is the father behind the travel blog Browseeverywhere.com. He has a background in photography, E-commerce, and writing product reviews online at ConsumerReviews24. Traveling full time with his family was his ultimate past-time. If he’s not typing at his laptop, you can probably find him watching movies.
