From choosing food that's grown using regenerative agriculture practices to buying clothes made from fabrics that embrace longevity, like organic cotton and hemp, choosing sustainable products is quickly becoming a popular purchasing habit for conscientious consumers. Hemp is also an increasingly popular choice of eco-friendly construction material for those looking for a sustainable and affordable type of building material. Houses made from hempcrete have been built in countries worldwide, including Switzerland, the USA, and Canada.
What Is Hempcrete?
'Hempcrete' is the popular term for hemp-lime composite building material. It's created by wet-mixing the chopped woody stem of the hemp plant, known as 'shivs' or 'cores,' with a lime-based binder to create a material that can be cast into molds. This forms a sustainable, 'breathable' and insulating material that's used to forms walls, floor slabs, ceilings, and roof insulation, in both new builds and restoration projects.
The Sustainability Benefits of Hemp for the Building Industry
Hemp offers the sustainable building industry a bio-based product that is virtually carbon neutral and can be used in many building applications. Here are five reasons why hemp houses are becoming all the rage with sustainably-minded people.
Helps Reduce Global Warming
Hempcrete is the only building material that can remove carbon from the air. The cement industry accounts for 5 percent of all CO2 emissions, making it one of the largest contributors to global warming. Hempcrete, on the other hand, doesn't require widespread chemical processes or the burning of fuel that releases greenhouse gas emissions. Hemp sequesters carbon dioxide from the atmosphere, locking carbon away within the walls. It has been estimated that a 35 cubic foot (1 cubic meter) of hempcrete wall can absorb and lock 242 – 364 pounds. (110 – 165 kilos) of carbon. The lime utilized as a binder in hempcrete can also capture carbon dioxide from the atmosphere, as the lime cycle's natural chemical processes allow hydrated lime to harden into limestone.
Additionally, using hempcrete as an alternative to traditional timber framing could reduce pressure on forests worldwide and cut back on the estimated 15 billion trees felled each year. Less deforestation would also lead to increased carbon capture.
Reduce the Need for Toxic Chemicals
Hemp can be produced as a renewable agricultural resource and doesn't require agrochemical products. Hempcrete is naturally fire-resistant, reducing reliance on chemical fire retardants, and is avoided by termites and other pests.
Moisture & Mold Resistant
Hemp is moisture absorbent, which makes it mold resistant. One square meter of hemp wall can absorb up to 14 liters of water, which can be released into the ground or recycled.
As industrial hemp can be grown in a wide range of climates and soils, it is also an excellent alternative to local building material. It can also be a vital crop to reactivate and strengthen rural economies.
Naturally Insulates Homes to Reduce Power Costs
Increasing the insulation in our homes is an important strategy to improve energy efficiency. Since a great deal of air is trapped inside a hempcrete wall, both within the hemp itself and the hemp shiv matrix in the cast material, it is a surprisingly good insulating material, providing an alternative to traditional fiberglass insulation. Hempcrete also stores heat in its wall's thermal mass, which is then released slowly as the building cools down.
While hemp is an amazingly resourceful and sustainable building material, there are a couple of things to remember — hempcrete is not sufficiently load-bearing to support roofs or multiple stories without a frame, and it is not suitable for foundations.