Hempcrete is a mixture of hemp hurds (shives) and lime (possibly including natural hydraulic lime, sand, pozzolans or cement) used as a material for construction and insulation. It is marketed under names like Hempcrete, Canobiote, Canosmose, and Isochanvre. Hempcrete is easier to work with than traditional lime mixes and acts as an insulator and moisture regulator. It lacks the brittleness of concrete and consequently does not need expansion joints.
However, the typical compressive strength is around 1 MPa, around 1/20 that of residential grade concrete. Hempcrete walls must be used together with a frame of another material that supports the vertical load in building construction, as Hempcrete’s density is 15% that of traditional concrete. Like other plant products, the hemp crop absorbs CO2 gas as it grows, retaining the carbon and releasing the oxygen. 165 kg of carbon can be theoretically absorbed and locked up by 1 m3 of hempcrete wall over many decades.