Hempcrete Has A Negative Carbon Footprint
Hempcrete is a bio-composite material. It is a combination of hemp hurds mixed with a lime binder that can be used as a material for construction and insulation.
Hempcrete is reportedly one of the best performing, non-toxic, ecological and renewable materials available and it has a negative carbon footprint. It improves air quality and energy consumption for heating and cooling, providing a comfortable and healthy living environment. Hemp absorbs CO2 and the carbonation of the lime during curing adds to this effect as the lime turns to limestone. Theoretically, 165 kg of carbon can be absorbed and locked up by 1 m3 of hempcrete wall during manufacture. Hempcrete is mold- (if cast properly), fire- and pest- resistant, has a high R-value and pulls CO2 from the air and emits oxygen, helping with indoor air quality.
Hempcrete is reportedly 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. The result is a lightweight insulating material ideal for most climates as it combines insulation and thermal mass. Hempcrete creates a monolithic structure, which acts as OSB, insulation and drywall. No cavity is necessary, but framing is still required. Hempcrete is a non-structural material which is cast around a timber, steel or concrete frame. Hempcrete will provide additional support to the frame.
An exterior hemp plaster finish can provide protection from the rain and also add to the exterior beauty of a building. The hemp plaster will provide an end result that looks similar to conventional stucco. Because hemp plaster contains more lime and water than the hempcrete wall mix, the plaster will further seal the structure as well.
You may also be interested in this article about the green commercial building study.