You’ve just discovered how the fibre is obtained when the hemp stalks are broken. The woody splinters shed during that process are prized as raw material in ecological house building. You probably remember that those left-over splinters are called shives. They’re very suitable as bulk insulation, since they keep their shape and are resistant to insect damage.
The reason hemp shives are such good insulation material is because they trap a lot of air. They’re excellent for both heat and sound insulation. Using hemp shives as cavity wall insulation is extremely effective. Besides, shives work very well in combination with clay – a case of ancient wisdom coming into its own again in modern mud-wall or loam construction.
You’ll have noticed the bricks lying on the floor. Go ahead and pick one up. Notice how lightweight this kind of brick is. That's because of the hemp shives, which not only make this mudbrick so light, they also increase its breathability and improve its insulating capacity.
This type of refined mudbrick is made of a modern composite material – a mixture of natural lime, hemp shives and water. The combination is especially strong, and no further additives are required. “Hempcrete” bricks like these are currently being developed and are ideally suited as ecological, yet inexpensive construction material even for conventional house building.
Walls built of hempcrete also have other unbeatable advantages: they’re fire-resistant and, as a natural material, even recyclable or compostable. The material’s eco-friendly nature is reflected in a negative carbon footprint: around 90 per cent more CO2 is stored in hempcrete than is released during its production.
All depictions: © Dagmar Trüpschuch