The synergy of two ancient building materials has resulted in a simple, yet magnificent and also very light building material: hemp-limestone, the building material combination of tradition and innovation.
Since humanity discovered lime as a building material and the use of hemp as an oil and fiber plant, the use of these raw materials has been a common thread through most cultures. What belongs together has finally been put together in the hemp limestone: the woody hemp shives, a waste product from fiber production, are mixed with a small amount of lime and water. This inhomogeneous mass is pressed into bricks and then air-dried. Hemp limestone combines the positive properties of hemp and lime: it is fire-resistant and moisture-tolerant (it also insulates when wet). Due to its inhomogeneous structure, it can absorb sound very well and has optimal insulating properties with a U-value of 0.07 W/m²K. Its massive nature also makes it an excellent heat store. Buildings using this energy-efficient, lightweight and sustainable construction method can remain stable and solid for centuries, are mold and vermin resistant and offer moderate radiation protection. Lastly, this building material is completely unproblematic to dispose of; after dismantling, it can either be used as loose bulk material or is biodegradable as compost. In terms of building physics, hemp limestone is characterized by its ability to transport moisture (via diffusion and capillary action). Due to its high insulation value, additional thermal insulation is unnecessary in most cases. Although hemp limestone cannot be used as load-bearing walls, there are many possible uses: • Exterior walls • Internal insulation • External insulation • Partitions • Subfloors • Acoustic walls • Renovation By the way, hemp is a Pro-Kima building material: It grows quickly, easily and abundantly and binds so much CO² during its growth phase that it has a balance of minus 90%: suitable for grandchildren in pure stone form.
