I’ve written before about how cob or “adobe” is the best building material on earth… and it was… until hempcrete.
Ten times stronger than concrete, and one sixth the weight, this amazing all-natural material is made of nothing but hemp pulp, lime binder and water.
Like cob, it’s non-toxic, super insulating, termite-resistant, fire-resistant, mold-resistant, rot-resistant, “breathable” and will last for hundreds of years.
Unlike cob, it has the added benefit of sequestering massive amounts of carbon from the atmosphere.
While the hempcrete is a new phenomenon to most of us alive today, archaeologists believe a similar technology was used as far back as ancient Egypt, a French architect says in the mini documentary below:
In the documentary, Clarke Snell of the Nauhaus Institute discusses one of hempcrete’s best features — it’s breathability:
“It’s breathable not in the sense that air gets through — it’s airtight — but it’s breathable for water,” Snell says
“In a typical wall you have a cavity that you seal tightly and fill with insulation.”
No matter how hard you try to keep it out, water will get inside that cavity, Snell says, “because that’s what water does.”
“So we want to create a wall that welcomes water, but doesn’t rot when it lets the water in. And that’s exactly what hempcrete does.”
When it becomes humid out, it absorbs the extra humidity and holds it until the humidity drops and then it will let it back out, regulating and balancing the humidity inside the home, he explains.