Hempcrete is ten times stronger than concrete, mold resistant, rot resistant, pest resistant, fire resisitant, and carbon negative. It’s even better than cob/adobe.
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.
In the meantime, because the high pH lime is wrapped around the cellulose, it won’t rot.
Not only does it help create ideal indoor environment, it helps the outdoor environment too, sequestering massive amounts of carbon.
Any cellulose material, such as wood or hemp, takes carbon in during its life, and lets it back into the atmosphere when it decays. If you take that plant and put it into a wall, the carbon is trapped inside and not released into the atmosphere, he explains.
Snell helped build the first LEED certified hemp house in the world in Asheville, North Carolina, which has sequestered 20,000 pounds of carbon.
Also, with walls from 12 to 18 inches thick, homeowners can expect to cut their energy costs (and carbon emissions) by at least half.
And… hemp can be grown from seed to harvest in just four months, on bad soil, over and over and over again, unlike trees.
“Hemp is abundantly productive and will grow forever on the same spot.” ~ Thomas Jefferson
And… the part of the plant that’s used to make hempcrete is the throw-away hurd, the woody core leftover after the fiber’s been extracted.
“My great difficulty is I look at the range of materials out there and I cannot find one to match hemp,” says another architect in the mini documentary above.
“It’s an incredibly expedient building method,” he says.
“Instead of pouring out heavy wet toxic caustic concrete, the hempcrete mixer poured out this fluffy, lightweight stuff like sawdust.”
Building doesn’t require any power tools, which means no cords lying around everywhere. This combined with the lack of toxins in typical building materials makes for a very healthy, safe buidling site, McCloud adds.
“Since the beginning of time, hemp is the only plant that can feed you, house you, clothe you and heal you,” adds Cliff Thomason of Oregon Hemp Company in the National Geographic video below.
“It has the strongest fibers found in nature.”
The only thing standing between Americans and a hemp house revolution is a silly old law that confuses hemp with marijuna, which soon could be overturned with the passage of this year’s farm bill. Contact your representatives and tell them to pass the Senate’s version of the bill, which includes the Hemp Farming Act.
For more info, check out The Hempcrete Book: