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.
Kevin McCloud, a British architect and chairman of Happiness Architects Beauty, says he “cannot find a material that does what hemp does.”
“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:
RELATED: 7 Reasons Hemp is the Most Powerful Plant in the World, Legalize It!
Comments
24 responses to “Why Hemp Houses Are The Best Houses In the World”
I’m in all for a more natural building material, but I’m afraid growers, especially commercial ones will just rape more tropical forests to grow it, as they have with oil.
Hemp repairs the soil it will do wonderful things here in United states. The corn belt would benefit from this greatly.what needs to happen is a non GMO addendum added to the legislation. We dont need a gmo version of a perfect plant. Then it would be a failure .GMO plants are failures.
How will we feed a world population of 8 billion people? As far as the corn belt, I live there and would not feel safe when our winds are 60-80 mph or tornados let alone temps in negative numbers for over a month.
This is very interesting, may I have a copy of your cited work? I’d like to review the tests done on the material and how they compare to “traditional” building materials.
I would like to see this as well.
Rick, I’m guessing you don’t mean that you expect the blogger to send you a book or paper, literally, but more like a link that you can download and review. I found several pages listing case studies and reputable sources by inputting a Google search “hempcrete case studies bibliography.” This appears to me to be pretty well-documented.
What can we do to promote these ideas, get hemp decriminalised, and used in building projects?
Have been seeking an answer to these issues.
Found it!!
Unlike US government legislators…
Growing building using hemp as a planet healthy priority makes too much sense to me!
what about the heating and cooling of these houses and how much do they cost per square footage?
Are there any websites that are just about hemp for building? Thanks.
What is the usage of it in cold temperature environments
It appears that the hempcrete finish is rough. Can we paint over it or get a smoother finish?
How would this produce work with say strawbale building?
I believe hempcrete is a great building system. I work as a Structural Engineer and have designed two so far, and promote it amongst builders and designers as ideal for our cool climate here in Tasmania.
There are some things in this article though that appear to be hype, which I believe harms the development and acceptance of natural building and hempcrete.
I’ve never heard of hempcrete being stronger than concrete. In the research I have done and in my design, hempcrete is far weaker than concrete. When touching it is has a slight give in it. In a wall it is typically used as an infill material, and does not support roof loads. Or am I reading it wrong? Can someone tell me if I am?
And no power tools needed? Perhaps not for the placing of the hempcrete, but for everything else, unless you want a seriously labour intensive build then it will need power tools. And lime is highly caustic like concrete, however because the lime is stored dry on site, and then only slightly moistened, there is lime dust around when placing it making breathing protection essential, and some tough gloves too to stop your hands getting caustic burns.
Thanks for your informed comment!
If it welcomes water how does it stay dry? Or is this a silly question? I’m not sure I understand. Could you expand on this.
Some Kansas farmers keep fighting for hemp!
Nice Read. Can you please cite your source for the claim that hempcrete is 10 times stronger than concrete? I have researched this extensively and hempcrete is not as strong as concrete. Please consider changing the subheading so that this remains a good promotion of hempcrete.
Marijuana prohibition is all about money. The big business lobby has spent billions brainwashing the public of this. Big pharma, big oil, big alcohol, textiles, and builders are all scared of something they can’t patent. If cannabis was discovered today, it would be hailed as one of the greatest discoveries in modern history. Fortunately people are getting wise to this and opinions are changing fast
Cannabis extracts improve neurogenic symptoms Especially for the people who are suffering from spinal injuries and they also relieve pain and inflammation.
How does this compare with papercrete?
I’m a builder in WV, and we recently built the first Hempcrete house in the state. It certainly is a very interesting material with lots of potential, but some of the benefits here are overstated. It is not even close to being as strong as concrete.
Also, I would not call it super-insulating, as the best R-Value achieved, based on my extensive research, is about 2.5 per inch. Less than fiberglass, much less than foam. Also, you certainly need power tools on a Hempcrete build.
I think Hempcrete is great, and I look forward to working with it again. But I think it is important to get the facts straight, otherwise folks will think its just another over-hyped fad.
Hempcrete is a non-load bearing building material, based on the research I’ve done.
As mentioned by Stephen in these comments, it used as an infill for a home that already has structural support. Mostly I see it as a form of insulation.
It would be a game-changer, especially for developing countries if it can be made into a load bearing brick. Someone please correct me if I’m wrong. But I cannot find any example of it being used this way.
This article was misleading to me in that respect. It appears to show someone building a free standing wall with hempcrete blocks. And the statement that it is 10x stronger implies it would be load bearing. Not sure what measure it is stronger in, but unfortunately not in carrying the weight of the roof.