Inhabitat

Hemcrete®: Carbon Negative Hemp Walls

sustainable design, green design, hemcrete, building materials, concrete, green building, architecture, carbon negative concrete, tradical

Buildings account for thirty-eight percent of the CO2 emissions in the U.S., according to the U.S. Green Building Council, and demand for carbon neutral and/or zero footprint buildings is at an all-time high. Now there is a new building material that is not just carbon neutral, but is actually carbon negative. Developed by U.K.-based Lhoist Group, Tradical® Hemcrete® is a bio-composite, thermal walling material made from hemp, lime and water. What makes it carbon negative? There is more CO2 locked-up in the process of growing and harvesting of the hemp than is released in the production of the lime binder. Of course the equation is more complicated than that, but Hemcrete® is still an amazing new technology that could change the building industry.

sustainable design, green design, hemcrete, building materials, concrete, green building, architecture, carbon negative concrete, tradical

Good looking, environmentally friendly and 100% recyclable, Hemcrete® is as versatile as it is sustainable. It can be used in a mind-boggling array of applications from roof insulation to wall construction to flooring. Hemcrete® is waterproof, fireproof, insulates well, does not rot [when used above ground] and is completely recyclable. In fact, the manufacturers say that demolished Hemcrete® walls can actually be used as fertilizer!

Available for years in the U.K., Hemcrete® is only now finding its way into North America. The species of hemp used to manufacture Hemcrete® is illegal to grow in the U.S., making Hemcrete® an expensive option for U.S. builders for now. As pressure for more sustainable building materials grows, lawmakers are certain to revisit this and other similarly restrictive statutes, particularly if there is money to be made. And judging from the success of Hemcrete® in Europe and elsewhere, there is plenty to be made; it is so profitable overseas that Hemp Technologies, one of the biggest manufacturers of hemp products in the UK, is actively recruiting as many new growers as it can.

+ Tradical Hemcrete

27 Responses to “Hemcrete®: Carbon Negative Hemp Walls”

s3xt0y Says:

August 24th, 2009 at 4:01 pm

Wow, thats pretty amazing, doesn’t say how much it is though, or maybe I’m not just looking hard enough.

Dead_Unicorns Says:

August 24th, 2009 at 6:13 pm

I can’t even enumerate all of the problems with this. But. here is a small list:

1. Cellulose aggregate concrete(Hemcrete) is NOWHERE near 7 times stronger than stone and sand aggregate concrete. Their claim is a flat out lie! In fact, their website states that the compressive strength is so low that it can’t be used fro load baring applications.

2. Doesn’t rot is an exaggeration that may be arguable. But, the mold problems with cellulose construction is a very real issue.

3. Insects, specifically termites are a real issue despite the manufacturer’s claims.

Cellulose reinforced construction is nothing new. It was used in ancient Egypt and in the Great Wall of China. But, as time and technology advanced, we found better construction materials. The new materials were stronger, cheaper, more durable and easier to manufacture. Not necessarily in that order. Hell there are better cellulose base construction materials already in common use. It’s called wood!

This is yet another by hemp growers to find a market for their product that nobody seems to want. Whether it’s hemp clothing or construction materials, no one, except for a few Birkenstock wearing granola crunchers is interested in hemp anything.

archonic Says:

August 24th, 2009 at 6:28 pm

Anyone know if it’s illegal to grow in Canada?

Planner7 Says:

August 24th, 2009 at 8:32 pm

Yet another application for hemp (food, fuel, fiber, paper, clothing, medicine, and now building material). This is the replacement for our petroleum economy. We would not have to grow any more cotton, which takes a ridiculous amount of water and pesticide. We could stop chopping down our forests for paper, creating a horrible byproduct in the process of turning wood into paper (not to mention that it lasts longer, and if you don’t believe me, just look at the Declaration of Independence). Now, we can even build with it. Problems aside, you should look at its environmental benefits, as well as the environmental degradation caused by the oil, timber, cotton, and pharmaceutical companies whose processes are just plain nasty! Sometimes the most environmental thing you can do is to keep it simple.

billster84 Says:

August 24th, 2009 at 9:26 pm

We are building what we think is the first home in the US using Tradical Hemcrete…and we chose it ourselves :) – not the hemp industry.

Our team has done a lot (a lot!) of research on it and, since I’ve only been with this group for the past few months, I can’t speak to all of Dead_Unicorns points but I can say that the “doesn’t rot” claim is pretty spot on (lime based binders prevent mold through their pH and by wicking moisture to the outside of the wall where it can evaporate). I can point our engineer or others to this post to answer the rest of your critiques. It is vapor but not water permeable which gives it several advantages over wood in terms of longevity. One other great point is its R-value (measure of thermal resistance used to “rate” insulative performance). Depending on the mix, which influences strength by the way, it can be R-2.5/inch or more. Closed-cell structure of hemp makes it different from other cellulose as well. Really, you can read all about why we like hemp crete in a post we made about our prototype… titled “Why We Like Hemp Crete”

http://www.thenauhaus.com/currentprojects/nauhausprototype/hempcrete.php
http://www.thenauhaus.com/currentprojects/nauhausprototype/prototype.php

dezholling Says:

August 24th, 2009 at 9:40 pm

Does anyone know if it would actually become financially plausible if hemp were legal to grow here? Or is that just the hope?

Jeff M Says:

August 24th, 2009 at 10:16 pm

Dead_Unicorns:

You clearly have some personal issues to resolve.

Nevertheless, I agree in that I did not see anything on the Tradical website claiming that Hemcrete is stronger than concrete. The FAQ page states “Hemcrete® is not load-bearing, so the limitation is only on the structural frame.” Additionally, Hemcrete structural blocks compressive strength is stated as 3 MPa, whereas “regular” concrete is in the range of 10-40 MPa.

I would not be surprised if Hemcrete is 7x stronger in tension, but that doesn’t seem relevant to a comparison of concrete without some explanation. So, this article does appear to be misleading, at best. Please explain, Daniel. Thank you.

billster84 Says:

August 25th, 2009 at 7:05 am

it grows incredibly well in many areas of the US. It’d be great to replace the tobacco farms of NC that have been disappearing for the last couple decades.

gerrymetal Says:

August 25th, 2009 at 7:26 am

Actually, hemp used to be the most important crop in the US. the first law concerning it was passed by the Virginia assembly in 1619 requiring every household to grow it (see Eric Schlosser, Reefer Madness for historical sources).
This is the most versatile crop in the WORLD! So, it would be financially plausible due to the crazy number of options open for return on the investment.
(sorry to nerd it up – 1st post!! :P)

mdandeneau Says:

August 25th, 2009 at 7:59 am

What makes me skeptical is that they fail to elaborate on the “7X stronger than concrete claim.” Concrete is much different in terms of compression-bearing loads vs. lateral, that’s why your local strip-mall Tae Kwon Do “expert” can break slats of the stuff but might have a problem putting his foot through a concrete floor. I’d beleive that Hemcrete is stronger laterally but find it very hard to believe it could bear higher compression loads which is basically the only thing non-reinforced concrete is used for anyways.

billster84 Says:

August 25th, 2009 at 9:06 am

Yes, but bear in mind, the title is that of inhabitat.com, not Tradical Hemcrete. I’ve been to some workshops with it and we have samples all over our office, finished and unfinished and the stuff is awesome. Our friends (Hemp Technologies, LLC) are some of the only ones distributing in the US, their site is http://www.hemtecusa.com/

open-minded Says:

August 25th, 2009 at 9:25 am

I don’t understand why the U.S. won’t legalize growing hemp, it’s such an incredibly versatile substance & so easily grown. I don’t think the hemp grown for industrial purposes would be fit to smoke if that’s what people are worried about. On that note, I believe medicinal marijuana should be legalized also.

I never knew » Blog Archive » Carbon Negative Hemp Walls are 7x Stronger than Concrete Says:

August 25th, 2009 at 10:12 am

[...] Good looking, environmentally friendly and 100% recyclable, Hemcrete® is as versatile as it is sustainable. It can be used in a mind-boggling array of applications from roof insulation to wall construction to flooring. It is seven times stronger than concrete, weighs half as much, and is less prone to cracking. Hemcrete® is also waterproof, fireproof, insulates well, does not rot and is completely recyclable. In fact, the manufacturers say that demolished Hemcrete® walls can actually be used as fertilizer! —Carbon Negative Hemp Walls are 7x Stronger than Concrete [...]

dukie564 Says:

August 25th, 2009 at 1:12 pm

This article is extremely misleading….this product cannot be used in compression and therefore in structural situations….therefore you cannot compare it to concrete…especially with respect to it’s strength.

It’s possible it is 7x stronger in tension…but that is irrelevant to concrete since unreinforced concrete is very poor in tension.

Correct this article….

greennoblework Says:

August 25th, 2009 at 1:14 pm

YES!! I’ve heard of experiments with hemp products being permitted in the US. through the issuance of special government permits to university researchers, so any of you in graduate schools or with connections could press for more of this until we can get the foolish ban on hemp undone. I’m concerned however, that our current ways of government and money system may come undone before this can be achieved.
I understand from my Green Conferences and Bioneers attendances that the state of Kentucky still has portions of the hemp collectives used back when it was legal and used to make garments, food (and the first flag) in early U. S. history, so it could more easily be grown there with growers sharing the know how and needed equipment. It WOULD indeed be a great boon to our economy as others have commented and would a step towards furthering a much needed appreciation, hopefully even sacred regard, as Native Americans had, for our mother earth. This latter quality, the OCCUPATION really, of Earth Steward or caretaker is one I’d like to see us all aspire to more, realizing that our own bodies are microcosms of Earth. This is much needed to transform and heal our, so called, Western Civilization, with it’s Romanized version of Christianity, essentially devoid of the sacred feminine, our Earth, Health Care System, and ourselves, our own bodies and minds. Care and Committment are key to making this happen.

jglass Says:

August 25th, 2009 at 1:24 pm

Anyone know about anything similar to Hemcrete, or aspaltic in nature, for roadways?

JDG

Trey Farmer Says:

August 25th, 2009 at 2:50 pm

http://www.sdearthtimes.com/et0199/et0199s11.html

There is a pretty good and brief history of our global prohibition on hemp. It is pretty absurd. But if this product gets use in the US it will put a lot of money into Canada, maybe then we will shift our laws.

willow_256 Says:

August 25th, 2009 at 3:47 pm

Not a chance this stuff is stronger than concrete in tension or compression. The website lists a strength of around 0.9 to 1.1 Mpa for the insulating mixtures. Thats roughly 150 psi, with most concrete at 4000 psi as an industry standard. So for compression this stuff is 27 times “weaker”. As for tension, a 4000 psi concrete would have a strength of roughly 475 psi, so again magnitudes stronger. But no structural engineer would design concrete to go into tension, hence the use of rebar.

Bascially, the only structural value is that this stuff would replace wood or GWB sheathing for shear wall applications. Vertical bearing wall loads and out of plane wind loads would need to be resisted by traditional methods. The kicker is that it looks like it needs to be formed, which creates lots of waste on construction sites and costs a lot in material in labor. I don’t see any advantages.

Knighted428 Says:

August 25th, 2009 at 4:23 pm

This “Birkenstock wearing granola cruncher” is also a designer and Architect who specializes in Green Tech ain Colorado. This product will be in demand in my market. We are all looking at ways to lower the carbon footprint and it starts when you build your home. This looks better than some of the pressed sunflower seed products we already use and much stronger too. I need a sample!

Weeble Says:

August 25th, 2009 at 4:37 pm

Has the product been investigated by ASTM? I would believe their statistics / properties without question as they are based on standardized tests for flame spread, compressive and tensile strength, mold resistance, r-rating etc. It would be a no-brainer if it could replace the tobacco industry and, the other legally produced products associated with “hemp” would add a significant economic spark to a region that could use it. You can only have so many golf courses! It could be used in non-structural applications until adequate research is available to document strength properties. I am sure we can bio-engineer an inert form of the plant to appease the fear associated with the illigal aspects. I’m not inclined to “just say no”, given the great many potential benefits of a product like this – but I have to have real numbers before I risk using it in any structural application. By the way, I think the jury is still out on our claim to have “improved” over the construction materials used for the Great Wall and Pyramids – cheaper, faster, more abundent – but “better” is still up for grabs.

Daniel Flahiff Says:

August 25th, 2009 at 8:27 pm

Hello all,

My apologies for the strength statistics quoted in this article. My research indicated that the product was in fact 7X stronger than concrete, information reported by seemingly reputable sources, but it appears not to be the case. Here is an update from Ian Pritchett, Chairman and Technical Director of Lime Technology Limited:

“Hemcrete® is not a direct replacement for concrete. It is a bio-composite, thermal walling material (or other insulation material). Hemcrete® is not stronger than concrete. In fact it is usually used in a non- structural way, along-side a structural timber frame. Hemcrete® is about 15% the weight if concrete. The hemp in the Hemcrete® does not deteriorate because it is preserved by the lime in the binder, but it is only used above ground with fully breathable finishes.

Many thanks

Ian Pritchett
Chairman and Technical Director
Lime Technology Limited”

Sorry again for the confusion.

Sincerely,

Daniel Flahifff

bloo Says:

August 25th, 2009 at 10:16 pm

Hey UNICORN, why don’t you throw out some references, as to where you come up with your fascinating information there?!?
MANY GREAT IDEAS ARE NOT “NEW” ….. ONLY, SIMPLY FORGOTTEN.
Go take a bong hit now or something…..

chrisp68 Says:

August 27th, 2009 at 8:13 pm

Then it should not be compared to concrete! It should be compare to stress skin panels instead. Just make large insulated walls of this stuff instead. Get the story and comparisons correct before the article is published!

bliss tick Says:

August 29th, 2009 at 8:24 pm

Concrete will be replaced to some degree in time and jobs will be lost only to be replaced by new jobs. Anyone in the building trades including product manufacturing are wise if they stay up to date with technology and need. If the concrete industry is blind then they will find themselves in a hole in the ground. Maybe they could use the influance they have to promote and establish any alternatives that will arise so they will benifit and help to strengthen their comunities rather then turn to dust or rust. Peace power.

Ed Saukkooja Says:

September 3rd, 2009 at 11:13 am

Noted by the retreat of our President concerning all things cannabis, it is evident big money and power are continuing to prohibit any industry from developing around the hemp or marijuana cultures. Once we as a nation are reduced to a third world status, hemp will be our only recourse.

keentolearn Says:

September 7th, 2009 at 12:11 am

Hey Dead_Unicorns,

Would like to hear more from you regarding your negative comments on Hemcrete.
What are you judging by? Is it personal experience or internet research?

Hope you get back to me.

Hemp_4_Victory Says:

October 22nd, 2009 at 11:02 pm

Hemp is very useful and was outlawed (labeled as marijuana) due to money, Politicians are afraid to try and make it sound good, after 70+ years of lies, propaganda, and rhetoric about how bad/dangerous this plant is from the government.

Good documentary narrated by Woody Harrelson http://www.youtube.com/watch?v=sknoKWsVlAA

Video made during WWII from United States Department of Agriculture, 1942 Hemp for Victory http://www.youtube.com/watch?v=jokV8xlJTNE

One of the most informing books on Hemp/Marijuana (The Emperor Wears No Clothes), and you can read it for free online. http://www.jackherer.com/chapters.html

$100,000 Challenge to Prove Us Wrong!

If all fossil fuels and their derivatives, as well as trees for paper and construction, were banned in order to save the planet, reverse the Greenhouse Effect and stop deforestation;

then there is only one known annually renewable natural resource that is capable of providing the overall majority of the world’s paper and textiles; meet all of the world’s transportation, industrial and home energy needs, while simultaneously reducing pollution, rebuilding the soil and cleaning the atmosphere all at the same time…

and that substance is the same one that has done it before . . .

CANNABIS HEMP! http://www.jackherer.com/challenge.html

Hemp is of first necessity to the wealth & protection of the country.”
- Thomas Jefferson

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