Another Use for Hemp: Home Construction

Tradical Hemcrete, a combination of hemp chips and lime-based binder, is the wall material of choice for a group of builders and designers in North Carolina

Devember 7, 2009 – Fabrics and rugs made with industrial hemp are often cited as acceptably green alternatives to floor coverings made from petrochemicals, or to woolen rugs treated heavily with insecticide. But hemp also has found its way into another domestic application.

And it is not the first alternative use that may come to mind.

Nauhaus Institute, a North Carolina-based coalition of designers, engineers, builders, developers, and others devoted to green construction, has been working with hemp as a wall-construction material. Called Tradical Hemcrete, the material is essentially a lime-based binder and industrial hemp chips (derived from the woody, pretty much unsmokable core of the hemp plant) that, when mixed with water, can be sprayed over a substrate on an exterior wall or poured into forms around timber or stick framing to create a thermally resistant but “breathable” barrier.

A wall-material bakeoff
As noted in a recent story in Asheville, North Carolina’s Citizen-Times, Nauhaus (pronounced “now house”) has two homes under construction that will feature Hemcrete walls. Nauhaus says on its website that, overall, hemp met sustainability, performance, cost, and aesthetic criteria better than competing materials.

“On the natural building side, we feel that earthen mixes don’t have adequate thermal performance in our climate while the vulnerability of straw bales to water damage concerns us,” the group’s partners say on the Nauhaus site. “On the high-performance commercial side, we are skeptical of the long-term durability of SIPS walls and feel that double-stick frame systems are too complex and prone to air infiltration weaknesses. These and other problems seem to be solved by what to us is a new material: Tradical Hemcrete.”

Hemcrete also is billed as insect- and fire-resistant. One issue the group couldn’t get around, however, is that, while industrial hemp products can be imported into the U.S., it is illegal to grow hemp here. Tradical Hemcrete is made in the U.K. by a division of Belgian firm Lhoist Group, a specialist in calcined-limestone products, and is distributed in the U.S. by Hemp Technologies, of Asheville.

A green quandary: shipping from the U.K.
The Citizen-Times story points out that shipping costs make Hemcrete considerably more expensive — the approximately 1,900 sq. ft. of Hemcrete required for one of the Nauhaus projects, with 3,100 sq. ft. of interior space and 12-inch-thick exterior walls, costs about $56,250. But Hemcrete walls also require less lumber, which reduces framing costs 30% to 40%, Greg Flavall, a co-founder of Hemp Technologies, told the paper. Another advantage to Hemcrete, says Nauhaus partner Chris Cashman, is that it serves as “your Sheetrock, insulation and Tyvek all rolled into one.”

Building-performance costs in both Nauhaus projects will be significantly lower than conventionally constructed homes of comparable size, although the smaller of the two structures, a 1,450-sq.-ft. four-bedroom that will serve as a Nauhaus prototype and test house, will have 16-inch-thick walls and solar panels on the roof to bring energy usage to net zero.

Not surprisingly, Nauhaus partners advocate legalizing industrial-hemp growing in the U.S. “Our feeling is, what a great crop this would be for North Carolina’s tobacco growers to get into,” Nauhaus partner Tim Callahan told the Citizen-Times. “Bringing this in from England is probably not the greatest idea (economically). If local farmers can benefit from this, it would be great for them and great for the economy.” Source.

 

United States: Why Should Farmers Grow Hemp?

Because hemp is the ultimate cash crop, producing more fiber, food and oil than any other plant on the planet.

December 1, 2009 – United States: Why Should Farmers Grow Hemp? According to the Notre Dame University publication, The Midland Naturalist, from a 1975 article called, “Feral Hemp in Southern Illinois,” about the wild hemp fields that annual efforts from law enforcement eradication teams cannot wipe out, an acre of hemp produces:

1. 8,000 pounds of hemp seed per acre.

* When cold-pressed, the 8,000 pounds of hemp seed yield over 300 gallons of hemp seed oil and a byproduct of
* 6,000 pounds of high protein hemp flour.

These seed oils are both a food and a biodiesel fuel. Currently, the most productive seed oil crops are soybeans, sunflower seeds and rape seed or canola. Each of these three seed oil crops produce between 100 to 120 gallons of oil per acre. Hemp seed produces three times more oil per acre than the next most productive seed oil crops, or over 300 gallons per acre, with a byproduct of 3 tons of food per acre. Hemp seed oil is also far more nutritious and beneficial for our health than any other seed oil crop.

In addition to the food and oil produced, there are several other byproducts and benefits to the cultivation of hemp.

2. Six to ten tons per acre of hemp bast fiber. Bast fiber makes canvas, rope, lace, linen, and ultra-thin specialty papers like cigarette and bible papers.

3. Twenty-five tons of hemp hurd fiber. Hemp hurd fiber makes all grades of paper, composite building materials, animal bedding and a material for the absorption of liquids and oils.

4. The deep tap root draws up sub-soil nutrients and then, when the leaves fall from the plant to the ground, they return these nutrients to the top soil for the next crop rotation.

5. The residual flowers, after the seeds are extracted, produce valuable medicines.

Our farmers need this valuable crop to be returned as an option for commercial agriculture.

While marijuana is prohibited, industrial hemp will be economically prohibitive due to the artificial regulatory burdens imposed by the prohibition of marijuana. When marijuana and cannabis are legally regulated, industrial hemp will return to its rightful place in our agricultural economy.

Hemp may be the plant that started humans down the road toward civilization with the invention of agriculture itself. All archaeologists agree that cannabis was among the first crops purposely cultivated by human beings at least over 6,000 years ago, and perhaps more than 12,000 years ago.

Restoring industrial hemp to its rightful place in agriculture today will return much control to our farmers, and away from the multinational corporations that dominate our political process and destroy our environment. These capital-intensive, non-sustainable, and environmentally destructive industries have usurped our economic resources and clear-cut huge tracts of the world’s forests, given us massive oil spills, wars, toxic waste, massive worldwide pollution, global warming and the destruction of entire ecosystems.

Prohibiting the cultivation of this ancient plant, the most productive source of fiber, oil and protein on our planet, is evil. In its place we have industries that give us processes and products that have led to unprecedented ecological crisis and worldwide destruction of the biological heritage that we should bequeath to our children, grandchildren and future generations.

Restore hemp! Source. By Paul Stanford

More Information on Hemp:
Why Can’t We Grow Hemp in America?
Hemp Facts
The Case for Hemp in America
The Versatility of the Incredible Hemp Plant and How It Can Help Create a More Sustainable Future

 

Research Centre Sheds Light on the Industrial Applications of Hemp

November 26, 2009 – Alberta Canada is going green, but not in the way some might think. Just outside the town of Vegreville, the Alberta Research Council is working to add hemp farming to Alberta’s list of lucrative industries.

The Vegreville nursery is home to the largest research and production facility of hemp in North America. Industrial hemp grown in Alberta can be used in a number of products ranging anywhere from textiles to fibreglass. Products made from hemp have less environmental impact than those made from glass or plastics, and in many cases are more energy efficient.

Jan Slaski, breeder and plant physiologist at the Vegreville facility, explained why this is the case.

“Bio composites produced from hemp are more environmentally friendly. Replacing glass fibre with bio-fibre produces a much lighter product. A lighter product means that your car, boat, or airplane is lighter and uses less fuel. High-end European car manufacturers, particularly German manufacturers, use bio-composites in their panels,” he said.

Historically, hemp has been grown in Canada for hundreds of years, but was banned in 1938 due to the associations hemp has with marijuana. This ban was later lifted in 1998. Industrial hemp, unlike marijuana, does not contain high levels of THC, the compound in marijuana that causes intoxication.

According to Slaski, Canada has very strict guidelines for hemp farmers.

“Cultivating hemp in Canada is regulated by Health Canada,” he stated. “The hemp that can be grown in Canada is strictly industrial hemp, and can only contain less than 0.3 per cent THC.”

This amount of THC is not enough to associate industrial hemp with narcotics. Such a low amount of chemical in industrial hemp should take the negative drug associations out of the industry.

The varieties of hemp currently grown in Alberta have mostly European origins. Researchers at the ARC have adapted European varieties to thrive in Alberta’s climate. Researchers have tested about 80 different cultivars (or plant varieties) from different regions to distinguish which varieties grow best in Alberta soil. The ARC has identified a Polish cultivar, also known as the Silesia variety, which has a 20–40 per cent higher crop yield than the cultivars presently allowed for cultivation in Canada. The group owns the sole rights to this variety of hemp in North America, and covers all aspects of hemp from development to processing to production, which is a benefit to the Alberta economy.

“ARC is offering solutions from seeds to the final product. This means we work with hemp to develop new cultivars and new agricultural practices. The new cultivars have a high yield and are adapted to our Alberta climate conditions,” Slaski said “We then take the hemp stock to our facilities in Millwoods, and soon we will have a processing facility in Vegreville, and process it.

The ARC oversees the hemp from seed to the final product. This means that all research, farming, and processing of the fibres is done locally keeping jobs and revenue within Alberta.

Slaski argued that this is a huge benefit to Alberta farmers and the overall economy. It’s also a benefit to individual farmers because hemp is a very lucrative crop.

“Farmers here in the province look for cash crops. They want something they can finally start making money on and hemp provides that opportunity,” Slaski said. Because industrial hemp is relatively new to Alberta, bio-composites are a bit more expensive, but the ARC is setting industry standards.

“At this point, it is a niche market,” Slaski said. “Working with mainstream industry, working with auto industries, buildings, textiles, it means we can get a much larger volume of materials produced and we can re-establish hemp as a valuable crop to Alberta.” By Krista Allan. Source.

 

Michigan Group Petitions to Allow Farmers to Grow Hemp

ATLANTA, MI– Could industrial hemp be the next cash crop for northern Michigan farmers? A group in Montmorency County hopes so.

Everett Swift went before the Montmorency County Board of Commissioners Wednesday morning urging them to pass a resolution that would open up opportunities for farmers to cultivate industrial hemp.

“It’s got over 25,000 different uses,” Swift said. “Textiles, biofuels, they’re making biodegradable plastics, concrete, building materials.”

Currently it’s legal to sell hemp products, however it’s illegal to cultivate, or grow, hemp without a permit from the federal government. While hemp and marijuana both belong in the cannabis plant family, supporters of the pro-industrial hemp resolution say they are very different.

“The difference, it’s like a male and female plant,” said Jolene Fowler, a local hemp jewelry business owner. “Hemp doesn’t flower, it doesn’t have any narcotic effects.”

During Wednesday’s highly attended county commission meeting, supporters took turns expressing their views on the topic. In the end the Montmorency County Commission declined to take any action on the topic. It’s not clear if or when they’ll revisit the issue.

 

Scientists Bioengineer Plastic Without Fossil Fuels

The move could see pollution drop down considerably by using Hemp biomass to create plastic.

November 24, 2009 – Up until now, scientists have always considered that the only possible way of producing plastic, one of the main materials in our civilization, is through modifying and altering fossil fuels, primarily oil. But now, a team of South Korean scientists has managed to produce the compound for the first time without using any of these polluting fuels. Rather than extracting it from chemicals, they have managed to bioengineer it, proving once and for all that changes can be made to our way of life through innovation.

The achievement does make one wonder how it is that it was not made in one of the countries where the oil companies ruled, such as the United States or Canada. In short, there is no interest in such products in these nations, where the extent of the influence that oil corporations have on governments is difficult to quantify.

The South Korean accomplishment also points at the fact that the oil industry is indeed dispensable. Previous studies, done elsewhere, also demonstrated that plastic-like compounds, even more efficient than the actual plastics, could be made of hemp as well.

“The polyesters and other polymers we use everyday are mostly derived from fossil oils made through the refinery or chemical process. The idea of producing polymers from renewable biomass has attracted much attention due to the increasing concerns of environmental problems and the limited nature of fossil resources. PLA is considered a good alternative to petroleum based plastics as it is both biodegradable and has a low toxicity to humans,” Professor Sang Yup Lee, the leader of the new study, explains. The research was done by the KAIST University and the Korean chemical company LG Chem.

Until now, the PLA compound has only been produced via an intricate fermentation and polymerization process, but, currently, the team believes that it may have discovered a cheaper, just-as-effective method of synthesizing it. Now, via the use of metabolically engineered strains of E.coli bacteria, the product can be obtained from a simple, direct fermentation process. “By developing a strategy which combines metabolic engineering and enzyme engineering, we’ve developed an efficient bio-based one-step production process for PLA and its copolymers. This means that a developed E. coli strain is now capable of efficiently producing unnatural polymers, through a one-step fermentation process,” Lee adds.

“Global warming and other environmental problems are urging us to develop sustainable processes based on renewable resources. This new strategy should be generally useful for developing other engineered organisms capable of producing various unnatural polymers by direct fermentation from renewable resources,” the expert concludes. Source.

 

Hemp Processing in Canada – 50% Goes to U.S.

A representative of HempOil Canada discusses the processing of hemp and materials made of hemp used in a myriad of products mainly destined for the United States:

 

Hemp Agriculture Doing Well in Canada

November 22, 2009 – Hemp is at the point where canola was 30 years ago.

That was one of the messages at the Canadian Hemp Trade Alliance’s national convention in Winnipeg this week.

Keith Watson, Hemp Specialist with Manitoba Agriculture, says the industry continues go grow.

He says they’ve seen an average of 20 percent growth in the hemp industry over the last five years.

While it can be said that hemp is at the same stage as canola was 30 years ago, watson predicts it will take half the time for hemp to become a staple in Manitoba crop rotations.

Meanwhile, grain yields were lower than normal for this year’s hemp crop.

Height was around average.

Watson says the cool weather set the crop back and yields would have been even lower if September had not been much warmer than normal.

Between 15,000 and 20,000 acres of hemp were grown in Manitoba this year.

That’s about twice as much as in 2007 and 2008 but nowhere close to the record number of acres grown in 2006. Source.

 

Building with Hemp in America: The Forefront of a New Green Construction Technique

November 22, 2009 – Leave it to Asheville N.C. to be the first place in the country to build not just one, but two houses largely out of hemp.

Well-established as a green building center, Asheville has two homes under construction – one in West Asheville, another off Town Mountain Road – that use hemp as a building material. The builders and Greg Flavall, the co-founder of Hemp Technologies, the Asheville company supplying the building material, maintain that they’re the first permitted hemp homes in the country.

“This area is known to walk the talk of being green,” Flavall said, adding that the Asheville area has by far the largest percentage of Leadership in Energy and Environmental Design, or LEED, builders of anywhere in the country. Hemp is derived from the same plant that marijuana comes from. Although it contains very little of the active ingredient that gets people high and is completely impractical to smoke, it’s still illegal to grow it domestically.

But builders can import industrial hemp products like Tradical Hemcrete, the material Hemp Technologies sells. When mixed with water and lime, it makes remarkably strong, resilient walls. Some builders generically refer to the walls as hempcrete.

Clarke Snell, of the Nauhaus Group, a collaborative of local companies building the West Asheville home at 67 Talmadge St., describes the resulting structures as “forever” walls. Should you take a wall down, the hemp inside is also reusable.

“Basically, the only thing that can tear this wall down is water,” Snell said, adding that it would have to be a steady stream.

Flavall said the last study done in Europe puts the life span of hemp walls at 700-800 years.

“And even at the end of that, you can use it as fertilizer on a field,” he said.

How it works

The hempcrete mixture starts with 55-pound bales of Tradical Hemcrete brand hemp shiv, or ground-up hemp plant stalks. Workers mix it into a standard concrete mixer, four parts hemp, one part lime and one part water. They pour the resulting slurry into small containers and then pack it between plastic forms that raise a wall two feet at a time. The walls are built around standard stick-built framing.

It takes about a day for a wall to dry and about two weeks before it’s ready for exterior or interior coatings of lime stucco or plaster. Even with those coatings, the material still breathes.

“One of the main reasons I was drawn to the lime and hemp mixture is the breathability – there’s no mold, no mildew,” said Anthony Brenner, whose company, Push Interior/Architectural Design + BuildTechnologies, is building the Town Mountain home. “The lime is constantly taking in carbon, so it’s carbon-negative.”

Hempcrete is also a natural deterrent to insects, and it’s extremely fire-resistant, mainly because of the high lime content. It takes about 2 acres worth of hemp to do one house.

Cost calculations

Hempcrete is more expensive upfront than traditional building materials, mainly because of the shipping costs. Flavall says his company has to import it from Europe, which about doubles the cost.

For the Town Mountain home, he’ll use about 1,875 cubic feet of hempcrete, at a total cost of about $56,250.

That’s higher than typical construction, but Flavall says you’ll net a 30-40 percent reduction in framing costs because less lumber is needed. You also have the potential for a lighter foundation because the hempcrete walls are lighter. Also, homeowners may be eligible for a 10 percent reduction in insurance rates because the product is so flame-retardant.

Nauhaus partner Chris Cashman points out another major advantage: “With this, it’s your Sheetrock, insulation and Tyvek (moisture barrier) all rolled into one.”

Calculating the cost of a Hempcrete home gets complicated.

“We think we can build a house like our prototype for anywhere from parity for a high-end custom home – think Biltmore Village – to 5-15 percent more for a typical home,” Snell said. “However, that’s not the point because construction cost is not your monthly cost.”

He points out that a typical homeowner’s monthly home costs include the bank mortgage, utilities, maintenance, insurance and more. If you’re building a house that uses 15 percent of the energy of a conventional home, then you can take money saved on utilities and put it into construction and end up with the same monthly cost.

“Our mission is to provide carbon-neutral housing for the same monthly cost as a typical home,” Snell said.

Tim Callahan, another of the Nauhaus partners, puts it this way: “The reason it begins to be affordable is because we’ve reduced the energy loads so much.”

The costs over the long haul should appeal to the green-minded.

“The bottom line of this and a traditional house is it’s about cost-neutral,” Brenner said.

Labor-wise, it’s quicker to put up the hemp and plaster than all those other materials like Sheetrock and insulation. Brenner said it will take them about a week to get all the hemp walls up. The Nauhaus guys have put up a test wall and are waiting on the plastic forms from Brenner to do all their walls.

Model efficiency

The house Brenner is building will have 12-inch thick walls, while the house on Talmadge Street will boast 16-inch thick walls and will be 80 percent more efficient than code requirements – so efficient that Snell claims it could be heated solely by the body heat of 18 people.

Besides hemp walls, the 1,450-square-foot, four-bedroom house will have solar panels on the roof to generate enough electricity to power the home, with a surplus. It will have an earthen exterior made from the soil on site, rainwater gathered from the roof and a mostly edible landscape.

The home will be a prototype that the Nauhaus group will use for tours and education.

The house will be owned by the Nauhaus Group itself, although chief engineer Jeff Buscher and his family will live it for two years before it’s sold to allow for energy-efficiency analysis and other research.

Brenner is building the 3,100-square-foot Town Mountain home for Russ Martin, a former Asheville mayor and retired stockbroker, and his wife, Karen Corp. “We’re not afraid of trying something new,” Martin said. “We’ve always been adventurous that way, and this looks like it’s going to work out really well.”

Snell stressed that getting the Nauhaus going has involved a massive, collaborative effort involving multiple local companies.

Based in Asheville, the project is led by Think Green Building, Eco Concepts Development, Eco Concepts Realty and Green Plan.

Both Brenner and the Nauhaus partners want to expand hemp building far and wide.

Brenner said he’s working on a commercial project in Maggie Valley and another home in the Leicester area.

And they’d love to see farmers have a chance to grow hemp legally.

“Our feeling is: What a great crop this would be for North Carolina’s tobacco growers to get into,” said Callahan, the Nauhaus partner. “Bringing this in from England is probably not the greatest idea (economically). If local farmers can benefit from this, it would be great for them and great for the economy.”

Still, as Snell puts it, right now “what you have is a product that you can’t grow but you can buy” in the United States.

Brenner thinks the technology will take off when potential homeowners and developers come to understand its advantages.

“We’ve been seeing interest from all over the country,” Brenner said.

“People are truly interested in green construction and green building, and I don’t know how much more green you can get than this.”

Flavall said another hemp house will start up next year in Franklin, and he’s receiving strong interest in other projects.

“I’m seriously of the belief that we’re making history here,” he said.

By John Boyle Source. On the Net:

 

House of Hemp & Straw Passes Fire Test

November 20th, 2009 – U.K. – A house built from straw-bales and panels of hemp has passed an industry standard fire safety test which exposed it to temperatures above 1,000C.

BaleHaus@Bath is part of a new research project at the University of Bath into how renewable building materials can be used for homes of the future.

The house is made from prefabricated cells of timber filled with straw or hemp, rendered with a lime-based coat.

During the fire resistance test for non-loadbearing elements, the panel had to withstand heat for more than 30 minutes. After more than two hours it had still not failed.

A panel had previously been put through structural tests for loadbearing elements and had passed.

Researchers Dr Katharine Beadle and Christopher Gross, from the University’s Building Research Establishment Centre in Innovative Construction Materials, will be monitoring the house for a year.

They will be checking its insulating properties, humidity levels, air tightness and sound insulation qualities to assess the performance of straw and hemp as building materials.

The technology was used last year to build an eco-friendly house in six days for the Grand Designs Live exhibition.

“I expect the results will show people that we can minimize the use of highly processed materials in building and genuinely make use of such sustainable building materials,” he said.

“It’s vital that we encourage people to recycle, insulate and minimize the use of fossil fuels to keep our buildings warm.”

The ModCell BaleHaus system has been created by White Design in Bristol and Integral Structural Design in Bath. Source.

 

Rapid Growth in Hemp-based Construction

November 18, 2009 – A visit to the Innovation Park at BRE in Watford has been arranged as part of the Natural Fibres 09 conference, which takes place at the Institute of Materials, Minerals and Mining in London from December 14-16.

The park showcases modern methods of construction and features over 200 different emerging technologies in a number of demonstration properties, including the Renewable Hemp House.

Speaking at the 60th annual congress of CELC – the European Confederation of Flax and Hemp – which took place in Strasbourg, France, from November 4-7, Claude Eichwald of French organisation Construire de Chanvre, said that the use of hemp in concrete was growing, with between 2-4,000 houses now constructed completely from hemp concrete, and many more employing it with mixtures of other building materials. The CELC conference also heard from Rémi Perrin of Strasbourg-based Soprema, which is now manufacturing flax roofing membranes, and Vincent de Sutter of Sutter Freres which has been making natural-fibre based door panels for almost 50 years.

In the latest copy of its journal, CELC outlines the components of a house entirely constructed from natural fibres, as show in the illustration above.

The unique energy efficient house made from hemp at the UK BRE Innovation Park meanwhile, showcases the future of low carbon and sustainable buildings.

The three bedroom Renewable House, which costs £75,000 to build (not including ground works or utilities), uses renewable materials to deliver a well designed, yet low cost, affordable home.

The external walls are constructed from Hemcrete, provided by manufacturer Lime Technology, made from hemp plants grown and harvested in the UK and lime based binder.

It is estimated the carbon footprint of this house will be around 20 tonnes lower than a traditional brick and block house. The hemp absorbs around five tonnes of carbon dioxide from the atmosphere during its rapid growth period, which then becomes locked into the fabric of the building, making the thermal Hemp-Line walling solution ‘carbon negative’.