Building with Nature. Hempcrete, the Revolutionary Building Material

Table of Contents

1. General information about Hemp and Cannabis
1.1 Definition
1.2 The Plant

2. History of the Plant
2.1 China
2.2 India and the Middle East
2.3 Africa
2.4 Europe
2.4.1 Napoleon
2.5 America and the Beginning of the Prohibition
2.5.1 George Washington and Thomas Jefferson
2.5.2 Henry Ford and the notorious Hemp car

3. Hemp as a Building Material
3.1 Industrial Hemp
3.2 Hempcrete
3.2.1 An introduction to lime
3.2.2 Hempcrete varieties
3.2.3 Examples of hempcrete homes
3.3 Performance of Hempcrete in a Building
3.3.1 Indoor Air Quality and Sick Building Syndrome

4. Legal and Political Issues

5. The Future of Hempcrete

Conclusion

References

List of figures

Attachment: Interview with WORLD HEMP CONGRESS CEO, Majda Robic

Abstract

The purpose of this research was to discover in what ways we could use hemp to benefit our society and the environment, as well as to gather more information on the latest invention “hempcrete” in construction industry. It has numerous beneficial aspects that other building materials do not possess. Another topic, which has to be discussed when doing research on anything hemp-related, is the prohibition of all sorts of cannabis since the early 1900s after a whole decamillennial of civilizations using hemp in innumerable ways in their everyday lives.

The writer of the following thesis gathered information on the detailed history of hemp, as well as the prohibition of the plant that began in the United States and is still active in some parts of the world today. Furthermore, she analyzed the possibilities of the once highly acknowledged plant being brought back into society, while mainly focusing on hemp as a building material.

On the one hand, this research paper is based on literature, and on the other hand, it contains a conducted interview with the organizer of the "WORLD HEMP CONGRESS", Ms. Majda Robic, WORLD HEMP CONGRESS CEO. Mrs. Monika Brümmer, German architect and founder of the company “Cannabric” also provided the writer of this thesis with essential information on green building, using hemp. Cannabric is a company that is engaged in projects of ecological and bioclimatic architecture, restoration of historic buildings, and rehabilitation of traditional cave dwellings.

Introduction: Personal impulse

Nowadays we as a society are more conscious of the food we consume, the amount of exercise we get on a weekly basis, and the environment we live in than ever before. The vast majority of the population is concerned with their overall health and is willing to spend more money in order to improve their health and quality of life. Simultaneously, we are causing more damage to the planet we live on every day by living a lifestyle we simply cannot afford. A few examples proving this claim right are that we are using materials like paper and cotton, as well as taking materials such as clay and cement out of the Earth. We are also producing our food in wasteful ways which leads to massive quantities of wastewater, as well as other resources, slowly beginning to run out. With over 7.5 billion people on the planet, as well as growing poverty, climate change, and pollution, more and more people are beginning to feel the negative effects. That means we must reflect on our actions and start living in a more environmentally friendly way. This is where the hemp plant presents a massive solution for the issues stated above.

Hemp is a plant, used by civilizations since approximately 8,000 BC in innumerable ways. It is a source of many types of foods, paper, clothing, building materials, cosmetics, consumer textiles, industrial products, and the list goes on. When building a house, for example, the individual building can use hemp bricks also known as hempcrete. They can bind them using lime and create hemp walls, add hemp carpets, hemp curtains, hemp lamp shades, hemp bedspreads, and lastly, finish off with a smoothie made from hemp milk, proteins, and seeds. The materials used to build the house will eventually be recycled and used as plant food without leaving any toxins behind. Hempcrete not only keeps the environment clean, it actually improves it due to its carbon negative properties. There is more CO2 locked up in the process of growing and harvesting hemp than released during the production of the lime binder, meaning that it actually cleans the air instead of polluting it. It also grows incredibly fast, takes up less space in comparison to other plants, and does not require pesticide use because it is resistant to most pests of any origin. Henry Ford once asked: “Why use up the forests, which were centuries in the making, and the mines, which required ages to lay down if we can get the equivalent of forest and mineral products in the annual growth of the hemp fields?”

1. General information about Hemp and Cannabis

1.1 Definition

”Hemp is the English name (from the old English haenep) for the cannabis plant. The words haenep and cannabis are both thought to derive from the Ancient Greek kannabis, which in turn evolved from an older word in an ancient Iranian language from around 2,500 years ago.”¹

1.2 The Plant

Cannabis belongs to the Cannabaceae family, alongside hops, Urticales order. There are three varieties of the cannabis plant: Cannabis sativa, Cannabis indica, and Cannabis ruderalis. These varieties originally grew in different climate zones and still differ in appearance, growth patterns and uses today. Cannabis sativa and Cannabis indica are the varieties seen as the more closely related species. Cannabis ruderalis differs from the other two in that its flowering occurs after a predetermined number of days, rather than being dependent on the seasons. Moreover, it contains very little tetrahydrocannabinol (THC), the psychoactive substance that gives the drug cannabis its active ingredient. C. ruderalis contains approximately 0.2-0.3% of THC, which does not have any drug-like effect on the body.²

It is crucial to mention that it is debated to this day, whether there are multiple types of cannabis, or there is one plant with many different varieties. This is why some scientists claim that industrial hemp belongs to the sativa group, while others call it ruderalis.³

Typically, cannabis is a medium to tall, erect, annual herb, but environmental influences strongly affect the growth habits of the plant. When provided with an open, warm and sunny environment, as well as a sufficient amount of nutrients and water, cannabis can grow to a height of 5 meters in less than six months, or one complete growing season. The best location for the plant are exposed riverbanks, lakesides, and agricultural lands. Today, cannabis is utilized over a remarkably wide geographical range, mostly as a result due to human-related movement.4 In temperate environments, seeds are sown in the springtime and take anywhere from three to seven days to germinate. Cannabis can grow taller by as much as 10 centimeters a day if provided with a warm and sunny climate and favorable soil conditions. The plant is normally dioecious, meaning that unisexual female or male flowers develop on separate plants, although bisexual monoecious or hermaphrodite examples with both sexes in one plant do occur on some occasions. Male plants begin to bloom 2-3 weeks before the female plants. They also ripen earlier, are smaller and have finer fibers than females.5

Figure 1. The varieties of the Cannabis plant

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Figure 2. Comparing the male and female flower

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2. History of the Plant

The hemp plant, thanks to its many uses, in particular, its most famous one, as a widely popular recreational drug, is one of the most instantly recognizable plants in the world.⁶ It was one of the very first plants to be domesticated, about 10,000 years ago, and has been advancing civilization in numerous ways ever since. Carl Sagan in 1977 hinted at the possibility that hemp might have been one of the first if not the first plant to be incorporated in agriculture:

"Modern humans emerged some 250,000 years ago, yet agriculture is a fairly recent invention, only about 10,000 years old ... Agriculture is not natural; it is a human invention. It is also the basis of modern civilization."⁷

2.1 China

It is said that the first people, who cultivated hemp were civilizations in Asia, more specifically, where China is located today. People used it primarily for its fibers approximately 1,000 years before discovering flax and cotton. Hemp was used as a building material, a source of vitamins, minerals and healthy oils, pottery, medicine, clothing, and more. It was popular among the rich, who could afford the luxury of hemp silk and were often buried wearing the exquisite material. Hemp was so famous in the region, that the region, where China lies today, was named the land of hemp. Many ancient records found in this particular location mention, the native people praised the plant extensively for its usefulness in every aspect of their lives. Soon, hemp paper became the latest invention. It was a bendy, strong, refined and waterproof material, and it was used for special books, calligraphy and important documents. Lastly, hemp also became popular in the medicine department, when Chinese doctor Hua Tuo (141-208 AD) invented ma-yo, also known as hemp wine, and ma-fei-san, or “boiled hemp powder”, which was used as an anesthetic during operations.⁸

2.2 India and the Middle East

Even though the Chinese were the first civilization to cultivate hemp, it did not take long before other tribes began including the plant into their own culture. The Indians, for example, began consuming cannabis during religious practices, and Indian soldiers were known for drinking hemp beer to calm nerves before their battles. The Aryans, who invaded India, spread through Europe all the way to France and planted hemp seeds on their way. To their surprise, Mesopotamia was already covered with hemp fields long before their arrival. One of the oldest archaeological findings on record is a piece of hemp fabric, found in Qatal Höyük (Asia Minor), and originates from the eighth millennium BC. The plant was often mentioned in Assyrian passages, by the name qu-nu-bu, meaning “the drug against sadness”, and used to help with stomach pains, burns or as a disinfectant. It was also consumed as an aphrodisiac. Additionally, it is important to mention that the Scythians, known as the Eurasian nomads, played a major role in the expanse of the plant, as they introduced it in the west, where their descendants finally settled.⁹

2.3 Africa

At the end of the third millennium BC, hemp was prominent in Egypt, where it was mostly used to create ropes from its fibers. Evidence of hemp was found in ancient graves of pharaohs, for instance, Ehnaton and Ramesses II. Hemp was used during the building process of the great pyramids. The dry fibers of the plant were a crucial binding agent in the sun-dried bricks used to build the pyramid and gave them their exceptional strength. Sufis (a Sufi is a member of the mystical, ascetic branch of Islam) connected their religion and the use of hashish to achieve a higher state of mind, but overused the drug, and ended up being boycotted by the Arabs. The authorities decided that the situation had become unbearable, and burned off the majority of hemp fields in the area. Despite the prohibition and several attempts of the destruction of the famous drug, the bond between hashish and the Arab culture is still strong to this day. A famous Arabic proverb says: “Kif (hashish) is like fire- if used in small amounts, it heats you up, if used in large amounts, it burns you down”. The oldest archeological evidence of the use of hashish found in Africa is from Ethiopian tribes around the year 1320. Two ceramic pipes with traces of cannabis were discovered near the Tana lake.¹⁰

2.4 Europe

The Scythians brought hemp to Europe through Greece and Russia, and soon after, the Arabs started moving into southern parts of Europe, also planting hemp seeds in Spain and the Mediterranean. The plant was cultivated mostly for fabrics and paper at that time. The Roman Empire produced masses of hemp fabrics and imported hemp materials mostly from the Babylonian town Sura. Remains of hemp seeds were discovered in the ruins of the city Pompeii, which was buried by the volcano Vezuva in the year 91AD. The Romans helped to spread cannabis all over the continent. With that being said, the plant was already known and cultivated in most parts of Europe despite that. The Vikings relied on hemp for sails, ropes, glue­like material, ships and more, and are suspected to have brought hemp to North America. Hemp seeds were found in the remains of Viking boats, built around 850AD. In the south, hemp was cultivated by the Franks, a confederation of Germanic tribes, who invaded the Roman land and later on took over the majority of Gaul.

As time went on, hemp was mixed into the European culture, as it was, for instance, in the French Ardennes, believed that smoking the herb as a woman brings luck to the whole family. Prior to the 15th century, northern countries fought for the sea in Western Europe, because it was a vital location for trade. England, in particular, was very co-depended on Russia, who provided them with 97% of the hemp required for building ships and making fabrics, paper, clothes etc... Feeling that their freedom was being jeopardized, England took to the West with the help of hemp and very brave seafarers. Christopher Columbus sailed across the Atlantic in 1492, bringing with him 80 tons of hemp ship-gear and massive amounts of hemp fabric. The ship “Mayflower”, also made from hemp materials, crossed the sea successfully, and delivered the good news for England- hemp was flourishing even better in America than anywhere else in Europe. The cannabis and human history had been intertwined since the beginning of agriculture, but have never been more depended on one another, then right there and then.¹¹

2.4.1 Napoleon

When Napoleon Bonaparte invaded Egypt in the year 1798, thousands of his soldiers, faced with the shortage of alcohol, turned to cannabis. Prior to that, the exotic plant was foreign to all, except well-educated Europeans, since Indian and European cannabis are not the same plant, but merely cousins. Consequently, the soldiers lost their focus numerous times, and Napoleon prohibited the use of the herb during battles in October of 1800.¹² Russia was the most important European producer of hemp at that time. In 1807, the French Emperor Napoleon signed a treaty with Tsar Alexander the Great of Russia, aiming to prevent Russia from trading hemp with Britain, the Enemy of France. Shortage of hemp would be harmful to the British navy, but Napoleon’s plan failed, as Russia continued with the hemp trade with American traders, who, in turn, supplied the British with the vital resource. Napoleon invaded Russia in 1812, in order to gain access to the Russian hemp supplies, only to fail miserably and herald the end of his power.13

2.5 America and the Beginning of the Prohibition

During 1901 and 1937, the US Department of State argued that cannabis was the most promising plant in American agriculture. People were convinced that hemp would become the leading cause for the end of the great depression, and between 1930 and 1937 the number of hemp fields in the United States multiplied by 14. Soon, hemp began replacing oil and wood, resulting in profits of the oil, chemical, and paper industries sinking rapidly. In fear that the versatile plant would become a big threat to these large businesses, the industries mentioned above, with the support of the biggest US banks, came up with a strategy to beat their competitor­cannabis.

Anti-cannabis propaganda began spreading among politicians, and the plant was soon described as the most harmful drug in the history of humankind. The leading light of the anti-cannabis movement was Harry J. Anslinger, leader of FBN, the Federal Bureau of Narcotics (which later became DEA, Drug Enforcement Agency), and had the support of his wife's uncle, and Mellow-Bank owner, Andrew Mellow. The bank was in support of Du Pont, an enormous company in the chemical industry. Anslinger promoted the propaganda, and soon, print media started covering false researches, making not only cannabis, but also immigrants look harmful to society. Racism in the Congress was the dominant opinion at the time, meaning that Anslinger's statements went hand in hand with the men talities of most powerful congressional representatives. Not long after, police also began prohibiting cannabis use. This was the case because the prohibition of alcohol resulted in less crime, and police officers started losing jobs due to lack of crime on the streets. In 1937, the Congress introduced large taxes on cannabis, and the plant was fully prohibited in 1938, labeled as the most dangerous drug. Doctors were arrested if caught prescribing cannabis to patients, and Anslinger banned all hemp-related news. Today, the pharmaceutical industry is the most profitable industry in the United States. The legalization of cannabis would pose a threat to Big Pharma, which might explain, why the plant is still prohibited and stigmatized in some States.¹³

2.5.1 George Washington and Thomas Jefferson

George Washington and Thomas Jefferson knew about cannabis cultivation firsthand, since both were also farmers aside from being involved in US politics. They were known for promoting hemp to farmers and preaching that it is the most useful plant to cultivate. Washington began planting ‘Indian cannabis' in the 1890's. He was well aware of the difference between normal, and so-called ‘Indian' cannabis, and saw numerous beneficial effects for society in both subspecies. Jefferson had the same opinion on the matter and preached that cannabis cultivation is much more important than that of tobacco. He also preferred hemp to flax, as he perceived flax as more deleterious to the soil and used hemp to make rope and textiles.¹⁴

2.5.2 Henry Ford and the notorious Hemp car

Amongst the thousands of products made from hemp, one of the most extraordinary is Henry Ford's plastic hemp car, built in the year 1941, almost entirely out of hemp materials. According to an article published in “Popular Mechanics Magazine”, Ford had been working on the plastic car for 12 years, somewhere between the end of World War I and the beginnings of World War II. It was not exactly an ideal time for those kinds of revolutionary ideas, though. Because of the war, car production slowed down intensively, meaning that Ford had to put the production of more plastic cars past the original prototype on the backburner. The world-shattering idea was eventually abandoned. Ford had presumably wanted the car to run on hemp­based bio-fuel.

A multitude of studies has shown that industrial hemp is a viable, and, fundamentally, sustainable energy source. A study conducted in the year 2010 by the University of Connecticut even concluded that hemp fuel could be efficiently used at lower temperatures than other types of biodiesel. Moreover, according to the press release, the hemp biodiesel showed a high efficiency of conversion. Ninety- seven percent of the hemp oil used was converted to biodiesel and passed all of the laboratory's tests.¹⁵

[...]

¹ Stanwix/Sparrow, p.15.

² Mead [online].

³ Clarke/Merlin, pp.312-314.

⁴ Stanwix/Sparrow, p. 15.

⁵ Hamilton [online].

⁶ Robinson, pp. 53-57.

⁷ Robinson, pp. 58-60.

⁸ Ibid. pp. 61-64.

⁹ Ibid. pp. 66-73.

¹⁰ Ibid. pp. 68f.

¹¹ Cf. Rengeo, pp. 16f, trans.

¹² Robinson, pp. 80-83.

¹³ Harper [online].