A lot of prejudice and contradictions surround the history of Cannabis sativa around the world. It is estimated that hemp was one of the first plants to be cultivated by mankind. Archaeologists have found remnants of hemp fabrics from ancient Mesopotamia (now Iran and Iraq) that date back to 8,000 BC. There are similar records in China documenting the consumption of hemp seeds and oils, dating between 6 and 4 thousand BC. Upon its arrival in Europe, its main use was for the manufacture of ship ropes and fabrics: even the sails and ropes of Christopher Columbus’ ships were made of this material. Likewise, the first books after Gutenberg’s invention of the printing press and many paintings by Rembrandt and Van Gogh were made of hemp.
The use of hemp for civil construction is not new either. Mortar made of hemp was discovered on the pillars of bridges built by the Merovingians in the 6th century, in what is now France. It is also well known that the Romans used hemp fiber to reinforce the mortar in their buildings. Nowadays, although there are legal barriers in many countries, the use of hemp as a construction material has had encouraging results, with research demonstrating its strong thermoacoustic and sustainable qualities. Hemp can be shaped into fibrous panels, coverings, sheets, and even bricks.
It is important to start by pointing out that while hemp and marijuana belong to the same species (Cannabis sativa), they are independent classifications with different characteristics. Marijuana has higher percentages – up to 20% – of THC (tetrahydrocannabinol), which is the main psychoactive substance in marijuana and is located mainly in the flower of the plant. Industrial hemp, in turn, is grown for its seeds, fibers, and stem, and contains about 0.3% THC, which is not enough to affect any person.