Dynamite, cellophane, silk and engine fuel: it's hard to imagine but hemp can be processed into all these diverse products - and that doesn't even scratch the surface of the list. Avid readers of the blog (namely my mom) might be familiar with the 1936 article in Popular Mechanics that extols the vivid industrial dreamland that hemp would soon produce: “Hemp is the standard fiber of the world. It has great tensile strength and durability. It is used to produce more than 5,000 textile products, ranging from rope to fine laces, and the wood "hurdes" remaining after the fiber has been removed contains more than seventy-seven percent cellulose, and can be used to produce more than 25,000 products, ranging from dynamite to cellophane.”
Unfortunately for us all (the environment included, as the plant would have replaced many petroleum products in the past century), the same year would see a concentrated attack on the industrious hemp plant. Applications of all types were abruptly halted in favor of racist drug enforcement policies - themselves a result of a newly-obsolete federal agency designed initially to eradicate alcohol trafficking. The prohibition of alcohol was over, but Harry Anslinger still needed a job.
Jump to present day: not only is the plant being prescribed by medical professionals and being sold over the counter in sports drinks, it's also being developed into a number of industrial products that should have been on the market a century ago. “A recent group of
Well, good for them. The project is expected to make strides in the building industry, but the reporting is sadly inaccurate - people have been building bridges out of hemp for at least 1,500 years!
Hempcrete is the name for a new industrial product based on a very old recipe. About the last thing I relate to this medicinal, flavor-diverse flowering perennial is concrete, but apparently there is no end to the plant’s applications. Humans around the globe have utilized hemp for centuries not only for it's unusual medical value but for it's unique properties as a building material as well. You may be aware that hemp is the world's strongest natural fibre, making it an obvious choice for early rope and clothing (even shoes), but the astute reefer historian will discover that it was commonly used for a rather staggering array of building materials.
We found in an article last month that hemp was an invaluable asset to ship building, but I neglected to mention one astounding figure: that the amount of hemp needed to build a British Naval vessel actually outweighed and out cost the amount of timber necessary to build that ship! Hemp not only provided the sails and ropes but the caulking to bind the boat's hull together. It may come as no surprise then, that applications for similar products have been found in much older sites on dry land.
Approximately 30 kilometres northwest of Aurangabad city in Maharashtra, India we find an interesting piece of hemp history at a World Heritage site known as The Ellora Caves.
The caves are astonishing in a number of ways. The construction of the 1,500 year old caves must have been exhausting: cut from solid stone into the face of a mountain, then decorated, insulated and fortified with a hemp concrete plaster.
“The 34 caves were man-made; cut into rock and plastered internally. The site was utilised for religious practices; with 17 Hindu, 12 Buddhist and 5 Jain caves...
...the plaster of one of the Buddhist caves, still in good condition, was examined and found to contain pounded shoots, leaves and the flower of the Cannabis Sativa plant.”
The study of the Ellora Caves has fortified confidence in manufacturing communities and instigated the development of hemp products like insulation and boarding as well. Exposed to the elements of intense wet seasons for 15 centuries, the Ellora Caves maintain a level of composer that defies logic in relation to modern standards of construction. This ancient site in India is not the only historical example of advanced hemp building, however. A bridge in France is just as old and uses a similar compound:
“Hemp mortar was discovered in bridge abutments of Merovingian bridges in France built between 500-751 A.D.”
Hemp is endlessly astonishing. Let's look at some of the major positives for this new take on an old recipe. According to the Hemp Gazette, “hempcrete is greenhouse negative, has high thermal mass, creates no toxic by-products, dampens sound, is fire-resistant, has higher vapour permeability and improves indoor air quality.” Made for centuries from a simple combination of hemp hurd, lime, clay, cement and water this bizarrely durable building material has come back into the fold of the mainstream and could be here to stay."