How Hemp Fibers Can Be Used As Building Material for Construction
Looking back in history, The Ellora caves of India, a UNESCO World Heritage site has 34 caves cut out one after the other on a high basalt cliff. The first of these caves date back to the 6th century and the latest ones to the 11th century. Both national and international tourists flock in at large numbers to visit these caves every year for their exquisite paintings and sculptures.
The question is, how these caves have withstood the test of time? It is actually a matter of wonder and of research. The mystery came to an end when in 2014, two Indian researchers discovered the secret. It was the use of a mixture of clay, hemp, and lime which helped in the preservation of these caves along with their paintings and sculptures.
A detailed report in the online version of Daily Mail, U.K in March 2016 quotes the researchers to explain the connection. The use of the hemp mixture as the plaster has kept humidity in check and guarded against the attack of destructive insects.
The converse applies in the adjacent Ajanta caves, also a UNESCO World Heritage site, dates back to the 1st and 2nd centuries have witnessed a lot of damage from humidity and insect since there is no use of hemp plaster in the Ajanta caves.
This is how valuable hemp as a building material can be, in modern terms it is referred to as ‘hempcrete’.
Why hemp is being considered now and not earlier?
The answer is simple, which deep inside we all know but, just refuse to believe – human fallibility! Hemp is not a new discovery; it is in fact one of the earliest plants to be cultivated and utilized for number of purposes. Hemp farming along with the production and use of items generated from this plant had been carried out right up until the early decades of the 20th century.
Subsequently, this was followed by a ban on hemp as a contraband substance. The Marihuana (Marijuana) Tax Act of 1937 is the first known attack against the cultivation and use of hemp along with its products in the US. Finally, the Controlled Substances Act, 1970, banned hemp all over the country.
This scenario was followed by most countries across the globe who soon followed suit. It is only recently that we have become aware of this grand error in judgement. A marked change of behavior has been observed towards the versatility and use of hemp with the turn of the 21st century. It has now been legalized at different degrees in several countries across the globe now. Hemp has only recently entered into public discourse but even now platforms like Facebook and even the might Google have bans on advertising if the word ‘Hemp’ is used in the advert.
What are the unique properties of Hempcrete?
Hempcrete holds incredible preservation capacity, as the Ellora caves have proved. Besides, buildings made of hempcrete are suitable for both warm and cold climates. Hempcrete has high level of breathability as it can both store and release warm air which helps a building made of hempcrete to maintain an optimal temperature.
Hempcrete is toxin-free, guards itself naturally against molds and pests, and is highly fire-resistant. Some insurance companies in the UK charge a lower premium on houses built with hempcrete insulation given its high durability.
Hempcrete can also, naturally absorb and store moisture. A study based in France reports that one cubic meter of it can hold up to 596 kilograms of water. It can hold this amount of water during situation of a humidity as high as 93%.
However, the best advantage which we can get from hemp is that, it can transform the construction industry. Hempcrete adds a new dimension to the notion of green buildings.
Most other insulation materials available in the market are not renewable and take a toll on the environment. They are also known to pose several health hazards.
Given all the above points, hempcrete, can actually prove as a great building material and its use reduces global environmental pollution.
