Will hemp eliminate the world's third largest CO2 emitter?

In 2014, Belgian architect Robbe Van Caimere was hired to modernize a bungalow near Ghent. The modernization of the building from the middle of the last century included insulating the building and improving its properties in terms of energy losses. Initially, the architect considered the use of insulators that were used at the time when the building was built - such as paper or wood chips. As the gap between the building and the external façade was narrow, Van Caimere was looking for alternative thermal insulation for the building. He decided to use previously unknown hemp concrete.

It was a calculated experiment for Van Caimere. “We haven't used hempcrete before,” he recalls, “but we were excited about the possibility because hempcrete works as cladding, insulation and vapour barrier all in one. It seemed like a very interesting solution."

It turns out that for architects hemp concrete is a complete novelty, which seems to be a surprise, due to the fact that the Romans used it 2,100 years ago. The Gauls strengthened bridges with a hemp-based mortar in 6th century France. So the so-called hempcrete has been known in construction for millennia.

Due to the fact that hemp sucks up more carbon from the air than is needed to transform the plant into an industrial product, many actually say that hemp concrete is carbon negative.

Is it accurate to name this hemp-based building material hemp concrete?

Traditional concrete is poorly insulating and requires huge amounts of coal and water to produce, but it has two advantages: conventional concrete is cheaper (by 10 to 30 per cent, depending on the country) and stronger, much stronger than the hemp concrete. "Hemp concrete mixes together like dough, it is then poured on-site using moulds, just like concrete, and it takes about four weeks to cure," says Joe D'Alo, founder of Hemp Building Company, a hempcrete producer based in Victoria, Australia.

photo: IsoHemp.com

“But it's not compressed. It almost always needs a secondary structure. " Sometimes hemp concrete is prefabricated and sold as something that resembles cinder blocks. These also require auxiliary supports. The hemp block is a non-bearing, glued masonry product, ”explains Charlotte de Bellefroid, Marketing Manager of IsoHemp, a major supplier of hempcrete in Belgium.

As stated on the website odnawialni.com.pl:

To make concrete, you need cement. The production of cement itself is not ecological, as during this process alone a lot of CO2 is released into the atmosphere.

And ecoreactor.org emphasizes that:

Concrete is as necessary as it is destructive. Concrete is the second most used substance in the world (after water) ... if the cement industry were a country, it would be the third largest carbon emitter in the world, with emissions of up to 2.8 billion tonnes per year, second only to China and the US.

The hemp construction industry in Ukraine is also developing very intensively thanks to Sergiy Kovalenkov, an entrepreneur who was educated in this field in Australia - we wrote about it in the article "ECO, not EGO, an inspiring interview with Sergiy Kovalenkov, founder of Hempire UA"

Hemp houses, as well as public buildings that use hemp, are built all over the world. There is a dire need to eliminate the cement industry, the third-largest emitter of carbon dioxide in the world. I keep my fingers crossed for architects and the hempcrete industries to eliminate traditional concrete from circulation.