Hempcrete is the sustainable building material we need in 2022

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Hempoffset will use hempcrete to build sustainable homes

A field of licensed hemp in Ireland.

Our vision is to plant hemp at scale, to stop climate change, and to build sustainable, hempcrete homes for everyone who wants or needs one.

Our target is to grow 400 million hectares of hemp every year. This will produce up to 2.8 billion metric tonnes of fibre. Which is a lot. And we need to sequester (lock away) as much of the fibre as possible. We believe that the most effective way to use all the fibre is in the production of hempcrete, which we will use to 3D-print houses, and use in modular blocks for commercial buildings such as data centres and food storage facilities.

The question of land may seem like an obstacle but, in reality, hemp is a very effective and efficient crop to grow, with high-value outputs. Our ambition is to have hemp growing on 400 million hectares, with each ha removing around 12 mt/CO2 annually (photosynthesis removes more CO2 from the air than can be measured by crop weight), double that in hot countries. This will require just 4% of the world’s arable land, with hemp also thriving in marginal land. Currently, 40% of the world’s arable land is used for dairy and livestock production, which is both a poor use of land for nutritional output, and also contributes significantly to GHG emissions.

The last global survey by the United Nations, in 2005, found that an estimated 100 million people were homeless worldwide. As many as 1.6 billion people lack adequate housing. We will fix this.

What is hempcrete?

We will use the harvested hemp fibre to make hempcrete (four parts hemp, one part each of lime and water) and 3D-print sustainable houses. 100% of the captured CO2 can be considered durably sequestered as it will be bound up in hempcrete. Hemp absorbs Carbon as CO2 from the atmosphere, releases the O2 and chelates the Carbon into stable molecules which constitute the plants’ biomass. We are sequestering Carbon from atmospheric CO2, combining it with silicates and other elements to form the molecules which comprise the plants’ biomass. This biomass is dried and mixed with hydraulic lime and water to form hempcrete, an enduring, inert (chemically inactive), stable, fire-resistant bio-composite construction material with great insulation and anti-mould properties. Hempcrete buildings from the 8th Century AD still stand in Europe, so there is no issue with durability.

Felix and Gary from Hempoffset with a hempcrete block at Ireland’s Hemp Coop conference 2022

By using the hemp fibre to make hempcrete, we can build houses for everyone in the world that needs a home. We expect our houses to stand for hundreds of years, which means that the CO2 is safely locked away. Hempcrete has the extra benefit of continuing to absorb CO2 from the air over those hundreds of years, through carbonation. So a further 25% of the weight of the hempcrete is absorbed in CO2 every 100 years!

Wikipedia: Hempcrete is easier to work with than traditional lime mixes and acts as an insulator and moisture regulator. It lacks the brittleness of concrete and consequently does not need expansion joints. The result is a lightweight insulating material ideal for most climates as it combines insulation and thermal mass.

Hempcrete is as durable as concrete but 6-8 times lighter. Concrete production contributes 8% of GHG emissions, so we plan to work with concrete producers to leverage their existing infrastructure to bring hempcrete to market quickly and economically. Hempcrete does not have the compressive strength of concrete, so it will require structural supports.

Hemp blocks in Ireland

There are suppliers of hemp blocks in Ireland, typically imported from other EU countries. Hempoffset.com aims to be the exchange platform for hemp blocks in Ireland and globally. Contact us to register your interest in supplying or sourcing hemp blocks.

Industrial hemp’s main power source is sunshine. There is some diesel used in crop harvesting, processing and transportation. The 3D printing system for hempcrete houses will be powered by electricity from a diesel generator and mixing is done by diesel-powered machines. Our next stage vision includes powering machinery with hemp biodiesel from our crops, a sustainable, carbon-neutral energy source.

We use conservative figures for hemp here, btw!

Hemp has multiple additional benefits

Because hemp does such an amazingly efficient job of converting CO2 to carbon compounds, the crop’s applications are almost limitless. To end fossil fuels, hemp is the only solution that allows us to carry on with everything we’re used to. 

We’re working with makers all over the world, to offer products in housing, including hempcrete homes, modular hemp blocks, and hemp fibre insulation. These products will be of better quality than existing products, the only carbon positive construction materials in their markets.

Tangible & measurable environmental co-benefits of hempcrete include:

  • Carbon storage – One hectare of hemp sequesters 7 to 15 tonnes of CO2, similar to the amount sequestered by a young forest, but it only takes five months to grow.
  • Breaking the cycle of diseases – Hemp helps to break the cycle of diseases when used in crop rotation.
  • Soil erosion prevention – Dense leaves of hemp become a natural soil cover, reducing water loss and protecting against soil erosion. Hemp covers the ground just three weeks after germination.
  • Biodiversity – Flowering cycle usually occurs between July and September, coinciding with a lack of pollen production from other crops. Hemp produces large amounts of pollen, just when they need it most.
  • Low or no use of pesticides – Hemp is tough, so the use of insecticides, herbicides, and fungicides can be avoided in most cases. This also benefits bees.

To learn more about how we can help your business go carbon neutral, quickly and effectively, get in touch!

Learn more

Read our report on the Irish hemp coop conference 2022, including hempcrete blocks

Hempcrete on Wikipedia: https://en.wikipedia.org/wiki/Hempcrete

BRE: https://projects.bre.co.uk/hemphomes/

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Founder and CEO at Hempoffset.com.

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By Gary Byrnes

Founder and CEO at Hempoffset.com.

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