Last Updated on 17th September 2020

As we all know there are many different uses for hemp. Historically it was used for making ropes and we still use it to make clothes today. But did you know that you can also build your home with hemp? Following on from one of our latest videos where we spoke with Henry Thompson of The Oldbuilders Company we now take a detailed look at hempcrete.

What is hempcrete?

Hempcrete is a material used in the construction industry. It is made from mixing hemp hurds and lime. Hempcrete is an eco-friendly hemp, lightweight, insulating material. It is also easy to work with and carbon negative.

How is hempcrete made?

The hurd is the inner woody part of the hemp plant. This is mixed with a binder, which is often lime. Hemp has a naturally high silica content, this allows it to bind easily with the lime. It’s made in a similar fashion to cement. The correct amounts of hemp and lime are added to a cement mixer with a splash of water. It’s important to get the mixture right. If it is too wet or too dry the hempcrete will not be structurally strong.

Hempcrete is a ‘cast in place’ material. This means that it is constructed on-site. After the frame of the building has been erected, a wooden framework is then attached. Hempcrete is tossed into the framework by hand and then compacted. It is often finished with a lime plaster.

What can you use hempcrete for?

Hempcrete is used as an insulator in the building industry. It is used in flooring slabs, walls and even roofs. While the material is not structural strong, it is self-supporting. Prebuilt, predried hempcrete blocks are also available on the market now, which quickens up the building process.

What are the benefits of building with hempcrete?

Insulation

Hempcrete is an excellent insulator. Even though it is a porous material it can trap heat very well. In some buildings, it has also been used as a thermal mass. A thermal mass acts as a temperature regulator. It traps heat in its walls during the day and then dissipates that heat at night. This lightens the load on your home’s heating and cooling systems.

Humidity is also regulated by hempcrete insulation. In traditional concrete homes, humidity is unable to escape through the walls. Because it is porous, hempcrete allows for the humidity to escape from within the home.

Carbon Negative

Hempcrete is carbon negative. This means that it removes more carbon dioxide from the atmosphere than it creates in its life. Hemp is grown naturally and can be compared to CBD, harvested and repurposed. This is much more environmentally friendly than using materials that must be mined and extracted from the earth.

Healthy

Hempcrete is a natural building material. There are no unnecessary plastics, glues or chemicals involved. This makes it much better for the builders working with it and also provides a healthy environment to live in for years to come.

Long-lasting

Buildings made with hempcrete are also very long-lasting. Once properly sealed, they are near impervious to mould, fire and vermin. This is thanks to the lime present in hempcrete.

Easy to use

As hempcrete is a ‘cast in place’ material, that means that it can be used in a wide variety of situations. It is fantastic in the construction of traditional flat walls and right-angle corners, but it is also great to use for curved surfaces.

Hempcrete can be used by people who are not industry professionals. While experts will obviously deliver great results, the average handyman can build a shed or tiny home out of hempcrete themselves. This is due in part to the step-by-step approach of the wooden framework and hempcrete tossing technique.

Is hempcrete expensive?

Initially, hempcrete is more expensive than traditional building materials. However, when you consider the lifespan of the product it works out to be cheaper. Hempcrete reduces the reliance on heating systems which will lower your bills and can reduce the chances of developing mould. Costs can also be kept down by doing the building yourself. Hempcrete is an intuitive material that makes it an ideal choice for the hobbyists latest project.

What buildings are made from hemp?

Hempcrete is beginning to appeal to architects and construction companies all over the world due it its unique benefits.

Belgian architects Martens Van Caimere Architecten completed a renovation of a house in Ghent, Belgium using hemp products. The result is a unique, natural home that blends beautifully into its surrounding environment. Hemp has also been used in this sustainable and affordable housing scheme in Elmswell, Suffolk. Hemp is used in the prefabricated home industry as well. Monocabin make Italian designed homes that pride themselves on their ability to regulate the temperature in warm climates. For UK wholesale hemp always used a registered supplier.