what is hempcrete

Will Hempcrete Change The Way We Build?

Most industries today would not be hard-pressed to find cleaner and greener alternatives to the most environmentally unsustainable components of their process. All that’s necessary is the willingness to try something new and keeping up with the latest research. An up and coming substitute for several products is hemp, which can be used in place of wood for paper, in place of cotton for clothing, and even in place of concrete for building!

History of Hempcrete

It might sound new-age, but just like hemp has a long history, so does hemp structures which have been around since Roman times. A hemp mortar bridge was built in 6th century Gaul, along with a number of other structures discovered in China and India. Modern-day France continues to use hempcrete in their construction activities.   

How is Hempcrete Made?

Hempcrete, sometimes also known as hemplime is a bio-composite material. This means that it is formed by a matrix (resin) and a reinforcement of natural fibers (in this case, hemp fibers). The matrix ensures that the natural fibers don’t get weaker over time, and they can bear the weight of the construction.

The basis of hempcrete is the ‘shiv’ or the wood-like core of the hemp plant. Hemp’s high silica content makes it easy for it to be combined with lime and water, and the resulting material weighs about one-seventh to one-eighth of concrete. If there’s any drawback to hempcrete, it’s that it takes very long to cure and harden, which is why it wasn’t often used in load-bearing walls, but manufacturers have figured out a way to work around this too! Hempcrete bricks are now increasingly popular. There are several ways that they can be made or molded, but the important thing to note about them is that once they are cured, they eventually turn to petrified rock. In other words, that hempcrete brick wall is going to last hundreds of years, and only get stronger with time!

 

Benefits of Hempcrete

Hempcrete benefits the consumer almost as much as it benefits the environment. Here’s why many analysts believe it is the future of construction:

Hempcrete is carbon negative: Yep, if you live in a hempcrete home you’re helping the environment every day – even if you didn’t get out of bed all day. While manufacturing hempcrete, more carbon dioxide is consumed than emitted. We have the hemp stalk to thank for this since it absorbs more than 2 times its weight in carbon dioxide during its growth phase. Additionally, the lime in hempcrete continues to absorb small amounts of carbon dioxide during its service life. Researchers believe that building or renovating your home with hempcrete can sustainably save more than 2 tons of carbon dioxide.

Temperature regulation: Hempcrete helps keep you cool in the summer and warm in the winter, which means you can use those heating and cooling appliances a lot less with this material. This is because hempcrete can diffuse accumulated heat, and is an insulating material with high inertia. If you live in an area that has drastic day and night temperature fluctuations, this could help with that too!

Humidity regulation: Hempcrete is permeable by water vapor but not weakened by it. It can reduce the indoor humidity by a whopping 50-55% by acting as a water buffer. This makes it an excellent option for places that might require low humidity, such as art galleries, museums, indoor swimming pool rooms and more.

Resistances: Hempcrete is impervious to mold and pests, and is highly fire resistant, providing benefits for both residential homes and community buildings. It is also acoustically insulated and blocks out ambient noises, so if you’re looking for sound sleep, this could help! Additionally, its low density makes it very resistant to cracking, even under movement. This makes hempcrete suitable for earthquake-prone areas.

house made of hempcrete

This is an example of a house made from hempcrete blocks. Photo Source: Isohemp.com

 

Homes Made of Pot?

Hemp is a strain of the cannabis sativa plant, which might make people wonder if hempcrete has anything to do with getting ‘high’. Short answer: no. The hemp used for making hempcrete is industrial hemp, which contains less than 0.3% THC, the psychoactive component of cannabis. The two plants look different and are grown in completely different ways, for completely different purposes. Hemp can’t be grown indoors as marijuana can – its long roots need deep soil. Farmers benefit from this greatly, since hemp roots are great at aerating the soil and making it healthier between other crops.

Legalities

The biggest challenge posed to making hempcrete mainstream is the aforementioned ‘drug’ association. Hemp is still highly regulated in the US. People looking to build with hempcrete will require special permits, the requirements for which can differ based on your county and state. Hopefully, once these restrictions are lifted, we’ll see a lot more sustainable homes around.

Could hempcrete be the future of building? In Europe, it’s the present. Hundreds of buildings now use hempcrete with no hassles during or post construction. The only thing standing in our way is vague and inconsistent legislation, a problem that can most likely be fixed in the near future with fervent campaigning and bipartisan support.