Hempcrete: Why We Need To Build With It
Houses built from hemp, or hempcrete, are an eco-friendly building material that’s made from hemp stalks, water, and powdered limestone. Once curated, hempcrete is formed into a brick-shaped building material that can construct houses and other commercial properties.
What is hempcrete?
Hempcrete is a composite material made of natural materials, lime, and hemp. There is a lime component that contains air lime that accelerates the setting process. In hemp hurds, stalks of hemp are used. Plant protection chemicals don’t have to be used to grow hemp, it needs little water, and it contributes to the regeneration of agricultural soils. Hemp and lime combined make a natural concrete that is lightweight, or even ultra-lightweight. With its thermal mass and vapor permeability, it produces high-performance buildings that meet current and future thermal regulations.
It’s not as far-fetched as it sounds, and a few cool buildings have already been made from hempcrete.
Benefits of Hempcrete
You’re probably thinking, “One lighter flick and that shit’s done,” however, you’d be wrong.
It has many beneficial properties that make it:
- Flame resistant, unlike timber houses
- Pest resistant
Hempcrete can last for hundreds of years, and it’s relatively easy to cultivate hemp into building materials.
In addition to this, hempcrete is a great insulator and can help to regulate your house’s temperatures. Many historical buildings in France were made with it, and hemp’s properties have been utilized for centuries. It’s relatively recent that our society stopped utilizing hemp, but like 90s fashion, we need to bring it back.
Why Should We Bother With Hempcrete?
You can build a house with all sorts of building materials, but why should we bother with hempcrete? Well, as the condition of our planet worsens, we need to find different ways to be eco-friendly.
Did you know that to make one ton of cement, 850kg of carbon dioxide must seep into our atmosphere? Considering that the U.S. built 1,233,000 new homes by August 2020, that’s an insane amount of carbon dioxide polluting our air.
So, how does hemp reduce these numbers? It works by producing less harmful chemical reactions, and it can cut carbon dioxide emissions by 80 percent. If we begin building with hempcrete, rather than regular concrete, we can save 5,000 to 10,000 carbon dioxide emissions with each house.
In addition to this, hempcrete can easily replace popular timber houses. Hemp is designed to be a rotation crop, so it puts nutrients like nitrogen back into the soil. So, hemp prevents soil erosion, and it grows faster than the trees cultivated for building materials. An acre of hemp can grow at a rate of 4x faster than an acre of trees, and it only takes four months to grow compared to trees that take decades.
It’s pretty lame that we let prohibition rampage our country, and now we’re stuck with shitty building materials that kill our planet.
Hempcrete vs Concrete
Concrete is stronger than hempcrete. As it is lightweight and not dense, it lacks the comprehensive strength of concrete. Hempcrete, however, is said to be fire-resistant, pest-resistant, a strong insulator, and capable of storing and dispersing moisture.
How strong is hempcrete?
We now have to answer the big question: “Is hempcrete stronger than concrete?”?Hempcrete has a compressive strength between 0.5 and 3.5 megapascals (MPa). There are 507.6 pounds per square inch (psi) equivalent to 72.5 psi.
The compressive strength of residential concrete is 17 MPa (2500 psi), while the compressive strength of commercial concrete is 28 MPa (4000 psi). An average stiletto heel exerts around 471 psi. Therefore, hempcrete may not be able to withstand the impact of stiletto heels!
Compressive strength refers to the resistance of a material to breaking when compressed. This is due to the construction of hempcrete, which has such a low compressive strength level. A minimal density of material composes it. It weighs about one-eighth as much as concrete. It is possible to reduce surface cracking with hempcrete when its fibers are used, thanks to its tensile strength. However, it does not increase compressive strength.
How much does hempcrete cost?
A hempcrete home should be cheaper to build in theory. Hemp homes are still a novelty, however, since there are few examples. As a result, the price point is relatively high. Asheville, North Carolina, mayor Russ Martin had his home built from hemp in 2010. It may have been the first hemp house in the United States.
A square foot of it costs about $133. At the time, the average house price in his region was just over $76 per square foot. The cost of hemp houses should drop significantly with an increase in hemp houses.
Why we are not using Hempcrete?
Unlike France, the U.S. has not built many houses from hempcrete. The reason being when our country outlawed cannabis, they also outlawed its cousin: hemp.
Unlike its cousin, hemp does not contain any THC. So why was it grouped into the psychoactive category? Well, hemp was outlawed alongside cannabis because our lawmakers don’t like to do their research. Or they don’t like to accept research and science. It’s mind-boggling.
So, now that we have the internet and anyone can research any topic, why the hell are we not using hempcrete?
The simple answer is: it’s hard for America to change. We like to stick to what we know, and it’s difficult for people to invest in something that isn’t entirely popular.
It’s already difficult to get everyone on the same page about climate change, and currently, there’s not a huge market for those wanting hempcrete houses. However, there are a few companies that can build you your own hempcrete house for a relatively good price.
When you think about commercial homes popping up, it’s unlikely that they will be made from hempcrete. Many Americans don’t think it’s necessary to switch to eco-friendly building materials, so you probably won’t see hempcrete houses spread like wildfire.
However, if you’re considering building a house or investing in some commercial property, just remember that hempcrete isn’t that expensive. It’s comparable to our current building rates with other materials, so you can build your hemp fortress without breaking the bank.
The bottom line is, hempcrete houses probably won’t take over the building industry anytime soon. However, in the next decade or so, who knows? Maybe our country will begin to take some baby steps to save our planet. If the building materials are relatively the same cost and provide many benefits, then our capitalistic society should be on board.
I hope to see more Americans invest in hempcrete, and continue to integrate hemp back into our society.