How Hemp Could Be Used In Construction

The more I write about hemp the more it looks like a “super” product capable of replacing a lot of day-to-day products and fabrics.

It makes me wonder if hemp can also be used in the construction industry.

The short answer is:

Yes! 

Believe it or not, but hemp can and is already used in the construction industry in a lot of different ways.

It even turns out that Hemp is already used in construction for a very long time.   

North America first introduces hemp back in 1606. Back then American farmers used the crop for fuel, paper, and ropes. They used the ropes for hunting, attaching, carrying, and lifting. 

Ancient Egypt

Ancient Egypt was one of the first cultures to grow hemp for many kinds of different uses. 

The old ancient Egypt describes the uses of hemp in paintings that were found on the walls of different temples and pyramids across Egypt. 

There is evidence found that the ancient Egyptian civilization was using hemp ropes to pull giant blocks of limestone that were required to construct the pyramids. 

The Egyptians also found an astonishing way to split those big limestone blocks into two or more pieces.

To split a giant block of limestone they fitted chunks of dry hemp in the cracks between the stones and then soaked them with water. 

When the hemp became wet it would expand so much that it would break up the rocks in two. 

Ships

Hemp was also utilized in the old days to make ships watertight. 

Hemp in combination with tar was used to fill the seams between the planks of a wooden hull to make the ship’s watertight.

Interesting fact: As a result of shipping, the Netherlands was an economic superpower!

But:

If it was without the use of hemp, The Netherlands would never be an economic superpower in the 17th century there would have been no Dutch Golden Age.

Another Interesting fact: The paper that we know today was formed in the beginning out of hemp. The first identified coarse paper, made from hemp dates to 200 years before the nominal convention of papermaking. Hemp paper reached Europe in the 13th century via the Middle East. The first copies of the Bible were created out of hemp paper.

There are really a lot of interesting things to find about the old use of hemp and too much to write about in this post.

For now, let’s stick with the topic, if hemp can be utilized for construction.

For what kind of construction materials is hemp used for?

Hemp is a very strong material to use for construction. When produced the right way, it’s even stronger than steel.

The question is:

What materials can hemp be turned into to be useful for construction? 

Hemp can be turned into a mass of useful building construction materials like “hempcrete”, this material can be used for construction and isolation. 

Hempcrete is easier to work with than traditional lime mixes and acts as a moisture regulator and an insulator.

The typical compressive strength is around 1 MPa, around 1/20 that of residential grade concrete.

It’s a low-density material and resistant to cracking under movement, thus making it highly suitable for use in earthquake-prone areas.

The great thing about hempcrete is the lightweight insulating material and is ideal for most climates around the globe.

Hempcrete walls must be used together with a frame of another material that supports the vertical load in building construction, as hempcrete’s density is 15% that of traditional concrete. 

Studies in the UK show that the performance gain between 9” (22cm) and 12”( 30cm) walls are insignificant.

Hempcrete walls are fireproofed, transmit humidity, resist mold, and have excellent acoustic performance. The perfect building material! 

If you want to more about the benefits of hempcrete and why to use it in your next dream house, check out this video that goes deeper in the explanation of it:

Could Hemp be used in different constructions?

Hemp can be used in quite a lot of constructions like house building, bridge building, pipelines, airplanes, cars, etc. Hemp can be used in so many ways, it’s just unbelievable. 

What are the benefits of using hemp for construction?

Low embodied energy—doesn’t require much processing in its production, meaning that it is beneficial to the environment.

Carbon storage—in its lifespan, it absorbs a large amount of CO2 from the atmosphere. During its growth stage, it will lock away up to 2 tonnes of CO2 per tonne of fiber harvested.

Great thermal insulation properties—it’s a medium density insulation material that is safe, efficient and durable. Low conductivity and a higher thermal mass enable it to keep heat and regulate thermal performance for a comfortable internal environment.

Non-flammable—when mixed with lime in Hempcrete construction, it is non-flammable.

Breathes, prevents condensation—it can absorb up to 20% of its weight in moisture without deterioration in its performance, unlike most other insulation materials. It can then release this moisture when required, regulating the internal humidity. Hemp is also mold-resistant.

Sustainable—hemp can be grown year-round and only takes up to 8–11 weeks to grow.

Low maintenance—Hemp doesn’t require much water or any chemical pesticides to grow.

Lightweight—Which makes it compatible in a wide range of applications in the construction industry, we can use it in lofts, walls, and inter-floors for example.

Recyclable—it’s biodegradable and non-toxic so it’s circular–it can completely decompose.

How much would it cost to build a hemp house?

In 2009, Russ Martin, the former mayor of Asheville built his 3,400 square foot home partly out of hemp. He used Hempcrete to build the walls (12-inch thick) of his house.

The cost of building his house was $133 per square foot. Although he was the first person in the United States to build a house of hemp, it was well above the average of $84 per square foot back in 2009. 

In the above example, the prices are high to build a house of hemp, but you should not forget that this was back in 2009, 9 years before the U.S government legalized industrial hemp. 

Now, 11 years later, the costs dropped quite a lot. If you ask how much it would cost to build a wall out of hemp, it would be almost (if not the same) the same costs as a normal concrete wall. 

If you watched the video above, you would probably understand why building a wall made of hemp is better to use instead of the normal traditional concrete wall. 

Conclusion

It blows my mind to see how hemp can be such a great resource for construction. It looks like there are just no boundaries on how hemp can be useful for us as humans, and for our planet. 

Also, the more I write about hemp and its benefits the more I begin to wonder why it was made illegal in history. It just doesn’t make any sense.

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