Facts About Hempcrete

Facts About Hempcrete


One of the most amazing and resourceful building materials, hempcrete is a building material that keeps both our environment and our homes safe. It is simply a mixture of hemp hurd or shives, lime binder and water. When mixed together they form a slurry, non-structural material which can be used in building residential houses and commercial buildings. Moreover, it is extremely cost-effective and an innovative alternative to insulating our houses throughout the year. Below are the many facts of hempcrete that you should know to fully understand its greatness.


How strong is hempcrete? Is It Stronger Than Concrete?

The typical comprehensive strength of Hempcrete is around 145 Psi (1 MPa), which is around 1/20 that of residential grade concrete. Hempcrete is low in density and that is why it does not exhibit the comprehensive strength of residential grade concrete.

With that said, it is easier and cleaner to work with than conventional lime mixes. It lacks the brittleness of concrete and does not require expansion joints.

Hempcrete is lighter than concrete and is typically not used to build foundation walls. Being less dense than concrete, hempcrete does not exhibit the compressive strength of concrete. However, when mixed with a lime binder, hempcrete gains its strength over time from exposure to the air. Learn more about hempcrete vs concrete.


Is hempcrete fireproof?

The fibrous hemp hurd used in hempcrete mixture is taken from the wood-like interior part of the hemp plant. When they are combined with lime and water, it results in a material which is completely fire-resistant. Meaning, building with hempcrete can prevent a house or building from catching fire.


How durable is hempcrete?

It is a very durable material.  Hempcrete blocks turn to petrified rocks, lasting for hundreds of years withstanding pressure and damage. Moreover, due to its durability and strength, this material is soundproof and bulletproof.


Is hempcrete structural?

Hempcrete is a non-structural material which needs to be cast around a timber, steel or concrete frame. Adding to the frame will provide additional support as well as various other advantages.


Is hempcrete load-bearing?

Hempcrete takes time to cure so it is not good to use for load-bearing walls. However, many companies have started making hempcrete bricks in a way that takes less time to cure so it can be used for load-bearing walls.


Can Hempcrete Maintain Insulation?

Hempcrete is unique in many ways and one such way is its ability to maintain insulation in every climate. Hemp hurds have a porous structure which accumulates the moisture on the internal surface area of the plant fiber and gets absorbed in its cellulose structure. Thus, when there is excessive moisture in the air, hempcrete absorbs and retains it.  When there is a need for moisture in the air, hempcrete releases it. Learn more about hempcrete insulation.


Is hempcrete biodegradable?

It is a natural plant material and thus completely biodegradable.  It is also 100% recyclable. Once demolished, hempcrete can also be used as an organic fertilizer.


Is hempcrete earthquake-proof?

Yes, it is earthquake-proof. An earthquake cannot crack a hempcrete structure. This is because hempcrete structures are 3 times more elastic and 7 times stronger than the walls which are constructed by traditional concrete. It produces micro-cracks during movement which bind themselves when moisture comes in contact with free lime. Therefore, it is very safe material that should be used in areas prone to earthquakes.


Is Hempcrete environmentally friendly?

One of the top reasons to use hempcrete for building houses is its eco-friendly nature. Homes made with hempcrete are carbon-negative which means they absorb and retain a large amount of carbon dioxide gas from the atmosphere. The carbon absorbed gets locked aways and gives durability to the building. It has been estimated that between 242 – 364 pounds (110 – 165 kg) of carbon can be absorbed and locked up by 0.0610 in3 (1 cm3) of hempcrete wall.


Can hempcrete be used for retrofitting existing buildings?

Hempcrete can be used during the restoration of historic and traditional buildings. It is most commonly used to repair or replace the infill panels used on the timber frame buildings or to add insulation to concrete walls in old buildings. This is because hempcrete is vapor-permeable and has the ability to mold itself precisely to uneven shaped walls in a historic building.


Is Hempcrete non-toxic?

It is a mild material and does not require any pesticides or chemical fertilizers for the plant’s growth. Once placed in the walls and dried, it does not release any toxins indoors.


Is Hempcrete Resistant?

It is a highly resistant material, particularly to insects, molds and fungus. Hempcrete is also a waterproof material and can withstand rain or wet environments. This resilient property makes it effective for all the weathers.