13 Main Hempcrete Advantages and Disadvantages |Problems With Hempcrete
Hempcrete Advantages and Disadvantages |Problems With Hempcrete | Hempcrete Uses and Applications
What is Hempcrete?
Hempcrete, also known as hemplime, is a biocomposite material made of hemp hurds (shives) with lime, sand, or pozzolans that is used for building and insulation. It is sold under the brand names Hempcrete, Canobiote, Canosmose, Isochanvre, and IsoHemp.
Hempcrete is an insulator and moisture regulator that is easier to deal with than standard lime mixtures. Because it lacks the brittleness of concrete, it does not require expansion joints.
As a consequence, a lightweight insulating material that combines insulation and thermal mass is created that is suitable for most climates.
Hempcrete Uses and Applications
Hempcrete is used to build non-weight bearing insulating infill walls since it lacks the strength required for foundation construction and is instead supported by the frame.
Hempcrete was also utilized to rehabilitate stone or lime-based structures. Right now, there are two major building approaches for using hempcrete.
The first method involves utilizing forms to cast or spray hempcrete directly on the construction site.
The second method involves stacking prefabricated blocks that are brought to the project site in a manner similar to masonry building.
Following the installation of hempcrete technology between wood frame, drywall or plaster is applied for aesthetics and enhanced durability.
The compressive strength is typically approximately 1 MPa, which is around 5% that of residential grade concrete.
It has a low density and is resistant to breaking when subjected to movement, making it appropriate for usage in earthquake-prone locations.
Because hempcrete has a density that is 15% that of standard concrete, hempcrete walls must be used in conjunction with a frame of another material that bears the vertical load in building construction.
Hempcrete walls are fireproof, transfer humidity, resist mold, and have good acoustics.
Hempcrete’s high R-value makes it an effective insulator because the higher the R-value, the better the insulation.
Hempcrete’s low thermal diffusivity and effusively impact longer temperature change periods and produce a warm impression to the touch.
Low thermal diffusivity correlates directly with enhanced thermal comfort within the building.
Hempcrete Advantages and Disadvantages
Advantages of Hempcrete
1. Hempcrete Is Affordable
Because the components used to make hempcrete aren’t typical building materials, they don’t benefit from the bulk price savings that other insulating choices provide.
Even before widespread market availability and the cost savings that will result, the cost of hempcrete is comparable to other insulating solutions, while providing benefits over those options in other ways.
2. Hempcrete is Lightweight
Because hempcrete is so lightweight, it can be used in place of traditional masonry materials.
Hempcrete walls provide insulation without the weight of the masonry unit that supports them, allowing structural elements to be moved into other locations within the structure.
This reduce the load on foundations because it is light weight material.
3. Hempcrete provides strong thermal mass
Adding a high-inertia material such as hempcrete to a building envelope increases static and kinetic loads on the envelope by adding support and mass above and below its surface.
4. Hempcrete is Environmentally Friendly
The use of lime and water, rather than cement in the making of hempcrete help to reduce the amount of carbon dioxide emitted into the atmosphere. It also acts as a carbon sink.
5. Hempcrete is Mold Resistant
Hempcrete stores moisture within its matrix, preventing mold from growing on its surface for extended periods of time.
6. Hempcrete is Durable
Exterior hemp walls should be coated with a Hemp lime, Lime, or other natural render or breathable finish for maximum longevity once cured.
Aside than that, this hemp lime need no special protection from the weather.
7. Hempcrete Consists of Only Renewable Materials
Hempcrete is made of hemp hurds, water, and lime. These are renewable resources with low embodied energy that contrast with the high embodied energy required in the production of cement and portland cement concrete.
8. Non-toxic building material
Hempcrete is a relatively safe material; fewer pesticides and herbicides are needed in growing, resulting in less environmental harm from the use of poisons on the fields.
9. Hempcrete Repairs in Place
A hempcrete wall can be repaired at the same time as repairs are being made to traditional masonry walls.
Hempcrete fills the gap between traditional materials and those which do not easily repair themselves, and so can be used where traditional materials simply do not function.
Hempcrete Disadvantages
1. Hempcrete is Difficult to Work With
Hempcrete is a composite material, which means that the primary material is made from the combination of multiple materials.
The resulting hempcrete is often difficult to install because it must be able to accommodate the installation process.
2. Hempcrete Is Expensive Compared to Other Materials
While there are methods of producing hemplime at lower costs, such as improving drying processes and developing forms for casting on-site, hempcrete is currently more expensive than concrete.
The upfront charges of utilizing Hempcrete can add 8% to 12% to the entire price of a house.
3. Hempcrete is Not as Easily Available
In most countries, hemp is not as easily available as traditional construction materials such as concrete, and it has been deemed banned in a few.
4. Not Widely Accepted
Although hempcrete is becoming more popular in the United States, there are very few installation professionals.
There is a relative scarcity of builders/architects who are conversant with the product. This has led to long delays for hempcrete homes to be built.
5. Lime is Harmful to Humans
Lime, which is crushed from limestone rocks and typically used as a binder in hempcrete, may cause respiratory problems if it is inhaled or ingested.
6. Environmental impact
The crop necessitates the proper application of fertilizer, which might have a detrimental influence on our ecosystem.
7. Weak Structural Integrity
Hempcrete has been found to be weaker than normal concrete. For this reason, hempcrete should only be used in buildings which do not have to withstand any significant weight (e.g. a house).
The mechanical characteristics of hempcrete are unsuitable for a strongly loaded structure.
8. It Reduces Square Footage of Living Space
One of hempcrete’s disadvantages is the Hempcrete walls are thicker than other types of walls when utilized in building.
As a consequence, homes benefit from increased insulation. This is fantastic news for individuals wanting to reduce their energy expenses.
With greater insulation, you can reduce your reliance on heating during the winter months.
As previously stated, hempcrete is inappropriate for load-bearing walls. This is because to the long curing period.
To address this issue, some businesses have developed hempcrete bricks. These bricks cure faster, allowing builders to stack them like cinder blocks.
These bricks, however, are significantly thicker than their concrete equivalent. As a result, your living space will be reduced. When you want to sell your house, this becomes a problem.
Problems With Hempcrete /Environmental Concerns Resulting from Hempcrete
Binder
The manufacturing of the binder is the primary source of environmental concerns for hempcrete.
According to reports, the carbonation process may recover 18.5 percent to 38.4 percent of the original emissions from binder manufacturing.
The binder is created by the calcination of lime in kilns at extremely high temperatures. Because it entails the use of fuel, the transportation phase has an embodied energy impact.
Diesel consumption is also caused by the operation of machinery used in the manufacture of hemp shives.
Abiotic depletion is produced by the consumption of lead and cadmium in the power generating process, which is most prevalent in the company’s production of hempcrete blocks.
The production of materials in the construction industry accounts for nearly 20% of carbon dioxide emissions. This is a result of the cement used as a binder, which is made by burning limestone.
Lime itself has a very low carbon footprint and uses far less energy to produce than cement
Since hempcrete saves space in construction, less concrete is needed, and therefore fewer tons of carbon dioxide are produced from that source.
Pesticides.
Pesticides are used in growing hemp crops. The crop necessitates the proper application of fertilizer, which might have a detrimental influence on our ecosystem.
Water
Hempcrete needs a lot more water than other building materials, due to the use of lime.
Extreme temperatures
Hempcrete does not have a long enough thermal mass to remain warm in extreme temperatures for an extended period of time without the use of additional insulation.
Not Fireproof.
Hempcrete is not fireproof and therefore requires fire regulations to be followed when building a structure out of hempcrete, as well as the regular maintenance that hempcrete requires from a fire safety perspective (flammable areas can be covered with insulation).
Hempcrete FAQs
What is Hempcrete?
Hempcrete is a bio-composite comprised of the inner woody core of the hemp plant and a lime-based binder.
The hemp core, often known as “Shiv,” has a high silica concentration, allowing it to bond effectively with lime. Among all natural fibers, hemp is the only one with this characteristic.
Is Hempcrete strong?
Hempcrete’s compressive strength is one-twentieth that of concrete, at 1 MPa, preventing it from being utilized as a foundation material or in load-bearing circumstances.
Because of its low density, it is resistant to cracking, making it an appealing choice in earthquake-prone locations.
Hempcrete also breathes, enabling moisture to escape (no mold), does not off-gas, and is termite-resistant. Hempcrete’s non-toxic and lightweight qualities make it easy to move around a job site.
Although hempcrete is becoming increasingly popular, it is still not readily accessible on the market.
Nonetheless, hempcrete is similar to other insulating solutions in terms of cost, and it will become more inexpensive as manufacturing numbers rise.
What are some benefits of Hempcrete?
The end product is a lightweight cementitious insulating material that weighs around one-seventh or one-eighth the weight of concrete. Hempcrete blocks that have been fully cured float in a pail of water.
It is not employed as a structural element, but rather as an insulating filler between the frame sections, but it does decrease racking. Internal framework supports all loads.
The most prevalent type of framing is wood stud framing, which is ideal for low-rise building. In Europe, ten-story hempcrete structures have been constructed.
What is Hempcrete’s R-value?
Hempcrete has an R-value ranging from 2.4 to 4.8 per inch, whereas concrete has an R-value ranging from 0.1 to 0.2 per inch.
Hempcrete may also reach a greater R-value than fiberglass batt and cotton batt, which have maximum R-values of 3.8 and 3.7, respectively.
Several factors, including the kind of binder used, moisture level, and density, might affect the thermal performance of hempcrete.
What Are the Pros of Hempcrete?
Hempcrete vents, enabling moisture to escape (no mold), does not off-gas, and is termite-resistant.
Hempcrete’s non-toxic and lightweight qualities make it easy to move around a job site. Hempcrete does not shrink, keeps a constant temperature, and can gain strength over time.
Other advantages include;
- An excellent insulator
- Extremely lightweight
- Capable of handling a greater degree of movement than concrete
- Exceptionally durable, it can last hundreds of years
- Non-toxic and good for the environment. It reduces the carbon footprint associated with construction drastically.
- Highly resistant to mold
What are the down sides of hempcrete?
Although it may not be considered a significant drawback, hempcrete cannot be utilized as a foundation construction due to its poor compressive strength.
Most of the time, it is not a load-bearing material. A project that may benefit from a lightweight foundation could use hempcrete instead of concrete, as long as it complies with local construction regulations and is certified by an engineer.
While hempcrete research and development are still in their infancy, first findings are quite promising.
