hempcrete disadvantages

Hempcrete | Features of Hempcrete | Construction & Price | Advantages and Disadvantages of Hempcrete

Table of Contents

Hempcrete is a bio-composite non-structural healthy building material that is made up of sand, lime and hemp hurds. It is also known as Hemplime.

The density of hempcrete is 300 to 900 kg/m 3 and compressive strength is about 1 MPa.

Hempcrete is derived from hemp and concrete ( i.e. lime is used as binding material, sand is used as fine aggregate and hemp hurd is used as a coarse aggregate).

( Note: Hemp is the fibre of the Cannabis Sativa plant. It is one of the fastest-growing annual crop plants. It has high tensile strength thus mostly used as a construction material. )

Hempcrete is mostly used as a construction and insulating material.

Industrial hemp is legally allowed to use as a raw material for the manufacture of hempcrete (because industrial hemp is not marijuana species of cannabis party). Only 0.3% of marijuana is present in industrial hemp.

As at the ancient time, industrial hemp was stored for centuries and still had strength and durability. People observed this and decided to use as hempcrete for constructing buildings. In France; 6th-century hempcrete was discovered in a bridge abutment.

1.1. Features of Hempcrete

Some features of hempcrete are:

a. It has high moisture storing capacity from the surrounding.

b. It has a low compressive strength of about 1 MPa. Thus, it is used in minor structural construction such as lightweight wall framing members.

c. It is not fire-resistant as it contains polyester type woody fibre.

d. The R-value of hempcrete is 2.4 to 3 per inch according to American standard. R-value determines the heat flow in hempcrete walls. Hempcrete has thermal mass(mass having inertia with thermal capacity). Thus, it is not suitable as thermal material but good as an insulating material with thermal mass.

e. As hempcrete has breathability, it should be only painted with lime-based paints which are expensive though.

f. Hempcrete foundation walls are stronger and elastic than concrete walls.

g. After a certain period of times, hempcrete hardens like petrified rocks. Its durability and strength give soundproof and bulletproof properties.

h. It is mixed at a site of construction.

i. It smells like the pungent smell of dead skunk.

1.2. Construction of Hempcrete

Hempcrete is made at the site by mixing raw materials like lime, sand, water and industrial hemp in certain proportion by a motor mixer with a horizontal and vertical shaft. This mixture takes 7-8 minutes to be properly mixed to gain binding property.

The mixture is then filled in the mould for casting purpose and compacted properly to avoid air voids from it. Then, it is left for sometimes for curing. Now, hempcrete is ready to use.

1.3. Price of Hempcrete

Hempcrete has efficient energy and durable properties. Although, it is more expensive than other building material. It has a high demand in the market. It’s price differ from place to place according to the availability of hemp and thickness of hempcrete used for the construction.

The fixed price for hempcrete materials is approximately $135 per square metre based on a 300 mm thick wall. If labour is subcontracted out to an installation team, the owner can expect to pay between $230 and $265 per square metre. This makes the overall cost (labour and materials) between $365 and $400 per square metre.

1.4. Advantages of Hempcrete

a. It is an eco-friendly carbon-reducing building material.

b. It needs less maintenance and repair.

c. Its plastering is waterproof and soundproof.

d. It is insulating and temperature maintaining building material.

e. It can be used in the construction of retaining walls, floors and roofs.

f. It is lighter than concrete.

g. It has high moisture handling capacity.

h. It can also be used for decorating purpose.

1.5. Disadvantages of Hempcrete

a. In some country, even industrial hemp is not permissible to use as it also contains 0.3% of hemp. Thus, legal permission is important to use it for construction of hempcrete. It is a long process.

b. It is an expensive building material.

c. It is hygroscopic. It has a high moisture handling capacity. Thus, it cannot be used for underground or marine works.

d. It takes nearly (7-8) weeks to dry and also it can be affected by weather change.

f. It has low mechanical properties to be used in heavy load bearing works due to low elastic modulus.

g. Materials used for hempcrete is not abundant.

1.6. Applications of Hempcrete

a. Hempcrete is usually used for the construction of minor load-bearing structures.

b. It is also used for plastering work.

c. It is used for the construction of floor slab insulation. and roof insulation.

d. It is used in the preparation of hempcrete blocks and bricks.

e. It is used for creating an air-tight seal around the home.

Hempcrete is a bio-composite non-structural healthy building material that is made up of sand, lime and hemp hurds. It is also known as Hemplime.

What Is Hempcrete | Hempcrete Blocks | Advantages & Disadvantages of Hempcrete Blocks | Applications of Hempcrete

Most Important Point In This Article

What Is Hempcrete?

Hempcrete is a bio-composite that is made from the inner wood core of the hemp plant and mixed with the lime and other natural materials. It is also known as hemp-concrete.

Hemp is a plant that grown without any use of plant protection chemicals. It required a very little amount of water and it will also help to contribute to the agricultural regeneration of soil.

Hemp is an agricultural crop that is used for construction material the combination of lime and cement. It is the fastest-growing annual crop that has high tensile strength.

Hempcrete is basically a bio-based Construction material that is widely used to build, renovate, and restore various types of structures. Hempcrete has low density but it can be used for minor structural purposes.

Hempcrete is a carbon-negative material that consumes carbon which makes it an ecofriendly construction material.

Hempcrete is fully Recycled material which can be reused for making fertilizers. It has a low carbon footprint and environment-friendly construction material.

Hempcrete Blocks

There are many products that are available in the market which are made up of Hempcrete. But Hempcrete blocks are widely used in the construction.

Hempcrete blocks are lightweight, durable, and have good insulation. Hempcrete blocks are generally used for insulation purposes.

Hempcrete consists of high silica content which helps to give high strength. The main function of the silica is to bind other natural materials with each other.

The density of hempcrete ranges from 300 to 900 kg/m 3 .

The compressive strength of hempcrete blocks is found to be around 1 Mpa.

Advantages of Hempcrete Blocks

Hempcrete blocks are eco-friendly and energy-efficient construction material.

Hempcrete blocks help in the thermal regulation which regulates the temperature of the building.

Hempcrete blocks are very light in weight and can transport easily from one place to another place.

Hempcrete blocks help in contributes to the breathable walls.

It is a disaster-resistant, which helps to ensure the safety of the buildings.

It is a strong and durable eco-friendly construction material.

Hempcrete blocks have good sound as well as heat insulation properties.

Hempcrete blocks are fire resistance.

Construction with the help of Hempcrete blocks is easy and fast.

Hempcrete is a sustainable construction material.

It provides a healthy indoor environment for the occupants.

Hempcrete can be the best option for which is used in the Renovation of the buildings.

It has high moisture handling capacity.

It is also used for decorative work.

Disadvantages of Hempcrete Blocks

Hempcrete walls are thicker in size as compared to other walls which reduce the carpet area.

Hempcrete has low compressive strength.

It also has low elastic modulus which makes it unsuitable for direct loads.

It cannot be used for heavy loads, it requires frames to carry loads.

The raw material required for Hempcrete does not grow everywhere.

Hempcrete cannot be used in the foundation of the buildings.

Hempcrete is not readily available as compared to the concrete, because it is difficult to find hemp.

Builders have a lack of knowledge about Hempcrete Construction.

Applications of Hempcrete

It is widely used in the Extension or Renovation of the buildings.

It is used for insulation for the old buildings.

It is also used for plastering work.

It is lightweight so that it is the best option where the dead load of the building is required to be less.

It is used for floor as well as roof insulation.

It is also used in the external and internal insulation of the buildings.

It is used for creating an air-tight seal around the home.

Hempcrete Construction

Hempcrete is a natural Construction material which comes with excellent insulation properties.

Hempcrete was constructed by mixing the raw materials on the site and placing that mixture in the formwork.

Nowadays there is an increase in the demand of Hempcrete due to its various excellent properties.

There are many Hempcrete products are available in the market among which the Hempcrete is one of the best and widely used Hempcrete product in the Construction.

Here are the steps which are used while the Construction of the Hempcrete blocks.

Mixing of Hempcrete

The raw materials like hemp shives, lime and water are mixed properly in the right proportion.

Moulding of Hempcrete

The mixed Hempcrete is then fill in the mould and compacted properly so that the air voids get removed.

Curing of Hempcrete

After that, the blocks are kept for curing in the open air. Curing is very important, which gives strength and hardness to the Hempcrete blocks.

Hempcrete Bricks

Hemp brick is a solid piece of construction material that is made up of fibre. Hempcrete brick is a natural eco-friendly construction material that is widely used for the construction of green buildings.

The benefit of hempcrete bricks is that it is fire resistance. Once the mixture set it will not catch fire.

Hempcrete bricks are energy efficient and sustainable construction material.

The walls which are made from hempcrete generally range from 250 mm to 500 mm thick in size. Due to this thickness, there is less carpet area, it is good in thermal and acoustic performance.

The bricks which are made from hempcrete does not use for load-bearing structure because hempcrete has low compressive strength.

How to Make Hempcrete Bricks

The process of making Hempcrete bricks is very easy and fast.

Hempcrete is properly mixed in the right proportion. The four parts of hemp and one part of lime which act as a Binder and one part of the water is used for making Hempcrete bricks.

Hempcrete bricks are durable and have various beneficial properties as compared to traditional bricks.

It helps to naturally regulate the building’s humidity and temperature and reduce condensation and energy consumption.

Hempcrete bricks also help to stay free from bacterial attacks.

Hempcrete Price

The Hempcrete price is a little bit high as compared to other Construction material. But it helps you to save money in the long term due to its energy efficiency and excellent properties.

It helps in the thermal insulation of the building. It helps to store heat and keep the indoor environment of the building cool and clean.

Sr. No. Size of Block Shape Weight In Kg. Per Block Rate Unit
1 Hempcrete Block 60 mm thick 5.5 blocks / m2 € 36.34 Sq.M.
2 Hempcrete Blocks 90 mm thick 5.5 blocks / m2 € 45.20 Sq.M.
3 Hempcrete Blocks 120 mm thick 5.5 blocks / m2 € 61.47 Sq.M.
4 Hempcrete Blocks 150 mm thick 5.5 blocks / m2 € 71.95 Sq.M.
5 Hempcrete Blocks 200 mm thick 5.5 blocks / m2 € 95.10 Sq.M.
6 Hempcrete Blocks 300 mm thick 5.5 blocks / m2 € 135.65 Sq.M.

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About Krunal Rajput

Hey, I am Krunal Rajput. The Man Behind CivilJungle. I started this site to spread knowledge about Civil Engineering. I am a Degree Holder in Civil Engineering.

Hey, I am Krunal Rajput . The Man Behind CivilJungle. I started this site to spread knowledge about Civil Engineering. I am a Degree Holder in Civil Engineering. You can find him on Facebook , Twitter, Tumblr, Instagram and Google News .