Hempcrete or Hemplime is bio-composite material, a mixture of hemp hurds (shives) and lime (possibly including natural hydraulic lime, sand, or pozzolans) which is used as a material for construction and insulation. It is marketed under names like Hempcrete, Canobiote, Canosmose, and Isochanvre.
Hempcrete is easier to work with than traditional lime mixes and acts as an insulator and moisture regulator. It lacks the brittleness of concrete and consequently does not need expansion joints. The result is a lightweight insulating material ideal for most climates as it combines insulation and thermal mass.
Production of Hempcrete Blocks
The production process is divided into three simple steps
The raw materials (hemp shives, lime-based binder and water) of hempcrete are proportionately dosed and mixed together.
Hempcrete obtained is poured in the blocks of widths between 6 and 30 cm in a special press.
3- Open-air Curing
After a while, the frail blocks of hempcrete are placed on an automatic conveyor belt which takes them to a storage area for open air-drying. This brings strength and hardness to the blocks. Depending on the width of blocks, it takes around 6-10 weeks for the blocks to become ready to use.
Applications of Hempcrete Blocks
1- As external and internal wall insulation
2- As floors and roof Insulation
3- Underneath floors
4- As Plasters
5- New Builds
6- For Insulating older buildings
Advantages of Hempcrete Blocks
1- Hempcrete has a negative carbon footprint of -72.0 kg/m² of the wall which makes hempcrete block construction energy-efficient and eco-friendly technique.
2- The construction doesn’t take much time and reduces the labour costs and results in a cleaner site.
3- Hempcrete is a low thermal mass material which means that it absorbs the heat during the day and emits it out during the night thus providing energy-cost savings.
4- The quasi ductile behaviour of hempcrete blocks makes it reusable without affecting its structural properties.
5- Hempcrete is a microbe and parasite resistant material.
6- Hempcrete blocks have a fire-rating of 60-120 minutes.
7- The low U-value (thermal transmittance) and enhanced insulation of hempcrete blocks help deliver low operating costs through reduced heating and cooling requirements.
8- Hempcrete blocks are light in weight and are easy to transport and handle.
9- Hempcrete blocks have excellent heat and sound insulation properties.
10- Hempcrete blocks help in constituting breathable walls.
Disadvantages of Hempcrete Blocks
1- Hempcrete has low compressive strength and elastic modulus which makes it unsuitable for bearing direct loads- It needs a frame to carry the loads.
2- Hempcrete walls are thicker which risks the reduction in carpet area.
3- The raw material hemp of hempcrete is illegal to grow at a lot of places which makes it necessary for you to have it shipped from some other place.
4- Forms are needed which must be continuously raised as you build.