What is Hempcrete?
Hempcrete is a bio-composite material made of the inner woody core or “shiv” of the hemp plant, mixed with a lime-based binder. The hemp hurd has characteristics that adapts extremely well with the lime, making it unique to this practice.
The result is a lightweight insulating material weighing about one seventh the weight of concrete. Fully cured hempcrete remains permeable and has excellent performance in thermal gain and insulation.
Supported by a lightweight timber structure, hempcrete is finished externally with geothermal render and can be left exposed internally or replicate the external.
Hempcrete requires no chemicals and is pest and rodent resistant including white ants.
it does not rot or mould and has carbon capture of 200kg/m2.
Hempcrete is fire retardant rated for BAL FZ (73-73-73) making it one of the best products in the world.
How is Hempcrete Applied?
Casting in Situ
Casting in situ has been the conventional method of hempcrete installation for decades. It requires a temporary formwork system attached to the subframe and is poured and tampered in. The mixing method requires a pan mixer and can produce Hempcrete at approximately 0.7m3 / Hour (based on a national average)
Casting in situ requires much labour to apply the formwork in layers as you work your way vertically. The formwork must be convenient to the installers of the hempcrete in order to maintain good consolidation and consistency.
The labour required is abundant yet gives an excellent finish of the natural product for the visual outcome.
Hempcrete has a very organic, relaxing and earthy appeal when it is left exposed and is a fantastic feature for any home which will please the eye to those who appreciate organic matter in its existence.
Mechanical Spray Application
The mechanical spray application of hempcrete is relatively new to the hempcrete industry yet carries much more benefits.
To describe simply, the hemp and the binder are transferred from various machines through pipes and meet at a distribution point known as a lance. The application does not require premixing as the ingredients chemically bond in the air as it is applied. This method allows excellent consolidation and consistency of the product.
The distribution of hempcrete through this method is calculated at an average of 5m3/Hour.
Spray applying hempcrete requires only one side of the wall to be formed, to which saves on waste, material and labour.
Typically, this method is not for visual effect or to be left exposed, however is up for discretion. (see cast in situ application)
Rendering (with lime render) is highly recommended due to the future performance of this application. Using the BCA approved method we can achieve great thermal, sound and fire resistant properties.
The performance of the product is enhanced with spray application, it is a perfect solution to using hempcrete for its properties in a more convenient and faster method that makes hempcrete projects more affordable.
Are there warranties or guarantees?
The Hempcrete co uses the best materials sourced from OzHemp Tradical® and is the only BCA certified method in Australia.
It carries a 5-year warranty when installed by a certified contractor.
How much does it cost?
Every hempcrete project is unique, therefore it is difficult to place fixed pricing.
Typically, Hempcrete varies from $300-$380 per m2.
The most cost effective option of mechanical spray application is $270-$350
Hempcrete is highly energy efficient and will reduce the running costs of your home, saving you money in the future for generations.
Is Hempcrete Safe?
Hempcrete is perfectly safe as a building material for people and pets.
There are no Volatile organic compounds (VOC’S)
No chemicals are added, and it does not release any gasses or toxins.
It is hypo allergenic therefore does not trigger any allergies or respiratory illnesses.
It is highly fire resistant, protecting you and your family by allowing you much escape time in the event of a bushfire and it will not spread in a contained environment.
Hempcrete is one of the safest building materials in the world!