Hempcrete FAQ
What is hempcrete?
Hempcrete or hemp lime is biocomposite material; a mixture of hemp hurds (shivs) and lime and water.
Is hempcrete stronger than concrete
When hempcrete is used as an insulating wall system, it is not stronger than concrete.
Is hempcrete load bearing?
Hempcrete is not load bearing when used as an insulation material.
Can hempcrete be used instead of concrete?
Hempcrete can be used instead of concrete wherever concrete is not load bearing.
How much does hempcrete cost?
Hempcrete materials cost around $600AUD per cubic metre.
For a 250mm thick wall, this is around $150 plus freight.
Is Hempcrete expensive?
Hempcrete is excellent value. There are other building materials that are cheaper, however they do not provide the hygrothermal properties of hempcrete. Hempcrete significantly reduces HVAC and maintenance costs compared to other materials.
Is hempcrete mold resistant?
The natural lime provides hempcrete with excellent properties to resist mold, fungus, bacteria and virus propagation.
Why do some hemp builders use sand?
For hempcrete insulation, it is not recommended to use sand. Sand is used for hygrothermal renders only.
What are the different ways of building with hempcrete?
Free-form hand applied to existing substrate (wall) in layers 20-50mm thick. Hand-cast between temporary form-work for internal feature walls. Mechanical projection onto substrate (sisal).
Why hempcrete instead of other natural building materials?
Hempcrete is the most carbon neutral, sustainable, healthy building material for liveable spaces. Its versatility means that hempcrete can replace many building materials and trades, thereby affording a more sustainable and valuable build.
Is hempcrete a registered building material?
OzHemp Tradical hempcrete is the ONLY CERTIFIED hempcrete material in Australia.
There are other hempcrete materials that proposedly are DEEMED TO SATISFY the Australian Building Code, however, these have not been independently certified.
How many hemp homes have been built in Australia?
As of 2021 nearly 1,000 hempcrete homes have been constructed in Australia.
Does hempcrete contain chemicals or additives?
No additives or chemicals are introduced to the mix…it is all natural.
Is Australia a good climate for hempcrete?
Due to the natural properties of hempcrete; durable, moisture resistant, heat resistant, fire resistant, mold resistant, termite resistant, hempcrete is very suitable to the harsh climates of Australia.
Will rain erode hempcrete?
Rain will slowly erode hempcrete (over many, many years) so it is recommended to provided a water repellent coating, render or cladding to weather exposed faces.
Is hempcrete waterproof?
Hempcrete can be made waterproof through the addition of natural waterproof renders and other coatings.
How long does hempcrete take to cure?
Hempcrete cures by releasing moisture into the atmosphere that was added during mixing.
Depending on the environmental conditions, the original water content, the wall thickness, the density and types of lime and hemp used, drying times will vary significantly.
What is the R-Value of hempcrete? (insulation rating)
The R-Value of Hempcrete depends on the type of hempcrete mixture used (wall, floor, roof, render) and the thickness of the application.
Hempcrete provides excellent thermal mass and insulation properties, it also regulates moisture levels by absorbing and releasing moisture as required to maintain optimum healthy air.
Is hempcrete a good insulator?
Hempcrete has superior thermal, acoustic and electromagnetic insulation properties.