“Have you heard about Hebel?” would have been a catchier title.  But while Hebel is the most well-known Autoclaved Aerated Concrete product, it is not the only product of it’s type on the Australian market.  

So what is Autoclaved Aerated Concrete?

“Autoclaved Aerated Concrete” or AAC, can be used in floors and walls, and be constructed as blocks, panels or steel-reinforced panels.  It’s made from sand, cement, lime, gypsum and small amounts of aluminium. The aluminium is added as the expanding agent, giving the aerated property.  The autoclaving (pressurising) is completed in a high-pressure, high-steam environment as the product continues to cure, giving further strength and aeration.

It’s been used widely in Japan and Germany for over 50 years, but is now increasing in popularity with Australian builders and home-owners.

So what is so great about it?

• It is energy-efficiency to produce, using about a third of the energy used to make other masonry products
• It has great thermal energy properties
• It has good acoustic insulating properties
• It has high fire resistance
• It is lightweight and easy to install
• It can be cut with saws etc.
• Because it is so easy to use, it results in lower building costs due to decreased labour

All new homes and major renovations require an Energy Efficiency Assessment in order to obtain certification. One of the major elements assessed is the insulating properties of the wall and floor system. AAC is a low-cost, highly energy-efficient product. A 110mm thick panel or block of AAC will give a R value of 0.85. (This is the same measurement that is used for ceiling and wall batts eg R1.5, R3.0). By comparison, a 110mm brick is only R0.18 and 110mm regular concrete (for example, a “Besser Brick” is only R0.10). In colder climates, the AAC will also contribute to the thermal mass that is desirable for trapping winter heat from the sun and then releasing it thoughout the night.

Where can I get it?

While the Australian market is dominated by CSR’s Hebel Product, there is another supplier: One Stop Building and Hardware (or OSBH), and it’s distribution arm Litew8 Panels, produces Ecol Mega Wall Panels, Floor Panels, Blocks and Privacy Walls. I caught up with (OSBH)’s General Manager, Gina Sabaziotis, who told me that the South Australian based family business had a focus on personal service, quality product, and on-time service, which resulted in savings to the customer as time-delays certainly lead to cost increases. Their 50mm AAC Panel is the most cost-effective, time saving system on the market, suitable for external walls, fire walls, boundary walls and bushfire zones.  

Will it suit my build?

AAC will not suit all builds, but is certainly worth asking your builder and designer about if you are interested in a rendered concrete or modern look to your build.

Are you interested in getting advice on products that will make your home thermally comfortable and energy-efficient? Contact us at BERA and we will be happy to look at your plans and give you some expert advice.