Hebel Rendering

Hebel is an autoclaved aerated concrete (AAC) manufactured by CSR. Rendering a brick wall is different from rendering a Hebel panel, as Hebel panels require a special acrylic coating system. If you get it right, you get secure, crack-free, smooth, elegant walls. Get the rendering job wrong, and you could end up with a mess on your hands.

What Are Hebel Panels?

​Hebel panels are CSR’s brand of autoclaved aerated concrete (AAC). AAC is made from a mix of cement, lime, sand and an expanding agent that creates millions of tiny closed air pockets. They are lightweight and commonly used across Sydney for multi-storey homes, extensions, and boundary walls because they’re easy to install and won’t rot or burn.

However, the main downside of AAC is that while the many tiny air pockets make it light and a good insulator, they also mean that if it is left bare, it can soak up water and moisture.

CSR recommends using an acrylic render on their Hebel panels. A good coating system should aim to:

• Stop rain and any moisture from entering the panels, but still let water vapour escape (‘vapour permeable’).
• Stand up to UV and the elements well.
  

• Stretch across any hairline cracks of at least 1mm in size.

How Rendering Hebel Panels Compares to Our Other Rendering Jobs

Rendering Hebel Panels: Step-by-Step

Most render jobs on Hebel panels follow the same basic steps, including:

Check the Panels

​Like any surface you render, Hebel panels need to be inspected for chips, holes, or damage. If you notice any damage, it is recommended that you repair it with Hebel Patch.

Check the Control Joints

​Control joints allow a building to move without the render cracking. For Hebel panels, joint spacing depends on the soil, so check whether the soil is stable or reactive, as this determines control-joint spacing.

Seal Joints and Gaps

​Fill control joints and gaps around the windows with an exterior-grade sealant. Apply this sealant before the base coat, and do not cut the sealant when trowelling.

Clean and Dry the Walls

​The Hebel panels need to be dry and free of dirt and mortar smears. If you are rendering near the beach or in a coastal suburb, wash the panels down with fresh water to remove excess salt before rendering.

Apply the Base Coat

​Use a high-quality acrylic base to level the wall and fill any small hollows or imperfections.

Apply the Texture Coat

​The texture is part of the finish and could be either a smooth, modern finish or a rough sponge texture.

Apply the Finish Coat

​A tinted acrylic top coat adds colour and extra protection against the elements. CSR recommends applying three layers of render to the Hebel panels.

Hebel panels should be rendered within 60 days of the panels being installed, so they don’t become damaged by rain or moisture.

Important Things To Remember When Rendering Hebel Panels

Hender Panels + Acrylic Render

​CSR strongly recommends acrylic render as their render of choice for Hebel panels due to its durability, resistance to cracking, flexibility and its wide range of finish options: from Mediterranean-inspired colours to polished concrete and Venetian plaster.

Reinforcing Mesh Installation

​After the Hebel surfaces have been rendered, use alkali-resistant (resistant to damage or degradation) glassfibre mesh to minimise the risk of cracks forming and to maintain the render integrity. Apply the mesh near doors and windows to reduce the risk of corner cracking.

Refrain from Rendering During Extreme Weather Conditions

​Like rendering over other substrates, rendering Hebel panels requires stable weather conditions to succeed. Avoid high humidity conditions and rainy days.

Manage Movement Joints

​Where Hebel panels meet other building materials, treat them as dedicated movement joints and use flexible exterior sealants. Different substrates move at different times.

How Much Does Hebel Rendering Cost in Sydney?

​There is no set price, but it depends on factors such as the number of Hebel panels you need to render, the finish you select, and the prep work required.

​The figures below are rough estimates for acrylic render, but should not be used as a set guide. We recommend that you contact a professional rendering company like Sydney Cement Rendering to get a better idea of the total cost.

For peace of mind, call Sydney Cement Rendering on 0402 704 984 for a fixed-price quote.

Common Mistakes to Avoid

​Here are the common mistakes associated with rendering Hebel panels:

• Using the wrong product: A traditional sand and cement render or a coat of regular paint doesn’t meet CSR’s coating requirements. Always follow their instructions for rendering over Hebel panels.

• Leaving Hebel panels uncovered for too long: CSR instructs that Hebel panels be rendered over within 60 days of installation. Otherwise, they can become damaged by the elements.

• Coating dirty or wet walls: Applying render straight onto damp or dirty Hebel panels can cause adhesion failure or blistering.

• Skipping the wash in coastal areas: On render jobs in coastal areas, Hebel panels need to be washed down with fresh water to remove excess salt so the render adheres better.

• Rendering over control joints: If render runs right across a joint, it will only crack when the structure moves. Don’t render over control joints; they need to open and close to function properly.

• Mixing brands: Mixing different manufacturers’ brands can put the warranty at risk and result in a lower-quality job.
• Ignoring upkeep or maintenance: Fix any cracks or imperfections right away. We recommend checking your Hebel panels and sealants.

At Sydney Cement Rendering, we take pride in being Sydney’s trusted rendering experts. From residential jobs to large-scale commercial projects, we provide our customers with the highest-quality rendering services and adapt to every situation and rendering style. To learn more about rendering over CSR’s Hebel panels and to get an accurate quote, call us on 0402 704 984 or visit our website https://sydneycementrendering.com/.

FAQs

Can You Use Cement Render On Hebel Panels?

​No. CSR strongly recommends using acrylic render on their Hebel panels. They don’t recommend cement render as it will eventually crack as the Hebel panels shift over time.

How Soon Should Hebel Panels Be Rendered?

​CSR says that their Hebel panels should be rendered within 60 days of installation. Ensure that the panels are dry and clean before any render is applied.

Can I Paint Hebel Panels Instead of Rendering It?

​No, a simple coat of paint likely won’t be enough to protect it. Hebel panels require a proper coating system that keeps rain out, lets vapour escape, and seals small cracks effectively.

How Many Coats of Render Do Hebel Panels Need?

​According to CSR, a three-layer acrylic render system works best: a base coat, a texture coat and a final layer.

How Much Does Hebel Rendering Cost in Sydney?

​Using acrylic render on Hebel panels can cost anywhere from 45-70 per m2 for easy-access walls. Other factors, such as scaffolding, repairs, and complex finishes, will likely push those prices up.

Please double-check with Sydney Cement Rendering or another rendering company before signing off on the price.

Is Hebel Render Prone to Cracking?

​Any rendered surface can crack when the building moves. That’s why it is recommended that render applied to Hebel surfaces needs to bridge cracks of at least 1mm. If you spot cracks, get them repaired as soon as possible to keep moisture out.

Do Hebel Homes Near the Beach Need Extra Care?

​Yes. Before applying any render, wash the Hebel panels with fresh water to remove excess salt. Otherwise, the render will not adhere well.