Hebel (AAC product)
Hebel is the CSR brand of autoclaved aerated concrete (AAC) panels and blocks, dominant in AU residential and Class 2. Lightweight, fire-rated, insulating.
Ask Chalkline about this →Hebel is the CSR-brand of autoclaved aerated concrete (AAC), the dominant AAC product in Australian residential and small-commercial construction. AAC is a lightweight, structural concrete made from cement, lime, sand, water and an expanding agent (aluminium powder) that creates fine air pockets; the cured material is roughly one-quarter the density of standard concrete with strong fire and thermal performance. Other AAC brands available in Australia include Powerblock and various imported equivalents, but Hebel is the volume default. For the generic concept and properties, see autoclaved aerated concrete.
Hebel residential product range:
| Product | Common application |
|---|---|
| PowerPanel 50/75 | External cladding panel over timber or steel frame |
| PowerBlock 200/300 | Loadbearing wall block (party walls, retaining) |
| PowerFloor 75 | Floor system (commercial, occasionally residential) |
| PowerRoof | Roof panel system |
Key properties for the builder:
- Density: ~500-700 kg/m³ (compared to ~2,400 kg/m³ for standard concrete).
- Fire resistance: typically -/60/60 to -/240/240 FRL depending on thickness and product.
- Thermal conductivity: ~0.13 W/m·K (~5x lower than dense concrete).
- Compressive strength: 3 to 5 MPa (lower than normal concrete; for design under engineer’s sizing).
Critical install rule: proprietary render system only.
Standard cement-and-sand render does not work on Hebel. The thermal expansion and water-absorption properties are too different from cement substrates; cement render develops cracks and debonding within 1 to 3 years.
Hebel-compatible render systems:
- Hebel Render (CSR’s own polymer-modified system).
- Dulux Acratex or equivalent polymer-modified acrylic render system rated for AAC substrate.
- Compatible primer + topcoat systems specified by the AAC manufacturer.
Using standard sand-cement render on Hebel is a regulator-prosecutable defect on Class 2 fire-rated walls because the cracking compromises the FRL.
Common defects on Hebel residential work:
- Standard cement render applied: cracking and debonding within 1-3 years.
- Hebel panels fixed to a timber frame with moisture-driven flexing; the AAC cracks at the panel joint because timber moves while AAC does not.
- Panel-to-panel joints not properly base-coated; water tracks through.
- Drilling Hebel without a TCT bit: blows out the back face.
Also known as: CSR Hebel; Hebel panel; Hebel block; aerated concrete (brand-misuse common).
Category: Materials.
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Last updated: 2026-05-16. Verified: 2026-05-16. Quarterly review for currency.