2026-09-18
B03 to B06 explained: which density matches which wall, climate and load.
Not all AAC is the same. The density grade (B-number) decides the balance between insulation and strength — and picking the wrong one costs you either in heating bills or in structural steel.
B03 (≤325 kg/m³) is the insulation specialist. With a dry thermal conductivity around 0.07 W/(m·K) it is closest to a true insulation block, but cube strength is only 1.0 MPa. It belongs in non-load-bearing infill panels and retrofit insulation, not in walls that carry floor loads.
B04 (≤425 kg/m³) and B05 (≤525 kg/m³) are the workhorses. B04 reaches 2.5 MPa and λ≈0.10–0.11; B05 reaches 3.5–3.6 MPa and λ≈0.13. This is where most external walls sit in Chinese practice — strong enough for 3–4 storey load-bearing walls, still light enough to save on foundations.
B06 (≤625 kg/m³) trades insulation for strength. At 5.0 MPa and λ≈0.15 it is used where acoustic separation or seismic robustness matters more than thermal mass — interior party walls, basement walls, high-rise cores.
Rule of thumb for Australian projects: external envelope wall use B04–B05; internal acoustic or structural use B06; dedicated insulation use B03. If a supplier only quotes one density, ask — it usually means they are pushing what they happen to have in stock.
Need specifications or a quote?
Send us your product, quantity and destination port — we reply within 24 hours.
Contact Us
Hengshuo
