Panel · 150–300 mm
Natural Fibre Composite — indicative fig. C·24
Fire A1 Non-combustibleEmbodied carbon -1.00kgCO₂e/kg Stores carbonCompressive 0.11?0.47 MPa (reported range in hempcrete studies)MPa StructuralDesign life 50yr
Hempcrete blocks are lightweight lime?hemp composites (typical density ~256?352 kg/m?) with low compressive strength (~0.11?0.47 MPa), suited to non-structural infill and insulation.
01 Physical
Density 16?22 lb/ft? (?256?352 kg/m?); literature reports ~300?350 kg/m?kg/m³
Specific gravity 0.25-0.40
Porosity 71-84%
Water absorption 300-400%
Hardness Soft
UV resistance Good
Chemical resistance Alkaline resistant
pH tolerance 11-13
Surface roughness 5-10µm
02 Mechanical
Tensile strength 0.01-0.035MPa
Compressive strength 0.11?0.47 MPa (reported range in hempcrete studies)MPa
Flexural strength 0.05-0.10MPa
Shear strength 0.05-0.15MPa
Poisson's ratio 0.15-0.20
Impact resistance Low
Creep resistance Moderate
03 Thermal
Thermal conductivity 0.06-0.10W/m·K
Specific heat 1250-1557J/kg·K
Thermal expansion 0.0001×10⁻⁶/°C
04 Compliance & Fire First question
Combustibility class Non-combustible
Fire resistance level 60
Ignition temp >300°C
Flame spread index <25
Smoke dev. index <50
Heat release rate Very low
05 Sustainability & Health
Embodied carbon -16 to -135
Carbon footprint -0.3 to -1.0
Embodied energy 30-50MJ/kg
Water footprint 200-400L/kg
Recyclability 100%
Recycled content 0%
Renewable content 84%
Circular score 9/10
VOC emissions 0
Toxicity rating Non-toxic
LEED contribution 3-5
06 Durability · Cost · Logistics
Expected lifespan 50-100+
Maintenance interval 10-15
Warranty period 10-25
Material cost (range) $109-330
Material cost (per unit) $15-45
Lead time 2-6
Lifecycle cost $400-600
Annual maintenance $0-5
Market availability Limited
07 Assessment
Advantages
- Carbon negative material (sequesters CO2)
- Excellent thermal insulation and mass combination
- Superior moisture buffering capacity
- Fire resistant (BAL-FZ rated with render)
- Non-toxic with zero VOC emissions
- Pest and mould resistant
- Lightweight (reduces foundation requirements)
- 100% recyclable and biodegradable
- Self-healing micro-cracks through carbonation
- Good acoustic absorption
Constraints
- Low structural strength (requires load-bearing frame)
- Longer drying time (4-6 weeks before rendering)
- Limited Australian manufacturers
- Higher initial cost than conventional masonry
- Requires specialist installation knowledge
- Susceptible to water damage during construction
- Not suitable for below-grade applications
- Alkaline nature can corrode unprotected steel
08 Applications
A1 Non-structural wall infill systems
A2 Thermal insulation for walls
A3 Acoustic insulation panels
A4 Retrofit insulation over existing frames
A5 Fire-resistant wall assemblies
A6 Passive house construction
A7 Heritage building restoration
A8 Bushfire-prone area construction
09 Sources & Standards
Sources pending — citations for this material are not yet recorded. Verify all figures against manufacturer data and current standards before specifying.