Board · 19–25 mm
Timber — indicative fig. O·13
Fire Combustible CombustibleEmbodied carbon -0.25kgCO₂e/kg Stores carbonCompressive 30-70MPa StructuralDesign life 25yr
Factory pre-weathered or naturally-greying timber cladding achieving immediate silver-grey patina. Treatment options include SiOO:X (silicon mineral network), CUTEK oils, or Accoya Color Grey (dyed through core). Silvertop Ash and Spotted Gum substrates achieve BAL-29 for bushfire areas.
01 Physical
Density 400-1100kg/m3
Specific gravity 0.38-1.10
Porosity 8-20%
Water absorption 3-12%
Hardness 4.0-11.0kN
UV resistance Good to Excellent (treatment dependent)
Chemical resistance Moderate to Good (treatment dependent)
pH tolerance 4-8pH
02 Mechanical
Tensile strength 42-125MPa
Compressive strength 30-70MPa
Flexural strength 44-130MPa
Impact resistance 20-70J/m
Creep resistance Good to Excellent
03 Thermal
Thermal conductivity 0.11-0.19W/mK
Specific heat 1200-1600J/kgK
Thermal expansion 0.003-0.005mm/mK
04 Compliance & Fire First question
Combustibility class Combustible — BAL rating per species
Fire resistance level BAL-19 to BAL-29 (species dependent)minutes
Ignition temp 280-400degC
Flame spread index 75-200FSI
Smoke dev. index 150-300SDI
Heat release rate 150-400kW/m2
05 Sustainability & Health
Embodied carbon -100 to 200 (species and accounting dependent)kg CO2-eq/m3
Carbon footprint -100 to 200kg CO2-eq/m3
Embodied energy 400-1500MJ/m3
Water footprint 40-150L/kg
Recyclability 90-100%
Recycled content 0%
Renewable content 95-100%
Circular score 8.0/10
VOC emissions <30ug/m3
Toxicity rating Non-toxic — all major treatment systems
LEED contribution 4-7points
06 Durability · Cost · Logistics
Expected lifespan 25-50years
Maintenance interval 5-15years
Warranty period 10-50years
Material cost (range) 95-250AUD/m2
Material cost (per unit) 5000-13000AUD/m3
Lead time 14-42days
Lifecycle cost 130-400AUD/m2
Annual maintenance 0.50-3.00AUD/m2/year
Market availability Good — multiple suppliers and treatment options
07 Assessment
Advantages
- Immediate weathered silver-grey aesthetic from installation
- Consistent colour and texture across entire facade
- Eliminates unpredictable natural weathering transition period
- Low-maintenance finish — SiOO:X provides 10-15 year protection
- BAL-29 compliant with appropriate Australian hardwood substrates
- Multiple treatment systems available (SiOO:X, CUTEK, Accoya Color Grey)
- Compatible with standard timber cladding installation methods
- Natural, non-toxic treatment options (SiOO:X is Red List Free)
- Continues to develop authentic patina over time
- Multiple Australian hardwood and imported species options
Constraints
- Premium pricing over standard timber ($95-350+ AUD/m2 installed)
- Treatment-dependent performance — SiOO:X, CUTEK, and Accoya have different characteristics
- Natural greying is uneven without treatment; treatment needed for consistency
- Batch-to-batch variation possible with natural timber substrates
- Some treatments require maintenance recoating (SiOO:X every 10-15 years, CUTEK every 3-7 years)
- Repairs and replacements may not colour-match immediately
- Limited colour range (silver-grey palette only)
- Fire performance depends on base timber species, not treatment
08 Applications
A1 External wall cladding systems Primary application — horizontal and vertical cladding in shiplap, T&G, or shadow-line profiles
A2 Feature walls and accent panels Interior and exterior feature walls with consistent weathered grey aesthetic
A3 Screening and privacy applications Batten screening and privacy panels in silver-grey tones
A4 Soffit and ceiling linings Sheltered exterior soffits and covered ceiling areas
A5 Commercial and residential architecture Contemporary facades for residential and commercial developments
A6 Coastal and bushland environments Naturally weathered aesthetic that integrates with coastal and bush landscapes
A7 Contemporary and modernist design Clean silver-grey lines for minimalist and contemporary architectural styles
A8 Renovation and retrofit projects Overcladding or replacing existing facades with immediately-weathered appearance
09 Sources & Standards
Sources pending — citations for this material are not yet recorded. Verify all figures against manufacturer data and current standards before specifying.