MATERIAL DATA SHEET

Pre-Aged/Greyed Timber Cladding (19mm, 21mm, 25mm)

Millwork
organic › Timber › Millwork
organictimbermillworkpre-agedgreyed-timbersilver-greyweathered-finishsiooxcutekaccoya-color-greysilvertop-ashcladdinglow-maintenancebal-29red-list-free
ATLAS CODE
ORG-TBR-MW-002
Pre-Aged/Greyed Timber Cladding (19mm, 21mm, 25mm)
Category organic
Material Family Timber
Regulatory Status Combustible — BAL rating per species
Density
400-1100 kg/m3
Carbon (A1-A5)
-100 to 200 (species and accounting dependent) kg CO2-eq/m3
Fire Class
Combustible — BAL rating per species
Lifespan
25-50 years
Description

Pre-aged/greyed timber cladding achieves the sought-after silver-grey weathered patina from day one through factory-applied treatments or naturally-greying timber species. Multiple approaches are available: silicon-based systems like SiOO:X that form a mineral silica network within the timber surface producing uniform grey tones after 10-16 weeks; penetrating oil treatments like CUTEK that protect while allowing natural silvering; or acetylated products like Accoya Color Grey that are dyed grey through to the core. Australian hardwoods including Silvertop Ash (Durability Class 2, BAL-29), Spotted Gum, and Rosewood are popular substrates that naturally weather to silver-grey tones. Available in 19mm, 21mm, and 25mm thicknesses for various architectural applications.

Primary Sectors
[Residential][Commercial]
Typical Uses
  • External wall cladding systems
  • Feature walls and accent panels
  • Screening and privacy applications
  • Soffit and ceiling linings
  • Commercial and residential architecture
  • Coastal and bushland environments
  • Contemporary and modernist design
  • Renovation and retrofit projects
Recycled Content 0
Renewable Content 95-100
Recyclability 90-100
Embodied Carbon -100 to 200 (species and accounting dependent) kg CO2-eq/m3
Embodied Energy 400-1500 MJ/m3
EPD Available Yes
Advantages
Immediate weathered silver-grey aesthetic from installationConsistent colour and texture across entire facadeEliminates unpredictable natural weathering transition periodLow-maintenance finish — SiOO:X provides 10-15 year protectionBAL-29 compliant with appropriate Australian hardwood substratesMultiple treatment systems available (SiOO:X, CUTEK, Accoya Color Grey)Compatible with standard timber cladding installation methodsNatural, non-toxic treatment options (SiOO:X is Red List Free)Continues to develop authentic patina over timeMultiple Australian hardwood and imported species options
Cautions
Premium pricing over standard timber ($95-350+ AUD/m2 installed)Treatment-dependent performance — SiOO:X, CUTEK, and Accoya have different characteristicsNatural greying is uneven without treatment; treatment needed for consistencyBatch-to-batch variation possible with natural timber substratesSome treatments require maintenance recoating (SiOO:X every 10-15 years, CUTEK every 3-7 years)Repairs and replacements may not colour-match immediatelyLimited colour range (silver-grey palette only)Fire performance depends on base timber species, not treatment
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TECHNICAL DATA: PERFORMANCE PROPERTIES ORG-TBR-MW-002
Density (Dry) 400-1100 kg/m3
Specific Gravity 0.38-1.10
Porosity 8-20 %
Water Absorption 3-12 %
Hardness 4.0-11.0 kN
UV Resistance Good to Excellent (treatment dependent)
Chemical Resistance Moderate to Good (treatment dependent)
pH Tolerance 4-8 pH
Available Colors
Silver-grey (natural weathered patina — all species endpoint)Light grey (SiOO:X Light Grey — 10-16 weeks development)Mid grey (SiOO:X Mid Grey)Slate grey (Accoya Color Grey — through-core stain)Warm silver (CUTEK Silvery Grey colourtone)Natural blonde-to-grey transition (uncoated Silvertop Ash)
Surface Finishes
SiOO:X Wood Protection — silicon-based mineral system, 10-15 year lifeCUTEK CD50 with Silvery Grey colourtone — penetrating oilCUTEK Extreme — maximum protection with natural greyingAccoya Color Grey — factory-impregnated through-core grey stainUncoated natural weathering — lowest cost, uneven resultsAbodo Protector Patina — designed for controlled greying
Texture Options
Sawn face — textured surface, deeper grey tones achievableDressed/planed — smooth surface, lighter grey tonesRough sawn — rustic weathered aestheticStructured face — textured SiOO:X finish (Duffield Timber)
Pattern Options
Shiplap (most common cladding profile)V-joint tongue and grooveT&G with expressed rebateShadow-line claddingVertical and horizontal orientation options
Compressive Strength 30-70 MPa
Tensile Strength 42-125 MPa
Flexural Strength 44-130 MPa
Elastic Modulus 8-21 GPa
Impact Resistance 20-70 J/m
Creep Resistance Good to Excellent
Abrasion Resistance Good to Excellent (species dependent)
Thermal Conductivity 0.11-0.19 W/mK
Thermal Resistance 0.10-0.18 m2K/W
Specific Heat Capacity 1200-1600 J/kgK
Thermal Expansion 0.003-0.005 mm/mK
Ignition Temperature 280-400 degC
Sound Transmission Class (STC) 20-28 STC
Noise Reduction Coeff. (NRC) 0.10-0.20 NRC
Optical
Light Transmittance 0 %
Light Reflectance (LRV) 15-35 %

The desire for weathered timber aesthetics in contemporary architecture developed from the natural observation that all timber species eventually weather to a silver-grey colour through UV exposure. Early approaches simply involved leaving timber uncoated, but this produced uneven results. Factory-controlled ageing processes emerged in the early 2000s, with SiOO:X (developed in Sweden) leading the silicon-based treatment category. CUTEK (Australian company) developed penetrating oil systems specifically for the Australian climate. Accoya's acetylation technology, combined with through-core colouring, arrived in Australia via Britton Timbers distribution. The New Zealand company Abodo developed thermally modified timber products (Vulcan, Malvec) specifically designed to weather gracefully with SiOO:X coating. Modern architectural practice increasingly specifies pre-weathered finishes to avoid the inconsistent transition period and reduce long-term maintenance burden.

CLAD MATERIALS ATLAS PAGE 2 OF 4
SAFETY, ECOLOGY & INSTALLATION ORG-TBR-MW-002
Flame Spread Index 75-200 FSI
Smoke Developed Index 150-300 SDI
Combustibility Class Combustible — BAL rating per species
Ignition Temperature 280-400 degC
Fire Resistance Rating BAL-19 to BAL-29 (species dependent) minutes
Heat Release Rate 150-400 kW/m2
Toxicity of Combustion Low
Embodied Carbon (A1-A3) -100 to 200 (species and accounting dependent) kg CO2-eq/m3
Embodied Energy 400-1500 MJ/m3
Water Footprint 40-150 L/kg
EPD Available Yes
Recycled Content 0%
Renewable Content 100%
LEED Points 4-7 points
Circular Economy Score 8.0 /10
VOC Emissions <30 ug/m3
Skill Level Qualified carpenter
Crew Size 2-3 people
Installation Time 2-4 hours/10m2
Curing Time 0 hours
Temperature Range 5-35 degC
Humidity Range 30-75 % RH
Required Tools
Circular saw with fine-tooth carbide bladePre-drilling equipment for fixingsStainless steel fixings recommended (prevents tannin staining)Level and measuring toolsTouch-up treatment for cut ends (SiOO:X, CUTEK, or Accoya stain)Standard safety equipment
Certifications Required
Carpentry trade certificate (CPC30220 or equivalent)Working at Heights (for upper-level cladding installation)BAL-rated installation requires compliance with AS 3959 detailing
Weather Limitations
Avoid installation in rain or wet conditionsProtect stored materials from moistureStandard timber installation weather requirements applySiOO:X curing benefits from dry conditions initially
CLAD MATERIALS ATLAS PAGE 3 OF 4
COMMERCIAL, LOGISTICS & REGULATORY ORG-TBR-MW-002
Material Cost 95-250 AUD/m2
Installation Cost 35-65 AUD/m2
Annual Maintenance 0.50-3.00 AUD/m2/year
Lifecycle Cost (50yr) 130-400 AUD/m2
Market Availability Good — multiple suppliers and treatment options
Lead Time 14-42 days
Supply & Logistics
MOQ Project-dependent
Design Life 25-50 years
Warranty Period 10-50 years
Maintenance Interval 5-15 years
Service Temp Range -15 to 65 degC
Dimensional Stability 1-4 % change
Certifications Held
AS 2796 — Timber hardwood — sawn and milled productsFSC Chain of Custody — Accoya (FSC-certified Radiata Pine)PEFC certification available for Australian hardwood sourcesFSC certification — Accoya (Radiata Pine source)PEFC certification — available for Australian hardwood sourcesAccoya EPD available (acetylated wood product declaration)Red List Free — SiOO:X treatment systemRed List Free — SiOO:X meets Living Building Challenge requirementsNon-toxic — Accoya contains no biocides or harmful chemicals
Fire Code Compliance
AS 3959:2018 — Construction of buildings in bushfire-prone areasAS 3959 Appendix F — Approved species for BAL-29 include Silvertop Ash, Spotted Gum, Blackbutt, Red Ironbark, Turpentine, MerbauNCC Volume 1 — Timber cladding permitted up to 2 storeys (non-BAL)NCC Volume 2 — Class 1 and 10 buildings with BAL rating compliance
Standards Compliance
NCC 2022 Volume 1 & 2 — Compliant as external cladding per species BAL ratingAS 3959:2018 — Bushfire construction (BAL-29 with approved species)NCC Part 3.5.4 / Part 7.5 — Timber and composite wall claddingAS 1684 — Residential timber-framed constructionASTM D2017 — Accelerated laboratory test of natural decay resistanceASTM E84 — Surface burning characteristicsISO 21930 — Environmental product declarations for building productsISO 14040/14044 — Lifecycle assessment methodologyEN 350 — Natural durability of solid woodEN 927 — Paints and varnishes for exterior woodwork

DISCLAIMER: This specification document is generated from the CLAD Materials Atlas Database. Information is for general guidance only and does not constitute professional engineering advice. Values are typical and may vary by batch, manufacturer, and production run. Verify suitability for specific project applications independently.

ID: ORG-TBR-MW-002 Schema: v3.0
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