MATERIAL DATA SHEET

Charred Timber (Shou Sugi Ban) Millwork

Millwork
organic › Timber › Millwork
organictimbermillworkcharred-timbershou-sugi-banyakisugifire-resistantweathering-resistantjapanese-techniqueaustralian-hardwoodspotted-gumjarrahironbarkbal-29chemical-freecladdingscreening
ATLAS CODE
ORG-TBR-MW-001
Charred Timber (Shou Sugi Ban) Millwork
Category organic
Material Family Timber
Regulatory Status Combustible - BAL rating per species
Density
650-1100 kg/m3
Carbon (A1-A5)
-50 to 200 (species and accounting dependent) kg CO2-eq/m3
Fire Class
Combustible - BAL rating per species
Lifespan
40-80 years
Description

Charred timber millwork utilises the traditional Japanese Shou Sugi Ban (Yakisugi) technique, applying controlled charring to create a 2-3mm protective carbon layer on premium hardwoods. This ancient preservation method, originating in 18th century Japan for cedar siding, enhances timber's natural durability while creating a distinctive architectural finish. The charring process transforms the wood surface into a carbon-rich barrier that resists moisture, insects, UV degradation, and fungal decay without chemical treatments. In Australia, the technique is applied to native hardwoods including Spotted Gum (BAL-29), Jarrah (BAL-19), and imported Burnt Ash, suitable for cladding, screening, and architectural detailing where superior weathering performance and unique aesthetic are required.

Primary Sectors
[Residential][Commercial]
Typical Uses
  • External timber cladding and screening
  • Architectural millwork and detailing
  • Feature walls and accent panels
  • Pergola and outdoor structure elements
  • Garden and landscape architecture
  • Bushfire-resistant construction (BAL zones)
  • High-end residential and commercial projects
  • Heritage and Japanese-inspired architecture
Recycled Content 0-30
Renewable Content 95-100
Recyclability 90-100
Embodied Carbon -50 to 200 (species and accounting dependent) kg CO2-eq/m3
Embodied Energy 500-1200 MJ/m3
EPD Available No
Advantages
Chemical-free preservation - no toxic treatments or leaching riskEnhanced resistance to UV, moisture, insects, and fungal decayDistinctive black aesthetic with natural grain textureBAL-29 achievable with Spotted Gum substrate (AS 3959)40-80+ year service life on durable hardwood speciesLow maintenance compared to painted/stained timber alternativesEliminates recurring VOC-generating paint/stain maintenance cyclesCarbon storage in timber plus reduced replacement frequencyMultiple Australian manufacturers and suppliers availableSuitable for Australian climate zones and bushfire areas
Cautions
Charring does NOT increase fire rating - BAL depends on base timber speciesChar layer is soft and wears away, especially on softwood substratesHigher cost than conventional timber ($255-350+ AUD/m2 supply only)Surface carbon may transfer on contact (handling/touch)Colour consistency challenges across batchesChar layer visible erosion expected around 4-5 years exposureEstimated 20-year char lifetime before re-charring/refinishing neededSpecialist installation and maintenance knowledge required
CLAD MATERIALS ATLAS PAGE 1 OF 4
TECHNICAL DATA: PERFORMANCE PROPERTIES ORG-TBR-MW-001
Density (Dry) 650-1100 kg/m3
Specific Gravity 0.60-1.13
Porosity 5-15 %
Water Absorption 2-8 %
Hardness 6.1-14.0 kN
UV Resistance Excellent
Chemical Resistance Good
pH Tolerance 4-8 pH
Available Colors
Deep black (heavy char)Charcoal grey (medium char with oil)Brown-black (light char revealing timber tones)Silver-grey (naturally weathered char over time)Warm black (with Cutek Black Ash oil)Matt black (with WOCA Black Oil interior)
Surface Finishes
Cutek CD50 Black Ash — standard exterior oil, lowest costWOCA Exterior Oil — premium exterior, +$10-20/m2WOCA Black Oil — recommended for interior applicationsUncoated — available but not recommended for longevityCustom oil finishes available on request
Texture Options
Heavy char — deep textured carbonised surface, most weather-resistantMedium char — balanced texture with visible grain beneathLight char — subtle charring with dominant natural grainBrushed finish — char partially removed exposing grain contrastFine sawn substrate — allows deeper char penetration (Jarrah)
Pattern Options
Alligator (heavy char with deep cracking pattern)Crocodile (medium char with textured surface)Smooth (light char with grain visible)Brushed (char brushed back to reveal grain contrast)Natural grain variations by species
Compressive Strength 40-80 MPa
Tensile Strength 80-150 MPa
Flexural Strength 90-150 MPa
Elastic Modulus 12-24 GPa
Impact Resistance 30-80 J/m
Creep Resistance Excellent
Abrasion Resistance Poor (char layer) / Excellent (base timber)
Thermal Conductivity 0.14-0.19 W/mK
Thermal Resistance 0.12 m2K/W
Specific Heat Capacity 1200-1600 J/kgK
Thermal Expansion 0.003-0.005 mm/mK
Ignition Temperature 400-500 (char layer) degC
Sound Transmission Class (STC) 20-25 STC
Noise Reduction Coeff. (NRC) 0.10-0.20 NRC
Optical
Light Transmittance 0 %
Light Reflectance (LRV) 3-10 %

Shou Sugi Ban (literally 'burnt cedar board') originated in 18th century Japan as a practical preservation technique for Sugi (Japanese cedar) siding. The method involves carefully controlled charring that creates a protective carbon layer while maintaining structural integrity. Traditional techniques used controlled fire application between paired boards leaned together, creating distinctive surface patterns and enhanced durability. Thousands of buildings in Japan retain functional charred timber cladding over 40 years old. The technique gained international architectural attention from the 2000s onward, with Australian adoption accelerating from 2015 as local suppliers developed processes for native hardwoods. Modern applications adapt the ancient craft for contemporary architecture, with Australian companies like Mortlock Timber spending years perfecting charring techniques to reduce warping and splitting. Recent developments focus on standardising the process for commercial applications while preserving traditional aesthetic and performance benefits.

CLAD MATERIALS ATLAS PAGE 2 OF 4
SAFETY, ECOLOGY & INSTALLATION ORG-TBR-MW-001
Flame Spread Index 0-25 (Class A charred cypress) FSI
Smoke Developed Index 100-200 SDI
Combustibility Class Combustible - BAL rating per species
Ignition Temperature 400-500 (char layer) degC
Fire Resistance Rating BAL-19 to BAL-29 (species dependent) minutes
Heat Release Rate 150-300 kW/m2
Toxicity of Combustion Low
Embodied Carbon (A1-A3) -50 to 200 (species and accounting dependent) kg CO2-eq/m3
Embodied Energy 500-1200 MJ/m3
Water Footprint 50-200 L/kg
EPD Available No
Recycled Content 30%
Renewable Content 100%
LEED Points 4-6 points
Circular Economy Score 8.5 /10
VOC Emissions <50 ug/m3
Skill Level Specialist / experienced carpenter
Crew Size 2-3 people
Installation Time 3-5 hours/10m2
Curing Time 0 hours
Temperature Range 5-35 degC
Humidity Range 30-75 % RH
Required Tools
Circular saw with fine-tooth blade (carbide tipped)Pre-drilling equipment for all fixingsStainless steel fixings only (no ferrous metals — tannin reaction)Router for joinery and edge profilingDust collection system (char particles are fine and pervasive)PPE: dust mask (P2), safety glasses, gloves (carbon transfer)Touch-up oil kit for cut ends and drill holes
Certifications Required
Carpentry trade certificate (CPC30220 or equivalent)Working at Heights (for upper-level cladding installation)OH&S for dust management (fine charcoal particles)BAL-rated installation requires compliance with AS 3959 detailing
Weather Limitations
Avoid installation in rain or wet conditionsProtect installed work from rain for 24-48 hours if freshly oiled on-siteStandard timber installation weather requirements applyEnsure adequate ventilation behind cladding (AS 3959 requirement for BAL-rated installations)
CLAD MATERIALS ATLAS PAGE 3 OF 4
COMMERCIAL, LOGISTICS & REGULATORY ORG-TBR-MW-001
Material Cost 255-350 AUD/m2
Installation Cost 35-65 AUD/m2
Annual Maintenance 1.50-5.00 AUD/m2/year
Lifecycle Cost (50yr) 280-450 AUD/m2
Market Availability Good - multiple Australian manufacturers
Lead Time 14-42 days
Supply & Logistics
MOQ Project-dependent
Design Life 40-80 years
Warranty Period 5-25 years
Maintenance Interval 5-10 years
Service Temp Range -10 to 65 degC
Dimensional Stability 1-3 % change
Certifications Held
AS 2796 — Timber hardwood — sawn and milled productsAS 1604 — Specification for preservative treatment (process replaces chemical preservation)Chain of custody certification available (FSC/PEFC for sourced timber)FSC certification available for sustainably sourced timberPEFC certification availableNo product-specific EPD currently available for charred timber
Fire Code Compliance
AS 3959:2018 — Construction of buildings in bushfire-prone areasBAL-29 compliance with Spotted Gum or Ironbark substrateBAL-19 compliance with Jarrah substrateNCC Volume 1 Part C — Fire safety (combustible material provisions apply)
Standards Compliance
NCC 2022 Volume 1 & 2 — Compliant as external cladding per species BAL ratingAS 3959:2018 — Bushfire construction (BAL-19 to BAL-29 depending on species)AS 1684 — Residential timber-framed constructionAS 1720.1 — Timber structures — Design methodsASTM E84 — Surface burning characteristics (Class A achievable for charred cypress)ASTM E119 — Fire endurance testingASTM D2017 — Accelerated laboratory test of natural decay resistanceISO 21930 — Environmental product declarations for building productsISO 14040/14044 — Lifecycle assessment methodologyEN 13501-1 — Fire classification (B-s1-d0 achievable for some products)EN 350 — Natural durability of solid wood

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-001 Schema: v3.0
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