organic / Plant-Based / Plant Fiber
Cork Board Insulation (25mm, 50mm, 75mm, 100mm)
100% natural expanded cork insulation board (ICB) from renewable cork oak bark, offering thermal conductivity 0.037-0.040 W/mK, verified carbon-negative lifecycle (-596.50 kg CO2/m3), zero VOC emissions, and 50-60 year service life without degradation or settling.
Atlas code
ORG-PLA-INS-002
At-a-glance signals
100% natural expanded cork insulation board (ICB) from renewable cork oak bark, offering thermal conductivity 0.037-0.040 W/mK, verified carbon-negative lifecycle (-596.50 kg CO2/m3), zero VOC emissions, and 50-60 year service life without degradation or settling.
Overview
Executive summary
Cork board insulation (Insulation Corkboard, ICB) is manufactured from expanded cork granules derived from cork oak bark, processed without synthetic binders through a natural steam/autoclave expansion process at approximately 350 degC. The cork's natural suberin resin acts as the binding agent, creating a 100% natural product with zero synthetic additives. This produces rigid insulation boards with thermal conductivity of 0.037-0.040 W/mK, compressive strength >= 100 kPa at 10% deformation, and an extraordinary service temperature range from -180 degC to +120 degC. The cellular structure provides excellent insulation while maintaining breathability and natural pest resistance.
Best when…
- 100% natural — no synthetic binders, adhesives, or chemical treatments
- Verified carbon-negative lifecycle (-596.50 kg CO2/m3 per Amorim EPD)
- Zero VOC emissions — safe for sensitive indoor environments
- Thermal conductivity 0.037-0.040 W/mK (standard density)
- Extraordinary service temperature range: -180 degC to +120 degC
- 50-60 year service life with no degradation, settling, or loss of properties
- Naturally breathable — excellent moisture vapour permeability for wall assemblies
- Self-extinguishing fire properties — does not propagate flame
- Natural resistance to insects, rodents, and mould (suberin content)
- 100% recyclable and biodegradable at end of life
Top advantages
- 01 100% natural — no synthetic binders, adhesives, or chemical treatments
- 02 Verified carbon-negative lifecycle (-596.50 kg CO2/m3 per Amorim EPD)
- 03 Zero VOC emissions — safe for sensitive indoor environments
- 04 Thermal conductivity 0.037-0.040 W/mK (standard density)
- 05 Extraordinary service temperature range: -180 degC to +120 degC
Top limitations
- 01 Premium pricing — 3-5x cost of synthetic insulation (EPS, XPS, PIR)
- 02 Limited availability in Australia — all products imported from Portugal/Spain
- 03 Higher thermal conductivity (0.037-0.040 W/mK) than PIR (0.022) or phenolic (0.020)
- 04 Long lead times for Australian delivery (6-12 weeks for special orders)
- 05 Euroclass E fire rating — lower than mineral wool (A1) or PIR (some achieve B/C)
Technical
Physical ·8
- Density
- 110-200 (standard 110-120) kg/m3 Standard density ICB: 110-120 kg/m3. High-density variant (facade/cladding): 140 +/-10 kg/m3. Very high density (decorative/CNC): 160-200 kg/m3. Three density grades available from Amorim. Source: Amorim Cork Insulation technical features; CorkLink expanded cork technical data sheet.
- Specific gravity
- 0.11-0.20 Very low specific gravity from expanded cellular structure. Standard: 0.11-0.12; High-density: 0.13-0.15. Source: derived from density data.
- Porosity
- 85-92 % Very high porosity from expanded cork cell structure — approximately 40 million air cells per cm3. Porosity provides both insulation and moisture vapour permeability (breathability). Source: cork cellular structure data; iCork Floor material properties.
- Water absorption
- 0.17 kg/m2 (partial immersion) kg/m2 Water absorption by partial immersion: 0.17 kg/m2 (high-density variant). Cork's suberin content provides natural water resistance while maintaining vapour permeability. Not suitable for permanent submersion. Source: Amorim high-density ICB specifications.
- Hardness
- Semi-rigid (characterised by compressive strength) Shore Semi-rigid insulation board. Firm enough for handling and mechanical fixing but can be cut with standard tools. Not measured on Shore or Janka scales — characterised by compressive strength instead. Source: Amorim product specifications.
- UV resistance
- Moderate (darkens but maintains performance) Moderate — ICB can be left exposed as exterior cladding (high-density variant) but will darken with UV exposure over time. Typically used in concealed insulation applications or rendered over. Source: Amorim exterior cladding application guide.
- Chemical resistance
- Excellent Excellent resistance to most building chemicals and environmental conditions. Suberin provides natural chemical resistance. Unaffected by mild acids, alkalis, or salts. Resistant to organic solvents. Source: CorkLink expanded cork technical data.
- pH tolerance
- 4-9 pH Natural cork is mildly acidic (pH ~5-6). Compatible with standard building substrates. No chemical interaction concerns with concrete, masonry, or timber. Source: general cork chemistry.
Mechanical ·5
- Tensile strength
- 50-150 kPa Tensile strength perpendicular to board face sufficient for adhesive-bonded insulation applications. Adequate for mechanical fixing and render system attachment. Source: CorkLink technical data sheet.
- Compressive strength
- 100-220 (at 10% deformation) kPa Standard density: compressive strength at 10% deformation >= 100 kPa. High-density variant (140 kg/m3): 220 kPa at 10% deformation. Suitable for inverted roof and under-slab applications with moderate loads. Source: Amorim Cork Insulation expanded ICB specifications; CorkLink technical data.
- Flexural strength
- 150-200 kPa Bending resistance >= 1.8 x 10^4 kg/m2 (approximately 176 kPa). Semi-rigid boards can accommodate minor substrate irregularities without fracturing. Source: CorkLink expanded cork technical data.
- Impact resistance
- Good (compresses rather than shattering) J/m Good impact resistance for insulation applications. Cork absorbs impact energy through cellular compression without shattering (unlike rigid foam boards). Source: cork material properties.
- Creep resistance
- Excellent Excellent long-term dimensional stability under sustained load. Cork recovers from compression and maintains insulation properties over 50-60 years. Peer-reviewed study on compressive creep behaviour of expanded cork agglomerate blocks confirms good long-term performance. Source: ScienceDirect compressive creep study.
Sustainability & Health
Embodied carbon & energy ·7
- Embodied carbon
- -596.50 (Amorim EPD) / -116.23 (peer-reviewed LCA) kg CO2-eq/m3 Verified carbon-negative: -596.50 kg CO2/m3 per Amorim Cork Insulation EPD. Among the lowest embodied carbon of any building insulation material. Cork oak forest sequesters carbon during 9-year bark regeneration cycles. Alternatively, -116.229 kg CO2-eq/m3 per ScienceDirect peer-reviewed study. Source: Amorim Cork Insulation EPD 2023; ScienceDirect carbon footprint study.
- Carbon footprint
- -5 to -1 (consistently negative) kg CO2-eq/kg Carbon-negative lifecycle confirmed. Cork insulation board has the lowest carbon footprint of any insulation material studied. Cork oak forests sequester approximately 14.7 tonnes CO2/hectare/year. Source: ScienceDirect carbon footprint study; Amorim sustainability data.
- Embodied energy
- 4-15 MJ/kg Very low embodied energy — autoclave process uses steam heat with no synthetic chemical inputs. Over 60% of Amorim factory energy from biomass (burning cork dust in carbon-neutral process). No fossil fuel-derived additives. Source: Amorim green production process.
- Water footprint
- 50-200 L/kg Cork oak forests are rain-fed Mediterranean ecosystems (Montado) — no irrigation. Water footprint limited to manufacturing steam process. Cork oak forests provide watershed protection ecosystem services. Source: Amorim sustainability; cork oak silviculture data.
- Recycled content
- 70-100 (from cork processing by-products) % ICB manufactured from cork by-products — bark processing waste that would otherwise be discarded. 100% recycled cork content in many products. Amorim's integrated production reuses all cork waste. Source: Amorim green production process; CorkLink product description.
- Renewable content
- 100 % 100% renewable content — cork bark regenerates every 9 years without harming the tree. Cork oak trees live 150-200 years. No synthetic binders or additives. Source: Amorim; cork oak silviculture.
- Circular score
- 9.5 /10 Near-perfect circular economy material: renewable harvest, recycled by-product feedstock, zero synthetic additives, fully recyclable, biodegradable, carbon-negative, manufacturing waste used as biomass energy. Source: circular economy assessment framework.
Compliance & Fire
Fire performance ·6
- Combustibility class
- Euroclass E (self-extinguishing) Euroclass E fire classification (EN 13501-1). Combustible material but self-extinguishing — does not propagate flame. No toxic fumes or flaming droplets during combustion. Natural suberin content provides inherent fire resistance. Source: Amorim Cork Insulation product specifications; CorkLink technical data.
- Fire resistance level
- Assembly dependent (cork layer contributes through charring resistance) minutes Fire resistance as part of wall/roof assembly depends on total construction. ICB charring behaviour is slow and predictable. Cork does not melt or collapse under fire exposure (unlike thermoplastic foam insulation). Source: cork fire behaviour literature.
- Ignition temp
- 300-400 degC Cork manufactured at approximately 350 degC during autoclave expansion — ignition temperature above manufacturing temperature. Self-extinguishes when flame source removed. Source: Amorim manufacturing process data.
- Flame spread index
- 25-75 FSI Low flame spread — cork is naturally self-extinguishing. Does not propagate flame or produce flaming droplets. Source: Amorim fire testing data.
- Smoke dev. index
- 25-100 SDI Low smoke production from natural organic material combustion. No synthetic components to generate dense toxic smoke. Source: cork fire performance data.
- Heat release rate
- 40-100 kW/m2 Low heat release rate from natural cork cellular structure. Cork chars slowly and self-extinguishes. Source: cork fire performance data.
Cost & Lifecycle
Capex & lead time ·6
- Material cost (range)
- 30-170 (thickness dependent) AUD/m2 Premium insulation product — approximately 3-5x cost of EPS/XPS. 25mm: $30-50/m2; 50mm: $55-90/m2; 75mm: $80-130/m2; 100mm: $100-170/m2 (estimated AUD including import and distribution). Prices vary with exchange rate, order volume, and distributor. Source: European pricing extrapolated to Australian market with import costs.
- Material cost (per unit)
- 25-150 (volume dependent) AUD/m2 Volume pricing for large projects — 10-20% discount typical for orders >200m2. Source: industry estimates.
- Lead time
- 14-90 days All ICB imported from Portugal (Amorim). Standard thicknesses may be held by specialist Australian distributors (2-4 weeks). Special orders from Portugal 8-12 weeks. Source: Australian insulation distributor estimates.
- Lifecycle cost
- 80-250 AUD/m2 High initial cost offset by 50-60 year service life with zero maintenance. No replacement cycles (unlike synthetic foam insulation which may degrade over 25-30 years). When annualised over lifespan, competitive with materials requiring replacement. Carbon credit value potential. Source: lifecycle cost analysis benchmarks.
- Annual maintenance
- 0 AUD/m2/year Zero ongoing maintenance cost — permanent installation with no degradation over 50-60 year service life. Source: Amorim durability data.
- Market availability
- Limited — specialist import only Limited specialist supply in Australia. No domestic ICB manufacturing. Imported from Amorim (Portugal) through specialist insulation distributors and Passive House suppliers. Growing demand driven by Passive House certification, Green Star, and NatHERS requirements. Key Australian contacts: EcoSupply Center, specialist Passive House suppliers. Source: Australian sustainable building supply chain.
Service life & durability ·3
- Expected lifespan
- 50-60+ years 50-60 years without loss of thermal, mechanical, or dimensional characteristics. ICB does not settle, degrade, or lose R-value over time — unlike some synthetic and mineral fibre insulation. One of the longest-lived insulation materials available. Source: Amorim Cork Insulation technical features.
- Maintenance interval
- None required (permanent installation) years Zero maintenance required once properly installed in concealed applications. Permanent insulation — no servicing, replacement, or top-up needed. Source: Amorim product specifications.
- Warranty period
- 25-50 years Amorim ICB rated for 50-60 year service life without loss of characteristics. Manufacturer warranties typically 25-50 years reflecting exceptional durability. Source: Amorim technical features.
Layer D
Where it's used
External wall insulation (EIFS) systems
Roof and ceiling insulation
Under-floor insulation
Thermal bridge breaking applications
Passive house and zero-energy construction
Historic building restoration (breathable insulation)
Acoustic insulation for sound studios
Cold storage and industrial insulation