Board · 6–22 mm
Timber-Based Composite — indicative fig. C·45
Fire Combustible CombustibleEmbodied carbon Data pending Per-m² sourceCompressive 12–20 (parallel) / 2–4 (perpendicular to face)MPa StructuralDesign life 30yr
Structural OSB/3 panels with oriented strands and waterproof adhesives; suitable for sheathing, flooring, and roof decking in dry and humid conditions.
01 Physical
Density 600–680kg/m3
Specific gravity 0.60–0.68
Porosity 3–8%
Water absorption 15 (24h, EN 317)% thickness swelling
Hardness 10–18N/mm2
UV resistance Poor — requires protection from UV exposure
Chemical resistance Moderate — adequate for typical construction chemical exposure
pH tolerance 4.5–6.0pH
Surface roughness 40–120 (unsanded)μm Ra
02 Mechanical
Tensile strength 7–14 (longitudinal) / 3–7 (transverse)MPa
Compressive strength 12–20 (parallel) / 2–4 (perpendicular to face)MPa
Flexural strength 14.8–25 (longitudinal) / 7.4–15 (transverse)MPa
Shear strength 1.0–1.8 (planar shear)MPa
Poisson's ratio 0.07–0.15 (longitudinal)
Impact resistance 20–40 (Charpy, panel face)J
Creep resistance Moderate — creep factor (k_def) 1.50–2.25 per EN 1995; sustained load reduction required
03 Thermal
Thermal conductivity 0.13W/mK
Specific heat 1700J/kgK
Thermal expansion 5–10 (parallel) / 10–20 (perpendicular)×10⁻⁶/K
04 Compliance & Fire First question
Combustibility class Combustible — Group 3 (AS 1530.1) / Euroclass D (EN 13501-1)
Fire resistance level Not rated (panel alone) — FRL per assembly testminutes
Ignition temp 250–290 (pilot) / 300–350 (auto-ignition)°C
Flame spread index 100–200 (untreated, AS 1530.3)FSI
Smoke dev. index 5–9 (AS 1530.3, untreated)SDI
Heat release rate 100–200 (cone calorimeter, 50 kW/m2)kW/m²
05 Sustainability & Health
Embodied carbon 1.0–3.7 kgCO2e/m2 (by thickness, biogenic excluded)kgCO2e/m²
Carbon footprint 0.3–0.6 (fossil GWP, biogenic excluded)kgCO2e/kg
Embodied energy 8–12 (cradle to gate)MJ/kg
Water footprint 0.5–2.0 (net process water, manufacturing)L/kg
Recyclability 5–15 (particleboard feedstock) / 60–70 (energy recovery)%
Recycled content <5 (predominantly virgin plantation timber)%
Renewable content 90–95 (wood fibre mass fraction)%
Circular score 5/10
VOC emissions <0.124 (PF-bonded, E1) / <0.01 (MDI-bonded)mg/m3
Formaldehyde emissions <0.124 (PF, E1) / <0.01 (MDI)mg/m3
Toxicity rating Low (in service) — wood dust during cutting is IARC Group 1, P2 protection required
LEED contribution 1–3 (partial, EPD + FSC + low-VOC credits)points
06 Durability · Cost · Logistics
Expected lifespan 30–50+ (protected) / 2–5 (exposed edges, no sealing)years
Maintenance interval Nil (concealed) / 1 (exposed temporary use)years
Warranty period 10–15years
Material cost (range) 15–38 (by thickness, supply only, AUD/m2, 2025)AUD/m²
Material cost (per unit) 63–110 (per 2400x1200mm sheet, 15–22mm, AUD, 2025)AUD/sheet (2400×1200mm)
Lead time 1–5 (ex-stock) / 42–98 (special order from Europe)days
Lifecycle cost 25–55 (50-year LCC, concealed structural use)AUD/m²
Annual maintenance 0 (concealed) / 1–3 (exposed temporary use)AUD/m²/year
Market availability Good for standard thicknesses — moderate for thinner panels
07 Assessment
Advantages
- Cost-competitive with structural plywood — typically 15–25% lower supply cost per m2
- Consistent, predictable mechanical properties across the panel with no voids or delamination risk
- Efficient use of plantation timber including small-diameter logs and mill residue
- OSB/3 grade rated for humid service conditions (EN 300), suitable for most Australian climate zones with sealing
- Available in large sheet formats (1200×2400mm, 1220×2440mm) reducing joints and labour
- Accepts standard woodworking tools — circular saw, jigsaw, router, drill — with carbide-tipped blades
- Compatible with standard framing connectors, nails, screws, and structural adhesives
- FSC and PEFC certified product available from leading European producers for green building projects
- MDI-bonded grades are effectively formaldehyde-free in service, suitable for low-emission interiors
- Biogenic carbon storage — wood fibre content locks up atmospheric CO2 for the service life of the building
Constraints
- No domestic Australian manufacturing — all product imported, resulting in long lead times (6–14 weeks) and freight-related cost and carbon impacts
- Edge swelling under sustained moisture exposure — panel edges must be sealed in wet or exposed applications
- 24-hour thickness swelling of ~15% (OSB/3) is higher than structural plywood; recovery after wetting is incomplete
- Rough, textured surface finish unsuitable for exposed or painted applications without significant surface preparation
- Directional mechanical properties (anisotropic) require careful orientation on framing — span must align with major panel direction
- Phenol-formaldehyde resin binders release formaldehyde during cutting and in poorly ventilated spaces during initial off-gassing
- Wood dust from cutting is IARC Group 1 carcinogen — respiratory protection mandatory during on-site fabrication
- Reduced fastener holding capacity at panel edges compared to structural plywood — edge distance and spacing critical
- Not suitable for prolonged external exposure without cladding or weather barrier — surface degrades under UV and repeated wetting
- End-of-life recyclability is limited — resin binder prevents composting; options largely restricted to energy recovery or landfill
08 Applications
A1 Structural Wall Sheathing Used as bracing panels and structural sheathing in timber-framed residential and light commercial construction, providing racking resistance and substrate for external cladding.
A2 Roof Decking and Sarking Applied as structural roof decking under metal roofing, tiles, or membrane systems, providing the structural diaphragm and fixing substrate.
A3 Floor Substrate and Underlayment 18mm and 22mm OSB/3 used as structural floor substrate on joist-framed floors, providing a stable base for carpet, vinyl, tiles, and engineered timber flooring.
A4 Site Hoarding and Temporary Enclosures Used for construction site hoardings and temporary enclosures; typically painted or sealed for weather protection and safety visibility.
A5 Packaging and Industrial Crating Lower-grade OSB and factory offcuts used for heavy industrial packaging, export crating, and pallet construction.
A6 Exhibition and Display Structures Used in temporary exhibition stands, trade display structures, and fit-out applications where structural sheathing or a solid panel substrate is required.
A7 Acoustic Wall Substrate Applied as a solid, rigid substrate behind fabric panels, perforated linings, or acoustic tile systems in walls and ceilings requiring controlled sound reflection.
A8 Flat-Pack Furniture Carcases Factory-processed OSB used for shelving, cabinet carcases, and furniture backs in cost-driven commercial and residential furniture applications.
A9 Raised Access Floor Substrate Proprietary raised access floor panels incorporating OSB core with melamine or HPL overlay, used in commercial office fit-outs.
A10 Internal Partition Substrate Used as a solid panel substrate in high-impact internal partition systems in schools, gymnasiums, and commercial settings where standard plasterboard alone is insufficient.
09 Sources & Standards
Sources pending — citations for this material are not yet recorded. Verify all figures against manufacturer data and current standards before specifying.