| Material definition | Wood–plastic composite decking combines wood fibers or flour with a thermoplastic polymer and performance additives. | Provides a consistent manufactured alternative to solid timber for outdoor floors, terraces, walkways, and public spaces. |
| Typical composition | Approximately 50–70% wood fiber or flour, 30–50% polymer and additives by weight; the exact ratio varies by formulation. | Different formulations can be selected for climate, load, appearance, slip resistance, and maintenance requirements. |
| Common polymer matrix | Common thermoplastics include polyethylene, polypropylene, and polyvinyl chloride. | The polymer type affects flexibility, thermal expansion, moisture behavior, processing temperature, and expected service performance. |
| Main raw materials | Wood residues may come from sawdust, wood flour, or processed fibers. The polymer may be virgin, recycled, or a controlled blend. | Use of wood-processing residues and recycled polymer can support material-efficiency goals when supply and quality are controlled. |
| Manufacturing step 1: preparation | Wood particles are screened and dried; moisture control is important because excess moisture can cause voids, surface defects, and dimensional instability. | Controlled preparation improves production consistency across different batches and climates. |
| Manufacturing step 2: compounding | Wood content, polymer, pigments, stabilizers, lubricants, and other additives are blended into a relatively uniform compound. | Uniform compounding helps maintain color, strength, density, and weathering performance throughout the profile. |
| Manufacturing step 3: extrusion | The heated compound is pushed through a shaped die to form a continuous decking profile, then cooled and cut to length. | Extrusion enables repeatable dimensions and surface designs for large-volume and multi-location projects. |
| Surface finishing | Profiles may be brushed, embossed, capped, or co-extruded to improve appearance and selected surface properties. | Finishes can help meet regional design preferences and project requirements for texture, color, and cleanability. |
| Moisture behavior | WPC generally absorbs less water than untreated wood, but it is not completely waterproof and can still expand or contract. | Appropriate gaps, drainage, ventilation, and substructure design remain necessary in humid, coastal, and rainy regions. |
| Dimensional movement | Thermal expansion is usually more significant than with timber because polymer content responds to temperature changes. | Installation details should be adapted to local temperature ranges, board length, joist spacing, and ventilation conditions. |
| Maintenance profile | Routine maintenance commonly includes sweeping, prompt stain removal, and periodic washing with suitable cleaning methods. | Lower routine maintenance can reduce labor and operating requirements over the service period, subject to local conditions. |
| Resistance considerations | WPC is generally resistant to rot and insect attack compared with untreated wood, but color fading, staining, scratching, and mold growth can still occur. | Project specifications should consider UV exposure, standing water, pollution, cleaning chemicals, foot traffic, and local biological conditions. |
| Slip performance | Slip resistance depends on profile geometry, surface texture, contamination, water conditions, and the applicable test method. | Wet-area projects should require documented test results under the standards and conditions relevant to the destination market. |
| Fire performance | Fire behavior varies with polymer type, additives, profile design, and installation; WPC should not be assumed to be fire-resistant. | Buildings and public projects should verify the required fire classification through testing accepted by the destination jurisdiction. |
| Typical applications | Residential terraces, balconies, pool surrounds, garden paths, pedestrian bridges, hospitality areas, and commercial outdoor platforms. | The material is suitable for many exterior applications when structural, drainage, fire, and slip requirements are properly assessed. |
| Specification checkpoints | Confirm board dimensions, load requirements, joist spacing, fasteners, expansion gaps, drainage, UV exposure, fire classification, slip test results, and installation instructions. | A performance-based specification helps reduce installation risk and supports compliance across different climates, codes, and procurement systems. |