Co-extrusion WPC (Wood-Plastic Composite) decking is a high-performance, multi-layered composite engineered for outdoor applications. It combines a durable polymer-rich cap layer (HDPE/PVC with UV stabilizers and anti-slip additives) and a structural wood-plastic core (60–70% recycled wood fibers, 30–40% recycled plastics). This stratified design delivers superior moisture resistance (<1% water absorption), UV fade resistance (ΔE ≤2.5 after 3,000 hours), and thermal stability (0.06–0.09% expansion per 10°C). Ideal for pool decks, boardwalks, and commercial terraces, it requires zero maintenance, supports heavy loads (35–45MPa flexural strength), and contains ≥85% recycled materials. A sustainable alternative to traditional wood or monolithic WPC, co-extrusion technology ensures 25–30 years of aesthetic and structural integrity.