How does WPC material perform in retaining structural integrity when wet?

Wood Plastic Composite (WPC) material demonstrates remarkable structural integrity when exposed to moisture, making it an excellent choice for outdoor and high-humidity applications. Unlike traditional wood that can warp, swell, or rot when wet, WPC maintains its dimensional stability due to its unique composition of wood fibers and plastic polymers. The plastic matrix creates a protective barrier that limits water absorption to typically 0.1-1% by weight, significantly lower than natural wood's 10-25% absorption rate. This minimal moisture uptake prevents the significant expansion and strength reduction common in wet wood materials. Even when continuously exposed to moisture, WPC retains approximately 85-95% of its dry flexural strength and modulus of elasticity. The material's resistance to water penetration also inhibits fungal growth and decay mechanisms that typically compromise wet wood structures. While prolonged saturation can cause minor swelling (generally less than 2% in any direction), this dimensional change is reversible upon drying without permanent deformation. For optimal wet performance, high-quality WPC formulations incorporate coupling agents that strengthen the wood-plastic bond, further enhancing moisture resistance. These characteristics make WPC particularly suitable for decking, fencing, and outdoor furniture where consistent exposure to rain, humidity, or ground contact is expected.