Wood-Plastic Composite Lumber vs. Real Wood Lumber
For about two decades there has been an alternative to real wood, and it’s all around us, in the form of decking, cladding, outdoor furniture, fencing and more besides. But is it as good as wood? There are some compelling arguments on both sides of the debate.
Wood-plastic composite materials (WPC) have some clear advantages – at least according to some. The problem with wood, especially for outdoor settings, is that it’s vulnerable to deterioration. It rots. Borer insects eat it, so it has to be painted with toxic preservatives and insecticides. Even insect-resistant woods may need a good deal more maintenance, protection and care, in the form of painting or varnishing.
WPC seems to beat these problems. It’s made of lumber by-products like wood fiber and dust, combined with resins and fillers that aren’t the average bug’s ideal meal. It can be made in all sorts of shapes and sizes, and an equally wide choice of finishes. It can also be made locally, instead of being transported in from distant plantations, with implications for its carbon footprint. Proponents argue that WPC lumber is quite simply greener than real wood, even if it’s not a natural product through and through. Sure, it uses chemicals, but even those are derived from recycled materials.
In reality, wood plastic composite lumber hasn’t quite lived up to all of its promises. The first generation of WPCs proved susceptible to mildew. Retailers had to stop claiming it required no maintenance, and specified that it needed washing to control mildew growth. And it didn’t stop there. Colors faded and some products stained. The strength of WPCs, and the effects of temperature changes, were both called into question. Cellulose fillers can absorb moisture and still be attacked by bugs. Most worrying, perhaps, is the fire safety hazard that WPCs may present. The extent of this problem is still being investigated.
There’s something about plastic wood that just doesn’t really appeal to our traditional sense of beauty and our fondness for real organic materials. We may have to set those attitudes aside as luxuries that we can’t indulge if we want to conserve the planet and its resources. Real wood has its own issues, although sustainable plantations and regulation have helped mitigate illegal logging and environmental destruction (as well as the exploitation of workers).
The problems of WPCs have been addressed in the next generation of products, mainly by sealing the exterior with a cap, typically of PVC (with other types of cap in development). Technological advances may mean that WPCs really are greener, though a major problem is that they are hard to recycle. Real wood, if it has been properly maintained, can be reused, repurposed and recycled.
The jury is still out on the superiority of WPC lumber. It clearly has a place in modern construction. Whether it’s the answer remains to be seen, as studies and assessments continue.