Defects of WPC

One of the most important factors when choosing WPC products is the composition itself. They are usually made up of 50–60% wood, 30% plastic, and in high-quality products, the remaining 5–10% consists of UV stabilisers, additives and colourants.

If polypropylene (PP) is used as the polymer in the manufacturing process, the boards become more brittle at low temperatures and freezing conditions, leading to the degradation of the material itself. The board weakens, resulting in material deterioration and the disintegration of the boards. Therefore, instead of PP, some manufacturers use polyvinyl chloride (PVC) as the polymer, which is known to release harmful phthalates when exposed to sunlight. That is why Woodlook™ boards use eco-friendly, recyclable high-density polyethylene (HDPE), which is harmless to health, and our laboratory tests showed no physical or chemical changes.

Many manufacturers use larger fraction softwood sawdust in production – even over 2 mm – which, in addition to giving a ‘chipboard’ appearance, results in more visible greying of these wood particles due to UV radiation. The use of such sawdust can lead to cracks forming after freezing conditions. This is caused by the natural absorbency of wood.

Recognising high-quality WPC decking boards is not easy at all, and even a high price may not be a guarantee. The same injection mould produces the same product shape, but identical appearance tells you almost nothing about the mixture’s composition. You often only find this out years later. The best and simplest way to assess product quality is to study the company’s history in detail. If the company has many years of experience, this should be a sufficient guarantee of quality for you.