Capped Composite Decking — Four-Sided Co-Extrusion WPC Boards

Co-extrusion WPC decking is made by extruding a protective polymer cap layer onto the WPC core at the same time the core is formed, so the two bond permanently. The cap covers all four sides and gives better UV, stain and scratch resistance than classic WPC, which has an open-pore composite surface throughout.

Both share the same 148 mm width and 23 mm thickness but differ in the internal core. The round hole profile has circular chambers; the M-shape uses an M-shaped internal structure that is stiffer across longer spans and spreads load more evenly, which suits wider joist spacing or heavier footfall. The round hole board is slightly lighter and performs equivalently at standard residential joist spacings.

The 148 mm board covers more area per board, so fewer boards, fewer clips and less labour on a large deck. The 138 mm profile gives a finer plank line that reads closer to traditional timber, which some buyers prefer on residential projects.

It is the highest specification in the range — a full-density solid core with the co-extrusion cap. Choose it where structural performance matters most: commercial boardwalks, high-footfall public areas, and residential projects where the deck is treated as long-term infrastructure.

An uncapped board goes through a natural weathering process over its first 3–6 months outdoors as surface pigments meet UV. A capped board reduces that shift substantially, because the pigments sit under a UV-stable polymer surface rather than in it. In high-UV locations — Australia, the Middle East, Southern Europe — capped is the grade we recommend.

Yes. All composite decking moves with temperature, which is why the gap between boards is a working allowance rather than a tolerance. Leave 5–8 mm between boards, and use the upper end of that range in hot climates. Our hidden clip system sets the gap automatically during installation.

An uncapped board has the composite exposed, so it marks more readily under furniture and grit. The cap layer on our co-extrusion range takes that wear instead of the core, and most surface marks wipe off. No composite decking is scratch-proof — dragging metal furniture will mark any board.

Yes. The cap resists chlorine splash, pool chemicals and sunscreen oils that stain an open-pore surface, and marks clean off with water and mild detergent. Both hollow and solid profiles suit pool surrounds; choose solid for commercial pool facilities or very high foot traffic. Note that this is a staining and chemical-resistance answer, not a slip classification: we hold R10 under AS 4586-2013 Appendix D on profile ZSGJ138H23A, which is the shod-wet ramp test. We do not hold the DIN 51097 barefoot wet classification that pool surrounds are normally specified against.

We recommend 5–8 mm between boards for thermal movement and rainwater drainage. The cap gives slightly better dimensional stability than an uncapped board, but the gap is still required. Our hidden clip system maintains it automatically; allow the upper end of the range in hot climates.

Yes. Boards in your chosen profile, hidden stainless steel or aluminium clips, joist and keel profiles, edge trims and end caps, all matched to the board profile and colour. Samples are available on request: we supply the board free of charge and the courier cost is invoiced to you, then credited against your first order.

Yes — we sell business-to-business only, direct from our factory in Guangdong, FOB Nansha or Yantian. We do not sell to homeowners. Buyers comparing capped composite decking manufacturers are welcome to request our ISO certificates and third-party test reports before ordering.

We are the plant. Among composite deck manufacturers that is worth checking rather than assuming: ask which port the goods load from. Ours are Nansha or Yantian, and both appear on our commercial invoices. A composite decking supplier who answers with a city rather than a port is usually buying the containers from someone else and reselling them to you.