Composite decking is manufactured by combining wood fibres, plastic polymers and additives before shaping the material into decking boards.
Most wood plastic composite (WPC) decking is produced through extrusion, although manufacturing methods and finishes vary between products.
In this guide, we’ll explain how composite decking is manufactured, including how the materials are combined, how boards are formed and how protective outer layers are added to certain products.
What is Composite Decking Made of, and How is it Made?
Composite decking is made by mixing wood fibres with plastic and a bonding agent before being shaped to resemble traditional wooden decking boards.
A colouring agent can be added to dictate the overall colour of the finished deck board.
Ecoscape composite decking is made from 45% recycled HDPE, and reclaimed wood fibres account for 55%, making it an eco-friendly option.
Composite decking material uses reclaimed wood fibres such as sawdust and wood chips that would normally be landfilled and mix it with recycled plastics and bonding agents. All the wood sourced by Ecoscape is FSC certified.
The mixture is then extruded or moulded into the decking boards. The boards that are created resemble traditional wood decking boards but offer greater resilience and durability.
Ecoscape produce both capped and uncapped composite decking boards. The outer layer of the capped decking boards greater protection against staining and scratching. It also offers UV stability.
Composite deck boards can also be created by using a method known as compression moulding, which uses heat and pressure to mould and bond the raw materials in a wood grain mould.
Different finishes can be created with smooth, wood grain effects and grooved boards available. We have been working on our techniques for years. The colour agents are added to the process in a way to create a natural streaking process to replicate timber decking but without the drawbacks. We also brush the decking once extruded to give the board a matte timber like finish.
What is Co-Extruded Decking?
Co-extruded boards are second-generation WPC decking boards that are capped.
This process covers the surface with a durable membrane that typically uses UV inhibitors, colourants, and antioxidants to conserve the materials and ensure the boards last longer.
Capped composite decking boards that have been covered on all four sides provide greater protection and longer-lasting boards.
While co-extruded decking boards are more expensive, they are high-quality, long-lasting boards that offer impressive performance. Investing in the best decking boards when installing a decking area is a cost-effective option that minimises maintenance needs.
How Manufacturing Affects the Finished Decking Board
The manufacturing process influences the appearance, structure and surface characteristics of composite decking.
Different production methods allow manufacturers to create boards with a variety of profiles and finishes, including natural-looking woodgrain effects, grooved surfaces and brushed textures.
Manufacturers can also produce different board constructions:
- Uncapped composite decking: The composite material forms the exposed surface of the board, as seen in Ecoscape’s Clarity decking range.
- Capped composite decking: An additional polymer layer is incorporated during manufacturing to provide enhanced surface protection.
The manufacturing process also allows different board colours and finishes to be produced.
Although the materials used influence the manufacturing process, their exact composition varies between products. Our guide to what WPC decking is made of explains the individual ingredients in more detail.
Types of Composite Decking
Composite decking can be manufactured with different internal structures and protective finishes. The main distinctions are between solid and hollow boards, and capped and uncapped surfaces.
Solid composite decking has a continuous core rather than hollow channels. This construction is used in products such as Ecoscape’s Clarity decking. The board’s composition, dimensions and performance characteristics are detailed in the Clarity technical specification.
Capped composite decking incorporates an additional polymer layer during manufacturing. This protective layer is designed to improve resistance to staining, fading and everyday wear. Ecoscape’s Forma decking is an example of this construction.
Hollow composite decking is manufactured with internal channels rather than a continuous solid core. These channels reduce the amount of material used and the board’s weight. The shape and arrangement of the channels vary between manufacturers.
For a fuller comparison of the two core constructions, see our guide to hollow vs solid composite decking.
Final Thoughts
Composite decking is manufactured by combining wood fibres, plastic polymers and additives before shaping the material into decking boards, most commonly through extrusion.
Different manufacturing techniques allow producers to create solid or hollow profiles, apply protective outer layers and introduce a variety of colours and surface textures.
These processes influence the finished board’s appearance, structure and performance.
For more information about the individual materials used in production, read our guide to what wood plastic composite (WPC) decking is made of.
