Composite decking is typically made from a blend of recycled wood fibres (like sawdust and wood chips), recycled plastic, and performance‑enhancing additives that bind and protect the board.

Quick Scoop

Think of composite decking as a recipe rather than a single material.

Manufacturers tweak the “ingredients” a bit, but the core idea stays the same: mix wood, plastic, and additives, then form them into durable boards.

Main Ingredients

  • Wood fibres / filler
    • Often sawdust, wood chips, or reclaimed wood fibre that would otherwise be waste.
* Gives the boards a more natural look and stiffness similar to timber.
  • Plastic (usually recycled)
    • Commonly high‑density polyethylene (HDPE), polypropylene, or PVC, sometimes from recycled sources like packaging or containers.
* Adds moisture resistance and helps stop the board from rotting like traditional wood.
  • Additives and bonding agents
    • Adhesives/binding agents that lock wood and plastic together into a stable composite.
* Pigments for colour, UV inhibitors to reduce fading, and anti‑oxidants to improve long‑term durability.

How It’s Made (In Simple Steps)

  1. Wood fibres, plastic, and additives are precisely measured and mixed together.
  1. The blend is heated and pushed through a mould (extrusion) or pressed (compression moulding) into board shapes.
  1. Boards are cooled and cured so they keep their shape and avoid warping.
  1. A colour and sometimes a textured, wood‑grain pattern are added to resemble natural timber decking.
  1. Some brands cap the board with an extra protective outer layer for better stain and fade resistance.

Different Composite “Styles”

  • Standard wood–plastic composite (WPC)
    • Roughly a 50/50 blend of wood fibres and plastic, though the ratio varies by brand.
* Often used not only for decking but also cladding and outdoor furniture.
  • Capped composite decking
    • Same core mix, but with a tougher outer shell of plastic and additives to boost stain, scratch and fade resistance.
  • PVC‑heavy or PVC‑only boards
    • Some “composite‑style” products lean more towards PVC for lighter weight and higher water resistance, though they may feel less wood‑like.

Why People Care What It’s Made Of (2024–2026 Trend Angle)

Over the last couple of years, composite decking has become a trending choice in home‑improvement forums and contractor blogs because:

  • It uses reclaimed wood and recycled plastics, appealing to eco‑conscious homeowners.
  • It promises lower maintenance than pure timber while still looking like wood.
  • Manufacturers now advertise the exact percentages of recycled content (for example, some products use around 45–55% recycled plastic and 45–55% reclaimed wood).

In many current forum discussions, the “what is composite decking made of” question pops up when people weigh eco‑benefits versus the more “natural” feel of real wood, with users often quoting the wood‑fibre and recycled‑plastic mix as the deciding factor.

Quick TL;DR

  • Composite decking is made from a mixture of reclaimed wood fibres, recycled plastic, and additives like bonding agents, pigments, and UV stabilisers.
  • The blend is heated, mixed, then extruded or moulded into boards and coloured/textured to look like wood.
  • Exact formulas differ by brand, but the goal is the same: a board that looks wood‑like, resists rot and fading, and often uses recycled materials.

Information gathered from public forums or data available on the internet and portrayed here.