Composite decking 101: what South African homeowners should know before they build

Composite decking has become the default recommendation from architects and installers across South Africa. There is good reason for that. It solves the two biggest frustrations homeowners have with a timber deck. Boards no longer need regular sanding and sealing. They also stop splitting, silvering or rotting within a few short years. Before you commit to a project, though, it helps to understand what this material is. You should also know how it performs, what it costs, and how installers fit it. That way, your decision rests on the full picture, not just a marketing headline. This guide covers the fundamentals every homeowner should know before they build.

What is composite decking, and how does it compare to timber decking?

Manufacturers make this decking from a blend of wood fibre and polymer. Then, they press the mix into boards that replicate the grain, colour and feel of timber. However, no single piece of wood is cut to make them. Timber decking is a natural product instead, so its performance varies with species and treatment quality.

Composite boards follow a consistent specification. Overall, every board in an installation therefore behaves the same way over time. In practical terms, this means the material resists the silvering, splintering and movement common with timber decking in South African conditions.

How long does composite decking last, and what maintenance does it need?

A well-installed deck can reasonably last fifteen to twenty-five years. The exact figure depends on the product specification and installation quality. Either way, that is considerably longer than most softwood decking achieves without re-treatment.

Maintenance stays simple too. Periodic cleaning with water and a soft brush removes surface dust and organic debris. Notably, sanding, staining and sealing are never required. For homeowners who previously owned a timber deck, this is usually the biggest quality-of-life improvement composite decking delivers.

What does composite decking cost per square metre, and what affects the price?

This decking generally costs more than entry-level softwood decking, board for board. However, the total cost of ownership tells a different story. Timber decking demands sanding, sealing and board replacement every few years, and those costs add up quickly. Specifically, price depends on the board profile, whether solid or hollow-core, plus the finish and substructure specification.

For a closer look at how these compare over time, read our full comparison.

Is composite decking suitable for pools, patios and other high-traffic outdoor areas?

This material performs well in exactly the environments where timber struggles most. Pool surrounds, patios and entertainment areas all fit that description. The boards do not absorb water, so they resist swelling and cupping far better than timber around a pool. Grooved or textured finishes also help maintain grip underfoot, even when wet.

As a result, composite decking suits family gardens and busy entertainment spaces well. It performs just as reliably in showcase areas that rarely get walked on.

How is composite decking installed, and what substructure does it require?

Installers lay the boards over a supporting joist substructure. Composite or treated timber battens usually do this job, spaced to the manufacturer's specification. Typically, fitters use a concealed clip system that locks into a grooved edge. This gives a clean finish with no visible screw heads on the walking surface.

Correct board spacing matters too, since it allows for thermal movement and drainage. For this reason, choose an installation team familiar with composite-specific fixing systems, rather than one that treats the job like a timber swap.

If you are still deciding whether composite decking is the right investment for your project, our detailed guide on whether it is worth it breaks down the numbers further. Otherwise, get in touch with the Acacia Composites team to discuss the right specification for your space.