Choosing the Right Composite Decking Profile: What You Need to Know
- Joel Livesey
- Sep 22
- 6 min read
If you’re planning to invest in composite decking for your garden in Merseyside or Cheshire, one of the most important — and often overlooked — decisions you’ll make is which board profile to choose.
At first glance, many composite decking boards appear identical, with attractive surface finishes and a range of colours. But beneath that surface, the internal profile of the board determines much more than looks. It affects:
The strength and stability of the deck.
How well the boards resist weathering in our damp North West climate.The lifespan of your investment.
And ultimately, whether your deck continues to look great in 10–15 years or starts to fail after just a few seasons.
Having worked with multiple composite decking systems over the years — and even sold some budget hollow boards in the past — we’ve seen first-hand how much difference the right (or wrong) profile can make.
In this guide, we’ll break down the most common board profiles, explain their pros and cons, and share our expert advice on which options to avoid and which are worth your investment.
1. Solid (Full Width) Composite Decking Boards ✅
Solid boards are the gold standard of composite decking profiles. Unlike hollow alternatives, these boards are made from a full, dense composite core that gives them maximum strength and durability. They’re the closest in feel and performance to traditional hardwood, but without the ongoing maintenance headaches.
Why Solid Boards Are Superior
Strength and Stability: With no hollow chambers, solid boards can handle heavier loads and are less prone to bending or flexing under pressure. This makes them perfect for high-traffic areas, steps, and edges.
Long-Term Durability: The dense construction helps them resist impact damage and everyday wear, meaning they’re less likely to crack, split, or fail over time.
Authentic Look and Feel: Premium solid boards, such as Millboard, Trex and NewTechWood’s solid ranges, have a more realistic timber-like weight and feel, which many homeowners prefer.
Better for Complex Designs: If your project includes cut-outs, angles, or curved sections, solid boards hold their shape more reliably when trimmed or routed compared to hollow profiles.
What to Watch Out For
Solid boards are generally heavier than hollow profiles, which can make the installation process more physically demanding. An exception is Millboard, which is uniquely lightweight despite being a solid board. Heavier boards often require more care during handling and fitting, and they also tend to wear down saw blades more quickly when being cut.
While they may take more effort to install, solid boards more than repay the investment — when professionally fitted, they can remain in excellent condition for decades, making them a truly long-term solution for your garden.
If you want maximum durability and peace of mind, solid boards are the safest choice.
2. Scalloped Composite Boards ✅
Scalloped boards have shallow grooves cut into the underside, which reduces the amount of material used and makes them slightly lighter. At first glance, some assume this means they’re weaker than solid boards, but in reality, when you buy from a reputable supplier, the performance difference is minimal.
Why Scalloped Boards Work Well
Comparable Performance: Premium scalloped boards, like those from NewTechWood and Trex, perform almost identically to solid boards in everyday use. They’re designed, tested, and warrantied to handle the same conditions.
Lighter Weight: Being a little lighter makes them easier to handle and install, especially when moving large quantities on site.
Cost-Effective: Because less material is used, scalloped boards are generally priced a little lower than solid profiles, offering excellent value.
Stylish Finishes: From the surface, scalloped boards look no different to solid ones, so you still get the same attractive timber-effect appearance.
What to Keep in Mind
The shape of the profile means scalloped boards can never be left with edges exposed — the underside grooves would show and spoil the finish. With solid or capped boards, the edges can be left visible and neatly painted to match the surface, but scalloped boards always need to be framed or trimmed for a professional result.
3. Hollow Chamber Composite Boards (Rectangular Holes) ❌
Boards with rectangular hollow chambers are cheaper to produce, which is why they’re often sold at low prices by a number of North West based suppliers. At first glance, they can seem like a cost-effective option — but the reality is very different.
At Duralive Decking, we know this from experience. In our early days, we used to sell hollow composite decking boards. It was only later, as our knowledge became more advanced and we started seeing the problems first-hand, that we understood the importance of avoiding this profile.
The boards were more prone to:
Splitting and cracking under load
Excessive flexing and movement
Moisture ingress, leading to early failure
That experience shaped the way we work today: we now only recommend solid or scalloped profiles from trusted brands that we know will perform reliably for years.
While hollow boards might look attractive on price, we strongly advise against them — they often end up costing more in repairs and replacements.
4. Circular Hollow Chamber Boards ⚠️
These boards contain circular holes running through the core. They perform better than rectangular hollow boards, but still tend to flex more and may not last as long as solid or scalloped options.
Sometimes acceptable if produced by a trusted manufacturer
Still weaker than solid or scalloped alternatives
Excessive flexing and movement
We only recommend these in very specific circumstances — ask before you buy.
5. Grooved Boards ✅
Grooved boards are designed to work with hidden fastener systems, which allow the boards to be fixed down without visible screws on the surface. Instead, clips lock into the grooves along the side of each board and attach securely to the joists below. This method creates a sleek, seamless finish that looks clean and professional.
Why Choose Grooved Boards
Cleaner Look: No screw heads on the surface means the deck has a more refined, modern appearance. This is particularly effective in small gardens or contemporary outdoor designs where every detail matters.
Consistency Across Premium Brands: Top brands, including NewTechWood and Trex, use grooved profiles as standard, proving how effective and reliable this system is.
Protects the Boards: By eliminating surface screws, you reduce the risk of splintering or cracking around fixings, which can sometimes happen with direct screw-down methods.
What to Keep in Mind
Correct System Is Key: Each brand has its own hidden fastening system, and it’s vital to use the clips and fixings designed specifically for those boards. Using the wrong fasteners can not only compromise the performance of the deck but also invalidate the manufacturer’s warranty.
Edge Boards Need Planning: Because the grooves are on the sides, perimeter or edge boards often need to be framed, trimmed, or screwed down with colour-matched fixings. This ensures the deck still looks polished from every angle.
Professional Installation Matters: Getting the spacing right for clips requires care. Professionals like us have fine-tuned the process to make sure every board is locked in securely and evenly.
Our Experience
At Duralive Decking, we almost always recommend and install grooved boards with hidden fasteners because of the superior finish they provide. Across Merseyside and Cheshire, homeowners love the seamless look, and it’s a feature that really sets premium decking apart from budget alternatives. When paired with the correct system, grooved boards not only look better but also perform more reliably in the long term.
For a modern, clean finish with lasting performance, grooved profiles are one of the best options available.
So, Which Composite Decking Profile Should You Choose?
If you want long-lasting, low-maintenance decking in the North West, we recommend:
Solid boards for ultimate strength and lifespan
Scalloped boards for a balance of durability and cost
Grooved profiles for a seamless finish with hidden fasteners
Avoid cheap hollow-core boards — they might save money upfront but usually end up costing more in replacements and repairs.
Expert Advice from Duralive Decking
At Duralive Decking, we design and install bespoke composite decking projects across Merseyside and Cheshire, using only trusted brands like Millboard, NewTechWood and Trex.
Still not sure which profile is right for your garden? We’ll guide you through the options and recommend the best decking for your design, budget, and lifestyle.
📞 Contact us today for a free consultation and expert advice on choosing the right decking for your home.
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