Hollow vs solid composite decking boards – the pros and cons

Composite decking can revitalise your outdoor space and bring a much needed design element to your garden. The right choice of composite decking boards can provide your garden with a modern look, a place for guests or patrons to congregate or even a durable, level surface to Exercise.

But for the deck to serve any or all of these purposes, it is important to balance cost, quality, sustainability and look, and there are many choices to be made along the way. If you’ve already settled on composite over wood – be it for its price or easier maintenance (wood plastic composite can be significantly less susceptible to mould and mildew), then the next choice is whether to go with hollow or solid decking boards.

There are advantages and disadvantages to each.

What are hollow composite decking boards?

Hollow composite decking boards, which have honeycomb pattern centres, tend to be more flexible and potentially better at absorbing shock. All other things equal, they also tend to be a cheaper option than solid decking boards.

Advantages and drawbacks of hollow boards

Thanks to their inherent flex, hollow boards are usually best used in areas that are likely to get heavy footfall – either in outdoor pub areas or for families planning to have lots of gatherings or use their deck for activities and sports.

The downside is that the hollow centres can collect water. This can mean that they require more and more frequent maintenance and may be susceptible to corrosion and mildew.

Realistically, hollow composite boards offer many of the same benefits as solid, including durability and resistance to mould and mildew. They could also be easier to carry and install. Due to their hollow, honeycomb-like centres, the boards benefit from incredible sturdiness and strength while maintaining a light weight. Additionally, while solid wood-plastic composite boards can be stronger than hollow ones, they are also significantly more affected by extreme weather fluctuations. Over time, solid boards expand and contract with high and low temperatures, respectively, they can become susceptible to cracks or just cause your deck’s surface to warp and fasteners to come loose. For this reason, if you live in an area with extreme temperature variation throughout the year, hollow boards may be your best option.

In particular, hollow boards may be a better option in hotter climates. Due to their plastic component, both hollow and solid boards will retain heat. However, solid boards have a higher density, which usually means they will retain more heat than hollow ones.

What are solid composite decking boards?

Solid composite decking boards, on the other hand, have less flex, but significantly higher load bearing capacity. They may prove to be the better option if you’re planning to place heavy objects, e.g. a barbecue on your deck. Additionally, these boards may be less susceptible to the harmful effects of weather and corrosion, as their solid centres are much less likely to their hollow counterparts and pure wooden boards to retain water.

Advantages and drawbacks of solid boards

One downside of solid wood plastic composite boards is that they are usually heavier and more difficult to install, which can make your project more challenging if you’re working on your own. Additionally, solid boards are more likely than hollow to warp and bend in extreme weather conditions, potentially loosening fasteners around the joists.

A potential upside, however, is that solid boards tend to better mimic natural wood, making for a more aesthetically pleasing outside area. Additionally, solid composite decking boards are better than their hollow counterparts at absorbing sound, which can be helpful if you’re hoping to reduce noise in your garden.

Lastly, depending on the brand, solid boards tend to come in more varieties and styles than hollow, offering you more choice in terms of exterior decor. If style is a priority for you, these boards may emulate the look of real wood more faithfully and, in the higher price ranges, the grain of individual boards will vary enough to be nearly indistinguishable from the real thing.

Ultimately, when comparing the relative strength of hollow vs solid boards, the best way to choose with certainty is to check your chosen brand and make’s test, as all composite decking should have public test data. Hollow composite decking boards are also a good option if you plan to fit your deck with electronic equipment, as the honeycomb centres allow you to relatively easily run wires through them and hide them out of view.

Once you’ve settled on WPC decking boards for your outdoor deck project, the choice between hollow and solid options comes down to the specifics of your environment, price range and the purpose of the deck. Both hollow and solid boards have particular applications to which they are best suited and, with proper care and maintenance, both can give you decades of use.