Hollow Vs Solid Composite Decking

Hollow and solid composite decking are rising in popularity due to their incredible durability and minimal upkeep required. These composite decking boards are manufactured using recycled plastic and wood components and other materials, including wood fibre cement and mineral and thermal features. Some are made 100% of plastic.

There are several factors to consider when deciding between hollow and solid composite decking. In many respects, both have various benefits that provides them with the edge over the other. In this guide, we will discuss the differences and outline the advantages and disadvantages of each.


What Is Solid Composite Decking?

Solid composite decking boards are available in various colours and designs. You will find that solid composite boards come in two main forms, capped and uncapped composite decking, and many may not know there is a difference between the two forms.

Both hollow and solid composite decking boards are robust enough to support heavier weights. However, solid boards are sturdier due to their composition. If you are considering adding a hot tub or heavy outdoor furniture to your deck, you should look. to reduce the centres on your joists so your deck is stronger.

Uncapped Composite Decking

Uncapped boards are generally more affordable. Due to the manufacturing time and exposed wood fibres, uncapped decking products have a shorter lifespan compared to their capped counterpart, about 20 years and 25-30 years respectively.

Uncapped decking is more susceptible to mould, fading and staining. And unlike capped solid boards, uncapped solid composite decking boards are readily scuffed and scratched, making them less durable in the long run.

Uncapped Composite Decking Board Benefits:

  • Low Maintenance: Although uncapped boards are cheaper, they are relatively similar to capped boards in their low maintenance requirements.
  • Slip-resistant: Uncapped decking tends to have a higher slip resistance and is the ideal composite decking option for pools and jacuzzis.
  • Cost-effective: Uncapped decking boards are affordable, but not ‘cheap’, and have a lifespan of 20 years.

Capped Composite Decking

Capped solid composite decking boards are far more expensive and offer everything that uncapped composite decking boards provide and more. They are manufactured with a cover bonded to the core, which makes these solid core boards more resistant to stains and damage. They are built with durability in mind and are heavier.

Although capped solid composite boards are more expensive, they have their own set of benefits.

Capped Composite Decking Boards Benefits:

  • Extra Layer of Protection: Uncapped decking has a protective polymer sleeve, which is an extra layer of protection that makes them resistant to sun and water damage. They’re also much more fade-resistant.
  • Scratch-resistant: The solid capped composite decking boards will not warp, are scratch-resistant, and are ideal for high foot traffic areas.


What Is Hollow Composite Decking?

Hollow composite decking boards are a relatively new concept that offer an economical solution to outdoor decking without surrendering style and functionality. Like solid composite decking, hollow decking boards are low maintenance for a fraction of the cost.

Multiple hollow channels run through each hollow composite board. The indentations in hollow boards significantly reduce the number of materials needed to manufacture one hollow composite decking board. This approach helps keep the costs down and is environmentally friendly.

Don’t be fooled by the indentations in the hollow composite deck boards. They are just as sturdy and durable as any solid composite board and do not compromise the structural integrity of the deck board.


Benefits of Composite Decking

Hollow composite boards offer many of the same benefits as solid composite decking boards.

Solid and Hollow Composite Decking is Durable

Both solid and hollow decking boards are built to last for many years to come. The composite material used to engineer the decking board is waterproof, airtight, and impenetrable. Composite boards, in contrast to wooden decking, are resistant to mould, rot, and warping under extreme elements.

Solid and Hollow Decking is Low Maintenance

Due to their durability, composite hollow and solid decking boards are exceptionally low-maintenance. You do not need to seal, stain, or paint your decking to protect it from weathering, nor will you need to sand it down or replace sections that have rotted or weathered. Cleaning your composite deck only requires soap and water.

Long-term Cost Savings

While the installation costs are expensive, composite decking boards pay for themselves in the long run. There is no painting, staining, or replacing wood decking in ten to fifteen years.

The long-term benefits of composite decking over wood can save maintenance costs for many years.

It’s Safer than Wooden Decking

The safety of children and pets is guaranteed because composite decking is modern, with no exposed nails, splinters around screw holes or fasteners. This gives it a smooth finish compared to wood decking.

Moisture and rain can cause wood to expand and swell, and this can cause warping, cracking and splitting when the water is absorbed in the wooden decking. Composite decking, especially capped decking boards are easy to wipe down. You never have to worry about composite boards splitting or cracking if installed correctly.

Eco-friendly and Sustainable

Hollow and solid boards are constructed from recycled wood fibres from sawmills and recycled plastic and contain no harsh chemicals or toxins. They are built to last and lower the carbon footprint.

A Variety of Customisable Designs

Composite decking is versatile in design and colour, making them customisable to suit your design aesthetic. The new and improved wood-like textures and surfaces and the soft contemporary colours of composite decking can fool the eye into thinking it is natural wood decking. The decking boards come in various designs that can elevate any backyard garden or front porch.


Disadvantages of Composite Decking

While the benefits of composite decking are evident, there are a few disadvantages you should be aware of.

Expensive Upfront Cost

The initial upfront cost can be relatively expensive, but it should be seen as an investment rather than a huge expense. They require minimal upkeep compared to wood deck boards which in the long run will end up costing you more to maintain than a composite deck. Composite decking does not rot, fade, or need to be pressure-treated.

Solid Boards are Heavier

Solid composite decking is much heavier than hollow decking, but both are heavier than wood decking. You will need a solid frame or structure for the installation process. Since it weighs so much, use a professional company to install your deck safely.

It Cannot Be Repainted

Composite decking boards can get hot to the touch in scorching weather. If you live in an area with hot summers, opt for decking boards that are lighter in colour. Darker colours absorb the heat, or go for a matte or textured finish that can help disperse the heat.


How Much Does Decking Cost?

Composite decking prices vary and could depend on individual circumstances, sizes, and requirements. You can expect to pay approximately £900 to £3,000 on average.

Our composite boards cost from £41.55-£66.12 per square metre. Wooden decking materials tend to be much cheaper, sometimes just £4 per metre-long plank, but do remember this doesn’t include the cost of treating the wood.

It is crucial to remember that the prices will vary since labour costs and additional costs like sealants and adhesives need to be considered.

Factors That Influence the Costs of Decking

  • Size of the deck: The larger the deck, the more composite decking materials you need.
  • The shape of your garden and deck: The shape of your garden could drive the cost up. If deck boards need to be cut to fit certain angles or you prefer a curved deck, the boards would need to be cut and customised to your garden’s unique specifications.
  • The design of the deck: A simple and straightforward design will cost much less than a deck that needs to be raised or have multi-levels. Multi-level designs can drive up the cost if stairs or planter boxes are included.
  • Preperation requirements: Preparing the ground is crucial before installing any composite deck. If removal of trees and roots is needed, or the ground needs to be levelled, this could drive up the costs.


Hollow vs Solid Composite Decking: Which Is Better?

While both hollow and solid composite decking boards are engineered for outdoor use, they are durable, low-maintenance, and offer a real wood aesthetic without the hassle of wooden decking. Both have advantages and disadvantages, so it might come down to your personal preference.

Both solid and hollow composite decking would be the better choice for longevity and the variety of design options. However, hollow composite decking is great value for money and is eco-friendly.

If you are on a tight budget, hollow composite decking boards are the better option. However, if durability is your main concern, capped composite decking would be the best choice.



Will an outdoor rug damage a composite deck?

The backing on certain outdoor rugs is made from materials that can scratch and stain your composite deck. Viscose, plastic, latex and outdoor rugs with metal grommets can cause discolouration, rust, and unsightly scuffs.

Can you power wash composite decking?

Although composite decking does not require much upkeep, basic care is necessary to keep your deck clear of stains and debris. You can easily clean your composite deck with soap and water or a basic power wash.

How long will a composite deck last?

Composite decking, in contrast to wood decking, can last a minimum of 25 to 30 years. Depending on the manufacturer, some composite decking comes with a warranty of 20 to 25 years against staining and fading too.

Should composite decking be sealed?

There is no need to seal composite decking. Composite decking boards are engineered to withstand the weather elements and will not shrink, swell or expand as wood does.

Are there different qualities of composite decking?

Regardless of the qualities, composite decking components and performance are roughly the same. If you are looking for versatility regarding the colour, texture and style, the big difference would be in the price you pay.


Final Thoughts

The type of composite decking you choose will come from your personal preferences and needs. When deciding on the decking material, consider the long-term effects and goals. Composite decking can last up to 30 years, so choose the hollow or solid composite decking that best suits your requirements.

The benefits of hollow and solid composite decking are on par and highlight the decking boards’ versatility and adaptability. Although hollow boards cost less than solid boards, both are low maintenance, and you will recoup your investment and enjoy your composite deck for years.

Gary is the founder and CEO of Ecoscape UK. Gary graduated from Liverpool JM University in 2007 with a 2:1 in Economics. A passion for innovation, design and sustainability, Gary has put to market numerous wpc products/systems, some of which have UK and European registered designs. Outside of work Gary enjoys spending time with his family, the great outdoors and watching Manchester United.