Composite Decking

Composite decking is still considered to be a new alternative to traditional wooden decking, but truth is, it has been around for a number of years. Early versions of it were expensive and often cost significantly more than wooden decking.

Early versions experienced issues including colour fade, sagging, and deuteriation. Modern materials, improved construction methods, and falling production costs have made composite decking boards a viable alternative to timber decking. An alternative to decking boards and a quick solution for flat surfaces are composite decking tiles.

What is composite decking?

Composite boards are constructed from a hybrid mix of wood fibres, plastics and bonding agents, or adhesives. This mix is heated then shaped into decking boards before being cooled. Being partially made from wood fibres, the resulting boards look more authentic than purely plastic alternatives.

Benefits of composite

The main benefit over traditional wood decking is that composite boards need far less maintenance.

The plastic content means that they are more durable and resistant to biological threats like damp, rot, and insect attack. Composite decking can be more resistant to staining, fading, warping, cracking, and splitting, than some types of wooden decking. They can also be more suitable for use around swimming pools, hot tubs, and other wet areas. Due to the increased durability of the boards, composite decking can have a longer lifespan than traditional wooden decking with many manufacturers offering guarantees of between 10 to 25 years. This said, many wooden decks can also last this long if well maintained.

Prices of composite boards have been coming down as popularity has increased and production costs have come down. They are still generally more expensive than many types of wood decking but for some, the additional cost is still a worthwhile investment because of the reduced time and costs involved in maintenance.

Types of composite decking

Capped vs Uncapped

There are currently two types of composite decking on the market, capped and uncapped. Uncapped boards tend to be cheaper and although the materials used are resistant and hard wearing, they do not come with the same protection against staining and colour fading as capped boarding.  This means that in the first couple of months, the boards may fade slightly as residual wood oils or tannins leach out because of weathering.

Capped composite boards come with an exterior plastic coating, which means that the boards provide better resistant against fading and staining. The boards are easy to wipe clean and keep their colour better when exposed to the environment.

Common problems with composite decking?

Although more resistant to colour fade and weathering, composite can still be prone to some of the issues that affect wooden decking such as mould. This said, as with wooden decks, mould on composite decks can be treated.

Even though production technology has improved over the years, some of the earlier and cheaper options on the market have been known to absorb water, just like wooden decking. This can result in decking boards swelling, shifting, warping, and shrinking.

When exposed to the elements including sun, wind and rain, composite decking can still stain and fade. Anything from the tannins of a few fallen leaves on the surface to an additionally spilled glass of wine or splotch of ketchup can potentially leave stains. When looking to buy, check the manufacturers literature to find guarantees and exclusions to these sorts of issues.

Composite decking is made of more plastic than wood fibres. This can result in a softer surface than with hardwood decking. This means that it may be more prone to scratches from patio furniture, BBQ grills, and children’s toys. Even the family dog’s claws can scratch or leave gouges in the surface. Unfortunately, gouges and scratches on composite decking can’t be fixed, unless you completely replace the board. If your wood deck gets scratched, it can be sanded down and refinished with a decking oil or stain. This isn’t an option with composite.

Always check for assurances and guarantees on slip resistance such as a specified slip resistance rating. The reason for this is that plastic is oil-based in nature which can cause water to sit on its surface if the decking is flat. This can make the decking slippery around pools and hot tubs. When installed, any decking should have a slight slope or gradient to allow water to run-off the surface. This will help to prevent water from pooling on the surface which in turn will help to prevent slipping and preserve the look and life of any decking.

Composite decks can retain a lot of heat making them uncomfortable or hot to walk across with bare feet.

Composite deck boards may also not be as strong as solid wood. When constructing the frame to support the deck, many manufacturers recommend that composite deck joists must be 12″ or less apart to prevent sagging, whilst a hardwood deck can be constructed with joists 16″ apart.

With all the above said, both composite and wooden decking have pros and cons. Making a choice is a balance between the properties and uses of each. Whilst composite may be a better option for one garden, wooden decking may be better for another.

How to maintain composite decking?

Composite decking is often advertised as the maintenance free alternative to wooden decking, but this claim has been proven to be untrue, by the thousands of people who have had it installed over the years. So how do you maintain composite boards? Well, this depends on the type of problem. Here we try to cover solutions to some of the more common problems and issues experienced.

Mould and Algae

Just like wooden decking, composite deck boards can be prone to mould and algae. This can be easily treated with a dedicated composite decking cleaner. This is also available in a kit which contains a decking cleaner and composite decking remover & protector, that removes dirt, grime, algae, and more.

Is composite decking bad for the environment?

There is an argument that the manufacturing of composite decking uses more energy than wooden decking. The alternative argument is that because it has the potential to last longer than some types of wooden decking, it prevents more trees being cut down which absorb CO2 in the atmosphere.

When buying composite decking boards, it’s worth checking to make sure that the boards are made from FSC certified wood and recycled plastic which would otherwise have ended up in landfill sites. Whilst some makes are made entirely from 100% recycled or reclaimed woods and plastics, not all are.

Is traditional wooden decking still a good alternative?

Although composite decking could be perfect for some, it’s certainly not the end for wooden decking. Wooden decks still have some distinct advantages over composite so it’s worth weighing up all the pros and cons for each before committing one way or the other.

If you already have a wooden deck and need help and advice on how best to treat and maintain it, see our decking care and maintenance guide.