Composite decking is available in many colours and wood grain patterns to choose from. The main difference is either a capped or uncapped composite decking board.

plastic decking type

Capped Composite Decking

As the name suggests, capped composite decking is capped or covered with a protective layer around the entire composite decking board. The key benefits of capped composite decking are stain, fade, mould and mildew resistance, as well as improved durability and a longer service life. The capping increases water resistance and provides better protection from the sun’s harmful UV rays, reducing colour fade. However, these added benefits generally come at an increased cost. 

With the above said, some manufacturers produce capped composite decking boards to cover only the top half of the composite decking board. In general, this is done to reduce production costs. These half-capped composite decking boards can be exposed to the elements from the bottom upward, which can lead to problems with the boards over time. 

Capped Composite Decking Terminology

Many industry experts use different terminology to describe capped composite decking such as 2nd generation, shielded or co-extrusion composite decking. When you hear or come across these different terms, they all describe capped composite decking and mean the same thing.

Uncapped Composite Decking

Uncapped composite decking, again, as the name suggests, is composite decking without the protective layer as described with capped composite decking. Please also note, with the introduction of capped composite decking, some industry experts and commentators often refer to uncapped composite decking as 1st generation composite decking.

With uncapped composite decking, you can still enjoy features such as strength, durability, fade and water resistance. Composite decking will not rot, splinter or crack when properly maintained. Uncapped composite decking is generally cheaper than capped composite decking. However, with regular cleaning and maintenance, uncapped composite decking can last for many more years than its wooden cousin.

Solid and Hollow Composite Decking

Both capped and uncapped composite decking are produced with a hollow core or as a solid board. Hollow boards can either be square or circular. Both offer the benefits of strength and durability with the circular hollow being slightly stronger.

Either a square or circular hollow composite decking board will be suitable for most gardens with a seating area and BBQ grill on top. If you plan to place heavier loads on top, such as a hot tub with considerable weight, the recommendation is to build the composite decking around the hot tub sitting on a concrete foundation.

Solid composite decking, given its increased strength, is often installed in public areas with high footfall. Although you can, if you wish, install solid composite decking at home, but expect to pay more for a solid capped composite decking board.


Since its first introduction in the early 1990, composite decking has come a long way. No longer does modern composite decking resemble a piece of plastic with a wood grain printed on top. Indeed, some manufacturers have developed composite decking boards that truly capture the beauty and aesthetics of natural wood in a variety of grains, colours and hues, but with the added benefits that composite decking offers.

Choose a trusted brand that offers good quality composite decking that represents the best value for your money. Long service life, durability and easy maintenance should be the key considerations when choosing the best decking option for your needs.

It is worth noting that “not all composite decking is made equally.” Buying cheap composite decking can be an expensive choice over the long term.