Will A Composite Decking Rot?

M. John
Learn Decking

Some have wondered if composite decking can rot like wood. Ultra Decking will not rot like timber decking. Even in the presence of moisture, the decking will still not decay. This makes composite boards superior to wood decking. Homeowners that are aware of this benefit of composite decking have replaced their wood decking with it. But why does composite decking not rot like wood if you expose it to moisture? It is good to know the reasons. This article will tell you more about composite decking.

What is Composite Decking 

Will A Composite Decking Rot?

Composite decking board is a strong and durable decking material that contains both wood fibres and recycled plastic. Because of its component, composite decking is commonly referred to as wood-plastic decking or plastic wood decking. Wood-plastic decking is very beautiful and comes in varieties of colours. Composite decking is different from timber decking since wood is natural and made from 100% timber.

Types Of Composite Decking

There are different types of composite boards. But in this article, we will discuss the capped and the uncapped composite decking.

Capped Composite Decking

The capped composite decking has a high resistance to water or moisture. It has an additional covering on its outer layer. The plastic coating around the capped decking prevents the board from absorbing moisture from the environment.

Since it has a plastic coating, capped decking is the best option for places with high moisture or wet areas. The decking board will not absorb water, so it will not rot. For a material to rot, it must have absorbed water or moisture. When the material absorbs moisture, it will decay over time. So if you want to build your composite decking yourself around a swimming area or close to a dock, capped composite decking is the best option.

 Uncapped Composite Decking

The uncapped composite decking is the opposite of the capped composite decking. It does not have an additional plastic covering on its outer part. Since it does not have a plastic coating around the board, it does not mean that it will not last long. Uncapped decking will not absorb moisture or water easily like wood. Remember that composite decking is made from both plastic and wood fibre. The plastic material in the decking prevents moisture absorption.

But, If you compare the two decking types, the capped decking is more resistant to moisture than uncapped decking. The uncapped decking is suitable in dry places or covered places. It is not suitable for installation in wet areas. Homeowners who want to build composite decking under a shed can use uncapped boards. The shed will prevent rainwater from dropping on the decking so that it won’t absorb moisture. Like the capped decking, the uncapped decking will not damage easily and will last long.

What Cause Decking to Rot


Wood decking is not resistant to moisture; that is why it will rot easily. When humidity is high, wood absorbs moisture from the atmosphere and swells. The high moisture content of the wood would eventually make it decay over time.


Timber decking is also not resistant to insects like termites. Termites can penetrate the wood and eat it, thereby making it rot. This insect bore through the structure, thereby damaging it.

Why Composite Decking Will Not Rot

Knowing what composite decking is and the types, let us consider why it will not rot. Remember that composite decking is made up of wood fibres and plastics. These two materials are mixed to form a composite decking board in the factory. It makes WPC decking highly durable than wood. And also, since the material contains plastic, it is difficult for the composite board to absorb moisture like wood. The composite decking has an extra coating on its outer layer that prevents moisture absorption.

Wood decking, on the other hand, does not have any protection on its outer part. The wood will readily absorb moisture from the environment if there’s a weather change. And when this happens, the timber will swell and rot over time. But composite decking will not absorb moisture, so it is unlikely to rot.


Will composite decking rot? The decking will not swell and rot when exposed to moisture. It makes complete decking superior to wood decking.



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