When choosing materials for your deck, you have a few options that you can choose. One of the most well-known selling factors of composite decking is its waterproofing. Unlike wood, composite decks have better water resistance, along with the issues related to moisture. But the question is, what makes composite decking boards waterproof? And why should you choose waterproof materials?

It’s Part Plastic

One of the main reasons why composite decking materials are waterproof is because of its design and makeup. Composites, also known as WPC or wood-plastic composites, are materials made from both thermoplastics and wood fibres. People mistakenly group it with PVC, but vinyl decking is pure plastic without any wood parts. The process to produce composites involves extruding the components, melting it and forcing it to shape into decking boards.

Because of the melted and mixed wood and plastic, it no longer absorbs as much moisture, making it water and moisture-proof. Because of this, it no longer experiences many issues associated with wood use, such as mould growth and rotting. Another problem with wood decks is warping due to moisture absorptions. While composites can still bend, it is not because of moisture and humidity. Instead, composites and other synthetic materials undergo thermal expansion. 

Composite Decking Have Caps

waterproof decking

Another feature that makes composite decking waterproof is because of its capping. Caps are exterior layers of thermoplastics, such as PVC, polyethene, or polyurethane, present in almost all new generations of composites. While uncapped boards are waterproof by itself, capped composites further protect the deck from problems aside from moisture.

If water and moisture is an issue, you will want to use capped composites over uncapped ones. However, there are various types of capped decking, according to how many sides have exterior capping. Most of the boards today either have three or four sides covered. Each one has its advantages and disadvantages. But the question is, which one is more waterproof? 

Full-capping – Full-sided capping has polymer exterior on its four sides. Because of this, it has superior protection against moisture absorption. Composites with full capping are also reversible. Because of this, not only do they look beautiful on outdoor decks but above ground level floor decking as well. However, there are a few reports of swelling on the exposed ends on some low-quality boards. Since the board is fully-coated, there are no other places for water to drain other than the ends. Full-capped composites are also generally more expensive. 

Three-sided Capping – Aside from fully-capped, there are also three-sided capping for composites. As far as durability goes, it is also resistant to water and moisture. But compared to full-sided capped composites, they can be slightly more prone to moisture absorption. However, since the underside of the boards is uncapped, it has better water drainage and less prone to swelling due to moisture. They are also often cheaper than four-sided capped composites. 

Why Choose Composite Decking

When building a deck, there are many reasons why you should go with composites. Many use it for its superior waterproofing. As mentioned, water can cause various problems with traditional decking materials. Wood is an excellent example of a material that can have issues regarding moisture. When exposed to moisture, it can warp, grow moulds, and rot. Composite decks are less likely to have these problems. Because of this, they are the superior choice if you want a waterproof deck. 

Another reason why composites hold better than any other materials when it comes to moisture is that it’s easier to maintain. A composite deck requires less effort and time to clean. Even if the water is stuck on the deck for a long time, it will just evaporate or drain. As for wood, you will have to dry it as soon as possible. Naturally, you still want to dry any spills on your decking as much as possible, whether its wood or composite. 

Another advantage of composite is that it doesn’t need painting or sealing for it to be resistant to moisture. Because of this, you don’t have to spend money on buying these products. The truth is, you can save more money when choosing composite decks due to its water-resistance and low-maintenance. A wooden deck may prove to be more expensive, especially with regular sealing, painting, and staining.