Is Composite Decking Slippery When Wet? How, Why, What to do

Safety is a big concern for any outdoor surface, and the same applies to composite decking. Is composite decking slippery when wet the same as wooden decking can be? We’ve been installing composite decking for years, and we have great reviews, so we know just about everything there is to know about composite decking and safety is something we take very seriously. So in this article, we’re going to outline all the reasons your composite decking might get wet and what you can do about it, starting with a quick answer to get you some much-needed help...


All types of decking can be slippery at times. Modern composite decking is designed with a capping surface that repels water but provides a firm contact surface. Assuming proper maintenance and care is carried out to remove surface debris and mould, the decking provides a firm grip even when wet.


For any outside or patio decking space, the material is key when considering any slip hazard. Not only in isolation, but how it compares to other products. And in this case that mostly means wooden decking as the next nearest alternative. Composite decking is a compact combination of plastic-coated wood shavings. It’s designed to be highly robust, even in harsh weather conditions. It’s also designed to be safe and has become safer over time. Most wood-plastic decking has a surface specially designed to provide grip in normal circumstances, such as in wet weather – which we’re mostly concerned about here.

The Safety record for Composite Decking

There are no specific scientific studies conducted on the safety of decking or patio surfaces. But all outside surfaces carry an element of slipping risk. Not necessarily due to the materials, but due to what can build up on the surface of the material.


Because of its non-porous qualities, people often see this as detrimental, allowing the pooling of water on the surface, especially when compared to wooden decking which soaks up liquid.

Modern Composite Decking

Depending on what your patio or outside space is subjected to, and depending on what maintenance it receives, most surface materials can indeed be slippery.

But modern composite decking is one of the safest decking materials to install.

Even stone patio areas can be slippery due to a number of factors. We’ll get into those shortly, but we first want to outline why composite decking is considered one of the safest non-slip materials to utilize.

“...modern composite decking is one of the

safest decking materials to install”


Modern grip surface

Composite decking has undergone improvements over the years that it’s been installed and manufacturers have learned a lot of lessons that have now been applied to new composite decking.

Like most other technologies, further iterations come about to develop and improve upon the product. Composite decking being prone to slipping has been one of those areas that have been tackled.

Early Composite Decking

Initial versions of composite decking had a tendency to absorb water but did not maintain a grip in the same way that wood does. This made them more prone to slipping. Not only that but absorption and retention of water over time meant greater build-up of mould and mildew. This only increase the sheen on the surface making it more slippery.

Latest Composite Decking

In an effort to reduce slipping and ensure a firmer contact with the decking, the product is now widely manufactured with a non-slip surface, otherwise known as a capping surface, which is a high-tech rubbery resin. Where this rubber resin finish is not available or is not on your current boards, you can add this layer yourself. We’ll get into that shortly, but let’s look at why your composite boards might be slippery as there are some actions you can take to fix and prevent slippery boards

Reasons why your Composite Decking might be slippery

As composite decking generally is a non-slip surface, then if you are experiencing some slipping it helps to understand the specific reason why this might be happening and taking the right steps can correct it; or better still prevent it.

Here’s the list of reasons to watch out for...

  • Fallen leaves and dirt

An accumulation of dirt, leaves and debris can build up over time. Sometimes without you realizing it. If left these will begin to decay and become slippery, in some cases making you liable for the safety of others.

  • Mould, fungus and mildew

A large part of slippery decking is due to the build-up of fungal spores that are allowed to grow. Particularly in continuous damp areas and shaded spaces.

  • Winter and icy condition

Although rarer in South Africa, there are occasions that ice and snow can build up on your decking, and we all know the dangers this can pose in terms of slipping. Avoid using salt as this can damage your decking.

Older Decking

Because earlier versions of decking didn’t have a specially treated non-slip surface, they were more prone to slipping. They were more likely to absorb moisture and retain it, thereby creating ideal conditions for wet, mouldy and slippy areas. Maybe it’s time to look at replacing your old decking for new modern, and safer composite decking.


How to fix or prevent slippery Composite Decking

We’re going into further detail on this in a further post, but we wanted to give you a quick summary of what you can do to help prevent slipping on your composite decking. Here’s the list.

  • Apply Mildew, Moss and Algae remover for effective treatment or prevention
  • Use non-slip or rubber-based paint, or apply an anti-slip coating
  • Apply a transparent sealant with added sand or grip material
  • Slip-resistant mats in prone or high use areas can be a simple solution to slipping
  • Anti-slip tape can be applied along the more prone boards to provide a sandpaper type grip
  • Attach shingles in areas such as stairs to add a top gripping layer to the steps
  • Ensure sufficient space between decking boards to prevent the build-up of dirt and debris
  • If ice or snow develops, be mindful of these areas and cover if necessary, avoid using salt
  • Regularly sweep your decking boards to remove potential slip-hazard stones and particles
  • Carry out a deep clean at least once or better twice a year
  • Building a covered area over your decking can help prevent a lot of slip hazards

Regarding the deep clean, use a specialist product. We recommend Timberlife Compowash. You can find out more about Compowash here. It’s a good idea to keep a bottle of this in your supplies so you can get straight on with the job once or twice a year.

More decking help...

We hope this has helped answer the question “is composite decking slippery when wet”. Technology in decking has moved on a lot in recent years. So looking to replace your old decking with new modern composite decking can solve most of the issues you’re likely to face. Indeed, old wooden decking can have many of these issues too, and more. So composite decking is definitely worth considering.


So why not get in touch and start the discussion around your deck replacement today. And take a look at photos of our previous projects to help get you inspired about how good your decking space can look.

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