Composite lumber is any man-made material composed of a mix of wood fibers, plastics, binders, and adhesives. Composite lumber is fairly popular in construction (i.e. plywood), but capped composite lumbers designed for decking didn’t really come onto the market until the ’90s. 

Over the past few decades, composite decking has skyrocketed in popularity as an alternative to wood. Many new decks are being made with composite decking rather than wood, as manufacturers have led homeowners to believe that their products are superior to any real wood.

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Composite Decking Problems

While composite decking certainly does have some advantages, it also has a number of problems that the average homeowner may be unaware of. Many homeowners have ended up learning the hard way that composite decking isn’t flawless and, in many cases, ends up being a frustrating, expensive mistake. 

Here are the five main problems associated with composites that you must be aware of before you invest thousands into your new deck or patio.

1. Moisture Resistance Doesn’t Stop Mold

Composite decking is often sold as a close to a waterproof material as you can get. While more advanced composite is exceptionally resistant to water, this doesn’t mean that mold isn’t capable of growing.

The texture of the surface of the boards and the very rough surface of uncapped ends can easily hold water within its grooves. Since the water doesn’t quite absorb, it becomes stagnant, with the moisture finally causing mold to develop.

Despite composite being “low care”, homeowners living in humid/wet regions might find them having to clean their decks excessively to control mold, fungus, algae, or moss growth.

composite decking next to wood decking
Image credit: Canva

2. Warping and Weakening Aren’t Uncommon

Another myth of composite that relates to its water resistance is that it won’t swell from water contact. What’s interesting to note is that composite decking boards are more apt to move around. Common complaints from homeowners include their composite decking board swelling, shifting, warping, and shrinking.

The cause of this isn’t exactly clear, but it’s suggested that the composite nature of the decking leads it to be much more sensitive to temperature and humidity swings as well as sun exposure. In this way, composite decking can be fairly unpredictable, even within boards on the same deck.

3. Staining and Color Fading Lead to Frustration

A significant attraction to composite decking is how many colors it comes in. Coupled with being sold as low-maintenance and not needing surface treatments leads homeowners to believe their new deck will look the same for its entire life span. 

In reality, composite decking is prone to fading, especially when it’s exposed to the elements and sun. Many composite decking materials also stain easily. Anything from the tannins of a few fallen leaves on the surface to an additional spilled glass of wine or splotch of ketchup can leave stains.

man washing pool decking
Image credit: Canva

The only way to fix the stains is to paint over them. Many composite manufacturers even offer matching paint for this reason. Since the vast majority of composite deck owners selected this material for not needing to be repainted or resealed, this is a major disappointment. However, there is a way to prevent this from happening. The way to achieve this is by applying a composite deck sealer, it will help preserve your deck’s color and avoid stains.

We recommend the DEFY Crystal Clear Composite Deck Waterproofing Sealer.

4. Easily Scratched Surface Can’t Be Fixed

Composite decking is typically made of more plastic than wood fibers, leaving the surface fairly soft. Homeowners quickly notice that their new deck scratches fairly easily compared to older wood decks. Patio furniture, BBQ grills, kids toys, and even the family dog’s nails can all leave gouges in the composite decking.

Worse yet, gouges and scratches on composite decking can’t be fixed, unless you completely replace the board. If your wood deck got scratched, it can be sanded down. This isn’t an option with composite.

5. Composite’s Characteristics Limit Usability

There are other characteristics of composite decking that limit its usability. Since these are natural attributes, there really is no way to avoid them. 

One example is the slipperiness of composite decking when it’s wet. The reason for this is that plastic is oil-based in nature which causes water to sit on its surface rather than absorbing like wood. Despite composite having texture, it does little to provide solid footing around pools or swimming docks.

Other characteristics that can cause problems include retaining heat and feeling hot to bare feet. Composite decking also isn’t as strong as solid wood, which is evident in that smaller joist spacing is required for the deck’s structure. While a hardwood deck can be constructed with joists 16′ apart, most composite deck joists must be built 12′ or less apart to prevent sagging.

Skip Composite and Stick With Real Wood

The main competitor to composite decking in the early years was pressure-treated (PT) lumber. In comparison to PT wood, composite decking does have advantages. For example, PT wood must be restained and/or resealed every few years while composite does not.

However, it’s important to remember that while a composite may be a better idea than a PT wood, it doesn’t mean it’s superior to all woods. Modified wood is a real wood product that offers far more benefits than composite, but with the beautiful look of natural wood. Similarly to composite, it requires no surface treatments and only basic cleaning. Modified wood is also non-toxic to the environment and to people. 

Image credit: Canva

Modified wood is stronger and longer-lasting than composite, not to mention more versatile. Modified wood can be used in any region or climate as well as alongside water as poolside decking, piers, or docks. Insects, rodents, and other wildlife will also not be attracted to your modified wood deck. Last, but not least, modified wood ages beautifully (even becoming a silvery-grey) and rarely splinters.

Editorial Contributors
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Matt Greenfield

Matt Greenfield is an experienced writer specializing in home improvement topics. He has a passion for educating and empowering homeowners to make informed decisions about their properties. Matt's writing focuses on a range of topics, including windows, flooring, HVAC, and construction materials. With a background in construction and home renovation, Matt is well-versed in the latest trends and techniques in the industry. His articles offer practical advice and expert insights that help readers tackle their home improvement projects with confidence. Whether you're a DIY enthusiast or a seasoned professional, Matt's writing is sure to provide valuable guidance and inspiration.

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