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A black and white cat lazily plays with toys in the sun on a composite deck.

Landscape Architecture

Five Things To Consider With Composite Decking

Thinking about building or rebuilding your deck? Maybe you’re looking at all the material options and feeling a little overwhelmed? If you’re considering composite decking as one of your options, let’s talk about some of the things you might want to mull over as you make your decision.

April 21, 2022

If spring has you starting to think about how you can update your yard, you might be considering replacing or installing a new deck in time for summer BBQs. Deciding what material to use for your new deck is an important first step that deserves some careful consideration. Way back in 2018, we covered the wide variety of wood materials available for decking. This post covers composite decking materials.

What are the main things you need to know about composite decking?

More than a decade ago, composite wood decking hit the markets as the low maintenance, eco-friendly, and long-lasting material of choice for exterior applications. As the name implies, composite woods are typically a composite or mixture of plastic (typically recycled) and sawdust (also sometimes a reclaimed byproduct of manufacturing, like lumber mill scraps). Composite wood comes in a variety of colors, and some even replicate the texture of wood by having wood grain patterns stamped onto the surface.

The low maintenance aspects reside in the addition of plastic to stabilize and limit the natural tendencies of wood to rot, thus avoiding annual, labor-intensive cleaning, sanding, and re-staining that wood typically requires. Its composition prevents splinters – a win for kids and pets – and the use of recycled elements makes everyone feel good.

Sounds appealing, right? As with everything, it depends.

We’ve seen this material in a variety of conditions and have some thoughts to share before you make a final decision.

Think About Your Sun Exposure

If your deck has a lot of solar exposure, the boards will heat up more than wood and will be really hot on bare feet. This is an important consideration if you have small children and pets. Outdoor area rugs and umbrellas could help alleviate some of this challenge.

Solar exposure will also fade the color of the composite, which cannot be rejuvenated to the original color.

Solar heat will also cause the plastic in the boards to swell and sag, while cold temperatures will cause the plastic to shrink. This back-and-forth can cause the boards to push up into each other as they swell creating tripping hazards or large gaps as they pull away from each other.

Think About the Structure

Speaking of sagging, plastic and sawdust are not structural. As with all decks, the structural components are your joists, beams, and posts which are typically pressure-treated dimensional lumber. Composite deck boards lack structural grain that lends wood its rigidity, so they tend to become springy which can be pretty unsettling to stand or walk on. This requires joists to be more closely spaced, which may increase your overall price.

Think About Your Climate

The wood component is not immune to rot – we’ve seen many composite decks become discolored and stained due to mold that has gotten into the wood portion of the decking. Pressure washing and bleach do not remove the staining. Instead, full boards will have to be replaced which may be difficult to color-match to the neighboring boards.

We’ve seen decks start to disintegrate and become really rough to touch – basically threatening splinters and making you want to avoid touching them. This can be problematic for handrails, top rails, and, of course, bare feet.

Think About Your Aesthetic

Though fake wood has merits, it can often look incredibly cheesy. You can probably recall off the top of your head a deck or other structure made with composite wood that looked a little less sophisticated than a wood counterpart. As an alternative wood product, there should be more options for stylish finishes that don’t try to replicate a natural look.

Think About the Future

If composite or plastic decking is absolutely the way you want to go, avoid any that contain PVC. This is a toxic, Living Building Challenge red list chemical that should be avoided whenever possible. It has a greater effect on those in closer proximity to the product, like kids and dogs.

It’s also not recyclable. In fact, while all untreated wood deck boards can be recycled, composite deck boards cannot.

How soon any of these potential challenges will become an issue for you depends on the location of your deck. Many manufacturers claim a 25-year warranty. We’ve seen only 5-10 years in many cases. There are many variables that can improve or impede longevity, and we’re always happy to discuss them with you.

Ask our Site Team if composite decking is the right material for your deck on your site. Manufacturers are always making improvements, and we hope to see more products on the market in the near future that we would be willing to recommend.

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