One of the perks of composite decking is its durability, but is it completely resistant to rot? We polled experts in the industry. Read on to learn more.

Alastair Boyd

Alastair Boyd

Alastair Boyd, Community Development Specialist at

Not easily

Normally, composite decking doesn’t rot that easily. But, it certainly depends on the environment and the quality of the material. To be honest, I would not say that composite decking doesn’t rot. If you search online, there are some complaints about it.

Untreated and non-resistant wood rot easily. Composite lumber resists rot, insects, etc., [but] as we know, composite decking includes wood that is chemically treated. So the wood doesn’t rot in a less humid condition, but in cases where it comes in direct and continuous contact with moisture, there are chances of rotting. For example, open areas like the back-garden. But on the other [hand], if the composite decking is done on raised garden beds, there won’t be any rotting.

So the most important aspect is where and how the composite decking is installed. And yes, it does rot! So ensure that you purchase good quality stuff to avoid any issues in the future.

Under certain circumstances

Most composite decks come from recycled plastic and wood scraps to make them eco-friendly. You can get them in a variety of earth tones and colors that help you match to your outdoor decor, and some companies will add fake wood grains to make them look more real. Composite decks come in a plank form, and this mimics more traditional wooden planks. You can now purchase tiles as well, and many of them snap together to make them quick and easy to install. But do they rot?

If you were to ask the manufacturers, they’d all say that the composite decking they sell won’t rot. However, a quick search shows that people who have this style decking materials claim that it will have a problem under certain circumstances. For example, if it’s constantly sitting right against the wet or soggy ground that never fully dries up, this could lead to mold growth that can weaken the structural integrity of the materials. A passing storm can deposit debris on the deck, or you could slide your patio furniture over it and scratch the surface. You can’t resurface composite decking like you can traditional wooden planks, and this gives way for moisture to get in and cause it to swell or warp.

Jen Stark

Jen Stark

Jen Stark is the founder of Happy DIY Home. She is a master gardener, interior designer, and home improvement expert, she has completed many home improvement, decor, and remodeling projects with her family over the past 10 years on their 4,500 sf Victorian house.
Andrew Bronson

Andrew Bronson

Andrew Bronson, Founder of Hard Money Property. We help individuals and corporations find private real estate loans for real estate investment projects.

May not rot

Composite decking is made up of a combination of wood scraps and recycled plastic which prevents the material from rotting. It is important to understand that composite decking may not rot, but it is still possible to scratch and damage composite decking. And since the material isn’t made out of pure wood, you won’t be able to effectively sand and refinish the material.

Won’t rot

Composite decking won’t rot. However, it’s still susceptible to other damage, such as stains and scratches. It’s important to take good care of your composite deck; if it does get stained or scratched, it cannot be sanded and refinished like natural wood.

Lisa Torelli-Sauer

Lisa Torelli-Sauer

Lisa Torelli-Sauer, Editor at Sensible Digs, a website geared toward helping people make smart investments in their homes.
Bryan Stoddard

Bryan Stoddard

Bryan Stoddard currently running a website called Homewares Insider.

Under certain conditions

I think that a better question would be under which condition can composite decking rot. In this case, I would say that though the material is very resistant to rotting, under certain conditions, it can rot. Here I mainly think about improper installation and the prolonged presence of water.

One of the main selling points of composite decking is that it doesn’t rot, and I agree that under optimal conditions you would hardly ever see any rotting. Unfortunately, there are situations when the installation was done badly or where there were outside damaging influences.

Cellulose is one of the major parts of composite decking, and when cellulose is introduced to water, it can become fertile ground for molds and fungi. Because it is a form of carbohydrate, it can allow fungi and molds to spread. If this goes [on] over a long time, for example if the water isn’t drained properly, people might notice visible signs of rotting. This can be prevented by regular cleaning and solving any issues that cause water gathering on deck.

To sum up, under certain specific conditions, composite decking (and regular wood) will absolutely rot away. Proper maintenance and inspections are key in preventing this from happening.

Vulnerable to fading

No material is completely maintenance-free, and while composite decking is designed to be eco-friendly as well as weather and rot-resistant, under specific circumstances composite decking can be vulnerable to fading, buckling, and mildewing. Minimal upkeep is required, but in relation to the annual treatment that wood requires, composite decking is vastly easier to maintain.

Jeff McLean

Jeff McLean

Jeff McLean works at Jeff McLean Company that provides industrial/commercial flooring and painting services for clients in Danvers, MA, and surrounding areas.

This is a crowdsourced article. Contributors' statements do not necessarily reflect the opinion of this website, other people, businesses, or other contributors.


  • Nate Barrett

    As the President of SRI Decks, my greatest satisfaction comes from the immediate sense of fulfillment that our work brings. From the initial design discussions with our customers to the moment we capture the final project in photos, I feel an immense pride in my team for their dedicated efforts. My passion for hands-on work and outdoor projects is matched only by the joy I derive from seeing a delighted customer when we’ve successfully completed a job. Fun Facts: I like hot chocolate in my coffee. I’ve been with SRI for 12 years, prior to ownership. I have a daughter, 3 dogs and a loving girlfriend.

    View all posts