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.
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.
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.
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.
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