Disposable plates, cups, towels and bags, there are too many things that just don’t last in our lives. Decks should not be one of them, especially with all the work and money required to build a deck. You want a deck and decking that will last. What is the longest-lasting decking material out there?
The longest-lasting natural decking material is Ipe, lasting over 75 years. The longest-lasting synthetic decking is TimberTech AZEK having a 50-Year Limited fade and stain warranty, which translates into the longest expected lifespan of all synthetic decking.
For questions like this, I wish I was old, that I had built decks with Noah. Yes, Noah, who built the Ark. Then I could say why yes, I built a deck with that material, and it lasted exactly 43 years. Then I built another one with the same decking material but with better ventilation, and it lasted 117 years. Know what I am saying? Time tested decking material. Used and enjoyed in real life, with a verifiable life expectancy.
But I am not, but I have been working with wood and synthetic decking for many years. I have seen them in their glory. And I have torn them out after rot made them ugly and unsafe. I have heard of decking lasting for decades and a deck I built for my in-laws, which had to be replaced in only eight years. I have seen and studied the whole spectrum of decking life span.
Not all decking lasts the same amount of time, but all decking lifespan is impacted by its installation. Some decks will last longer, and others will find their demise sooner, but this is about how long on average decking material will last.
|Pressure Treated Decking||15+ years|
|Composite Decking||25+ years|
|Cedar Decking||30+ years|
|PVC Decking||50+ years|
|Ipe decking||75+ years|
Now that is a big range of how long decking will last, over 60 years difference. But even within decking material, there is a variance of life expectancy. Let’s go through each material and discuss how long it will last.
Pressure Treated Decking has the shortest life expectancy of 15+ years
This is partly deceiving as pressure-treated decking can last over 40 years. But I must clarify a few things, explaining why I say 15 years when it can last over 40.
Most pressure-treated decking is pine treated with chromate copper arsenate (CCA) or alkaline copper quat (ACQ), which is toxic to fungi and insects. But these are only a limited element of how long the decking will last. How long it will last depend on three factors, level of treatment, maintenance, and environment.
Like everything, the more it is protected, the longer it will last. Most decking is treated with 0.15 pounds per cubic foot of treatment. Preserving it for many years in a well-ventilated environment. This was my mistake with the deck I built for my in-laws. It was a low deck without ventilation and without treatment. Lasting only eight years, much too short for a deck. But even treatment deteriorates over time, especially with increased moisture, which it is not treated for.
Treated decking will last longer if it is sealed and protected against moisture. The cooper treatment only protects against rot from fungi and insects but not against water damage. Regular sealing or staining will help the decking to last many more years.
Treated decking in a wet environment will deteriorate quickly. To protect against high levels of moisture treated decking not only needs to be seal or stained to lockout moisture but also allowed to dry.
Deck ventilation is key to long decking life. Treated decking generously spaced, 3/16″ (5mm), along with skirting that allows ventilation. You can read more about deck ventilation by clicking here. But in short, if treated decking is ventilated, drying between rains, it will last for many years.
When treated decking is correctly installed with sufficient ventilation to dry and is maintained with regular sealing or staining, it can easily last as long as any other decking. But most treated decking is not. It is neglected soon after being installed. Lasting only a short time of 15 years or less.
Composite Decking will last longer, 25-30 years
The wonderful thing about composite decking is it will last 25 years or more without little maintenance, a blend of wood fibres and plastic minimizing the need for maintenance. To keep its beauty, it still needs to be regularly clean, but without demanding sanding and staining.
How long composite will last also depends on manufactures. For example, Trex, the largest manufacturer of composite decking, provides a 25-year warranty for its capped composite decking. But TimberTech gives 30 years for TimberTech Pro series but only 25 for TimberTech Edge line.
Here lies the trouble with composite decking, actually all synthetic decking. These are warranties based on lab testing. Which is all fine and dandy, giving a sense of how long the decking will last but without real-life testing.
Capped composite decking started being installed on decks around America in late 2008. So, it doesn’t matter if its Trex or TimberTech or any other composite decking, we don’t really know how long it will last. Tests give us a good sense, but time will only tell if it truly lasts 25 or even 30 years.
Unfortunately, many of the earliest composite decking did not last the expected 25 years. A few years after rolling out of labs in the late 1990, mould and other issues started to crop up on some decks. I believe the polymer cap has remedied most of these problems, and I am optimistic as I install composite decking that it will last for years, but it may not.
The good news is if it lasts longer than ten years, it will still be worth it with all the savings in time and cost by not needing to be stained or sealed.
Cedar Decking lasting, even more, 30+ years
Back to natural decking, cedar is a wonderful looking decking with the ability to last more than 30 years. Old-growth cedar has a natural resin that prevents rot, helping it to last for many years. Unfortunately, it is a natural product varying in the level of resin. A lot of the current cedar decking being sold does not have the same level of resin as it did years ago.
If you luck out with the cedar boards with a high level of resin, your deck can last 30 or more years. If not, it will rot sooner.
Even though cedar is naturally resistant to rot, it is better to stain or seal it against moisture and fungi regularly. The stain will help it to last longer while preventing is natural wood beauty being lost to greying. Still structurally sound when greyed but not as beautiful as when protected.
PVC Decking possibly lasting over 50 years
PVC a newer option for decking but with great promise. PVC decking is polyvinyl chloride material capped with a polymer shell, containing no wood or any organic material. It will not rot, because it can’t rot. There is nothing contained in PVC decking that can rot be wholly a synthetic product.
And here lies its promise of long life. If rot destroys decks, how long can decking last if it will not rot?
But as I said with composite, this is only theory. Tested theory, Yes, but theory none the less. Capped PVC decking from Azek, having the longest warranty of all decking, was only launched in 2012. That is only a short time of real-life deck experience.
All the theories are good. Or, as A&W restaurants say, “Good food makes good food.” All the material that goes into PVC decking should last for the 50 years or more. Good material in should result in good decking material.
The biggest limitation of composite and treated decking was wood. As wood can rot and be eaten by insects. So, if you remove the wood from the decking, it should last forever, or at least longer then any other decking containing wood. Giving us the promise of decking lasting 50 years or more.
Ipe, the proven longest-lasting decking, 75 years or more
Ipe is a naturally hard wood, which cannot be eaten by insects or fungi. The very density of the decking protects it for many years. It is rated 3,510 lbs (15,620 N) on the Janka Hardness scale. This is its strength; unlike cedar, which varies in level of resin, Ipe is just plain hard, dense. So hard and dense that it repels water and insects. Sealing itself from all that can harm it.
The Coney Island Boardwalk in 1923 was constructed using Ipe decking, which lasted over 90 years, in a harsh, wet and salty environment. It truly has proven itself.
But like all-natural decking, it will look better if regularly oil sealed. Sealing is not required to extent Ipe’s life but does improve appearance.
Aluminum Decking, another long-lasting decking but not very common
I build residential decks, so this is not decking I have much experience with because of its industrial look. Since most of us enjoy being surrounded by nature and natural products.
So, our default setting is wood for decking. A natural product, even synthetic decking, has a large push to be more wood looking. The more expensive PVC and composite decking are all capped to look more like wood.
The other day I was listening to a podcast of a TimberTech rep talking about how their new line of decking behind a sheet of glass could not be distinction from wood. An appealing element that alludes aluminum decking. But aluminum decking is durable lasting 30 years or more at often a lower cost than comparative lasting decking.
Conclusion of How Long the Decking Material Will Last
In summary, Ipe decking will last longer than all other decking materialnatural or synthetic. If you want to build your deck once, never to be repeated again in your lifetime, deck it with Ipe. It will outlast you and possibly even the house it’s attached to. But it will require experience and skilled installation. This is not decking for DIY. Ipe may last more then 75 years, but if installed incorrectly, it will not matter.
For synthetic decking, Capped PVC decking from Azek will last longer than all others. Constructed of material that will not and can not rot. It will last a lifetime, of 50 years or more. There are some limitations with installation and technics that need to be used in installation but a durable decking it is.
But when selecting the right decking for your home. Longevity is not the only factor. For a much broader comparison of decking material, click here where I compare in much greater detail the performance of different decking material. What will it cost? What can damage it? And many more elements of decking.