You have probably seen AZEK decking filed under composite decking on a retailer’s website, in a contractor’s quote, or in a search result that brought you here. It is one of the most common mixups in outdoor building products, and it is not really your fault. The boards sit on the same rack, cost about the same to install, and get sold by the same people.
But AZEK boards are not composite, and the difference is not a technicality. It comes down to one thing: what is inside the board. That single fact drives how the deck handles water, how often you have to work on it, how hot it gets in July, and why it costs what it costs.
Here is what AZEK decking is actually made of, why the composite label keeps getting stuck to it, and what the material choice means for a deck in Cincinnati.
The Short Answer
AZEK decking is made of PVC, the same family of plastic used in pipe and vinyl siding. There is no wood in it.
- The core is all polymer. No wood flour, no sawdust, no wood fiber of any kind.
- The cap is also polymer. A harder outer shell is bonded to the core during manufacturing. It carries the color and the grain texture.
- Composite means something different. A composite board mixes wood flour with recycled plastic in the core. That wood content is the whole distinction.
- Recycled content is real but oversold. The manufacturer puts PVC collections at roughly 60 percent recycled material, with up to 65 percent claimed for the category. The higher 85 percent figure you may run across applies to their composite lines, which include reclaimed wood.
So when a listing says azek composite decking, the product is real and the label is wrong. You are looking at a PVC board.
What Advanced PVC Means on the Label
The manufacturer’s own term for these boards is Advanced PVC. That phrasing matters, because it is more precise than the shorthand people reach for.
You will sometimes see AZEK described as 100 percent PVC. That overstates it slightly. A capped board is two materials by construction, a core and a cap bonded together, even when both are polymer. What the manufacturer actually says, and what holds up, is that the boards contain no wood fibers. That is the claim worth repeating, because it is the one that changes how the deck behaves.
Why Half the Internet Calls It Composite Anyway
Three things keep the wrong label alive, and knowing them makes shopping easier.
- Retailers file it that way. Plenty of lumberyard and online store category pages list AZEK collections under composite decking, because that is the browsing category shoppers use. It is a shelf label, not a product fact.
- One brand sells both. TimberTech sells PVC lines and wood composite lines side by side. The collection names give you no hint which is which. Legacy and Reserve sound premium and are composite. Harvest sounds mid tier and is PVC.
- Composite became a generic word. For most homeowners, composite has quietly come to mean any board that is not wood. In everyday use that is harmless. When you are comparing warranties and spec sheets, it stops being harmless.
If you want to know what is in front of you, ignore the collection name and look for the words PVC or wood composite on the spec sheet. That is the only reliable tell.
AZEK, TimberTech, and Which Name Is Current
The naming got more complicated in the last two years, and it is worth a short detour because it affects what you search for and what a salesperson tells you.
James Hardie completed its acquisition of The AZEK Company on July 1, 2025. Under the combined company, the brands are split by what they go on rather than what they are made of. TimberTech covers decking, railing and outdoor living. AZEK Exteriors covers PVC trim, siding and moulding.
For decking specifically, the current name is TimberTech Advanced PVC. The older name has not disappeared. The product pages still use azek in their web addresses, and the fade and stain warranty document is still titled with the AZEK name, so existing owners are not left guessing. But if you walk into a supplier and ask for AZEK decking, expect to be shown TimberTech.
What Taking the Wood Out Actually Changes
This is the part that matters once the deck is built. Removing wood from the core changes some things a great deal and other things not at all.
What genuinely changes
- Water stops being a threat. There is nothing in a PVC board for water to soak into, so swelling, cupping and soft edges are off the table. On a capped composite, the cap handles this well, but cut ends and drilled holes expose the wood filled core.
- Rot and insects lose interest. Fungus and termites need wood. A PVC board offers neither a meal nor a home.
- Sealing disappears from your calendar. Not only is sealing unnecessary, it is prohibited. Applying paint, stain or any coating voids the warranty outright.
- The boards are lighter. PVC is the lightest of the three materials, which makes handling easier on elevated framing.
What does not change
- The frame is still wood. AZEK does not make PVC joists or beams. The structure under your deck is treated lumber or steel, and it ages the way treated lumber or steel ages. The surface is the only part you upgraded.
- It still gets hot. The manufacturer markets Cool Touch technology and a claim that the boards stay up to 30 degrees cooler than competitive composites. No published test method or lab report backs that number up, so treat it as a marketing claim rather than a measurement. Their own documentation says plainly that all decking gets hot in the sun and that darker colors feel hotter. Color moves that number more than material category does.
- It can still be damaged. Metal snow shovels, grills too close to the surface and reflected light off Low-E window glass all cause real problems, and all are excluded from warranty coverage.
Where the Material Costs More
PVC sits at the top of the decking price ladder, above capped composite and well above treated lumber. Board cost alone runs roughly 5 to 13 dollars per linear foot depending on the collection, with Harvest at the low end and Vintage at the high end.
Installed cost is harder to pin down, and you should be skeptical of any single number. Published estimates for AZEK range from about 20 dollars to 80 dollars per square foot installed, and that spread is not a rounding error. It reflects the difference between a simple ground level rectangle and an elevated deck with railing, stairs and a permit. If you are early in budgeting, it helps to see how the decking materials compare on price before you narrow to a brand.
One cost note people miss: switching to PVC does not reduce your framing cost. The substructure is the same treated lumber either way, and on a rebuild it is often the framing, footings and ledger flashing that drive the number, not the boards on top.
What PVC Means for a Deck in Cincinnati
Our freeze and thaw cycle is the local argument for PVC. Water that gets into a material, freezes, expands and thaws again is what takes decks apart here. A board that cannot absorb water in the first place sidesteps that mechanism entirely.
That does not make the material choice automatic. Treated lumber is still the value option, and if you are weighing it seriously, it is worth knowing the wood species that hold up in this climate rather than treating all wood as one category.
There is a paperwork angle too. Your decking material can affect how a plan is reviewed, and how Cincinnati treats composite and wood decks at permit time is worth reading before you submit, because it is easier to answer the question up front than to answer it twice.
One more local note. Installation requirements tighten near reflective glass. Low-E windows can bounce concentrated sunlight onto a deck surface and cause melting or warping, and the manufacturer requires closer joist spacing and top down fastening in those zones. On newer builds with large window walls, this is worth checking before boards go down, not after.
Frequently Asked Questions
Is AZEK decking composite or PVC?
PVC. It contains no wood fiber. Composite boards mix wood flour with plastic in the core, which is the distinction the two words describe.
What is AZEK decking made of exactly?
An all polymer PVC core with a harder polymer cap bonded to it. The manufacturer puts recycled content at roughly 60 percent for the PVC collections.
Is AZEK the same as TimberTech?
They are now the same company’s products. Since the July 2025 James Hardie acquisition, decking is branded TimberTech and the AZEK name covers exterior trim and siding. The PVC deck boards are sold as TimberTech Advanced PVC.
Does AZEK decking need to be sealed or stained?
No, and it must not be. Applying paint, stain or a coating voids the product warranty.
Is AZEK PVC decking worth the extra cost over composite?
It depends on what is failing on your current deck. If moisture is the problem, PVC removes that failure mode. If you mainly want to stop sealing every couple of years, a capped composite does that too at a lower board price.
Can you put PVC decking over an existing deck?
No. The manufacturer’s installation guide prohibits installing over an existing deck. The old surface comes off and the framing gets inspected first.
The Bottom Line
AZEK decking is PVC, not composite, and that one fact explains most of what follows from it. No wood in the core means no rot, no swelling and no sealing, at the cost of the highest board price on the rack. What it does not buy you is a cool surface in August or a frame that lasts forever, because the structure underneath is still wood.
If you are deciding between materials, the useful next step is to price the same deck two ways, PVC and capped composite, with the framing held constant. That isolates what you are actually paying for the surface upgrade and usually makes the decision obvious within a few minutes.
And if a quote or a product page in front of you says azek composite decking, you now know enough to ask the one question that settles it. Is there wood in the core? For these boards, the answer is no.