Walk into the decking aisle and capped composite and PVC look like the same product in different colors. They’re not. The differences matter most in three places: what they cost up front, how they behave in your climate, and which install tradeoffs you’ll inherit. Here’s the practical comparison.
What they’re actually made of
- Capped composite is a core of wood fibers (sawmill waste, usually) mixed with HDPE plastic, wrapped in a plastic shell. The cap is what gives it stain and fade resistance; the wood-fiber core is what keeps the price below PVC and gives it convincing grain.
- PVC is 100% plastic, top to bottom — polyvinyl chloride, often with a foam core in newer products to cut weight. There’s no wood in it anywhere, which is exactly the point: nothing for mold and rot to grab onto.
That single chemistry difference drives nearly everything below.
Upfront cost
For our standard 320 sq ft deck, installed by a pro:
- Capped composite: roughly $38–$70 per square foot, so $12,200–$22,400. Trex Enhance and Fiberon Good Life sit near the bottom; premium TimberTech composite and Trex Transcend near the top.
- PVC / capped polymer: roughly $50–$80 per square foot, or $16,000–$25,600. TimberTech AZEK is the dominant brand; Wolf, Aeratis, and Versatex round out the field.
So PVC adds roughly $2,000–$4,000 to a typical deck. Real money, but the gap is much smaller than going from wood to either synthetic. Plug your own size with the deck cost calculator — it has both materials and applies the state adjustment.
Climate is where they actually differ
This is the conversation most showrooms don’t have:
- Wet, humid, shady installations: PVC wins decisively. With no organic content, there’s nothing for mildew to colonize. Capped composite is well-protected but the unprotected ends of cut boards (your installer’s saw cuts) and older uncapped composite can develop mildew in damp, shaded conditions. Screened porches, poolside decks, deep-shade north-facing decks in the Southeast — lean PVC.
- Hot, sun-blasted installations: roughly equal, with a slight nod to PVC if you pick light colors. Both get hotter than wood; both make dark colors painful in afternoon sun. The board’s color matters more than the material; either way, avoid the darkest grays and browns if your deck gets unshaded south-facing exposure.
- Cold, big temperature-swing climates (mountain states, upper Midwest, Northeast): composite has a slight edge on stability because PVC’s thermal expansion is higher. PVC works fine here too, but the install needs more attention to gap spacing — and a bad install is more likely to show up as gapping or end-pop in PVC.
The install tradeoff people forget
PVC is lighter and stiffer than composite, which sounds like an unambiguous win — easier to carry, faster to lay. The catch is thermal expansion: PVC moves about 1.5–2× as much as composite for the same temperature change. Manufacturers compensate with longer end gaps (typically 1/8”–3/16” at every joint vs. composite’s 1/16”) and shorter recommended run lengths.
In a careful install this is invisible. In a sloppy one — the install crew that’s been doing wood for twenty years and hasn’t read the PVC instructions — you get end gaps that close up in summer and yawn in winter, or worse, boards that buckle. If you’re going PVC, make sure your installer has done it before, or commit to reading the manufacturer’s install guide cover to cover if you’re DIY.
Lifespan and warranty
Both will outlast a wood deck by a wide margin, but PVC nudges ahead on paper:
- Capped composite: 25–30 year stain-and-fade warranties from the big brands, 25-year limited structural.
- PVC: typically 30–50 year limited warranties, structural and aesthetic.
In practice the deck framing (pressure-treated 2×8s and 2×10s, the part underneath you don’t see) is what limits the deck’s life — not the boards. Both materials will outlive the framing on most installs, so the difference between a 25-year and 50-year warranty matters less than it reads.
The look
This is the only category where opinion has to do real work:
- Composite still has the edge on convincing wood grain. Premium boards have shading variation along the length, embossed grain that’s not perfectly uniform, and a slightly muted finish that reads as real from six feet away.
- PVC has caught up dramatically but tends to look a touch more uniform up close — the grain is regular, the color is even. Some people prefer that “clean, modern” look; others find it plastic-y.
Neither one will fool anyone from across the yard. They’re both clearly engineered products. Go to a showroom and put samples in actual sunlight before you decide — color, surface texture, and how the cap reflects light vary enormously between brands and lines.
So which should you pick?
The honest decision tree:
- Pick composite if the upfront cost matters and your deck isn’t constantly wet. You get the convincing wood look, lower price, and a fully fine product for the next 25+ years. This is the right answer for most decks.
- Pick PVC if any of: the deck is poolside, screened in, or otherwise constantly damp; you want the longest possible warranty and you’re staying in the house; you specifically prefer the cleaner, more uniform look; or you’ve had mildew problems with a previous deck in the same spot.
- Pick neither (go pressure-treated wood) if your budget is tight and you don’t mind staining every 2–3 years. The cost gap to either synthetic is much bigger than the gap between composite and PVC, so wood is the real money-saver. See the composite vs. wood calculator for that comparison head-to-head.
The boring meta-advice: don’t shop the marketing, shop the brand line. Within composite, premium Trex Transcend behaves very differently from entry-level Trex Enhance; within PVC, TimberTech AZEK premium is a different product from their entry tiers. Get the spec sheets, compare warranty terms in writing, and pick on the deck you can stand to live with for the next twenty-five years.
Frequently asked questions
Is PVC or composite decking more expensive?
PVC. Installed PVC runs about $50–$80 per square foot for a typical deck, versus $38–$70 for capped composite. On a 320 sq ft deck the upfront gap is usually $2,000–$4,000 — real but not enormous. Both are well above the $25–$45 you'd pay for pressure-treated wood.
Which gets hotter in the sun?
Both get hotter than wood, and dark boards of either material can be uncomfortable barefoot in direct afternoon sun. Light-colored PVC tends to run a touch cooler than equally-colored composite because it reflects more solar energy — but color of the board matters more than the material. If your deck is in full sun, choose a lighter shade in either material.
Which lasts longer?
PVC, marginally — most manufacturers warranty PVC against structural failure for 30–50 years, versus 25–30 years for capped composite. Both will easily outlast a wood deck. In real-world conditions, the deciding factor for either is the framing underneath; the surface boards almost never fail first.
Does composite or PVC handle wet climates better?
PVC, because it has no organic wood content for mold and mildew to feed on, and it doesn't absorb water at all. Capped composite is well-protected too but uncapped or older composite can grow mildew in shaded, damp installations. For a screened porch in the Southeast, a poolside deck, or anything constantly damp, PVC is the lower-risk pick.
Do PVC boards expand and contract more?
Yes — PVC has a higher thermal-expansion coefficient than composite, which is why manufacturers spec wider end gaps and shorter run lengths. It's not a problem when installed correctly, but it makes installation a little less forgiving. Hire a crew that has worked specifically with PVC before, or read the maker's install manual cover-to-cover if you're DIY.
Which looks more like real wood?
Premium capped composite still leads on convincing wood-grain texture; PVC has caught up considerably in the last five years but tends to look slightly more uniform up close. From across the yard, neither one fools anyone — they're both clearly synthetic boards. Color and grain at the showroom is the only honest way to choose.
Heads up: this guide is general information, not legal, engineering, or financial advice — building codes and permit rules are set locally and change, so confirm the specifics with your own building department or a licensed pro before you commit. Cost figures are planning ranges, not quotes; see our methodology.