Composite decking cost: what boards and a finished deck cost
Composite decking costs $5–$32 per square foot in materials, or $16–$45 per square foot fully installed. A typical 12×12 deck comes to $2,304–$6,480 installed. The range is wide because different sources count different things: some quote the boards alone, others include the substructure, clips, fasteners and labour.
Here is the short version.
| What you are pricing | Per square foot | Included |
| Boards only | $5 – $14 | Decking boards |
| Boards + substructure | $7 – $19 | Boards, joists, framing, clips, fasteners |
| Fully installed | $16 – $45 | Everything above, plus labour |
Everything below breaks those numbers out — by board type, by deck size, against timber, and by the four things that move a quote.
What composite decking costs per square foot
Composite decking costs $5–$14 per square foot for boards alone, $7–$19 including the substructure, and $16–$45 fully installed. Which end of that range you land on is decided almost entirely by the board.
| Tier | Material cost / sq ft | Typical lifespan |
| Entry-level uncapped | $5 – $9 | 10–15 years |
| Mid-range capped | $9 – $16 | 25–30 years |
| Premium PVC / mineral core | $16 – $32 | 30–50 years |
The gap between the top and bottom of that table is not marketing. It is the difference between a board with a co-extruded polymer cap on all four sides and one without, and it shows up ten years later as staining, swelling or fading. A fuller breakdown of per-square-foot pricing by profile and by region is on composite decking price per square foot.
Cost by board type: capped vs uncapped
Capped composite costs $9–$16 per square foot, uncapped entry-level boards $5–$9, and premium PVC-core boards $16–$32.
Uncapped composite is a wood-plastic blend with no outer shell — wood flour and plastic extruded together, colour running through the board. It is the cheapest option and the one that behaves most like wood: it takes up moisture, it can stain and it will fade, usually grey rather than rot. Ten to fifteen years is a realistic life. It is a legitimate product at a legitimate price — the mistake is buying it expecting capped performance.
Capped composite adds a co-extruded polymer cap bonded to the core during extrusion. The cap is what resists staining and fading, and it is what most buyers mean when they say “composite”. Twenty-five to thirty years, soap-and-water cleaning, no sealing.
PVC and mineral-core boards replace the wood flour with a synthetic or mineral core. They are the heaviest, the most dimensionally stable and the most expensive — $16–$32 per square foot — and they are the right choice in humid or coastal climates where moisture movement is the main threat to a deck.
Within any one brand, colour and profile also move the price. It is rarely the same number for a grooved board and a solid-edge board in the same range.
What a finished deck costs: worked examples
A finished composite deck costs $1,600–$4,500 at 10×10, $2,304–$6,480 at 12×12, $3,072–$8,640 at 12×16, and $6,400–$18,000 at 20×20 — installed, all in.
| Deck size | Square feet | Material only | + Substructure | Installed |
| 10×10 | 100 | $500 – $1,400 | $700 – $1,900 | $1,600 – $4,500 |
| 12×12 | 144 | $720 – $2,016 | $1,008 – $2,736 | $2,304 – $6,480 |
| 12×16 | 192 | $960 – $2,688 | $1,344 – $3,648 | $3,072 – $8,640 |
| 20×20 | 400 | $2,000 – $5,600 | $2,800 – $7,600 | $6,400 – $18,000 |
These are the four sizes installers quote most often, and the arithmetic behind them is simple enough to check: square footage × the per-square-foot rate for the board you picked. A 12×16 deck is 192 square feet; at $9–$16 per square foot for mid-range capped material, that is $1,728–$3,072 in boards, before framing or labour.
Three things are not in those numbers, and they are the usual reason a real quote comes in above the table:
- Stairs and railings. Railing alone commonly runs $30–$70 per linear foot installed, and a deck with stairs can carry a third of its cost in the access, not the floor.
- Removing an old deck. Demolition and disposal of an existing timber deck is a separate line, typically quoted by area.
- Site access. A deck that a wheelbarrow can reach costs less to build than one that has to be carried through the house.
Allow 10% on top for waste and offcuts, and price the frame in the same material family as the boards — a composite deck on steel or aluminium framing is priced differently from one on timber joists, and that difference is bigger than most buyers expect.
Composite decking cost vs wood and pressure-treated
Capped composite costs $9–$16 per square foot in materials against $3–$6 for pressure-treated pine — but pine needs staining or sealing every two to three years, and composite does not.
| Material | Material / sq ft | Installed / sq ft | Maintenance |
| Pressure-treated pine | $3 – $6 | $10 – $15 | Stain or seal every 2–3 years |
| Cedar / hardwood | $6 – $12 | $15 – $30 | Oil annually, refinish periodically |
| Composite (uncapped) | $5 – $9 | $12 – $25 | Wash; fades and stains over time |
| Composite (capped) | $9 – $16 | $16 – $45 | Soap and water |
| PVC / mineral core | $16 – $32 | $25 – $60 | Soap and water |
The honest version: on day one, timber is cheaper. Over fifteen years it usually is not. Staining a 300-square-foot deck every third summer — material, labour or your own weekend, plus the boards you eventually replace where water sat — narrows the gap to somewhere between “roughly even” and “composite ahead”, depending on how much you value the weekend.
Where composite loses is on structure rather than surface. Any deck needs a frame, and framing costs the same either way, which is why the material saving on cheap boards is a smaller share of the total than the per-square-foot numbers suggest.
The average composite deck cost — and why averages mislead
Published averages run $10,000–$30,000 for a full deck, and that single number hides the two variables that actually set your price: board type and deck size.
An average is a survey answer, not a quote. Announce a $18,000 figure and it tells you nothing about whether that deck is 200 square feet in premium PVC or 400 square feet in entry-level uncapped board — a 2× spread in both directions, multiplied together, and the average lands in the middle of it.
Two numbers are worth more than the average:
- Your deck’s square footage — length × width, plus stairs and landings.
- The per-square-foot rate for the board you actually want — $5–$9, $9–$16 or $16–$32 from the table above.
Multiply those, add railings and any demolition, and you have a figure you can hold a contractor to. That is also the only way to compare two quotes that look different but are not: one priced in capped boards with the frame included, the other in uncapped boards with the frame extra, is not a $4,000 difference in price. It is a difference in what was quoted.
What moves the number
Four things move a composite deck quote: board type, substructure, fastenings, and labour or site access.
Board type is the largest single swing — $5–$9, $9–$16 and $16–$32 per square foot are three genuinely different products, not three prices for one product. Capped versus uncapped is the line that matters.
Substructure is where quotes quietly diverge. A composite deck sits on a frame, and whether that frame is treated timber, aluminium or steel moves both the material and the labour line. When you compare two quotes, compare the frame spec before anything else.
Fastenings and trim — hidden clips, starter clips, screws, fascia boards, stair nosing — are usually priced as separate lines. Whether they are included or bolted on can move the effective unit price by 8–15%.
Labour and site access is the local variable: day rates, access, ground conditions and how much of the build is stairs. Two quotes for identical material can differ by a third on labour alone.
If you are buying a single deck for your own house, that is the whole list. If you are buying at trade volume — by the container, from a factory — the picture is different: there the number that matters is not the per-square-foot price at all, but the FOB unit price, what loads into a container, and what the boards cost landed and cleared. Those layers are set out on our trade and wholesale terms page, from quoting bases (FOB, CIF, DDP) and price tiers to container utilisation and payment terms.
FAQ
How much does composite decking cost in total?
A finished composite deck typically costs $1,600–$18,000 depending on size, or roughly $16–$45 per square foot installed. A 12×12 deck runs $2,304–$6,480; a 20×20 runs $6,400–$18,000.
Is composite decking cheaper than wood?
No — not up front. Composite costs $5–$32 per square foot in materials against $3–$6 for pressure-treated pine. It becomes cheaper once you count maintenance: pine needs staining or sealing every two to three years, composite needs soap and water.
Is composite decking worth the cost?
It is worth it if you plan to stay. Capped composite lasts 25–30 years and PVC-core boards 30–50 years, both without the annual upkeep timber needs. If you are selling the house in three years, the maths usually favours timber.
How much does composite decking cost per square foot?
$5–$14 for boards alone, $7–$19 with the substructure, and $16–$45 fully installed. Board type sets which end of those ranges you land on.
How long does composite decking last?
10–15 years for entry-level uncapped boards, 25–30 years for capped composite, and 30–50 years for premium PVC or mineral-core boards.
Do I need to seal composite decking?
No. Sealing is not required and is not recommended — capped boards are cleaned with soap and water. Only uncapped boards benefit from any treatment, and even then it is cosmetic.
Can I buy composite decking wholesale?
Trade buying works on a different basis from retail: boards are quoted per square metre FOB, with a minimum order quantity per board profile, price tiers that follow container utilisation, and freight, duty and port charges sitting outside the unit price. The structure of a trade quote is explained on our trade terms page; for a quote on your own quantity, size and destination port, send us the details.