Composite vs pressure-treated deck: cost comparison

The short answer

Pressure-treated (PT) lumber wins on upfront cost — a 12×16 family deck runs about $9,000–$15,400 installed in PT against $9,200–$17,100 in composite — but it needs staining and sealing every 1–3 years and lasts about 15–20 years. Composite (Trex, TimberTech) costs more on day one, then asks for little beyond a soap-and-water wash and typically lasts 25–50 years. And because framing, railing, stairs, and labor dominate the project cost, the composite premium on a typical deck is smaller than most people expect — roughly $200–$1,700 on a 12×16. If you pay a pro to maintain a wood deck, composite usually wins the 10-year total outright; if you do the maintenance yourself, PT stays slightly cheaper in cash and you pay the difference in Saturdays.

The figures below are planning ranges, not bids — installed cost for a typical attached residential deck including substructure, railing, stairs, and labor, before regional and site-specific variation. Price your exact size, material, and railing with the deck cost calculator, then use the band to sanity-check any contractor bid.

*Installed bands are the deck calculator’s 2026 output for a 12×16 (192 sq ft) attached deck with railing, stairs, and permit — about $47–$89 per square foot all-in. A simpler ground-level 10×12 runs $4,200–$7,100 ($35–$59/sf); per-square-foot cost falls as decks get bigger and simpler. Board costs and lifespans per the same calculator (informed by HomeGuide, Angi, Trex, and TimberTech guides).

Pressure-treated lumber: cheapest to build

Pressure-treated pine is the default American deck for a reason: it is the cheapest board at the lumberyard and every carpenter knows how to work with it. Boards run $4.70–$8 per square foot, and a popular 12×16 family deck lands around $9,000–$15,400 installed including substructure, railing, stairs, permit, and labor — the deck calculator’s published 2026 band. (A simple ground-level 10×12 with no railing needs runs $4,200–$7,100.)

The catch is ongoing work. PT decking needs a stain-and-seal roughly every 1–3 years to slow checking, cupping, and graying, and even well-kept boards may warp, crack, or splinter over time. With regular maintenance a PT deck lasts about 15–20 years; neglected, it fades and roughens much sooner. None of this is a defect — it is simply the trade you make for the lowest sticker price.

Pick PT if: upfront budget rules, you plan to move within 5–10 years, or you are happy running a roller and a pump sprayer on a spring weekend. Model your exact size and railing in the deck cost calculator.

Cedar: the natural-wood middle ground

Cedar sits between PT and composite on price — boards at $7–$12 per square foot, which puts the same 12×16 deck at about $9,600–$16,500 installed. It is naturally rot-resistant and insect-repellent without the pressure-treatment chemicals, and it lasts about 20–30 years.

Left alone, cedar weathers to a silver-gray many homeowners like; if you want to keep the warm tone, plan on sealing it on a similar cadence to PT. In other words, cedar buys you a nicer board and a longer life, not freedom from maintenance — that is composite's territory.

Composite (Trex, TimberTech): pay once, wash it

Composite decking is wood fiber and plastic capped in a polymer shell. It never needs stain, sealer, or sanding — upkeep is a rinse and an occasional soap-and-water wash. Entry lines (Trex Enhance, TimberTech Edge) run $5–$9 per square foot for boards and put a 12×16 deck at about $9,200–$16,000 installed; premium lines (Trex Transcend, TimberTech Pro) run $8–$13 per square foot and about $10,000–$17,100 installed, with deeper grain and multi-tone coloring. The surprise in the calculator’s line items: because the pressure-treated frame, railing, stairs, permit, and labor are the bulk of any deck’s cost, upgrading the boards from PT to composite adds only about $200–$520 for an entry line and $1,000–$1,700 for a premium line on this size.

Part of the premium is invisible: composite calls for 12-inch joist spacing on diagonal layouts and some entry lines (16 inches on center is fine for most straight-lay residential installs per Trex and TimberTech span charts), hidden fasteners slow the install, and crews price the tighter tolerances in. What you get back is a 25–50 year service life backed by manufacturer warranties in the same range, and boards that will not splinter under bare feet. Two honest caveats: dark composite can run hot in full summer sun, and the frame underneath is still pressure-treated lumber — the low-maintenance promise applies to the surface you see, not the structure below it.

Pick composite if: you are staying put, you never want to stain anything again, or the deck is big enough that maintenance would be a real recurring bill.

PVC (AZEK): the no-wood premium option

PVC boards (AZEK / TimberTech AZEK) contain no wood at all — they are fully waterproof, the lightest boards on the market, and the longest-lived at 50+ years. Boards run $9–$13 per square foot, which puts the 12×16 at about $10,300–$17,100 installed — the most expensive mainstream choice.

For most backyard decks the extra spend over a good capped composite is hard to justify. Where PVC earns its price is standing water and constant splash: poolside decks, docks, low decks over damp ground, and coastal exposure.

The 10-year math

Upfront price is only half the comparison, because wood keeps charging you after the build. Take the most popular size — a 12×16 (192 sq ft) attached deck — and use the deck calculator's installed ranges: $9,000–$15,400 in PT, $9,200–$17,100 in composite.

Now add maintenance. Hiring out a stain-and-seal typically costs on the order of $2–$4 per square foot per application — roughly $400–$770 per visit for this deck — and PT generally needs it every 1–3 years. Call that three to five professional visits over a decade, or roughly $1,200–$3,900. Composite's decade of upkeep is soap, water, and a stiff brush.

Read it honestly: the upfront gap is only $200–$1,700 on this size, so if you hire out the maintenance, composite wins the 10-year total outright — a single decade of professional stain-and-seal costs more than the entire board upgrade. If you do the maintenance yourself, PT stays clearly cheaper in cash over 10 years; you are paying the gap in your own labor, several weekends per decade. Stretch the horizon to 20 years and the picture tilts further toward composite, because a PT deck is reaching the end of its 15–20 year life just as a composite deck is hitting the middle of its warranty.

Maintenance figures are conservative planning estimates, not quotes — stain-and-seal pricing varies with local labor, deck condition, and railing complexity. Upfront ranges are the deck calculator's published 2026 bands.

Frequently asked questions

Is composite decking cheaper than pressure-treated over 10 years?

Pressure-treated is cheaper upfront, but by less than most people expect: on a 12×16 deck the calculator’s bands are $9,000–$15,400 for PT versus $9,200–$17,100 for composite, because framing, railing, stairs, and labor dominate the cost. Composite then eliminates the staining and sealing a PT deck needs every 1–3 years, so if you hire maintenance out, composite usually costs less over 10 years.

How much does a 12x16 deck cost in composite versus pressure-treated?

A 12×16 (192 sq ft) pressure-treated deck typically runs $9,000–$15,400 installed in 2026, including substructure, railing, stairs, permit, and labor. The same deck in composite (Trex or TimberTech) runs about $9,200–$17,100 depending on the board line and railing.

How much does it cost to stain and seal a deck?

Hiring out a stain-and-seal typically costs on the order of $2–$4 per square foot per application — roughly $400–$770 for a 12×16 deck — and PT decking generally needs it every 1–3 years. Doing it yourself cuts the cash cost to stain and supplies, usually well under $150 per round, but costs you a weekend.

How long does composite decking last?

Composite decking typically lasts 25–50 years, and the major brands back it with 25–50 year warranties (Trex Enhance and TimberTech Edge at the lower end, Trex Transcend and TimberTech Pro at the upper). Pressure-treated decking lasts about 15–20 years with regular maintenance; PVC boards run 50+ years.

Does a composite deck pay for itself?

Often, if you would otherwise pay a pro to stain and seal. The board upgrade costs about $200–$1,700 on a 12×16, while three to five professional maintenance cycles run $1,200–$3,900 — so pro-maintained PT usually costs more over 10 years than composite. If you do your own maintenance, PT stays slightly cheaper in cash; you pay the difference in labor.

When is pressure-treated still the better choice?

When upfront budget is the constraint, when you plan to move within 5–10 years, or when you are comfortable staining and sealing it yourself. PT is also the standard choice for the substructure under any deck — even composite decks usually sit on a pressure-treated frame.

Which should you pick?

• Tightest budget, or moving within 5–10 years? Pressure-treated — lowest upfront cost, and the maintenance bill mostly lands on the next owner.
• Happy to stain it yourself every couple of years? Pressure-treated stays the cheapest in cash over a decade — you pay the gap in weekends.
• Staying 10+ years and done with maintenance? Composite — a basic Trex or TimberTech line often overlaps a pro-maintained PT deck's 10-year total.
• Want real wood without PT chemicals? Cedar — nicer board, longer life, but it still wants sealing to keep its color.
• Poolside, dock, or constantly wet site? PVC — the only fully waterproof board, and the longest-lived.

Whichever way you lean, price your exact size, height, railing, and region — then check any contractor quote against the band with the built-in bid check:

Deck cost calculator →

Estimates are planning ranges, not contractor quotes. We don't replace your contractor, your permit, or your inspector — always compare licensed local bids on an identical written scope before you build.

Sources and assumptions

• Trex deck cost planner — composite board pricing and project-cost methodology.
• HomeGuide: cost to build a deck — independent market cross-check on installed deck pricing.
• HomeGuide: deck railing cost — the installed railing rates used in the 12×16 project band.
• BLS OEWS 47-2031 (Carpenters) — the loaded labor-rate benchmark behind the calculator’s crew rates.

Every dollar figure on this page is the ProjectCostPro deck calculator’s 2026 planning band — line-item engines (materials, labor, equipment, permits, contractor markup) calibrated to BLS OEWS wage data and the references above. Planning ranges, not quotes.