What does composite decking cost per square foot installed?
Plan on $40–$62 per square foot for a finished composite deck platform. That range covers footings, treated-lumber framing, capped composite boards, hidden fasteners and labor, and it comes from 2026 published market data (HomeGuide's national cost pages blended with published Treasure Valley contractor pricing). The table applies it to common sizes at three heights.
| Deck size | Ground level (under 12 in) | Raised (1–4 ft) | Second story (8 ft+) |
|---|---|---|---|
| 144 sq ft | $5,000–$9,000 | $5,500–$10,000 | $7,000–$13,000 |
| 200 sq ft | $6,500–$12,500 | $7,500–$14,000 | $9,500–$18,000 |
| 300 sq ft | $10,000–$18,500 | $11,000–$21,000 | $14,500–$27,000 |
| 400 sq ft | $13,000–$25,000 | $14,500–$28,000 | $19,000–$36,000 |
How much do Trex and TimberTech lines change the price?
Brand matters less than the line within a brand. Both major manufacturers sell an entry tier, a middle tier and a premium tier, and the jump between tiers is bigger than the gap between brands at the same tier. HomeGuide's 2026 pages list these installed ranges; we have not been able to re-read the live pages, so treat them as indicative.
| Product family | HomeGuide installed range | Where it sits |
|---|---|---|
| Composite (all brands) | $40–$80 per sq ft | Wide range reflects entry to premium lines |
| Trex | $45–$70 per sq ft | Enhance (entry), Select (middle), Transcend and Signature (top) |
| TimberTech composite | $40–$70 per sq ft | Edge (entry, three-sided cap) and Pro (four-sided cap) |
| AZEK / TimberTech Advanced PVC | $60–$80 per sq ft | All-polymer boards, longest product warranties |
Warranty length tracks the tier. Trex publishes 25-year limited residential warranties on Enhance, 35 years on Select and 50 years on Transcend and Signature. TimberTech lists 25-year product and fade-and-stain coverage on its Edge Prime and Premier boards, 30 years on Pro Reserve, and a limited lifetime product warranty with 50-year fade-and-stain coverage on AZEK Vintage and Harvest. Our Trex vs TimberTech comparison goes line by line.
Two product details change the price of a specific job. Trex notes that Select boards are slightly thinner than its Enhance, Transcend, Signature and Refuge boards and should not be combined with them, so extending an older Select deck in a different line needs a planned break such as a step or a border board. Fire-rated boards are the other: TimberTech sells WUI-compliant Reserve boards as a special-order fire-resistant SKU, and its AZEK Vintage collection carries a Class A flame spread rating. Special orders add lead time as well as cost.
The framing and hardware behind a composite price
Composite boards sit on a wood frame, and that frame is where a lot of the money and most of the long-term risk live. Five details separate a cheap composite deck from a durable one.
- Joist spacing. Composite spans less than 2× lumber, so straight-laid boards commonly need joists at 16 inches on center and diagonal layouts tighter still. Check the installation guide for the exact line; closer joists mean more lumber and labor.
- Hidden fasteners. Grooved boards use clips between boards instead of face screws. They cost more per square foot than screws but leave a clean surface.
- Picture-frame border and fascia. A border board around the edge and composite fascia over the rim joist add material and cutting time.
- Matching railing. Fixr's 2023 composite railing range is $80–$165 per linear foot installed; aluminum is often cheaper and thinner.
- Framing protection. Joist tape over the tops of joists is optional but slows rot in the one part of a composite deck that can still rot.
Treasure Valley factors that raise composite costs
Local codes and conditions add cost on top of the material. Composite does not change the permit rules, but it does interact with heat, HOA color rules and wildfire zones in ways wood does not.
- Permits: Boise and Nampa require one above 12 inches; Meridian exempts only detached decks of 200 square feet or less that stay at or below 30 inches and do not serve an exit door. Drawings and plan review are part of the cost of any raised composite deck.
- Footings: Boise's 24-inch frost depth sets the minimum footing depth no matter what goes on top.
- Heat: a sunny composite deck has to live through roughly 55 days of 90°F-plus weather a year. Light colors and heat-mitigating lines cost little or nothing extra but change how the deck feels in July.
- HOA color approval: many Meridian, Eagle and Star boards approve specific colors, so a sample submittal is part of the schedule.
- Wildfire overlay: in Boise's Foothills IR1 area, listed fire-rated boards, such as TimberTech's fire-resistant Reserve boards (special order) or AZEK Vintage, push the price toward the PVC range.
For the code side, see Boise's deck permit rules and the snow load guide; composite decks are framed to the same 20 psf ground snow load as wood.
Is composite decking worth it over wood in Boise?
It depends on how long you will own the house and whether you would actually re-stain wood on schedule. On a 300-square-foot raised deck, the midpoint of the composite range is about $6,000 above the midpoint for pressure-treated pine. Treated pine in Boise's sun and dry air needs cleaning and re-staining every two to three years. Price a professional clean-and-stain from a local quote, multiply by the cycles you expect while you own the house, and compare that with the gap.
Resale math leans the other way. The Remodeling / JLC Cost vs. Value 2025 report's Mountain region figures (a multi-state region that includes Idaho) list a composite deck addition at $26,342 in cost and $21,630 in estimated resale value, 82.1% recouped, against about 97% for the wood version. Composite's return is in the years you spend not sanding and staining. The composite decks service page covers what we build with it.
Comparing composite deck quotes
Make every bidder name the same things. Composite quotes hide differences in the line, the frame and the railing more easily than wood quotes do.
- Brand, product line and color written on the bid (for example, a named Trex or TimberTech collection), not 'premium composite'.
- Board profile: grooved for hidden fasteners or square-edge for face screws.
- Joist size and on-center spacing, matched to the manufacturer's span table.
- Railing system and linear footage, and whether stair rail is included.
- Footing count and depth, ledger flashing, and who handles the permit.
- Who registers the product warranty and what the installer's own workmanship terms cover.
To test a budget before you call anyone, open the deck cost calculator, choose capped composite and enter your size and height. If you are replacing an old wood deck, the deck replacement cost guide adds the tear-out side.
Run your own numbers with the deck cost calculator.
Frequently asked questions
- How much does a Trex deck cost per square foot?
- HomeGuide's 2026 pages put installed Trex decks at roughly $45–$70 per square foot nationally, with Enhance at the low end and Transcend or Signature at the top. Our 2026 market range for capped composite of any brand is $40–$62. Railing, stairs and demolition come on top, and height changes the framing cost.
- What does labor cost to install composite decking?
- Fixr's January 2023 data puts deck labor at about $10–$35 per square foot nationally, depending on material and complexity. Composite usually sits mid-range: boards cut cleanly, but hidden fasteners, closer joist spacing and picture-frame borders add hours. Most contractors quote labor and material together, so ask for the split if you want to compare.
- How much does it cost to replace a wood deck with composite?
- If the frame is sound and joists are close enough for composite, new boards on the old frame cost much less than a rebuild. If footings are shallow, the ledger lacks flashing or joists are too far apart, you are paying for a new deck plus demolition. Fixr's 2023 national replacement range is $20–$70 per square foot.
- Can you build a composite deck in winter in Boise?
- Yes, with limits. Composite boards install in cold weather, but they move with temperature, so end gaps must follow the manufacturer's chart for the install temperature. Footings are the harder part: concrete needs unfrozen ground and protection from freezing while it cures. December through February is the slowest window.
- Does composite decking need special framing?
- It needs tighter framing than most wood decking. Many lines call for joists at 16 inches on center for straight boards and closer for diagonal patterns, and the exact limit differs between lines. Stair treads often need stringers at 12 inches on center. Always check the specific line's installation guide before framing.
- Is composite decking cheaper than PVC?
- Yes, as a rule. In 2026 market ranges capped composite runs $40–$62 per square foot installed and PVC $55–$78. On a 300-square-foot raised deck that works out to roughly $11,000–$21,000 against $15,000–$26,000. The PVC premium buys lighter all-polymer boards and, on TimberTech's AZEK lines, a limited lifetime product warranty.
Sources
- HomeGuide — Composite decking prices (2026)
- Fixr — Cost to Build a Deck (updated January 2023)
- Remodeling / JLC Cost vs. Value 2025 — Mountain region
- City of Boise — Current codes and design criteria (frost depth, snow load, wind)
- City of Boise — Residential construction permit brochure
- City of Meridian — Residential detached accessory structures handout
- NOAA NCEI U.S. Climate Normals 1991–2020, Boise Air Terminal (USW00024131)
Last reviewed .