12x12 Deck Cost (2026): $11,589 to $17,829, Itemized
Building a 12x12 pressure-treated deck about 3 feet off grade costs about $11,589 to $17,829. A 144-square-foot pressure-treated deck off a back slider, about 3 feet up: footings, framing, decking, railing and one stair, itemized with crew hours.
Describe it
Every line, by trade
The 12x12 deck in the Clamp app: described in plain words, then the estimate at $8,914.50 job cost, every line grouped by trade. Sample data. Illustration of the Clamp app.
The job at a glance
One build, fully itemized, with crew hours.
| Build | Job cost | Labor | Crew hours | Materials | Illustrative selling price |
|---|---|---|---|---|---|
| A. 12x12 pressure-treated deck | $8,915 | $4,025 | 49 to 70 h | $3,494 | $11,589 to $17,829 |
Dump fees and other costs ($1,396) are the same in every build and included in the job cost. Materials include allowances. Illustrative selling price is the job cost at a 30% to 100% markup; your price depends on your own overhead and profit. Labor hours are a planning range and include setup, daily cleanup and material runs; they are never a charge to the customer. Permit and inspection fees are not included; requirements vary by jurisdiction.
Which price is closer to yours?
- Lean, +30%: A handyman or owner-operator who does the work with a small crew and no office. Usually the lowest quote. The owner handles scheduling, questions and callbacks around the work itself.
- Standard, +50%: A remodeling company with a crew, an office, insurance and someone to answer the phone. Close to the average remodeler's overhead in the National Association of Home Builders cost-of-doing-business survey.
- Full-Service, +100%: A design-build firm with designers, a salesperson and a project manager who runs the job. The extra pays for planning, coordination and one point of contact from design to final inspection.
Higher markup means more business behind the job, not by itself better work, and a lower markup is not by itself a better deal. For contractors: how each markup splits into overhead and profit is in the overhead categories guide.
The build in detail
A. 12x12 pressure-treated deck: $8,915
Four pier footings are poured; a flashed ledger is bolted to the house and 2x8 joists go in at 16 inches; 5/4 pressure-treated decking goes down; a wood railing runs the three open sides and one four-riser stair drops to grade. Labor is $4,025 of the $8,915 job cost, or 45.1%. It is about 49 to 70 hours of work, including setup, daily cleanup and material runs.
Labor cost by trade
Labor only. Materials, allowances and dump fees are in the line items below. Hours are person-hours at typical production from Clamp’s labor hours catalog, as a range: a planning figure, not a schedule and not a charge to the customer.
| Trade | Hours | Labor cost | Lean×1.30 | Standard×1.50 | Full-Service×2.00 |
|---|---|---|---|---|---|
| Carpentry | 42 to 62 h | $4,025 | $5,233 | $6,038 | $8,050 |
| Setup, cleanup and material runs | 3 to 12 h | in the prices | |||
| All labor | 49 to 70 h | $4,025 | $5,233 | $6,038 | $8,050 |
Every line item
Labor $4,025 + materials and allowances $3,494 + dump fees and other $1,396 = $8,915 direct job cost. Hours are person-hours at typical production, on labor rows only, and the direct-cost row adds about 15% for setup, daily cleanup and material runs; an allowance or material row names the labor line that installs it, and a subcontract row has none, because the sub’s price includes their own time. Some labor quantities include a difficulty factor, so they can exceed the measured area; each row’s derivation is in the downloadable data.
| Item | Qty | Unit | Hours | Labor | Material | Line cost |
|---|---|---|---|---|---|---|
| Carpentry | ||||||
| Deck Decking Install Labor | 144 | sf | 7 to 16 h | $936 | $0 | $936 |
| Deck Framing Labor | 144 | sf | 8 to 18 h | $1,044 | $0 | $1,044 |
| Deck Materials AllowanceLabor on: Deck Framing Labor | 144 | sf | $0 | $1,116 | $1,116 | |
| Deck Pier Footing | 4 | ea | $0 | $0 | $1,300 | |
| Deck Railing Install Labor | 44.4 | lf | 11 to 24 h | $1,243 | $0 | $1,243 |
| Deck Railing Materials AllowanceLabor on: Deck Railing Install Labor | 46.62 | lf | $0 | $2,098 | $2,098 | |
| Deck Stair Build (per step) | 4 | ea | 5 to 12 h | $700 | $0 | $700 |
| Deck Stair Materials (per step)Labor on: Deck Stair Build (per step) | 4 | ea | $0 | $220 | $220 | |
| Ledger Flashing Install Labor (per lf) | 12 | lf | 1 to 2 h | $102 | $0 | $102 |
| Ledger Flashing Materials (per lf) | 13.2 | lf | $0 | $60 | $60 | |
| Ledger Area Self-Adhered Membrane Flashing (per lf) | 12 | lf | $0 | $0 | $96 | |
| Carpentry subtotal | 42 to 62 h | $8,915 | ||||
| Carpentry subtotal | 42 to 62 h | $8,915 | ||||
| DIRECT JOB COST | 49 to 70 h | $8,915 | ||||
| DIRECT JOB COST | 49 to 70 h | $8,915 | ||||
Methodology & reproducibility
One reviewed snapshot for this build. The build is frozen from its own estimate run and priced by the published pricer.
Direct cost equals the sum of each row’s rounded quantity × (labor + material + other). Amounts are shown in whole dollars; every column adds to its total.
Scope selection, prose accuracy, arithmetic and provenance mapping reviewed; not independent market-rate verification.
- deck-12x12-pressure-treated/v2: JSON, CSV, field dictionary
Questions
Why is the railing so much of the cost?
A 12x12 deck has 36 feet of open edge plus stair rails, and railing is slow, fussy carpentry. On a small deck the railing can cost more than the decking, which surprises homeowners who price decks by the square foot.
What can push this job higher?
Composite decking, a taller deck that needs bracing and longer posts, a deck more than 30 inches up on more sides, poor soil that needs deeper footings, or a second stair. Each is its own line.
Is the markup on top of this?
Yes. Direct job cost is what the deck costs a contractor to build. The markup table shows what it sells for at illustrative markups of 30% to 100%.
Sources & provenance
- 12x12 pressure-treated deck reviewed snapshot Clamp Research