A deck repair in Seattle starts at $199, and a new deck starts at $18 per square foot in wood or $28 per square foot in composite, installed. Across the city, Angi’s Seattle cost data puts the average deck repair at $3,248 and the average new deck at $10,133. Where your project lands depends on size, height, material and what is under the boards.
This guide breaks down every cost line for 2026: repairs, replacement, new decks by size and material, railing, stairs, staining, permits and sales tax. New projects get up to 25% off, and the free on-site estimate puts your exact price in writing before any work starts. Call (206) 202-8768 to book it.
| Project | Starting price | What moves the price |
|---|---|---|
| Deck repair | From $199 | What failed and how far the water got |
| Board replacement | From $125 per board | Board size and matching the existing deck |
| New wood or cedar deck | From $18 per sq ft | Size, height, footings, stairs and railing |
| New composite or PVC deck | From $28 per sq ft | Product line, color and framing |
| Ipe hardwood deck | From $50 per sq ft | Supply, pre-drilling and hardware |
| Old deck tear-out | From $3 per sq ft | Size, height and haul-away |
| Railing | From $20 per linear ft | Wood, metal, cable or glass |
| Stairs | From $25 per step | Number of steps, landings and handrails |
| Staining and sealing | From $1 per sq ft | Deck size, condition and prep |
| Deck restoration | From $600 | Cleaning, repairs and refinishing |
| Deck inspection | Free | Included with every estimate |
Deck Repair Cost in Seattle
Deck repairs in Seattle start at $199 for a single fix, such as a loose board, popped fasteners or a wobbly handrail. Angi’s Seattle data shows most repair jobs between $1,276 and $5,231, with small fixes from about $400 and major structural work up to about $12,000.
Common repairs and where they start:
- Damaged or split deck boards: from $125 per board.
- Loose or rotted stair treads: from $25 per step.
- Wobbly or broken railing: from $20 per linear foot.
- Mold and early rot: about $200–$500, and mildew cleanup about $50–$110, by Angi’s estimate.
- Popped nails and screws: about $0.30 per square foot, by Angi’s estimate.
Rotted deck repair is the most common call in Seattle’s wet climate. Rot on a few surface boards is a small job. Rot that reaches the joists, beams, posts or the ledger board where the deck attaches to the house is structural work, so the price follows the damage, not the board count. See our deck repair service for what each repair covers.
Decks built over a living space, a garage or a roof also have a waterproof layer under the surface. When one leaks, the repair covers the membrane, flashing and drainage along with any damaged framing, so it is priced after the inspection. Our rooftop deck page explains how those decks are built.
Repair or Replace? The Question That Changes the Price
Many Seattle homeowners call about a repair and find out the deck needs a new surface or a new frame. New boards on a rotted frame look fine for a season and then fail again, which is why the inspection matters more than the first number you hear. See our guide to repairing or replacing a rotted deck for what each warning sign means.
Signs a repair will not hold:
- Soft or spongy spots in several places, not just one board.
- Rot, cracks or dark staining on posts, joists or the ledger board.
- The deck moves or sways when you walk across it.
- Railings still wobble after the screws are tightened.
- A wood deck near the end of its 15–25 year life that has been patched before.
When the frame is sound, replacing only the boards and railing costs far less than a rebuild. When it is not, deck replacement starts at $18 per square foot in wood and $28 in composite, plus tear-out from $3 per square foot. The free deck inspection that comes with every estimate tells you which one you need.
Deck Replacement Cost in Seattle
Replacing a deck means taking the old one out and building new, usually with new framing and often new footings. Replacement starts at $18 per square foot for wood or cedar and $28 per square foot for composite, and tearing out the old deck starts at $3 per square foot. Angi lists demolition alone at $5 to $15 per square foot in Seattle.
Example: a 12×16 deck is 192 square feet. Rebuilt in wood it starts at about $3,460, in composite at about $5,380, plus about $580 to remove the old deck. Height, stairs, railing and access change the total, and the written estimate shows each line.
New Deck Cost by Size
Size drives most of the price of a new deck. The table shows starting prices at our base rates next to the range Angi reports for Seattle.
| Deck size | Area | Wood, from | Composite, from | Typical Seattle range (Angi) |
|---|---|---|---|---|
| 10x10 ft | 100 sq ft | $1,800 | $2,800 | $4,920–$7,380 |
| 12x12 ft | 144 sq ft | $2,592 | $4,032 | $7,085–$10,627 |
| 12x16 ft | 192 sq ft | $3,456 | $5,376 | $6,642–$13,284 |
| 12x20 ft | 240 sq ft | $4,320 | $6,720 | $11,808–$17,712 |
| 14x20 ft | 280 sq ft | $5,040 | $7,840 | $13,776–$20,664 |
| 16x20 ft | 320 sq ft | $5,760 | $8,960 | $15,744–$23,616 |
| 20x20 ft | 400 sq ft | $7,200 | $11,200 | $19,680–$29,520 |
Starting prices are for a ground-level deck with a simple layout. A raised or second-story deck needs taller posts, bigger beams and a guardrail, so it costs more per square foot than the same size near the ground. See deck installation for what a new build includes.
New Deck Cost by Material
Material changes the price per square foot and how much upkeep the deck needs afterward.
| Material | Installed, from | Good to know |
|---|---|---|
| Pressure-treated wood | $18 per sq ft | Lowest upfront cost; needs regular stain or sealer |
| Western red cedar | $18 per sq ft | Natural look; plan on a fresh coat every 2–3 years |
| Composite (Trex Enhance, TimberTech) | $28 per sq ft | No staining; occasional cleaning |
| Trex Transcend | $35 per sq ft | Premium Trex line with deeper grain |
| PVC | $28 per sq ft | No wood core; often chosen for rooftops and damp sites |
| Ipe hardwood | $50 per sq ft | Very dense tropical hardwood with a long service life |
Composite and PVC boards still sit on a wood frame, so footings, framing and labor are part of every quote whatever surface you pick. Compare the options on our cedar, composite, Trex, TimberTech, PVC and Ipe pages, or read which decking material holds up best in Seattle rain.
Railing and Stair Costs
Railing starts at $20 per linear foot. For reference, Angi’s Seattle figures by type are $59–$88 per linear foot for wood, $80–$124 for metal, $117–$241 for composite, $168–$256 for cable and $205–$307 for glass. The height and spacing rules a railing has to meet are in our deck railing code guide.
Stair repairs start at $25 per step and new deck stairs at $31 per step; Angi lists Seattle staircases at $31 to $62 per stair. Under the residential building code, a deck more than 30 inches above the ground needs a guardrail and stairs with four or more risers need a handrail, so both show up in most raised-deck quotes.
Staining, Sealing and Restoration Costs
Upkeep costs far less than repair. Deck staining starts at $1 per square foot, re-staining at $0.50 and sealing at $0.75. Cleaning starts at $100, refinishing at $2.20 per square foot, and a full restoration, with cleaning, repairs and a new finish, starts at $600. Angi puts professional staining in Seattle at $805 to $1,829 on average.
With Seattle rain, most wood decks need a fresh coat every two to three years. Skipping it is how surface wear turns into rot. See deck staining, deck refinishing and deck restoration for what each service includes.
Permits, Sales Tax and Other Seattle Costs
- Permits: Seattle requires a permit for a deck more than 18 inches above the ground, a roof deck or a deck in an environmentally critical area. Most decks need only a subject-to-field-inspection permit. A deck more than 8 feet above the ground, over 750 square feet, with beams 14 feet or longer, or on a roof needs a full addition or alteration permit. The fee depends on the project; see SDCI deck guidance and our Seattle deck permit guide.
- Sales tax: in Washington, sales tax applies to residential construction labor as well as materials, and Seattle’s combined rate is a little over 10%.
- Height and access: second-story decks, steep lots and narrow side yards need taller posts, more framing and more labor.
- Framing labor: Angi lists Seattle framing labor at $11 to $15 per square foot, which is why keeping a sound frame saves money.
How to Keep Your Deck Cost Down
- Fix small problems early. A $199 repair this fall costs less than a frame repair after another wet winter.
- Keep a sound frame. Replacing only the boards and railing avoids the cost of new framing and footings.
- Choose the size you will use. Every square foot adds to the total.
- Ask about current offers. New projects get up to 25% off.
- Spread the cost. Ask about financing.
- Start with the free inspection. You get a written price before you buy anything.
Frequently Asked Questions
How much does it cost to build a deck in Seattle?
New decks start at $18 per square foot in wood and $28 in composite, installed, so a 12×12 deck starts at about $2,600 in wood. Angi’s Seattle data puts the average new deck at $10,133, with most projects between $5,272 and $14,994.
How much does a 1,000 sq ft deck cost in Seattle?
A 1,000 sq ft deck in Seattle starts at about $18,000 in pressure-treated wood or $28,000 in composite, installed, at our starting rates of $18 and $28 per square foot. Railing (from $20 per linear foot), stairs (from $31 per step), height and the permit add to that, and the written estimate lists each line.
How much does deck repair cost in Seattle?
Repairs start at $199 for a single fix. Angi reports an average of $3,248 in Seattle, with most jobs between $1,276 and $5,231. Rot in the frame or ledger costs more than work on the surface boards.
Is it cheaper to repair or replace a deck?
Repair is cheaper when the frame is sound and the damage is limited to boards, railing or stairs. When posts, joists or the ledger are rotted, a replacement usually costs less over time than repeated patches. The free inspection tells you which applies.
How much does a composite deck cost in Seattle?
Composite decks start at $28 per square foot installed for lines such as Trex Enhance and TimberTech, and Trex Transcend starts at $35. A 12×16 composite deck starts at about $5,380 before railing and stairs.
Do I need a permit for a deck in Seattle?
Yes, if the deck is more than 18 inches above the ground, on a roof or in an environmentally critical area. Larger or taller decks need a full addition or alteration permit. Check SDCI deck guidance for your site; the written estimate states who handles the permit. How many deck permits Seattle issues each year, by neighborhood, is in our Seattle deck permit data.
Get Your Free Seattle Deck Estimate
Call with the size of your deck, what is wrong with it now and the material you have in mind. We inspect the deck and frame on site for free and give you a written price before any work starts. New projects get up to 25% off. Start with a call to our Seattle deck builders.