How Much Does Deck Repair Cost in Seattle? 2026 Price Guide

Updated November 2026 · Written by the Craft Boys crew. We're licensed Washington deck builders (Lic. #HOMERRA771N2) based in Redmond and have built, repaired and restored 300+ decks across Seattle and the Eastside.

Most deck repair calls we get start the same way. Someone steps on a board and it gives a little, or the railing moves when a guest leans on it, or there's a brown stain on the ceiling under the upper deck. The next question is always "how much will this cost?" This guide answers it item by item with 2026 prices for the Seattle area. It covers boards, joists, posts, the ledger, stairs, railings, sealing and waterproof membranes. It also explains when a repair stops making sense and a replacement is the smarter money.

Key takeaways

• Most deck repairs in the Seattle area cost $400–$6,000 in 2026. Cosmetic fixes sit at the low end; structural repairs to joists, posts or the ledger sit at the high end.
• Replacing a few boards usually costs $250–$900. Sistering or replacing a rotted joist runs about $200–$450 per joist once the decking is opened up.
• Ledger repairs are the most expensive common fix ($2,000–$6,500+). The siding, flashing and sometimes the house rim joist have to be dealt with too.
• Waterproofing ranges from $0.75–$4 per sq ft for sealing a wood deck to $12–$25 per sq ft for a walkable vinyl membrane over living space.
• If repairs approach 40–50% of the cost of a new deck, or the framing is 20–25+ years old with no flashing, replacement is usually the better investment.
• In our wet climate the cheapest repair is the one you catch early. A $500 board fix becomes a $5,000 framing job once rot reaches the structure.

In this guide

1. How much does deck repair cost in Seattle in 2026?
2. Deck board repair and resurfacing
3. Joists, beams and posts: structural repair costs
4. Ledger board and flashing repair
5. Railing and stair repair
6. Deck waterproofing cost: sealing vs. membranes
7. Repair or replace? The 50% rule
8. Warning signs you shouldn't wait on
9. Repair costs across Seattle, the Eastside and Snohomish County
10. Do deck repairs need a permit?
11. How to keep repair costs down
12. Deck repair cost FAQ

How much does deck repair cost in Seattle in 2026?

In 2026 most professional deck repairs in Seattle and on the Eastside cost between $400 and $6,000. Swapping a few boards or tightening a railing is a few hundred dollars. Structural work costs more because the decking has to come up first, as with rotted joists, sinking posts or a failing ledger. That work typically runs a few thousand. National cost guides put the average deck repair at about $1,500–$3,200. Seattle-area labor, sales tax and our long wet season push local projects toward the upper half of that range.

Table 1. Typical deck repair costs in the Seattle area (2026, installed, before sales tax)

These are market ranges for a typical ground-level to one-story deck. Second-story decks, steep lots, tight access and hidden damage push prices up. Hidden damage is found once boards come up, and it happens more often than anyone would like. That's why an on-site inspection beats any calculator. Learn more about how we approach deck repair, or see the full picture of new-deck pricing in our Seattle deck cost guide.

Deck board repair and resurfacing

Replacing a handful of cracked, cupped or soft boards costs $250–$900. Most of that is the trip, matching material and careful removal without damaging the boards next to them. If more than about a quarter of the boards are failing but the frame underneath is solid, resurfacing often makes more sense. That means new decking and often new railing on the existing frame, at about $20–$35 per sq ft in wood or $35–$55 in composite.

• Cedar and pressure-treated boards are easy to source; the new boards will look brighter for a season.
• Composite boards need the same brand and color line. Discontinued colors are common after 8–10 years, so sometimes a section or the whole surface gets redone.
• Soft boards are a symptom. If a board is spongy, we always check the joist under it. Replacing the board alone over a rotting joist just hides the problem.

Joists, beams and posts: structural repair costs

Structural repairs cost more because the deck has to be opened up and sometimes temporarily supported. Sistering or replacing a joist typically costs $200–$450 per joist. A new post with a proper footing and metal post base runs $400–$1,200. Beam work is $1,000–$4,000 depending on span and height. Sistering means bolting a new joist alongside the damaged one.

In the Pacific Northwest, rot almost always starts in the same places:

• Tops of joists under board seams, where water sits after every rain. Butyl joist tape prevents this on new work.
• Post bottoms buried in soil or cast into concrete instead of sitting on a raised metal base.
• Joist ends at the rim and around rusted hangers, especially on older decks built with non-galvanized hardware.
• Under planters, hot tubs and doormats, where the wood never dries.

The quick check: push a flat screwdriver into the wood. If it sinks in more than about a quarter inch with hand pressure, the fiber is gone and that member needs repair, not paint.

Ledger board and flashing repair

The ledger is the board that bolts the deck to your house, and it's the single most important connection on an attached deck. Repairing or replacing it with proper flashing typically costs $2,000–$6,500 or more. The price climbs when siding has to come off, when the house's rim joist has rotted too, or when the deck has to be shored up while the ledger is replaced.

Many older decks around Seattle were built with the ledger nailed straight onto the siding and no flashing at all. Water runs down the wall, gets behind the ledger and slowly rots both the deck and the house framing. Signs to look for:

• Water stains, peeling paint or soft siding just below where the deck meets the house.
• A gap opening between the ledger and the wall, or the deck sloping toward the house.
• Nails instead of through-bolts or structural screws holding the ledger.
• Stains or moisture on the basement or garage ceiling behind the deck.

Ledger failure is the most common cause of serious deck collapses, so treat it as a priority, not a someday project.

Railing and stair repair

Railing repairs typically cost $300–$2,000, from re-anchoring a few wobbly posts to rebuilding a run of railing. Full replacement is priced per linear foot. Expect about $20–$60 for wood and $60–$200 for aluminum, plus Seattle-area labor. Stair repairs (new treads, a new stringer or a rebuilt landing) usually run $300–$1,500.

When railings or stairs are rebuilt, they have to meet current code. Guards are required where the deck is more than 30 inches above the ground and must be at least 36 inches high. Openings can't let a 4-inch sphere through, and stair risers can be no taller than 7¾ inches. A railing that moves when you push it is the number one safety problem we see on older decks, so it's usually the first thing we fix. See our railings and stairs service for material options.

Deck waterproofing cost: sealing vs. membranes

"Waterproofing" means two very different jobs, and the price difference is large:

• Sealing a wood deck protects the boards from rain, UV and moss. Water still drains through the gaps. Cost: $0.75–$4 per sq ft, every one to three years in our climate.
• A waterproof walking surface stops water completely, so the space below stays dry. A vinyl membrane does this on a deck over a bedroom, garage or living room, and on roof decks. Cost: about $12–$25 per sq ft installed, more if the old surface has to be torn off or the plywood substrate replaced.
• Under-deck drainage works with an open-board deck. It catches water below the joists and turns the space underneath into a dry patio or storage area. Cost: roughly $10–$25 per sq ft, depending on the system and gutters.

Table 2. Deck waterproofing options and costs (Seattle area, 2026)

The most common leak we're called for isn't the membrane itself. It's the details: where the membrane meets the wall, door thresholds, post penetrations and the drip edge. If your membrane deck leaks, a targeted repair of those spots often costs a fraction of a full replacement. Read more about our deck sealing and waterproofing service, including membranes and under-deck drainage.

Repair or replace? The 50% rule

A good rule of thumb: if the repair estimate reaches 40–50% of the cost of a new deck, replace it. Do the same if the framing is near the end of its life, even when the boards look fine. A new deck in the Seattle area costs about $45–$105 per sq ft installed, depending on material. On a 320 sq ft deck that's roughly $14,000–$34,000. Repairs that creep past $7,000–$10,000 on a 20-year-old frame are rarely good money.

Table 3. Repair, resurface or replace?

Replacement also opens options a repair can't. You can make the deck bigger, add composite or a covered area, or fix stairs that never felt right. Our Redmond deck rebuild and expansion started as a repair inquiry and became a larger, low-maintenance deck for not much more than the patch job would have cost. If you're weighing materials for a rebuild, our guide to composite vs. cedar vs. pressure-treated decking compares them for the Pacific Northwest.

Warning signs you shouldn't wait on

Rain from October to May means small problems grow fast here. Call a professional if you notice any of these:

• A railing or post that moves when you push on it.
• Spongy or bouncy spots when you walk across the deck.
• Posts sitting directly on soil, or cracked and crumbling footings.
• Rusted joist hangers, nails or bolts, often with black stains around them.
• Water stains on the siding below the ledger, or on a ceiling under the deck.
• A deck that slopes toward the house, or a gap opening at the wall.
• Mushrooms, heavy moss or soft wood on the framing underneath.

Repair costs across Seattle, the Eastside and Snohomish County

Deck repair prices are fairly consistent across the Puget Sound region. The labor market is the same from Seattle to Everett. What changes from town to town is access, permitting and the kind of decks people have.

Table 4. What moves repair prices in different parts of the region

Craft Boys is based in Redmond and works across King and Snohomish counties. See all service areas, or ask us if you're not sure we cover your street.

Do deck repairs need a permit?

Like-for-like cosmetic repairs usually don't need a permit. Replacing boards, refinishing and fixing a stair tread fall in this group. Structural work generally does. Examples are replacing the ledger, posts, beams or a large share of the joists, rebuilding stairs or railings, or adding a membrane over living space. In Seattle, decks more than 18 inches above the ground and all roof decks fall under permit rules. Most Eastside cities draw the line at 30 inches, attached decks or decks over 200 sq ft. Our permit table by city has the details. We confirm the requirements for your address during the estimate and handle the paperwork and inspections.

How to keep repair costs down

• Fix it in the dry season, inspect it in the wet one. Fall and winter show where water sits and leaks start. Repairs and sealing can then be scheduled for the first dry stretch.
• Bundle the work. Opening the deck once to fix joists, the ledger flashing and a few boards together costs less than three separate visits.
• Re-seal on schedule. Sealing a wood deck every one to three years costs a few hundred dollars and prevents most board rot.
• Keep the deck clear. Move planters and mats, clean the gaps between boards and keep gutters from dumping water onto the deck.
• Ask for an itemized estimate. You should see exactly what is structural, what is cosmetic and what can wait a season.
• Use financing for bigger jobs. We offer deck financing through GreenSky, so a necessary structural repair doesn't have to wait.

Every Craft Boys repair is backed by our 10-year workmanship warranty. Our crew is in-house, not subcontracted, and you can read what homeowners say about us on our reviews page.

Deck repair cost FAQ