How Much Does It Cost to Replace a Deck in Washington?

A national cost guide puts deck replacement cost at $20 to $62 per square foot for a same-size deck. That works out to $6,000 to $18,600 for a 300 square foot deck. The same guide prices the tear-off at $500 to $1,000, with demolition and disposal. Another guide puts the tear-off at $5 to $15 per square foot.

Add the first guide’s tear-off to its replacement range, and a 300 square foot deck comes to $6,500 to $19,600. These are market numbers, not our price list. We are a custom deck builder based in Langley on South Whidbey Island. We price each replacement deck from the real site.

What does each part of a deck replacement cost?

A deck replacement is two jobs. The old deck comes off and gets hauled away. Then a new deck goes up in its place. These are the published national ranges for each piece.

The two tear-off rows come from different guides, and they measure the work in different ways. For new-deck prices by material, see what a new deck costs per square foot.

Should you replace the boards or rebuild the whole deck?

New boards on an old frame only pay off when everything under the boards is sound. The board prices above are market information. The work we do is the full replacement deck.

Pull up a board or two and look at the frame. A full rebuild is usually the better answer when you find any of these:

• Rot at the ledger. The ledger is the board that fastens the deck to the house. Rot there can let water into the house wall too.
• Soft joist ends. Joists tend to rot at the ends, where they meet the ledger and the beam and water collects.
• Old footings. Footings that have sunk or cracked need to come out.
• Guards that no longer meet code. A low or loose railing on an old deck gets replaced. A new deck gets a railing built to the current code.

Fixing those one part at a time adds up. A national cost guide lists these prices for single parts:

When the ledger and the footings both need work, the repairs are rebuilding the deck one piece at a time. At that point a new frame is the cleaner job.

What makes deck replacement cost more on Whidbey Island?

Salt air. Island County’s deck handout prints the deck section of the 2021 Washington residential code. Within 300 feet of a salt water shoreline, it calls for stainless steel fasteners and connectors. Stainless hardware costs more than standard hardware, so plan for it on a lot near the water.

Railing height. The code calls for guards where a deck surface is more than 30 inches above the grade below. On a bluff or a sloped lot, most of the deck may sit above that line. We build cable railing on view decks.

Wet winters. Water gets behind a deck ledger when the flashing fails. Wet island winters keep that wood damp for months. On an old deck, check the ledger at the house wall first.

A permit. In unincorporated Island County, a deck skips the building permit only if it passes four tests. It is no more than 200 square feet and no more than 30 inches above grade at any point. It is not attached to the house, and it does not serve the required exit door. Most replacement decks miss at least one test, so plan on a permit and confirm it with the county.

Shoreline review. Island County’s shoreline jurisdiction covers lands within 200 feet of the ordinary high-water mark. There, the county generally requires shoreline review for new construction and for exterior changes to existing structures. On a waterfront lot, ask the county early whether your replacement deck needs it.

What does an Island County permit add to a deck replacement?

The county’s fee schedule values a deck or porch at $25 per square foot for the permit. A covered deck or porch is valued at $34 per square foot. That is the county’s permit valuation, not the cost to build the deck. A 300 square foot deck is valued at $7,500, or $10,200 if it is covered.

A 3% technology fee is added to the total permit cost. An after-the-fact permit, for work done without one, costs double the normal fee. Inside Langley or Coupeville, the city or town runs its own permits, so confirm the fees there.

Washington retail sales tax applies to a custom construction contract unless an exemption applies. That rule comes from the state Department of Revenue. Our guide to Island County building permits covers the rest of the process.

Is replacing a deck worth it?

One national cost guide says a new deck returns 50% to 65% of its cost in home value at resale. The rest of the value is a deck you can use without worrying about soft framing.

The material sets how long the new deck lasts. The same guide says cedar decks need replacing after 15 to 20 years. It says composite boards often last 30 years or more, and ipe hardwood decks can last over 50 years.

Composite costs more up front. That guide lists cedar boards at $3 to $7 per square foot and composite boards at $12 to $45. We prefer ironwood (ipe) for its durability and its looks.

What should a deck replacement quote include?

Two quotes for the same deck can cover very different work. Before you compare totals, check that each quote lists these items:

• Tear-off and disposal of the old deck, including any old footings that come out.
• Footings for the new deck: how many, and how deep.
• Ledger and flashing where the deck meets the house.
• Framing: the joists, beams and posts.
• Hardware: stainless steel fasteners and connectors within 300 feet of salt water.
• Decking: the board material, and its price per square foot.
• Guards and stairs, built to the current code.
• Permit: who applies, and whether the county fees are in the price.
• Sales tax, shown on its own line.

Ready to replace a deck on Whidbey Island?

The prices above are market numbers, not our price list. Your number depends on the size and height of the deck, the railing and what the tear-off finds. We give free estimates, so call or text (360) 544-9027. See how we build replacement decks on Whidbey Island, from ironwood decking to cable railing on a view deck.