Signs it's time to replace
- Soft or spongy spots that a screwdriver sinks into, especially near the house.
- Rot or dark staining at the ledger, joist ends or post bases.
- A deck that sags, bounces or slopes toward the house.
- Railings that move when you lean on them, or guards lower than about 36 in on a raised deck.
- Boards that are cupped, split and splintering faster than you can replace them.
- Rusted hangers, nails pulling out, or posts sitting directly in soil.
If a railing or stair is loose, stay off it and treat it as a repair first.
Resurface or rebuild?
| Resurface | Full rebuild | |
|---|---|---|
| What happens | New decking, fasteners and usually new railings on the existing frame | Tear out to the footings; new posts, beams, joists, ledger and surface |
| When it fits | Joists, beams, posts, footings and ledger test sound | Rot in the framing or ledger, moved footings, or a layout you want to change |
| Watch for | Composite often needs closer joist spacing than old wood decking | Permit, plans and possibly engineering on raised or hillside decks |
| Cost | Less than new; demolition is limited to the surface | New-build cost plus $5–$15+ per sq ft demolition (Angi) |
Inspect the framing and the ledger first
The ledger is the board bolted to the house that carries one side of the deck. Without flashing above it, water runs behind it and rots both the ledger and the house framing. A good builder pulls a few boards near the house, probes the ledger and joist ends, and checks how the ledger is fastened before quoting a resurface.
Permits for a replacement deck
Walnut Creek only exempts decks of 200 sq ft or less, no more than 30 in above grade, not attached to the dwelling and not serving the required exit door (City of Walnut Creek). Most replacement decks exceed at least one of those limits, so plan on a permit. Lafayette, Moraga, Alamo, Blackhawk and Diablo go through Contra Costa County inspections; Danville runs its own. Deck permit rules by city.
Fire-zone materials near the house
If your home is in a mapped fire hazard severity zone, ask whether the new deck surface within 10 ft of the house has to meet California's ignition-resistant requirements. State rules were written for new buildings, but local amendments and the scope of your project can change that. What the fire rules say.
Demolition, disposal and timeline
Tear-out of a typical deck takes a day or two; old redwood and treated lumber go to disposal or recycling depending on what it is. A straightforward replacement can be framed and decked within a couple of weeks once the permit is issued; hillside rebuilds and engineered decks take longer, and permit review often sets the start date.
What it costs
Angi puts deck replacement at about $8,000 on average, typically $4,500–$18,000+, with demolition at $5–$15+ per square foot (Angi). Composite, height and Bay Area labor push local quotes higher. Full breakdown in the deck cost guide; considering a switch to composite? See composite decks.