Should you repair or replace your deck?
Updated August 2026
← Every repair-or-replace call
Re-board a deck when the posts, joists, and ledger are sound; rebuild it once the framing has rotted or the ledger is pulling away from the house. Fresh decking and railings over good framing run $1,000–5,000 depending on square footage, a fraction of the $5,000–20,000 a full rebuild costs in pressure-treated lumber or composite. This is not a cosmetic distinction. A ledger board that has lost its bolts or rotted behind the flashing is the leading cause of deck collapse, and no quantity of new surface board fixes it. Probe the wood before you price the job.
The short version
Split the deck into two systems and judge them separately. The surface, meaning decking boards, railings, and stair treads, is consumable: it weathers, splinters, and gets replaced every 10–15 years on a deck whose bones are good. The structure, meaning posts, beams, joists, and the ledger bolted to the house, should last as long as the deck itself, and when it fails the whole thing comes out. A screwdriver is the test. Push the blade into the post base at the soil line, into the joist ends near the ledger, and under the stair stringers. If it sinks more than about 1/4 inch, that member is rotten. One soft joist gets sistered for $150–400. Soft posts, a frame that racks, or a ledger with rust-streaked bolts means a rebuild.
Your situation, decided
| Situation | Verdict | Why |
|---|---|---|
| Boards splintered and gray, framing solid | Repair (re-board) | A $1,000–5,000 resurface on a frame with years left |
| One or two soft joists, rest of the frame dry | Repair | Sistering a joist runs $150–400, far below a rebuild |
| Ledger pulling from the house or rusted lag bolts | Rebuild | The top collapse cause; new boards do nothing for it |
| Post bases crumbling at the soil line | Rebuild | The deck has lost its footing and everything above is at risk |
| Railing loose but posts firm | Repair | A $200–600 railing rebuild plus new blocking behind it |
| Past 20 years with repairs every season | Rebuild | Beyond the 15–20 year life of pressure-treated framing |
What each path costs
Repairs typically run $1,000–5,000; a replacement is $5,000–20,000 installed. Deck boards last 10–15 years, pressure-treated framing 15–20, composite surfaces 25 or more. Repair while the frame is sound; rot in the posts, joists, or ledger ends it. Price your own number on the home maintenance cost calculator before you commit either way.
The repair-or-replace call is easy when you know the unit's age and service history. OnOtto keeps both, plus the maintenance that delays this decision for years.
Start your home's service log, freeFrequently asked questions
How do I tell if my deck is unsafe to use?
Four checks find most of it. Push hard on the railing, which should not move more than an inch. Bounce in the middle of the deck, since a springy floor means undersized or rotted joists. Look where the deck meets the house and confirm the ledger is fastened with lag screws or through-bolts, not nails, and flashed above. Probe the post bases at the soil line with a screwdriver. Do this inspection every spring, and stay off any deck that fails the ledger check.
Can I put composite boards over my existing framing?
Only if the framing has another decade in it and the joist spacing suits the product. Composite decking is heavier than wood, and many brands require joists 16 inches on center, or 12 inches for diagonal patterns, so older decks framed at 24 inches need blocking or new joists. Composite also costs $8–15 per square foot installed against $5–9 for pressure-treated. Putting a 25-year surface on 20-year framing throws away most of the upgrade.
Is sealing a deck actually worth the trouble?
It is the cheapest thing that changes the answer to this question. Sealer keeps water out of the end grain and the fastener holes, which is where rot begins, and a $150–400 reseal every 2–3 years routinely doubles the useful life of the boards. What it cannot protect is the part that decides repair versus rebuild: the post bases in the ground and the ledger behind its flashing. Keep to the reseal schedule and inspect the framing on its own.
Is it cheaper to rebuild or repair a 20-year-old deck?
Price the framing, not the boards. Pressure-treated framing lasts 15–20 years, so a 20-year-old deck sits at the end of its structural life even when the surface still looks passable, and $3,000 of new decking over tired joists buys only a few years. If an inspection finds solid posts, dry joists, and a properly flashed ledger, re-boarding at $1,000–5,000 is real value. If two or more framing members probe soft, put the money into the $5,000–20,000 rebuild.