Should I repair or replace my old deck?

What's actually broken matters more than how it looks

A deck has three layers: the structure (footings, posts, beams, joists, ledger), the surface (deck boards), and the trim (rails, lattice, fascia, stair treads). They fail in different ways and on different timelines.

Surface failures look bad — gray weathered boards, splinters, popped fasteners, loose stair treads. But cosmetic-and-surface problems on a structurally sound deck are repair territory. Structural failures look fine until they don't, because the joists and posts are hidden under the boards.

When repair is the right call

• Surface boards only. A few cracked or warped deck boards on otherwise solid framing — swap the boards, sand and reseal if it's wood, or upgrade to composite if you want to stop maintaining it. 1–2 day job.
• Rails only. Wobbly or rotted rails on a sound deck — replace the rails (or upgrade to aluminum) without touching the substructure.
• Hardware failure. Rusted or pulled fasteners can usually be replaced with stainless or coated structural screws. Lag bolts at the ledger can be re-driven if the framing they bite into is still healthy.
• Localized damage. One rotted post (often from ground contact with no proper footing) can be replaced without rebuilding the whole deck.

When replacement is the right call

• Rotted joists or ledger. The ledger board attaches the deck to the house. If it's rotted, the deck is one bad storm or one heavy gathering away from coming off the house. This is the most dangerous failure mode and not a repair.
• Rotted posts at the footing. If the wood below ground (or where it touches the concrete pad) is gone, the deck is sitting on what's left of the post. Replacing posts in place requires bracing the entire deck — at that point, full rebuild is often cleaner and not much more.
• No flashing at the ledger. Many older decks were installed without proper flashing between the house siding and the ledger board. Water has been wicking into the house framing for years. Tearing the deck off lets us flash it properly and replace any rotted house framing.
• Bouncy deck. If the deck flexes when you walk on it, the joists are either rotted, undersized for the span, or installed at too-wide a spacing. Repair won't fix a span problem.
• It's not built to current code. Decks built more than 15 years ago often don't meet current spans, footing, or rail-height code. Major repairs trigger inspection, and an inspector may require code upgrades on neighboring structure — at which point rebuild is simpler.

The math: when does replacement actually win?

The repair-vs-replace tradeoff comes down to scope. A simple rule of thumb:

• Up to ~25% of structural framing rotted: repair is usually cheaper.
• 25–50% rotted: it depends. Get a quote both ways.
• Over 50%: replace. You're paying for new framing either way; the labor to weave it in alongside old framing often costs more than tearing it all out.

The hidden factor: a repaired deck still has aging framing underneath. The clock is still ticking on the parts you didn't replace. A new deck resets that clock for 20+ years.

What we look at on a free estimate

• Ledger board condition (water test + visual).
• Joist condition (probe with a screwdriver every few feet).
• Post bases at ground contact.
• Stairs and rails for wobble.
• Flashing — or absence of it — at the house connection.
• Whether the existing layout / size still works for how you use the space.

We'll quote both options if both are honestly on the table — and we'll tell you straight if only one of them makes sense.