Maintenance & Lifespan

Is Your Deck Safe? 7 Signs It Needs Repair or Replacement

The Peaks & Valleys field teamWritten by the crews and inspectors on the roofs

Guide5 min readLast reviewed August 7, 2026How we research

The short answer

The dangerous failures are the ledger pulling away from the house (the number-one collapse cause), rotten posts at grade, wobble or sway, soft and springy boards, loose railings, and rusted or undersized fasteners. Most of it lives underneath, where our damp does the damage you can't see from the top.

Part of our guide to The PNW Roof Maintenance Calendar: What to Do, When, and What It Buys You.

A deck is the one structure on your house that holds people up in the air, and in the Pacific Northwest the parts that fail are almost never the ones you’re standing on. Our forty inches of annual rain does its damage underneath — in the ledger, the posts, the framing, and the fasteners — where you don’t look until something moves. Here are the seven signs that mean your deck needs a real look before the next gathering.

1. The ledger is pulling away from the house

This is the one that drops decks. The ledger is the board that bolts your deck to the house, and its flashing is what keeps rain from running behind it into the wall. When that flashing is missing or wrong — which it often is on older and DIY decks — water rots the ledger and the house framing it’s attached to, from behind, invisibly. Watch for rust streaks or dark staining where the deck meets the wall, a gap opening between deck and house, or a floor that slopes away from the siding. A failing ledger is the most common cause of deck collapse, and it’s never something we judge from the surface.

2. Rotten posts and footings at grade

The posts carry the whole deck down to the ground, and the ground is exactly where our climate attacks them. Where a post meets soil, concrete, or a footing, moisture wicks in and rots it from the base up — often behind a skin of sound-looking wood. Push on a post low down; if it gives, flakes, or shows soft punky wood at grade, its bearing is compromised. Footings that were undersized or never set below frost line heave and settle, and a post that’s lost its footing is holding the deck up on faith.

3. Wobble, sway, or bounce

Stand on the deck and shift your weight, or have a few people move at once. If it sways side to side or bounces underfoot, the lateral bracing or a key connection is loose. Decks need bracing and proper connectors to resist the horizontal push of people moving on them — that’s what keeps the structure from racking. Sway is not a personality quirk to get used to; it’s a connection working loose, and it’s most dangerous exactly when the deck is full.

4. Soft or springy boards

A board that flexes, feels soft, or gives underfoot is the surface symptom of a deeper problem. Soft decking usually means moisture has already reached the joists and beams beneath it — the framing you can’t see. One spongy board near the house or the stairs is worth pulling up, because the rot that softened it rarely stops at the surface. Filler and paint hide the symptom while the framing underneath keeps going.

5. Loose or low railings

Lean on your railing. If it moves, flexes, or wobbles, it’s a fall waiting to happen — and it’s rarely just a loose screw. The post or its blocking is usually rotting where it meets the frame, so the rail has nothing solid to hold to. Height matters too: a guard has to be tall enough to actually stop a fall, and older decks were often built to a lower standard or have settled below it. Railing height, baluster spacing, and how the posts are anchored are all governed by code that varies by jurisdiction and by how high the deck sits.

6. Rusted, popped, or undersized fasteners

The metal holding your deck together is on a corrosion clock in this climate. Popped nails, rust streaks bleeding down the wood, corroded joist hangers, and bolts weeping orange are all signs the fasteners are failing — and undersized or wrong-for-the-job hardware fails faster. Cheap electro-galvanized fasteners in a wet climate rust out and lose their grip; the connection they were making quietly stops making it. Fasteners are small, but they’re the difference between a frame that’s bolted together and one that’s just leaning on itself.

7. What you can’t see under the boards

Here’s the whole point: everything that actually decides whether your deck is safe lives under the boards. The ledger, the posts, the beams, the joists, the hangers, the footings — the surface you walk on is the last thing to show trouble. That’s why a general home inspector’s glance at the deck surface answers the wrong question, and why we assess the structure in person, photograph what we find, and never call a deck safe or unsafe from a page. In our climate the boards are the report card, but the framing underneath is the test.

What to do about it

If you’re seeing any of these — especially rust streaks at the house, a soft spot, wobble, or a moving rail — keep the load light and get the structure looked at. We repair decks when the damage is contained and rebuild when the framing’s gone, and either way we inspect the parts that fail before we put a number on anything. A documented deck safety assessment puts the ledger, footings, and framing in writing so you know what’s urgent and what can wait. See how we build decks for this weather, and if you’re weighing a repair against a rebuild, what actually drives deck cost here.

Not sure what’s holding your deck up? Book a free inspection — we’ll look at the ledger, posts, and framing in person and give you a straight answer on repair versus replace. See deck repair.

Questions homeowners actually ask

Is a wobbly deck actually dangerous?

It can be. A little wobble often means the lateral bracing or the ledger connection is loose, and those are the parts that give way under a crowd. Wobble is not a cosmetic quirk to live with — it is your deck telling you a connection is working loose. Keep people off it until someone looks at the framing underneath, not just the boards on top.

What is ledger flashing and why does it matter so much?

The ledger is the board that bolts your deck to the house, and its flashing is the metal that keeps rain from running behind it into the wall. When flashing is missing or wrong, water rots the ledger and the house framing it is bolted to — silently, from behind. A failed ledger is the single most common cause of deck collapses, which is why we inspect it in person and never judge it from photos.

How long do decks last in the Pacific Northwest?

It depends far more on how the structure was built and detailed than on the surface boards. A deck with proper footings, a flashed ledger, and corrosion-rated fasteners lasts a long time here; one with a bare ledger and buried posts can be unsafe in a decade. Sun, shade, drainage, and upkeep all swing it. The honest answer is that lifespan is set underneath, where our rain does its work.

How do I know whether to repair the deck or rebuild it?

Repair when the damage is contained — a few soft boards, a loose rail, a re-flashable ledger — and the core structure is sound. Rebuild when the rot has reached the framing broadly, the footings are failing, or the deck was never built to carry the loads it now sees. We inspect the ledger, posts, and beams in person before advising either way, because the parts that decide it are the parts you can't see from the surface.