Most decks that fail early fail in five ways: a bad ledger connection to the house, water where it shouldn’t sit, undersized or over-spanned framing, the wrong fasteners, and posts that rot from the base up. Almost all of it starts out of sight, which is why the visible damage is usually the last symptom rather than the first.
Here’s what each failure is, and what a homeowner can notice from above.
The ledger connection
The ledger is the board bolting your deck to the house, and it’s the most serious failure point a deck has, because when a ledger lets go the whole structure goes with it. The mistakes are consistent: fastening into siding rather than the house’s structure, using nails where structural fasteners belong, too few fasteners, or no flashing above the board so water runs behind it for years.
What you might notice from above: a gap opening where the deck meets the house, doors near the deck that suddenly stick, or staining and soft wood on the wall behind. Any of those is a stop-using-it-and-book-an-inspection sign, not a weekend project.
This is also the reason structural deck work is permitted work. Austin exempts only the smallest, lowest, freestanding decks from permitting, those under 200 square feet, no more than 30 inches above grade, unattached to the house, and not serving as an exit path (source: City of Austin, Work Exempt from Building Permits, and the city notes that exempt work still has to meet code. Anything touching a ledger is on the other side of that line.
Water where it shouldn’t sit
Water is the slow one. It doesn’t break a deck; it removes the deck’s ability to resist everything else. It sits in unsealed cut ends, gathers where boards meet posts, wicks up from soil contact, and hides behind unflashed ledgers. Every one of those spots was a detail someone either did or skipped during the build, and in Central Texas the sun-then-rain cycle finds skipped details fast.
From above it reads as dark staining that never dries, spongy spots underfoot, or mushrooms and moss where the deck meets the ground.
Framing that was never sized for the job
Joists spanning further than their size allows, beams undersized for the load, or joists spaced too far apart all produce the same feeling: a deck that bounces. Span requirements come from code tables and depend on species, size, spacing, and load, which is exactly why this post won’t hand you a number; the correct span for your deck is a determination, not a rule of thumb.
From above it’s the trampoline effect: noticeable flex when someone walks past your chair. A little movement is normal. Bounce you can feel across the deck is not.
The wrong fasteners, or the right ones failing
Fasteners are the cheapest part of a deck and a disproportionate share of its failures. Nails where structural screws or bolts belong. Interior-grade hardware rusting outdoors. Galvanic problems where the wrong metal meets treated lumber. Joist hangers installed with the wrong fasteners, or with holes left empty.
From above: screws standing proud of the boards, rust streaks bleeding down the wood, or a railing that wobbles because its connection has been working loose for a decade.
Posts rotting from the bottom
A post sitting directly on soil, or in a footing that holds water like a cup, is a post on a timer. The failure happens at the base where you can’t see it, and by the time it shows above ground the structural cross-section is already compromised.
From above it looks like a deck that’s settled unevenly, a railing that’s gone out of plumb, or stairs that have started to pull away. Poke the base of a post with a screwdriver, gently; if it goes in easily, that’s your answer.
Why professionals check underneath first
Every failure on this list starts somewhere you can’t see from the surface, which is the whole argument for looking underneath before drawing conclusions. It’s also why patching visible damage over an unexamined frame is the most expensive shortcut in the trade: the boards look fine and the problem keeps growing beneath them.
That’s the reasoning behind how we approach deck repair: diagnose the cause first, fix that, then repair what shows. When the picture is unclear or the deck is old enough that nobody’s ever looked, a written condition report settles it properly.
What this post deliberately doesn’t tell you
How to fix any of it. Structural repair on a deck is not a homeowner project, and a blog post that pretends otherwise is doing you harm. Knowing what failure looks like is genuinely useful; performing structural surgery based on a web page is not. If something on this list matches your deck, the right next step is having it looked at.
Frequently asked questions
My deck bounces a bit. Is that dangerous?
Some flex is normal in any wood deck. Bounce that’s noticeable across the whole structure, or that’s gotten worse over time, deserves a look. The change matters more than the sensation.
How often should a deck be inspected?
Once every couple of years is reasonable for an older deck, plus any time something changes: new movement, a soft spot, or a railing that gives. Decks over a decade old that have never been inspected are the ones we’d prioritize.
Can I tell anything from above?
Quite a lot, actually: the signs listed in each section above are all visible from the surface. What you can’t do from above is judge the frame, which is where the answers live.
Does a home inspection cover the deck?
Usually briefly. General home inspections cover everything, which means decks get a fraction of the attention a dedicated deck inspection gives them.
Worried about something on this list?
Schedule a deck estimate or call 737-363-4018, and we’ll come look properly.