A deck almost never fails in the middle. The boards stay on the joists and the joists stay on the beam. What lets go is the inboard edge — the frame peels off the house in one piece, toward the door everybody just walked out of. The part that failed is one piece of lumber laid flat against the wall, taking every joist at once, with nothing underneath it.
That board also sits in a slot cut through the siding, on the surface of the house water runs down, and it is the first thing on the job to get covered up. Structure and drainage in the same joint, buried by the time the boards go on.
Half the deck lands on one board
Deck boards span across joists, and each end of a joist carries half of what it spans. So the ledger carries about what the beam out in the yard carries. The difference is what happens next. The beam stands on posts, on footings, on undisturbed soil below the frost line — a straight path to the ground. The ledger has fasteners, in shear, into somebody's floor framing.
Two directions of force act there. Weight is the one people picture. The other is horizontal: a crowd crossing the deck together, or wind on a railing and a privacy screen, pulls the frame away from the wall, and fasteners in shear are not the right tool for a pull.
That is the job of lateral hold-down hardware — tension devices tying deck joists back to the floor framing inside the house, so the deck and the house are joined rather than set alongside one another. It is the detail most often missing on an older deck, and the one people are most surprised by, because fitting it means working from inside: a basement ceiling opened, or drywall cut and patched. If the room below is finished, finding that mid-build is how it becomes a change order rather than a line in the original scope.
Nails and deck screws are not a ledger connection
A nail holds by friction along its shank. Treated lumber arrives wet, dries through its first summer, shrinks, and loosens its grip on everything driven into it. The coated screws sold by the box for deck boards carry no published structural capacity here either.
What belongs there is through-bolts, or structural screws with an evaluation report behind them, in the staggered pattern the prescriptive table in the residential code gives for the span being carried. The table is the answer, not a rule of thumb — spacing tightens as the joist span grows, and the rows have to stay clear of the edges of the ledger and of the framing behind it. Fasteners set by eye are a guess at the one connection in the deck with no second path.
The fastener has to end up in something
This is the part nobody can check afterwards. The target is the rim joist — solid sawn or an engineered rim board — or, on a low deck, the foundation wall with anchors rated for concrete or grouted masonry. Sheathing is not a target. Neither is a hollow block cell. A lag that went through the siding, through the OSB and stopped in the cavity has a head identical to one that landed correctly, and it holds long enough for everyone to walk away. So somebody has to know what is behind that wall before drilling, and the honest way to know is to take a band of siding off and look — at what is there, and at what condition it is in.
The metal matters as much as the pattern. Copper-based preservative in treated lumber corrodes plain steel from the inside of the hole outward, so bolts, washers, hangers and hanger nails are all hot-dip galvanized or stainless — the rule that governs every fastener in the frame, covered alongside the boards in deck materials against Indiana weather. A perfectly bolted ledger with joist hangers fastened by roofing nails is still a failed connection, one hanger at a time.
Flashing is a stack of layers, not a strip of metal
Water running down a wall keeps going until something interrupts it, and a ledger is an interruption. Flashing has to catch what comes from above, carry it over the ledger, and put it back outside the siding below without leaving it anywhere to sit. That runs on the principle a roof runs on: every layer laps over the layer below it, everywhere. Reverse one lap and you have built a funnel aimed into the wall. In order, from the sheathing out:
- Siding comes off in a band wider than the ledger, and the weather-resistive barrier is cut and held back rather than torn away.
- A self-adhered membrane goes onto the sheathing across the whole ledger location and past both ends, so every fastener is driven through something that seals around its shank.
- The ledger is fastened through that membrane into the rim.
- Metal head flashing caps the top edge, with a vertical leg up the wall and an outer edge turned down over the ledger face with a drip, so water leaves instead of tracking back underneath.
- The housewrap laps over that vertical leg. Never under it.
- Siding goes back with a gap above the deck, and the bottom stays open, because a drainage plane has to drain somewhere.
Caulk appears nowhere on that list. A bead of sealant across the top of a ledger is the most common thing we find in place of flashing, and it is worse than none: it holds long enough to hide the joint, lets go at one end, and turns the ledger into a trough with a lid. Sealant closes a gap in a system that works. It is not a system. Metal choice is its own trap — aluminum bends easily and is what gets grabbed off the shelf, and aluminum against treated lumber corrodes for the same reason plain steel does. Copper, stainless, coated steel or a rigid vinyl belong there instead.
What the wall above sends down
How much water reaches the joint is not a constant. If a roof plane dies into the wall over the deck, a whole roof's worth of runoff concentrates in one place and needs a kick-out at the bottom of the step flashing to throw it clear. Downspouts count too — a leader discharging onto the deck or straight at the ledger is where the roof water goes aimed at a joint with bolts through it. Whatever sits in that joint over winter freezes in it, and the repetition is what does the damage, the same mechanism working on exterior mortar and grout.
Three walls that will not take a ledger
Sometimes the correct answer is that the deck does not touch the house.
- Brick and stone veneer. Veneer is a skin hung off the structure with an air gap and weep holes behind it, carrying nothing but itself. Bolting through it hangs load on a non-structural wythe and punches the cavity that keeps the wall dry. On a lot of houses around Fishers, Carmel and Noblesville that one fact decides the build, and a bid quoting a ledger bolted through brick is a bid to stop reading.
- Cantilevered floors. Plenty of houses run the floor past the foundation for a bay or a breakfast nook. That rim is at the unsupported end of joists already working, so hanging a deck on it is an engineering question, not a carpentry one.
- Stucco and EIFS. These have a drainage plane that does not tolerate being punched full of penetrations, and the detail to do it anyway gets drawn before anyone buys lumber.
There is a fourth case, and it is one we find rather than plan for: the rim is already gone. Under an old unflashed ledger a rim joist can be soft straight through and give nothing away from the yard. Where it shows is inside, as a dark band along the top of the foundation wall behind the storage shelves — we have met it from that side starting a basement finishing job, which is one more reason reading a basement for water comes before drawing anything down there. Decks on older Hamilton County houses carry more of it, for the ordinary reason that standards moved and nobody went back.
Free-standing is not the consolation prize
A deck on its own posts and beam along the house side has no ledger, no penetrations through the wall and nothing to flash into the siding. The whole category of failure this post is about does not exist on it.
What it costs is another line of footings, and those reach below the frost line. Central Indiana practice is commonly in the range of 30 to 36 inches, and the depth that governs your deck is the one your local building department gives — that argument, and what heave looks like when it wins, is its own subject.
It has to solve its own bracing, though. An attached deck borrows lateral stability from the house; a free-standing one gets diagonal bracing or moment connections at the posts, or it racks. And standing close to the wall it still wants a gap and flashing at that line, because water comes down siding whether or not there are bolts in it. On a difficult grade, on poor soil, or against any of the three walls above, it is usually the better deck — worth pricing both ways rather than assuming it is the expensive one.
What an old ledger tells you from the yard
Most of the evidence is readable before anything comes apart.
- A gap between the deck boards and the house that opens in winter and closes by summer. Something is moving, at the ledger or at a footing.
- Rust streaks below fastener heads, or a black halo around each one.
- A bead of caulk along the top of the ledger with no metal above it.
- Siding cut tight down onto the boards, so the wall cannot drain.
- Joist hangers with the wrong nails in them, or holes left empty.
- Bounce at the house end rather than out in the middle of the span.
None of it is proof on its own. All of it is reason to pull a board and look, which is the cheapest way of finding out.
All of it is visible for one short stage
A deck is structural work on the exterior, which puts it in front of a building department. Fishers takes residential applications through the city's online portal and says a complete submittal is typically handled in no more than 15 working days; Carmel, Noblesville and Westfield each run their own, so do not assume the process matches. What triggers a permit here is its own post, and covenants about railing style and projection are cheaper to read before the design than after the lumber lands.
For this joint, sequence is the thing. The rim, the fasteners, the hold-downs and every layer of flashing are exposed for one stage of the build and then under deck boards for the life of the structure. Everybody gets one look. Same logic as checking the walls before drywall: a photograph taken before the cover goes on is worth more than any assurance afterwards.
Questions worth asking before anyone bolts anything to your house
- Attached or free-standing, and why that one for this wall?
- What is behind the siding where the ledger lands, and how do you know?
- What fasteners, in what pattern, from which table?
- Are lateral hold-downs included, and where do they land inside the house?
- Describe the flashing, layer by layer, from the sheathing outward.
- When can I see the ledger and flashing, before the boards go down?
Anybody who builds decks properly answers all six without pausing. The broader set of questions applies here too; these are the ones aimed at the joint that fails.
The short version
The ledger has no redundancy, and it sits where the water concentrates. Fastened into a sound rim, tied back with hold-downs, flashed with layers that lap the right way, it outlasts the boards on top of it. Nailed to sheathing under a bead of caulk, it is a countdown nobody is watching.
The rest of the deck is decisions you can revisit — board color, and when the wood is dry enough to stain, can wait. This one cannot. The decks in our gallery look the same from the yard as decks built the other way, which is the whole problem with this part of the trade.
If you have a deck you are unsure about, or a back door and a bare yard, ask for an estimate and we will look at the wall first.
