The ledger board — the most dangerous connection in your house

The ledger board is the horizontal board that attaches the deck to the house. More than 90% of catastrophic deck collapses trace back to ledger failure. We crawl under the deck with a flashlight and inspect:

• Fastener type: code requires 1/2" lag bolts or carriage bolts, not nails. Nails pull out in freeze-thaw cycles. Older decks with nailed ledgers get flagged for reinforcement.
• Spacing: 2 bolts per 16 inches staggered, not a random pattern.
• Flashing: proper metal flashing behind the ledger keeps water out of the house band joist. Missing flashing is the #1 cause of hidden interior rot at the rim.
• Band-joist rot: probed where accessible. Soft wood behind a ledger means the deck's attachment is failing.

Beams, posts, and footings

• Beams: size, span, and condition. A 2-ply 2x8 beam spanning 10 feet is undersized for most deck loads.
• Post-to-beam connection: must be a proper bracket (Simpson PC, AC, or equivalent). "Toe-nailed" posts are a red flag.
• Posts: 6x6 preferred on modern decks; 4x4 acceptable on short-span older decks. Checked for rot at the base, split grain, and plumb.
• Footings: concrete piers extending below the Minnesota frost line (42 inches). Visible pier tops should be at or just above grade, not buried. Precast blocks resting on topsoil are a red flag.

Joists and deck boards

• Joists: properly sized for span, set in joist hangers (not nailed in end-grain), and free from rot.
• Joist hangers: galvanized or stainless; the right model for the joist size; with structural nails (hot-dipped galvanized 1-1/2" joist-hanger nails, not drywall or deck screws).
• Deck boards: proper spacing, no rot, no major cupping, no protruding nails/screws.
• Stair stringers: not notched more than half their depth; proper hanger or ledger attachment to the deck.

Guard rails, handrails, and stairs — the safety fundamentals

• Guard height: 36 inches minimum on residential decks; 42 inches on commercial. Grabbed and pushed — does it feel solid?
• Baluster spacing: must not pass a 4-inch sphere. Children-safety critical.
• Handrail: required on any stair with 4 or more risers; 34–38" above the tread nose; grippable (not a 4x4).
• Stair stringers and treads: uniform rise and run, no more than 3/8" variation between steps.
• Stair landing: required at the top and bottom for any stair over a certain rise — checked per local code.

Balconies and second-story decks

Second-story and cantilevered balconies are higher-stakes versions of the same issues. We pay extra attention to the ledger connection, the interior framing continuity, and any signs of water intrusion at the balcony-to-wall transition (a common Minnesota townhome problem).