How do I know if my deck ledger board is failing?

A failing ledger usually announces itself. Look for the deck pulling away from the house, a gap or tilt where the ledger meets the wall, rusted or missing bolts, a ledger held on only with nails, soft or dark wood at the ledger or on the house framing behind it, and no flashing above it. Any one of those is a reason to stay off the deck until a licensed contractor has looked at it.

This matters because the ledger is the connection that holds one whole side of an attached deck. Collapses and failures of decks, porches and balconies account for thousands of injuries each year, according to the Consumer Product Safety Commission.^[1] Fairfax County's building official puts the advice plainly: if you see any issues with the connection points or wood quality, consider staying off your deck until a professional inspects it, repairs it or replaces it.^[1]

What a ledger is and how it should look

On an attached deck, the ledger is a board fastened flat against the house. The deck joists hang from it in metal hangers, and it is fastened through to the house's band board, the framing at the edge of the floor. A sound ledger sits tight to the house, level, with a row of bolts or structural screws, metal flashing above it, and dry, firm wood.

Warning signs you can see from the yard or basement

You do not need tools to spot most of these. Look from the yard, from under the deck where it is safe to stand, and from inside the basement or crawlspace behind the ledger.

The deck is separating from the house. Simpson Strong-Tie, which makes deck connectors, says wobbly railings, loose stairs and ledgers that appear to be pulling away from the home are all causes for concern.^[4] A widening gap at the wall, a ledger tilting outward at the bottom, or a deck that slopes away from the house are the visible forms of it.

Nails where bolts should be. Simpson also says that if you see nails but no screws or connectors, your deck may be unsafe.^[4] A ledger is meant to be fastened with heavy fasteners; Fairfax County's deck details call for ½-inch lag screws or through-bolts, or approved ¼-inch wood screws, at a set spacing.^[2] A ledger held only with nails falls well short of that.

Rust and corrosion. Metal connectors and fasteners can corrode, especially if a product with insufficient corrosion resistance was originally installed.^[5] For decks framed in treated lumber, Fairfax specifies: "Fasteners shall be hot-dipped galvanized, stainless steel or approved for use with preservative-treated lumber."^[2] Orange rust streaks, flaking bolt heads or hangers eaten thin are signs the connection is losing strength.

No flashing, and water marks. Under Fairfax's details, the house siding has to be removed where the ledger goes, and continuous flashing is required at the ledger when it is attached to wood framing.^[2] If there is no metal or plastic flashing over the top of the ledger, or the ledger was fastened straight over siding, water may have been running behind it for years. From the basement, dark staining or soft wood on the band board behind the deck can be a clue.

Rot and splits in the ledger. Deck framing members that have decayed may no longer be able to perform the function for which they were intended,^[5] and large cracks or excessive splitting can weaken deck framing members.^[5] Watch for crumbling wood around the bolts, fungus, or boards that look soaked long after rain.

A ledger attached to the wrong thing. Some attachments are never allowed. Fairfax's details prohibit a ledger fastened through brick or stone veneer, to open-web floor trusses, or to a chimney, an overhang or a bay window: "In such cases, a free-standing deck or engineering design is required."^[2] They also say lead anchors are prohibited.^[2] If your deck hangs on a brick face, have it looked at even if it seems solid.

Why ledgers fail inspection

County inspectors see the same faults again and again. Loudoun County lists among the most common reasons a deck fails inspection that the ledger board is not attached to approved material at the existing house wall, and the ledger attachment does not comply on bolt diameter, spacing, tightening or flashing.^[3] Loudoun also says inspectors may request access to the existing house to verify solid ledger attachment.^[3] The rule behind all of this is simple: "The existing band board shall be capable of supporting the deck."^[2] A deck can only be as strong as the house framing it hangs on.

How often to check

You should evaluate your deck annually, Fairfax's building official says, and have it inspected regularly by a licensed contractor; the older your deck, the more often you should have it inspected.^[1] Simpson Strong-Tie suggests inspecting at least annually, ideally before the seasons when the deck is used most.^[5] For a broader check of the whole deck, see how long a wood deck lasts.

When to call a licensed pro

Call one as soon as you see any of the signs above. Repairing or replacing a ledger means work on the deck's structure and the house framing behind it, and Virginia's building code says a permit is needed for installations or alterations involving any structural component.^[6] A contractor will open up the area, check the band board and decide whether the ledger can be refastened and flashed, must be replaced, or should give way to a free-standing support.

Virginia's Board for Contractors says work valued at $1,000 or more needs a valid Virginia contractor's licence, and that the contractor should apply for and obtain any necessary building permits.^[7] Before you hire, check the contractor's licence. If the deck has to be rebuilt, read what building a deck involves and what it costs.

Find help on Loclis

Loclis lists licensed businesses from Virginia's DPOR register, with each one's licence number and class. Browse deck and porch repair, find exterior contractors in Blacksburg, see more exterior answers, or describe the problem once, with photos of the ledger, and local contractors quote it.