Exterior Walls

How should a ledgerboard be secured?

The ledgerboard is like a joist attached directly to the house wall. Joists are typically supported on the ledgerboard. Joists may sit on top of the ledger or be secured to it with joist hangers. The ledgerboard may be attached to a wood frame structure by lag bolts into studs or the rim joist every 24 inches. You may also see multiple nails every 16 or 24 inches. For attachment to a concrete or masonry foundation, you may see bolts set into lead plugs, or masonry screws.

The ledgerboards can

become loose over time
be loose as a result of poor original installation
have insufficient fasteners, fasteners that are too short or the wrong type, or rusting fasteners
be attached to a weak material such as a rotting rim joist or stud wall
be attached to foundations which are too weak to support ledger bolts

The ledgerboard itself may crack or rot, causing the fasteners to slip. A loose ledgerboard could cause the deck to collapse. This is a life safety issue.

Check how and where the ledger is attached to the house. Check for signs of the ledger pulling away from the house, or the joists pulling away from the ledger.

Look for rot in the board itself. If possible, probe it with your screwdriver or an awl. The proper ledger construction detail (when installed over a wood frame wall with siding) is to install a flashing that extends up behind the siding and out over the top of the ledger. This detail is often omitted.