The Most Common Deck Repairs (and When to DIY)

Most deck problems are predictable and repairable before they become structural failures. Catching them early costs a few hundred dollars; missing them can cost thousands in framing replacement.

Loose or springy decking boards

Boards bounce underfoot when the fasteners have backed out or the wood has shrunk away from the screw head. Drive new screws an inch from the original holes; if the joist wood itself is punky (soft when probed with a knife), the joist needs sistering or replacement.

Rotted posts and footings

Post rot almost always starts at the bottom — at the post base connector, where water pools. Probe the post base with a screwdriver: if the wood is soft or hollow, the post is compromised. Short posts can be replaced by jacking the beam; tall posts in inaccessible locations may need a structural engineer to assess the repair scope.

Corroded fasteners

Green staining on decking boards under existing screws means the fasteners are corroding and leaching iron into the wood. Replace corroded screws with stainless steel or hot-dip galvanized screws rated for the preservative treatment used in your lumber. Check joist hanger nails and post base bolts too.

Failed ledger connections

The ledger is the highest-consequence connection on a deck. Signs of failure include the deck pulling away from the house, a gap opening at the ledger-to-house interface, or the deck feeling loose laterally. Do not attempt this repair without determining whether the original ledger attachment meets current code requirements. A failed ledger is the number-one cause of deck collapses.

Railing wobble

Railing posts must be tested to resist 200 pounds of lateral force at the top rail. A wobbly post is a life-safety issue, not just a cosmetic one. Most railing post failures trace back to inadequate fastening at the base — surface-mounted post bases without blocking, or toe-nailed posts. Rebuild the connection with proper through-bolts and blocking between joists.

When to call a structural engineer

Call a professional for: any rot in the ledger or main beam; multiple failed post bases; a deck that has shifted, settled or separated from the house; any repair that requires removing a load-bearing element. A deck inspection from a licensed contractor runs $150–$300 and can catch problems a homeowner would miss.