Summer Deck Safety Inspection Checklist

Why deck inspections matter

The Consumer Product Safety Commission estimates that deck collapses injure over 30,000 people annually in the United States. Most failures stem from deteriorated connections — ledger boards pulling away from the house, corroded joist hangers, or posts rotting at ground level. A 20-minute visual inspection each spring or early summer can catch problems before they become catastrophic. Decks over 10 years old and those built before modern code requirements deserve extra scrutiny.

Structural check: ledger board and connections

• Ledger board — This is the single most critical connection. Check where the deck attaches to the house for any gaps, soft wood, water stains, or missing lag bolts. A ledger that has pulled away even 1/4 inch needs immediate professional attention.
• Joist hangers — Every joist should sit in a galvanized or stainless steel hanger with all nail/screw holes filled. Missing fasteners or rusted-through hangers are common failure points.
• Posts and footings — Push firmly against each post. Any movement indicates a footing problem. Check the base of each post for soft, spongy wood — ground contact is where rot starts.
• Beams — Look underneath for cracks, splits, or sagging between posts. A straight edge laid across the beam reveals deflection.

Surface and railing inspection

• Walk the entire deck surface and note any boards that flex excessively, feel spongy, or have visible rot. Probe suspicious areas with a screwdriver — sound wood resists penetration; rotten wood crumbles.
• Check for popped nails and screws — they are trip hazards and indicate boards are warping or fasteners are corroding.
• Test every railing section by pushing firmly with your hip (roughly 200 lbs of lateral force, the code requirement). Any wobble means the railing needs reinforcement.
• Verify balusters are spaced no more than 4 inches apart (a soda can should not pass through) — this is a code requirement to prevent children from getting stuck.
• Confirm stair railings are secure and stair treads are not cracked or loose.

Fastener and hardware check

• Look for white or orange corrosion on metal connectors — this indicates the galvanizing has failed and the metal is degrading.
• If the deck was built with pressure-treated ACQ lumber (common since 2004), confirm all fasteners are stainless steel or ACQ-rated. Standard galvanized fasteners corrode rapidly in ACQ-treated wood.
• Tighten any loose bolts. Replace any bolt with more than 1/8 inch of visible rust pitting.

When to call a professional

Call a licensed carpenter or structural contractor if you find: ledger board separation, rotted posts or beams, more than 25% of decking boards needing replacement, any railing that fails the push test, or sagging that is visible to the naked eye. A professional structural inspection costs $200–$500 and includes a written report. Deck repair costs vary widely: $500–$2,000 for railing and fastener repairs; $2,000–$8,000 for structural beam or post replacement; full deck replacement runs $15,000–$35,000 depending on size and material.