Start where the deck meets the house
The ledger is the board bolted to your house that the deck joists hang from. It is where most of the deck's weight meets the house, and it is the place to look first. The American Wood Council's deck construction guide, DCA 6, sets out how it should be done, and it is a useful yardstick for an older deck.
DCA 6 calls for the ledger to be fastened with half-inch lag screws or bolts with washers, and it prohibits lead anchors. It also prohibits attaching a ledger to brick or stone veneer, hollow masonry, or a cantilevered floor overhang or bay window. If your deck hangs off brick veneer with a handful of nails, that is the single most important thing on this page.
Then look for the lateral connection, a detail many older decks never had. DCA 6 calls for hold-down devices in at least two places, within two feet of the edges of the deck, each rated for at least 1,500 pounds, to keep the deck from pulling away from the house sideways. They are metal brackets tying the deck joists back to the house floor framing.
Look for flashing too. DCA 6 requires corrosion-resistant flashing wherever a ledger meets a wood-framed wall, and says the siding must come off behind the ledger before it goes on. Without flashing, water runs behind the ledger and rots both it and the house framing it is bolted to.
Probe the wood for rot
Rot hides under paint and stain, so test it. The North American Deck and Railing Association's consumer checklist says to probe the ledger, posts and joists: wood that a screwdriver sinks into a quarter to half an inch, or that shows small insect holes, may be rotting. Check these spots:
- The ledger, especially along its top edge and around the fasteners.
- The bottom of each post, where it meets the footing or the ground.
- Joist ends, where water sits longest.
- Stair stringers, the notched boards that hold the steps.
- Any board that feels soft or bouncy underfoot.
A gray, splintery surface on its own is cosmetic. Soft wood in the frame is not. (The screwdriver is also a good excuse to look busy while everyone else sets up the grill.)
Hardware, railings and stairs
Look at every metal connector, hanger and bolt you can see. NADRA advises replacing rusted anchors, especially in the ledger, and says the deck should feel stable without sagging or sway. Stand in the middle and shift your weight side to side; a deck that moves with you is missing bracing or connections.
Then push on the railings, firmly. DCA 6 requires a guard on any deck more than 30 inches above grade, and the residential code sets it at least 36 inches high, with gaps small enough that a 4-inch sphere cannot pass through. Wobbly posts, loose balusters and wide gaps are worth fixing even on a low deck with children around.
Finish with the stairs. Check that each tread is solid, that the stringers are not split or soft where they meet the ground, and that the handrail holds when you lean on it. Stairs take more wear and more water than the rest of the deck, and they are where people tend to carry things.
Warning signs and what they usually mean
| What you find | What it can mean | What to do |
|---|---|---|
| Nails, not bolts, at the ledger | The deck relies on fasteners not made to hold it | Stop heavy use; have it looked at |
| No flashing above the ledger | Water getting behind the ledger | Check the ledger and house framing for rot |
| Screwdriver sinks into posts or joists | Rot in the frame | Replace the affected parts or the deck |
| Rusted hangers or bolts | Weakened connections | Replace the hardware |
| Deck sways when you shift your weight | Missing bracing or loose connections | Add bracing and tighten connections |
| Railing moves when pushed | Loose or undersized guard posts | Re-fasten or rebuild the railing |
Repair, replace or rebuild
If the frame is sound, new boards and railings can give an old deck years more. In North Carolina, replacing the decking, railings, pickets and stair treads of a deck is exempt from a building permit on jobs of $40,000 or less. Repairing the posts, beams, joists or ledger is structural work and needs a permit.
If the ledger or several posts and joists are rotten, rebuilding is usually the better spend. A new deck needs a permit and inspections, and DCA 6 notes it should not be used until the final inspection is approved. In Mecklenburg County, footings have to go at least 12 inches below grade. More on what a new deck involves is on our decks and porches page.
What we'd do this week
Pick a dry afternoon, take a flashlight and a flat screwdriver, and start under the deck at the ledger. Probe the ledger, every post and a few joist ends. Push each railing post. Photograph anything soft, rusty or loose.
If everything is solid, a cleaning and fresh finish may be all it needs. If you find soft wood in the frame or a nailed ledger, keep gatherings off the deck until someone has looked. Small fixes like a loose stair rail fall under our home repairs service, and our guide to remodeling permits in Charlotte explains when deck work needs one.