Fix popped deck nails that keep working up

Why deck nails work their way up

Each deck board is held down by nails driven through it into a joist, the long framing board underneath. A smooth nail holds only by friction against the wood fibers. Wood swells when it soaks up rain or dew and shrinks as it dries out. This Old House points to that seasonal movement, plus foot traffic and short or badly driven nails, as the usual causes of popped nails. Each cycle can lift a nail a tiny bit and widen its hole. Over a few years the head ends up above the board.

A screw works differently. Its threads bite into the joist, so swelling and shrinking don't pull it loose as easily. That is why a screw is the usual long-term fix. The treated wood council's installation tips say screws are more secure and don't pop out of the wood like nails do. Pressure-treated wood also contains copper, which can corrode plain steel. So the replacement screw needs a coating or metal made for treated lumber, like hot-dip galvanized or stainless steel.

Why a deck nail pops up

Let's fix it

1. Mark the nails and check the woodWalk the whole deck in daylight, slowly, in shoes. Put a strip of painter's tape beside every raised head. Look at each board around the nail. A healthy board is flat, firm and doesn't rock when you step on it. Now press the tip of a flathead screwdriver into the wood near the nail. Firm wood resists, and the tip only dents it. If the tip sinks in easily or the wood crumbles, the board is rotting. Stop and replace that board instead of refastening it. Also look under the deck if you can reach. A joist that is soft, split or sagging is a job for a deck builder. If the wood is sound everywhere, go to Step 2.
   Done

   Something went wrong?

   • The whole board is cupped or rocks Refastening may flatten a mildly cupped board. If it's split, soft or badly warped, replace the board instead.

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2. Set the nail with a hammer and nail setThis is the quick fix, and it costs nothing if you own the tools. Put on safety glasses. Choose a nail set with a tip a little smaller than the nail head. Hold the set straight up and down, centered on the head. Tap the set with a claw hammer, using short, controlled strokes from the wrist. Don't hit the nail with the hammer alone, because a miss dents the board. Stop when the head is just below the wood, about 1/16 inch down. Check it by sliding your palm over the spot; you shouldn't feel the head. A reset nail often pops again within a season or two. If it does, go to Step 3.
   Done

   Something went wrong?

   • The nail bends or won't go down Stop tapping. A bent nail won't seat. Pull it out as in Step 3 and replace it with a screw.
   • The nail just spins and sinks with no resistance The hole is worn out. Pull the nail and put a screw beside the old hole.

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3. Pull the nail over a scrap blockPut on safety glasses and gloves. If the head sits above the wood, slip the claw of a hammer or a flat pry bar under it. If the head is flush, tap a cat's paw under the head first. Set a scrap block of wood beside the nail, then rest the tool on the block. The block spreads the force so the bar doesn't crush the deck board. Rock the handle back slowly to lift the nail. Move to a taller block as the nail rises, so it pulls straight. Keep your face out of line with the nail. If the head snaps off, leave the stub, set it below the surface with your nail set, and drive the new screw beside it. Our guide to pulling a stuck nail has more tricks.
   Done

   Something went wrong?

   • The pry bar is denting the board Use a wider or thicker scrap block, and lift in smaller moves.

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4. Pick a deck screw that fits the woodMeasure a pulled nail. Buy exterior deck screws a little longer than it, so the threads reach deeper into the joist. This Old House suggests a 3-inch deck screw for this repair. Don't use drywall screws, which are brittle and rust outdoors. Check what your deck is made of. Pressure-treated lumber corrodes plain steel. The treated wood council recommends hot-dip galvanized fasteners meeting ASTM A153, or stainless steel. It says to avoid electro-galvanized fasteners. Near salt water or a pool, choose stainless steel; Type 316 is suggested for salt exposure. Many coated deck screws say on the box which treated lumber they suit. If the box doesn't say so, pick another brand. Buy a box of 50 or more.
   Done

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5. Pre-drill and drive the screwChoose the spot. You can reuse the old hole if it's tight, but a spot about 1/2 inch beside it bites fresh wood. Stay over the joist; the old nail line shows where it is. Near the end of a board, pre-drill first, because a screw there can split the wood. Use a drill bit slightly thinner than the screw's shank, or a counterbore bit made for deck screws. Wear safety glasses. Drive the screw with a drill or impact driver, raising the clutch until it seats, holding it straight. Stop when the head sits flush or just below the surface. Don't sink it deep, which crushes the wood and holds water. If the board pulls down tight and stops moving, it's right.
   Done

   Something went wrong?

   • The board split Back the screw out. Pre-drill a new hole about 1/2 inch away, and drive the screw gently.
   • The screw spins and never tightens It missed the joist or hit soft wood. Move it over and check the joist with a screwdriver.

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6. Fill, seal and check the frameFill any empty nail holes with an exterior wood filler, pressing it in with a putty knife. Let it dry as the label says, then sand it smooth. Brush a wood preservative or deck sealer into fresh holes and bare spots. The treated wood council says to treat drilled holes with a brush-on preservative, since stain alone may not protect them. Oil-based stains and their rags can catch fire on their own. Lay used rags flat outside to dry, or follow the label. While you're out there, bounce gently on the deck and look for sway. A springy floor, a joist pulling away or loose posts mean you should stop and call a pro. When all the heads are flush, you're done.
   Done

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Watch it done

How To Fix Loose Deck Nails...(Deck Nails Keep Popping up? Here's A Quick And Easy Repair!)By The Honest Carpenter on YouTube. Their method may vary a little from ours.

Watch on YouTube

If it comes back

If reset nails keep popping, switch to screws on that board, or on the whole deck over time. Replacing a few per weekend works. Our hammer guide covers using a nail set without denting the surface.

If a board keeps lifting even with screws, it may be cupped, split or soft. See replacing a deck board. Keeping the deck sealed slows the swelling that loosens fasteners; see cleaning and sealing a wood deck.

If the railing moves too, its bolts may have loosened for the same reasons. Fixing a wobbly deck railing walks through it. Sway, sagging or a deck pulling from the house needs a pro.