Seasonal expansion and contraction in decks frequently cause deck nails to work themselves loose. An exposed nail heads is a real eyesore. Even worse, they are an extreme safety hazard!
This article and short video show you the best way to deal with loose nails on your deck or porch. Use the trick below. You’ll not only save money, you’ll also never have to worry about fasteners coming loose again.
Pry Bar (optional)
Why Do Nails Come Loose?
Unfortunately, this problem is so common, In fact, I’m often surprised when I walk onto a nail-fastened deck and don’t find any sticking up!
Fastening deck boards with nails is by far the fastest, easiest, and cheapest way to build decks. Whole boards are attached in less than a minute with a framing nail gun. Generally, the exterior-grade nails used work fine for a good long while.
However, the problem is that nails are only held in by means of friction.
You see, the nail blasts its way into lumber. It squeezes in so tightly that it can’t be pulled back out without a great deal of force. Generally, the lumber drying out over the next few weeks won’t really loosen this hold.
Over the Years
Eventually, though, seasonal changes generate enough force to work some nails loose.
In the low humidity of winter, boards shrink. This causes nail holes to open up. Conversely, in summer, the boards swell with moisture. The wood re-grips the nail and forces it upwards as the board gains thickness. As winter comes back around again, the boards loosen and settle. This leaves the nail head very slightly elevated.
After just a couple years of this, you can often see a nail head “standing proud” by 1/2″!
The effect is especially bad on decks that get bombarded with sunlight during the day. Boards also twist and warp. The grain loosens and cracks. As light, heat, and UV rays work on them continuously, the process accelerates.
(UV in particular is very harmful to nearly every surface of your house. Here’s a pretty interesting article on how even home interiors can suffer sun damage.)
Pretty soon, you have dozens of nails sticking up at various intervals.
These nail heads create tripping hazards for people wearing shoes. But for animals, and people going barefoot (as they often do on decks), they can cause hideous gashes!
The problem definitely requires a solution.
The Fix: Replace Those Nails With Screws
At best, driving the nails back down with a hammer is a temporary solution. Really, it doesn’t do much good. The nail hole has become too big to grip the nail at this point.
Here’s the key:
The best thing to do is just replace the nail with a screw!
Screws don’t rely on friction for their fastening power. Instead, the numerous threads act as little pawls to prevent the fastener from backing out.
Also, screws tend to be significantly wider than nails, because they have a shaft and orbital threads.
These two facts combined make screws the ideal fastener for deck boards.
(In a perfect world, all decks would be originally built with screws. Unfortunately, few deck builders take the time and effort to install them. Few homeowners want to pay the additional cost to build with them. That’s just the reality of construction.)
Step 1: Pull Out the Old Nails
To begin, use a framing hammer to pull the old nail out of the deck. The claws were designed for exactly this!
Careful, don’t use too much force to do this. If the deck is in bad shape, yanking and prying can could damage the surface. Or mar the stain.
Likewise, if the nails themselves are in bad shape, there’s a chance you’ll strip or break the heads in the process.
Use a firm, steady prying motion. If the nail just doesn’t want to come up, switch to a pry bar or crow bar. Also, put a prying block of scrap wood beneath the claws. As a last resort, if the head breaks off, use a “cat’s paw” nail puller.
Throw the old nail away so no one steps on it!
Step 2: Use the Correct Screws
For the replacement, use exterior-grade screws. Choose one that are longer than the original nail. This way, you drive the screw past the nailing depth. It bites into untapped wood deeper in the joist.
To do this, measure the removed nail to see how long it is. Chances are it’ll be in the 2-1/2″ to 3″ range.
Your deck may be topped with 5/4 deck boards (which are 1″ thick). If so, the nails are probably 2-1/2″. Replace them with 3″ screws. In the same vein, if your deck is topped with 2x framing lumber (which is 1-1/2″ thick), use 3-1/2″ screws.
As mentioned above, use only exterior-grade screws as replacements. Preferably, ceramic-coated. Also, if your deck is brownish in color, get brown deck screws. It makes the replacements blend in much better.
Step 3: Drive the Screws
Use an electric drill to drive the screws. Even better, use an impact driver to set the new screws firmly in the deck. Here’s a The Honest Carpenter video on drills vs drivers:
Place the screw point-down in the old nail location. (The existing nail hole actually acts as a guide for the screw, much as a pre-drilled hole would.)
Begin driving the screw. Be aware that it will probably sink very quickly. That’s because it passes through the bored-out hollow where the nail sat. It’ll slow, though, when it hits the bottom of the hole. Continue driving it in from this point.
You feel resistance as the threads bite the joist lumber below. As you’ll see, the head sinks slightly into the board surface. That’s it, the screw is set.!
If it keeps spinning, the hole is compromised.
If so, drill a new hole right beside it. Use a drill bit that is only about the width of the screw shaft (not the threads). Drive the screw into this hole. No matter what, use screws as a you replacement fasteners.
Loose Nails Wrap-Up:
Repeat this process anywhere that you find nail heads sticking up. This includes on railings and stairs! Nails pop up everywhere, and most every part of your deck is probably built with nails.
Also, if your deck is stained, dab the screw head with a drop of matching stain. This really helps the screw blend in with its surroundings, making it far less obvious.
If a particular deck board is in very bad shape overall, replace it. The process really isn’t all that difficult. Check out this post or video to see how it’s done:
How to Replace Deck Boards (video)
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