Stop cold drafts from outlets and switches

Why outlets and switches let in cold air

A wall on the outside of the house has siding and sheathing on the outside, insulation in the middle and drywall on the inside. The drywall and paint act as part of the air barrier that keeps outdoor air from moving into the room. Every outlet and switch on that wall needs a hole cut in the drywall for its box, and the box itself often has knockouts, gaps where wires enter, and a small gap around its edge. Air that gets into the wall cavity from outside, through gaps in the siding, sheathing or at the top and bottom plates, follows the easiest path out, and those holes are an easy path.

Wind pushes air into the house on one side and pulls it out on the other, and warm air rising in the house pulls cold air in near the floor. That's why low outlets on windy sides feel the coldest. Foam gaskets made to fit behind the cover plate close the plate slots and edges, and caulk closes the gap between the box and drywall. Together they cut down most of the draft you feel. A strong, steady stream of cold air means the wall has a bigger opening or missing insulation, which sealing an outlet won't fully fix.

Why outlets feel drafty

Let's fix it

1. Find the drafty outlets and switchesChoose a cold, windy day. Close windows and doors, and turn on bathroom and kitchen exhaust fans to pull air in from outside, which makes leaks easier to feel. Hold the back of your hand, a damp fingertip or a lit incense stick 2 to 3 inches from each outlet and switch on outside walls. Smoke that wavers or blows sideways, or a cool feeling on your hand, marks a leak. Make a list or put a small piece of painter's tape on each one. Indoor walls rarely leak; start with outside walls and the windy side of the house.
   Done

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2. Turn off the powerFind the breaker for the room in your electrical panel and switch it off. Panel labels can be wrong, so test: plug a lamp into the outlet, or hold a non-contact voltage tester to the outlet slots and switch screws, to confirm there's no power. A switch box can contain wires from more than one circuit, so test each one. You only need to flip the breaker, not open the panel. Keep a flashlight handy if the lights in that room go off too.
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3. Add foam gaskets behind the cover platesUnscrew the cover plate's center screw or screws and take the plate off. Use foam gaskets made for outlets or switches; they come precut, usually in packs of a dozen or more for a few dollars. Press the gasket over the outlet or switch so its cutouts line up with the device, and the outer edge lies flat on the wall. Put the cover plate back on and tighten the screws until snug. Don't overtighten, which cracks plastic plates. If a plate won't sit flat with the gasket, trim the gasket edges with scissors. Switch gaskets and outlet gaskets have different cutouts, so count each type on your list before you buy. If you see a gap around the box, do the next step before putting the gasket and plate on.
   Done

   Something went wrong?

   • The plate won't sit flat The gasket's cutouts may not line up, or the outlet sticks out. Re-seat the gasket, and if the outlet sits proud of the wall, have an electrician adjust it.
   • The cover plate cracked Replace it; plates are inexpensive. Snug the screws only until the plate stops moving.

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4. Seal the gap around the boxWith the plate off, look at the edge where the drywall meets the electrical box. If there's a gap wider than about 1/8 inch, run a thin bead of paintable acrylic latex caulk around the outside of the box, filling the gap between the box and drywall. Keep caulk out of the box and off the outlet or switch. For gaps wider than about 1/4 inch, the drywall may need patching first, or the box may need an extender ring, which an electrician can install. Let the caulk dry for the time on the tube, often 30 minutes to an hour, before putting the plate back on.
   Done

   Something went wrong?

   • The gap is bigger than the cover plate Don't fill it with foam. Patch the drywall around the box first; see the drywall patch guide, or have an electrician fit an extender ring.

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5. Plug unused outletsAir also leaks through the slots of outlets you don't use. Push plastic child-safety plugs into unused outlets on outside walls; they block the slots and keep small fingers out. Some outlet gaskets come with matching plugs. Once everything is sealed, turn the breaker back on and test each outlet with a lamp and each switch with its light. Check again on the next cold, windy day with your hand or the incense stick, since you may find a few outlets you missed. Leave plugs out of outlets you use every day, since you'll just lose them; the gasket behind the plate does most of the work.
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6. Look for bigger leaks if it's still coldIf cold air still pours out, or the wall around the outlet feels icy, the wall has a bigger problem than the outlet. Common culprits are gaps where siding, trim or a window meets the wall, a missing or settled section of insulation, or open framing at the top or bottom of the wall. Check the outside of that wall for gaps around pipes, vents and trim, and seal them with exterior caulk. An energy audit, often subsidized by utility companies, uses a blower door and infrared camera to find leaks and missing insulation precisely. Fixing those outside gaps often does more for comfort than the outlet gaskets alone, because the cold air was getting into the wall there first.
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Watch it done

How to Seal Up Drafty Outlets and Switches | The Fixer ClipsBy The Fixer 2 on YouTube. Their method may vary a little from ours.

Watch on YouTube

If it comes back

Gaskets last for years, but they can get compressed if plates are removed often. Replace them when you change cover plates or paint.

Windows and doors usually leak far more air than outlets. See how to stop drafts around windows and how to weatherstrip an exterior door.

If an outlet is loose in the wall, plugs fall out, or it feels warm, that's a different problem. See how to replace an outlet, or call an electrician.