electrical outlet insulation

It might not seem significant enough to warrant attention, but the small air gaps around your electrical outlets and boxes are leaking a lot more air than you think. To put things into perspective, a small 1/8-inch gap around six of your outlets equals having a 4-inch hole cut right into your ceiling! In the winter, that’s a lot of lost heat.

To stop the drafty feeling in your home, use these electrical outlet sealing and insulation tips. You’ll be warmer and richer in no time. And your properly insulated outlets and boxes will continue to block airflow and save you money for years to come.

Keep the Air Out with Foam Gaskets

One common method of insulation is to place foam gaskets between the cover plate and the receptacles. This works, but it doesn’t offer the most effective seal. Although improved, cold air will still be able to enter and warm air will still be escaping.

To more permanently and effectively seal your electrical outlets to keep out the draft, you’ll need an afternoon, about $30, and a DIY attitude. In terms of materials, you’ll be using a caulk gun, caulk, and aerosol foam.

This simple and inexpensive investment may be the best home improvement project you take on this year!

Getting Started

The gaps around your wall and ceiling boxes need to be sealed with something called “intumescent” caulk or foam product. It is sometimes known as “fire blocking” caulk or foam. This is because an intumescent caulk or foam will bloat or expand when hot in order to prevent any airflow. Contrarily, a non-intumescent caulk or foam will simply burn when too hot, opening the gap and further feeding the fire!

Ask your local hardware store for their best fire-blocking caulk and foam products. Mention if you’ll mainly be insulating wall or ceiling boxes and they’ll help you with the rest.

Ceiling Boxes

Step-by-Step Ceiling Box Insulation:

  1. Turn off the power
  2. Remove the light fixture
  3. Put down a cloth to protect your floor in case you accidentally drip some foam
  4. Using fire-blocking foam, push the tube into the gap around the electrical box and the ceiling wall
  5. Squeeze the tube and slowly pump out the foam into the gap, filling any space
  6. Let it sit for about 2 hours
  7. Cut off excess foam that is in the way
  8. Reinstall the light fixture

Electrical Box Insulation Seal Wire Intrusions
Source: familyhandyman.com

Flush-Mounted Wall Boxes

There are two main portions to this project. First dealing with the wire intrusions, and secondly the gaps around the wall box itself. Use the following guide to get through the job in a jiffy.

Step-by-Step Wall Box Insulation:

  1. Shine a light into the box to see where the cables enter the box.
  2. If you can’t find the cable entry points, turn off the power and pull the receptacle out far enough until you see them. Now you know where to inject the foam!
  3. Using your fire-blocking foam, first seal the wire intrusions by squeezing a small amount around the box opening. Keywords: small amount!

Ceiling Box-Gaps with Foam
Source: familyhandyman.com

  1. Then finish the job by sealing the gaps around the flush-mounted box using foam or caulk (pictured below).
  2. Let it sit for about 2 hours
  3. Use a serrated knife to cut off the extra and the edges
  4. If you put too much foam around your box and can’t get the cover plate back on, don’t worry, just buy a bigger plate and cover up your mess! It will still function perfectly.

air-seal around flush mounted box
Source: familyhandyman.com

Are your wall boxes recessed and not flush-mounted? It’s time to buy a box extender. 

In order to seal a recessed wall box, you will first need to buy and install a box extender.

How to install a box extender:

  1. Unscrew the switch or receptacle and twist it at an angle
  2. Slide the box extender over the device into the wall box
  3. Remount the device
  4. Straighten it
  5. Tighten the screws

man putting in electrical outlet with draft stopper
Source: familyhandyman.com

After the box extender has been installed, you can now use your intumescent caulk to cover up the gap around it. Squirt the caulk deeply between the box extender and the wall. Smooth the caulk out with a wet finger. This will prevent mess and ensure longevity.

Using these DIY methods, you’ll insulate your home for under $30. Especially as the coldest months approach, homeowners need all the help they can get to protect their family from the discomfort of the cold.

Happy Holidays! Stay warm and safe.


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