Tuesday, September 14, 2010

Low Tech, High Results - Sealing and Insulating Electrical Outlets

There is one simple upgrade that almost every house will benefit from.  You’ll have greater comfort, less drafts, and see energy savings in summer and winter.

What is this simple, low tech upgrade?  It is electrical outlet insulation pads (aka wall-plate insulation, or foam gaskets).

Decora Outlet Showing Insulation Gap
Decora Leviton Style Outlet
When electricians install power outlets or light switches, they cut a hole in your drywall and leave an area that has no or minimal insulation (see photo at left).  This presents an easy path for outside air to enter your home (aka ‘air infiltration’).

In fact, this gap presents such an easy entry point that in many houses you can literally feel the draft on cool and windy days.  To demonstrate this point, my new construction house in the Arizona desert (not exactly a location known for cold) was actually quite drafty in the winter until I added my wall-plate insulators.

The solution for this is quite simple – purchase a few packages of foam wall-plate and switch-plate insulators (sometimes called ‘foam gaskets’), and install them.

The biggest ‘trick’ to installing these is actually purchasing the correct type/shape in the first place.  the gaskets/insulators are designed to create a tight fit, and made to fit the exact size of the protrusion in the outlet.

Electrical sockets are generally the same in most construction (with some exceptions - especially GFCI outlets).  However, switch plates vary drastically depending on the age of your home.  Recent construction uses ‘decorator’ or ‘decora leviton’ style switches, which are large, flat, rectangular shaped rocker switches or outlets.  The photo above is a Decora style outlet, which is one of those "exceptions" I just mentioned.

Older construction uses much smaller switches that protrude from the wall a half inch or so.   You can either purchase the Gasket Covers by themselves, or part of a kit that includes door sweeps at Amazon.  Note that the kit linked to the left is for the older style outlets and switches.  The best source for Decora Leviton style gasket covers seems to be outletsealers.com.

Decora Outlet With Foam Insulation Gasket
Foam Gasket Placed On Outlet

You can also purchase small packets of insulators from your local hardware store or from a number of online sources.  However, your best bet is online sources, where you can purchase bulk quantities at a discount. 

As an example, you should be able to find 50 foam gaskets for around $18 or less online, but you'd probably pay double that at the home improvement store.   Further, you’ll be more likely to find specialized gaskets to fit those multi-gang switch plates that cover multiple switches. 

It’s difficult to estimate payback on this improvement because air infiltration alone is not enough to calculate energy consumed.   You would need to know how much air infiltration is occurring, the average temperature deviation from your preferred temperature for that air, and then factor how efficient your heating and air conditioning system is in dealing with that air.  So for this one you’ll have to take my word on the value. 

Foam Outlet Gasket Installation

Installation could not be much simpler.  If you’re like me, if you try to estimate the number of outlets and switches you have on outside facing walls, you will definitely underestimate the quantities.   Your best bet is to survey each room and keep a tally.

All it takes is removing the wall plate, inserting the foam (see photo), and then screwing the wall plate back on.  Best practice would be to turn off the breaker prior to performing any action with the wall plate.


  1. This outlet insulation method is a TOTAL failure because, the air is simply displaced and then forced out the sides of the electrical outlet/switch plate or through the plug and small air holes, around the foam. Even if one covers the plug holes, the air is still forced out of the sides of the switch/electrical plate at greater pressure.

    You would think that a country that can send a man to the moon could invent proper insulation for electrical outlets and switch plates. Just why is it that electrical boxes are not automatically insulated at installation? Why does one have to purchase extra things that do not work because of an original design failure?

    Bah—What a lot of work and expense for nothing! :(

  2. Sorry to hear about your bad experience. I can't say I've had the same issues. Perhaps the cutouts in your wall were a bit too wide? Or the outlet recessed too much?

    I know I had a couple of outlets (out of 25+) which I had to caulk around (with the faceplate removed) to make the seal nice.

    Anyway, my main recommendation is to shop around of the outlet insulators/gaskets. It should not be "a lot of expense" if you buy bulk online from the right places. Certainly it can be a lot of expense if you buy those little 10 packs from the home depot or local hardware store.

    Good luck and thanks for leaving your insights.

  3. First of all, let me say, I love this product. I've used these in two residences already and it's unbelievable how much a difference that this item makes. The product that I purchased comes in a variety pack of 14 which includes 8 sockets, 4 small switches and 2 designer switches.

    To answer the problem with Unhappy Customer, if you have extra air space around the gasket, use masking tape to tape on the bits and pieces of extra foam from the perforated cutouts that you will surely have. It doesn't matter how pretty or ugly it looks because it will get covered eventually. You can always cut out the excess.

    In fact, I have a lot of the designer light switches in my home. You know, the large vertical rectangular type? I just use one foam insert, of that style and use it as a template to cut my inserts from the small switch inserts. That way, I end up using each and every foam insulation pad available.