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Cold air through electrical outlets

FranchescaS's picture

Last year I purchased a home built in the '70s.  Last winter I noticed that several electrical boxes are loose, and most have cold air leaking through them.  Is there a safe way to make these tighter?  I think that more is required than putting those insulators behind the decorative plates.  Also cold air blows in where pipes enter the house.  

The house is built over a craw space and I wondered whether sealing up the points where wires and pipes enter the house is a good idea or could that cause problems later.

Thanks for your comments.

If you notice problems both (post #194311, reply #1 of 12)

If you notice problems both around electrical outlets and around pipes, I'd say the house is poorly insulated, quite possibly throughout.

Could be a big problem.

Not necessarily. I (post #194311, reply #10 of 12)

Not necessarily. I constructed a house w/ 2x6 and insulated it carefully (although not meticulously). I slept on a mattress on the floor and noticed significant air flow through the outlets. It's important to seal the exterior well and create a good air barrier to limit air flow in and through walls (which I wasn't really aware of at the time I built the house ... in the late 70s).

Poorly sealed maybe, but not necessarily poorly insulated at all.

There ain't NO free lunch. Not no how, not no where!

Greetings, and welcome to BT. (post #194311, reply #2 of 12)

It is always a good idea to seal penetrations at the exterior, to limit entry of air, water, and vermin.  Not a good idea to use spray foam only.  In large gaps you might want to start with spray foam deep in the cavity, but do not let it bleed out thinking that is good (seals it up real good..........not really as all exposed spray foam will deteriorate soon.). 

In gaps of a half to 3/4's inch around whatever penetration you will need to pack it back in with something.........."backer rod"-a foam rope found at masonry supply houses and maybe big box.  Comes in sizes (diameter) from 1/4 up to an inch for sure.  In reality you can use anything to pack the opening- but the beauty of backer rod is it doesn't absorb moisture.  Packing should be back 3/8" from the finished surface.  1/4" is fine too, just harder to control.  This backing will give the caulk something to stop it from filling alot of air space and limit it's adhesion to just the pipe/wire/whatever and surrounding hole.  Caulk holds good to two things, not so good when pulled in another direction.

Then get some polyurethane caulk and carefully place it around the penetration.  Be neat and clean.  Urethane caulk is a nightmare to use and absolutely the best at sealing out water, air, and vermin.  Easily found in white or grey-some other colors available depending on the supplier.

Electrical boxes-as has been said-air coming out of those means air movement in the wall cavities-some of which you are sealing up.  Others you can't see easily-wire bores from the crawl through the plates into the walls for wiring, plumbing perhaps, and in the attic space-the same.  If you could seal all those up, you wouldn't have much air through the walls.  Great idea, not totally possible in many cases.

Seal as many as you can.

Caulk around the electrical boxes to drywall/plaster.  Remove device and caulk holes in the boxes themselves (again, use the good caulk-the other will just dry out and flake away).  BE CAREFULL, cut the power and tape around the device (over the contacts/bare wire)...............Do not fill the box with spray foam. 

The foam plate gaskets will work somewhat and you can use those too.

Finding out why the electric boxes are loose would be a good thing to do.  Probably should use an electrician, one that know what's available to tighten them up.  Some new house only electricians will have you opening the walls to secure the boxes.  Depending on how they were fastened in the first place, there might be other ways to tighten them up.

Best of luck.

A Great Place for Information, Comraderie, and a Sucker Punch.

Remodeling Contractor just outside the Glass City.


We had this same problem (in (post #194311, reply #3 of 12)

We had this same problem (in buckets) in our house built in 1976 (standard wood frame over basement, with fiberglass insulation, that brown sheathing board, and hardboard siding).

When we replaced the siding we added Tyvek.  No/zero/zilch problem with air through the outlets since then.

But over a crawl you first need to work at sealing all the penetrations through the floor and sill area.  This includes pipes, wires, etc.  Spray foam is good for this, or you can use several kinds of putty.  (You will also want to seal similar penetrations through the ceiling from the attic.)

But air will still get into the exterior walls, and so those foam gaskets are more or less worthwhile (unless you're going to rip off the siding and install Tyvek).  Also, with some styles of boxes you can open them up and carefully plug openings in the back of the box with putty and the occasional squirt of spray foam.

Note that if you're getting air blowing out of outlets on interior walls that's a sign that air is getting into that wall big time.  Usually this will be due to pipe/wire penetrations in the crawl/attic, but sometimes it's due to a "drop ceiling" or some such.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

Fix the ceilings first (post #194311, reply #4 of 12)

Franchesca, the above posts are great for fixing your symptom.  The cold air leaking in around your outlets is a symptom of a bigger problem.  The problem is warm air leakage out of the top of your house.

As warm air pushes up and out the top of the house, it sucks cold air in from the bottom of the house. The warm air is the driving force.

So if you want to fix the real problem, with the side benefit of saving energy, you need to air seal the top of the house.

If you simply want the cold air to stop coming in at an outlet or two then go ahead and fill all around the boxes with gun foam.

But keep in mind this will not save energy and will simply move that cold air intake to somewhere else.  Usually to the basement/rimjoist area.  In extreme examples (perhaps like DanH did) if you seal all the walls up without fixing the ceilings, you force all the cold air intake into the basement, and perhaps even back down chimneys for furnaces and water heaters.  This creates an even larger suction in the bottom of the house.

A builder customer of mine (because he wouldn't listen) tried this for 3 winters in a row.  We call this "chasing the leak."  The cold air just moves somewhere else.  The third winter it moved to coming in around the pipes under the kitchen sink.  They froze and burst.  Only THEN did the builder see the light.  There was about 8 square feet of air leakage built in to the attic.

The first question I would ask when getting a call about an existing appliance that suddenly started backdrafting was "Did you just have your house re-sided?"

Please search this site for "Fred Lugano."  He wrote several fantastic articles in the 90's that detail this perfectly.  They are free in the archives here.


P.S. - We weatherized hundreds of houses (with no call backs) and never sealed an outlet, caulked a window, or weatherstripped a door.  Actually, I take that back.  We caulked windows on one house, but that was to keep ladybugs out.

The ceiling could be (post #194311, reply #5 of 12)

The ceiling could be perfectly sealed, and still you could have cold air blowing in the outlets.  It doesn't take much of a breeze outside to create enough pressure differential to blow air in through any hole in the house, no matter where it is.

And no house is perfectly sealed (especially one built prior to about 1985), and perfect sealing is generally unobtainable.  What one has to do is attack as many air leaks as possible, given time, money, and other resources available.  Get the low-hanging fruit first, which is generally things like pipe chases, flu chases, etc.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

You might as well break down and buy the stock as well. (post #194311, reply #6 of 12)

That is, stock in the manufacturer of Great Stuff, I think it is Dupont. I have spent 12 years finding and filling gaps in my 1926 built brick home. I should have bought the gun, instead of fighting with the plastic nozzle that is provided on the cans. If you are diligent, it eventually makes a big difference sealing up all those openings. I must have gone thru several dozen cans by now.

Good luck.

Re: Air leaking out the (post #194311, reply #11 of 12)

Re: Air leaking out the top

What if you have bathroom exhaust fans located at the upper most point in a three story structure?  Talking about a chimney effect.... ouch!  Well, I have that situation.  Does air travel out of the structure through those fan ducts?  If so, how or can you fix it?

The fans generally have a (post #194311, reply #12 of 12)

The fans generally have a damper, with a spring strong enough to prevent a "natural" draft.  If that's your only problem you're in pretty good shape.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

I did all of my boxes after (post #194311, reply #7 of 12)

I did all of my boxes after the fact with a good caulk.  I didn't turn the power off and got zapped more then once when twisting the gun to get to the right spot in the back.  I would suugest you get a short length of plastic tubing and put that on the tip of your caulk tube.  You will be able to get to the back of the box much better that way.  Still will likely need to stick your finger in and smear it around to cover all teh holes.


While you at at it, you might want to think about changing out the outlets themselves especially if they are the butt ugly (IMO) tan ones they used almost exclusively in the 70's because I am sure they are yellow.  New outlets, switches and wal plates will cost you a pittance but will look great.  I also took the time to make sure the outlets/switches were set at the right depth (with washers where necessary) and that they went in plumb.

Also check your return air to see if it is drawing cold air in from outside.  In my area, they simply use the wall cavities for return air chases without any metal ducts.  I found several cold air returns ON INTERIOR WALLS were pulling in air from the outside via plumbing and electrical wire holes above the cold air returns.  2x4 blocking pounded into place above the return and sealed with caulk solved this problem. (if the return doesn't also go to a second floor).  Caution: you might need to get an HVAC guy out to make sure you are still getting enough air to the furnace because they may have set the thing up based on the outside air it was sucking in.

Cold air at the electrical (post #194311, reply #8 of 12)

Cold air at the electrical boxes .... sealing the boxes is addressing the symptom, not the disease.

The likely cause is outside air infiltrating into the walls - which suggests that either the walls are badly in need of caulking & sealing, or that your gas-burning appliances need a LOT more fresh make-up air. Sealing the boxes will ignore the first problem, and make the second much worse.

Or, maybe you're not really feeling cold air coming in - maybe the boxes are just ice cold, and creating their own air currents. If that's the case, the wall really needs more insulation.

A warning note: In the mid-to-late 70's there was a craze about 'sealing buildings to save energy.' This was followed in the 80's by the boom in 'mold remediation' and 'argon testing' businesses. Considering the date of your home, I'd dig a LOT deeper before I was comfortable with any proposed solution.

Our home was built in 1976 -- (post #194311, reply #9 of 12)

Our home was built in 1976 -- standard frame -- drywall, fiberglass, brownboard sheathing, hardboard siding.  It leaked like a sieve, especially the NW corner where the prevailing winter winds would hit.  There wasn't just a draft coming out of the outlets, there was a regular breeze.

But when we resided we installed Tyvek, carefully taped.  After that, no hint of a draft from the outlets.  Our dining room, which had been too cold to inhabit in the winter, became a favorite place to hang out.

What the OP is experiencing is real, and unfortunately fairly "normal" for a home of the era.

Yes, sealing the boxes is just treating a symptom, but reducing the draft out of the outlets WILL improve comfort, and slightly reduce the heating load.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville