air sealing outlets/switches

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Coal Reaper

Minister of Fire
Aug 10, 2012
783
NJ
i have read through this thread: https://www.hearth.com/talk/threads/air-sealing-satisfaction.104200/
most of the outlet/switch reference seamed to be geared to new construction and what i deduced is that the foam seals under the covers are not worth it? is this true?
my house gets hit with a lot of wind and now that we are heating with wood and keeping the house warmer i can really tell where the air infiltration is. number one is the front door which we are currently saving up to replace. number two seems to be exterior electrical boxes, especialy on the north side of the house that gets hit with the dominant cold wind. is it worth it to try to seal these? if so, what is the preffered method for walls that are sheetrocked already?
house is 2400sqft with vaulted cielings in every room. 2x6 construction of 1989 that i think is insulated well. its just the air leaks that are bothing me. i plan to address better sealing the exterior in a few years when we replace the wood siding.
thanks in advance.
 
For what it's worth, any hardware store will have small foam panels that are designed to seal outlets & switches. They aren't perfect, but they will cut down on SOME of the air flow...
 
For what it's worth, any hardware store will have small foam panels that are designed to seal outlets & switches. They aren't perfect, but they will cut down on SOME of the air flow...
Some, is the key word, they help, they are cheap, but they don't stop everything, because the device itself is not weather tight.
 
New houses now, caulk the gap between the box and the drywall, and seal the box where the wire comes through. There are special boxes also that use a foam seal, but that is for new installs mainly.
 
most of the outlet/switch foam seals under the covers are not worth it? is this true?
Figuring about $.10 and a minute of labor, it dosen't matter. Maybe add $.01 worth of tape over unused outlets. You could just poke through the tape with the plug if needed. Spend $.20 to replace the messed up cover if you ever sell the house.
 
i use them on all walls facing the outdoors - why not given ease and low cost of installing. when you take off an old outlet cover you often see spider webs - a small sign of draft.
 
a google search yielded some hits that suggested fire rated caulk for between the box and the sheetrock and also where the wires come into the box if you want to take the time to remove the outlet/switch and reinstall. says its much better than just the foam under the panel. i guess i will give that a shot.
 
They might help for switches, but I've found that most outlets allow plenty of cold air through the holes for the prongs, so unless you seal those too, you'll still get a draft (assuming the outlet was drafty in the first place). Despite it being listed as an energy-saving myth, I had two huge problem outlets in one room. I sealed the perimeter with caulk, jammed rope caulk to try seal where the wire penetrated, and used the foam too. The result was so dramatic that I had to partially close the central air duct in that room because that room contained the thermostat and the rest of the house was becoming too cold before the thermostat kicked in!

TE
 
Sealing the outlets as suggested is rather useless unless airtight drywall construction techniques were used when building the house which is uncommon in the states.
You can add the foam gaskets but air will still enter through the outlet itself and air not exiting at the outlet box will just exit elsewhere such as where the drywall meets the floor or window and door framing.

Basically you can create air infiltration barriers at the outer shell (eg. Tyvek over sheathing), at the inside (e.g. airtight drywall) or both. In your case, as with most U.S. houses the house was probably built with some attempt to establish an air barrier at the outer shell. Your time is best spent trying to address leakage there.
 
... air not exiting at the outlet box will just exit elsewhere such as where the drywall meets the floor or window and door framing.
Not really true, air will take the path of least resistance, and any reduction in places for air infiltration/exfiltration is still a reduction. For the minimal cost, effort or disruption of a foam pad and some caulk, probably worth the effort if there is a noticeable draft from the outlet, but in most cases will not produce a detectable difference. Mine did, but there were very obvious outer air sealing issues which were the root cause of the problem, and unless I wanted to remove 20ft of siding, wasn't going to be fixed.

TE
 
We have some bad outlets also. I used fire rated caulking to go around the box, but I need to address where the wiring enters the box itself. The gaskets did cut the drafts some, but I also find if the cover doesn't sit flush with the wall the gaskets become useless. After using the gaskets, we still had a bit of air entering the plug-in, and I used cheap child protectors which blocked that air. It's not perfect, but made a difference. The only good thing about this cold is, it's easy to find the leaks in the house.
 
Semipro said:
... air not exiting at the outlet box will just exit elsewhere such as where the drywall meets the floor or window and door framing.

Not really true, air will take the path of least resistance, and any reduction in places for air infiltration/exfiltration is still a reduction. For the minimal cost, effort or disruption of a foam pad and some caulk, probably worth the effort if there is a noticeable draft from the outlet, but in most cases will not produce a detectable difference. Mine did, but there were very obvious outer air sealing issues which were the root cause of the problem, and unless I wanted to remove 20ft of siding, wasn't going to be fixed.

Your efforts are much better spent addressing leaks in the already established outer barrier than trying to create a new one inside when the house wasn't designed for it.
I think of it like blowing air into the small end of a cone (like a megaphone). You could restrict the large opening on the big end of the cone by half and still never see any difference in flow rate though the cone. Restrict the small end though and you'd see a difference.

Many that install these gaskets feel they've improved things. They're typically basing that on that they feel less air coming out around outlet box area. Did they then go and feel around the baseboards and windows to see if flow increased there? Of course not, and they wouldn't be able to feel the difference because those leaks are so large to start with because sealing at the inner wall was never intended.

I really feel this exercise is counterproductive because you're led to believe you've made improvements when you probably haven't.
 
exploring this, what can be done to improve exterior air leaks? wont have funds available to wrap and re-side for a few years...
_1 phota was taken in evening, camera facing NE. cold winds come from the right of picture 1150 (left of _1) from accross the valley.
i understand not to expect vast improvment from sealing electrical boxes, but i dont see how it can hurt.
 

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Many that install these gaskets feel they've improved things. They're typically basing that on that they feel less air coming out around outlet box area. Did they then go and feel around the baseboards and windows to see if flow increased there? Of course not, and they wouldn't be able to feel the difference because those leaks are so large to start with because sealing at the inner wall was never intended.

I really feel this exercise is counterproductive because you're led to believe you've made improvements when you probably haven't.

I don't mean to sound argumentative, I agree with much of what you are saying, (e.g. a gasket alone will do almost nothing, and that exterior sealing is better), but even if the only thing achieved was diverting the same leak to the baseboard, there is a comfort improvement by moving that draft lower and distributing it. As someone else said, it can't hurt, so unless you have a better alternative that takes as little time, money or effort, saying that a much more expensive solution would be better isn't a fair comparison. I've spent a lot of effort on both interior and exterior air sealing over the past few years, and my heating and cooling bills have steadily declined accordingly. My windows and doors remain my biggest source of heat loss, but I'm not going to spend tens of thousands of dollars replacing them with the best possible windows, does that make my other improvements pointless?

TE
 
exploring this, what can be done to improve exterior air leaks? wont have funds available to wrap and re-side for a few years...
_1 phota was taken in evening, camera facing NE. cold winds come from the right of picture 1150 (left of _1) from accross the valley.
i understand not to expect vast improvment from sealing electrical boxes, but i dont see how it can hurt.
No, sealing the boxes won't hurt.
Our house is very similar to yours. I also spent a lot of time at first trying to address air infiltration at the inside.
Then I had an energy survey done with a blower door test and far IR imaging. This was very revealing.
Given your constraints, and my experience with a similar house I think you time would best be spent making sure weatherstripping at doors and windows is tight, sealing around doors and windows with expanding foam by pulling the trim. At our house this space was stuffed with fiberglass which you'll find serves pretty much as a good air filter only. In many cases the door thresholds are not adequately sealed to the floor deck.
I'd also check all mechanical exits for driers, vent hoods, bathroom vents etc. to make sure they're sealing well. Our drier vent was hanging wide open because of lint buildup. Our bathroom vent hoods didn't seal well so I replaced them with better ones. If you have cantilevered overhangs you can pull down the soffit board to make sure air is not entering the space between floors there (very common).
Also, focus on the potential leaks at higher areas since that's where your most likely to have leaks because of the stack effect. This is one place where sealing electrical boxes from the inside will be effective.

Edit: The band joist areas above basement wall is also an area where you may be be able to stop air leaks in the outer shell from the inside. I'm doing that now at our house.
 
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I don't mean to sound argumentative, I agree with much of what you are saying, (e.g. a gasket alone will do almost nothing, and that exterior sealing is better), but even if the only thing achieved was diverting the same leak to the baseboard, there is a comfort improvement by moving that draft lower and distributing it. As someone else said, it can't hurt, so unless you have a better alternative that takes as little time, money or effort, saying that a much more expensive solution would be better isn't a fair comparison. I've spent a lot of effort on both interior and exterior air sealing over the past few years, and my heating and cooling bills have steadily declined accordingly. My windows and doors remain my biggest source of heat loss, but I'm not going to spend tens of thousands of dollars replacing them with the best possible windows, does that make my other improvements pointless?

TE
I understand where you're coming from. Its sounds like you and I are doing a lot of the same things. As said in the post above I've also attacked leakage at the inside but found out I was really wasting my time.
I just don't want anyone to think that sealing an electrical box diminished the overall air entering their house just because they no longer feel the cold air coming through the outlet. Most if not all of that cold air is leaking in elsewhere. If that makes someone feel more comfortable in your house that's great.
I'm just saying that time spent sealing outlets would be better spent addressing that sliver of light you see around a door, the cold dryer vent hose, air leaking under sills, etc.
 
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It depends on the house. Ideally you shouldn't need to do this. But all houses are not made or sealed equally. Our house for example has no sheathing wrap, not even tar paper. It is very susceptible to winds. I have sealed it up a lot, but there are a few places where the outlet gaskets help. The house now also has a very thick coat of high quality paint on it that is helping seal up the clapboards.
 
We had air that could be felt from 4 to 5 feet away from some outlets. Especially here recently when we had -50 windchills. Stopping those leaks improves some comfort, but I will agree it won't fix the overall problem. For us to fix the problem in our kitchen, it will have to be gutted and remodeled. It was just gutted 12 or 13 years ago, insulated, vapor barrier and drywall. Unfortunately, it's the coldest room in the house. The walls weren't airsealed before insulating, so the insulation is useless. We have Dutchlap siding, then tar paper, then asbestos shingle. Every single gap in the Dutchlap under everything leaks air, making sealing the house almost impossible. I found duct mastic to work well and seal these gaps effectively, and quickly. This summer, the exterior will be caulked, about 42 windows will get recaulked and sealed outside, then the house will get painted. I'm hoping all the exterior work will make a significant difference.
 
Not really true, air will take the path of least resistance, and any reduction in places for air infiltration/exfiltration is still a reduction. For the minimal cost, effort or disruption of a foam pad and some caulk, probably worth the effort if there is a noticeable draft from the outlet, but in most cases will not produce a detectable difference. Mine did, but there were very obvious outer air sealing issues which were the root cause of the problem, and unless I wanted to remove 20ft of siding, wasn't going to be fixed.

TE

Nothing either of you said was incorrect. Air sealing from the outside is far more beneficial in that it keeps wind from whipping through your insulation and rendering it far less effective than the rated R value. But this approach is far more expensive. Air sealing the inside can add to efficiency since you can effectively reduce air changes for relatively cheap materials and small effort. Both is the right approach if you can do it.
 
So I spent about two hours yesterday sealing up about 12 outlets (huge kitchen). And I can tell you that it did make a big difference. The thermostat is on the wind side of the house on an interior wall but near an exterior wall. It was very windy yesterday and the drafts have been significantly reduced on that wall.

I used the non expanding window and door great stuff. I also chalked with some silicone I had laying around from window installs. I just stuck the tube of the great stuff to the back of the outlet and sealed off where the wire entered the box.
 
Good suggestion semipro. If the house has forced air heating sealing up those ducts and duct boots can help too.
 
We used the UL approved foam inserts and the child proof socket plugs in two different houses for two different situations.

House #1: 1950s brick and block bungalow, with brick, block, plaster and mud walls (outside to inside) and no wall insulation. Due to the brick and block construction, it would be difficult (we are told) to have insulation blown into the walls. The house had typical double pane vinyl replacement windows when we bought it, as well as R19 batting insulation in between the attic's floor joists over the original rock wool insulation.

House #2: 2007 stick built with 6" exterior walls, good vinyl double pane windows, R49 blown insulation in the attic.

House #1: This is our Empty Nest- a 1410 sq. ft. bungalow that we've renovated mostly via DIY (with some work contracted out where that was the best/safest/sanest option) and which we heat mostly with a pellet stove. We've added a radiant barrier to the attic, as well as R30 batting rolled out perpendicular to the floor joists and the existing insulation. (The R19 between the joists was in good shape so we left it in place.) The pellet stove, which supposedly can carry 2000 sq. ft. still required help from the gas furnace on the coldest days. Early this fall we went all honey badger on what air leaks we could address without tearing things up: sealing penetrations from the ceiling to the attic (light fixtures, ceiling fans, exhaust fans, etc.) and adding the foam inserts behind the switch and outlet covers as well as the child proof socket plugs in outlets that are not used continuously. We also caulked around the quarter round trim on the base boards with paintable, clear drying caulk. The hardwood floors have been refinished a couple of times and sanding left a gap. We could feel the draft coming into the room from this gap.

Since we did all of these things at once it's hard to say what, exactly, the foam inserts contributed- but I can tell you that there is one wall of our house that takes the weather and wind coming from the west more than the other walls. Before adding the foam inserts and the outlet plugs to the outlet on that wall, I could feel the cold draft coming into the room through that outlet. Now, not so much. It was sort of difficult to tell, sometimes, if I was feeling a cold draft or simply conductive/convective cold from the wall. Believe me, when it's in the teens or below and the wind is hitting that wall, the interior plaster wall is COLD. But yes, the inserts did help us, as did the socket plugs. Now when I put my hand next to the outlet on that wall, I can still feel the conductive cold rays emanating from the wall- but at least the air is not blowing past my hand.

House #2: This is the home to which we hope to retire in a few years. One side of the house faces an open field with no wind break. On the other side of that field is two+ miles of unobstructed water. There are times in the winter when the wind comes down the river and across that field at over 60 mph, and that's without any storm system in play. That's just because it's Tuesday and it's a great day for wind! Even though there are 6" exterior walls and good windows, and the house was built by a local builder who has lived in this climate all his life and he knows how to build for it, and the house was built for a retired builder who had common sense things in mind when he built it like the appropriate materials and construction for the climate (and we ended up buying it, long story but our good fortune) that wind is wicked. We could stand in the rooms on the back of the house and feel the wind coming in, as others have said, through the prong openings in the sockets. I don't mean a cold draft coming in through the prong openings. I mean you could feel the wind coming in through the prong openings. If it had whistled as it came through the prong openings I would not have been surprised.

Did the foam inserts and the socket plugs help? You betcha they helped.

This is a small thing to do- it's easy and relatively inexpensive- so why not? It did help us.
 
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