# Electrical outlet sealers versus draft sealing



## joecaption (Nov 30, 2011)

DIY's are always looking for the quick, cheap magic fix.


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## bluefoxicy (Nov 5, 2012)

joecaption said:


> DIY's are always looking for the quick, cheap magic fix.


This "cheap, magic fix" seems to work like those $MAJOR_REPAIR_OF_THE_WEEK-in-a-can engine treatments that claim to fix everything from failed seals to bent rods in your engine without actually opening it up. Those mostly do actual damage to your engine--typically by either gunking up the oil filter or the galleys, causing a reduced oil flow and faster engine wear; sometimes they screw up the catalytic converter.

In this case it seems like pouring sawdust into your oil: the engine is broken, something is severely wrong (probably a sticking valve), but this makes it quiet so you can't tell it has a problem that's still there (and still causing a loss of power, poor emissions, etc.).


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## Gary in WA (Mar 11, 2009)

The poly ones are useful to stop any moisture from going to the wall cavity and condensing on the outer half of the stud at outdoor temp. They also keep humid indoor air from contributing to the stack effect, natural or mechanical, if you missed any top plate holes to supply your attic ventilation system. http://www.wag-aic.org/1999/WAG_99_baker.pdf

Make sure to get them all; http://www.greenbuildingadvisor.com/wind-can-push-drafts-through-house

You can always do a "blower door" test to check your work; http://www.homeenergy.org/show/article/year/1995/id/1173

With fiberglass, you still need a six-sided air barrier to get rated R-values; https://docs.google.com/viewer?a=v&...whJgNT&sig=AHIEtbT0wgPl1yn5T5V8M8l_EeA2F-qvvA

And even blocking the sheathing cracks, holes, etc., you still may get convective looping inside any low-density fiberglass batt= R-19, R-13, R-11; pp.45-48;http://www.buildingscienceconsultin...010-03-10_When_R-Value_Doesn t_Measure_Up.pdf

Sealing the sheathing is a good idea, as I've said on here a few times before;pp.21;http://www.engr.psu.edu/phrc/training/understandingbarriers.pdf

As your house is pressurized, the RH in the room air is forced into the wall cavities and the FG R-value is reduced from moisture condensing there to loose 60-70%; http://archive.nrc-cnrc.gc.ca/eng/ibp/irc/bsi/90-controlling-heat.html
I spent the few $$ on outlet covers years ago, with or without a draft. 

Gary


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## bluefoxicy (Nov 5, 2012)

Gary, you're saying that the whole "use these to stop cold air coming into your house" angle is a gimmick, but that they're actually intended to address an entirely different issue?

My house gets negative pressure from home air blowing out the chimney. As for low-density fiberglass, I'm running high-density mineral wool batts (Roxul 5.5 inch R-23 in 2x6 walls). It's not as good at handling moisture as real wool, but it handles moisture better than fiberglass; and being denser, I assume it's better at preventing convective looping.

Odd: the pressure thing carrying moisture in demands an interior seal; yet sealing the sheathing creates a sealed space, which then... yeah, now you have a moisture trap, not recommended. There's a combination of good things here that need to not be used together.


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## TWX (Jul 18, 2012)

I took a firestopping and penetrations class a few weeks ago, and it well could be to prevent smoke and overpressure from a room with a fire in it from spreading into conduit or into the wall, to leak out through the cover in another room.


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## Gary in WA (Mar 11, 2009)

"Gary, you're saying that the whole "use these to stop cold air coming into your house" angle is a gimmick, but that they're actually intended to address an entirely different issue?"----------------------------- no, I didn't say that. I gave you another reason why to use them, because you already sealed the exterior sheathing cracks/plate holes/exterior light boxes. So you eliminated one reason to use them by doing that. Air seal the drywall (ADA) before you install it to help keep moisture from your MW insulation; http://www.dow.com/scripts/litorder.asp?filepath=styrofoam/pdfs/noreg/179-04569.pdf

"My house gets negative pressure from home air blowing out the chimney."--------------- isn't that expensive to heat?

"Odd: the pressure thing carrying moisture in demands an interior seal; yet sealing the sheathing creates a sealed space, which then... yeah, now you have a moisture trap, not recommended."----------------------- you are confusing a double-sided vapor barrier with vapor permeable drywall (50perms) and plywood sheathing (10perms/OSB=2perms) which do let moisture out in a vapor form.

Gary


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## gregzoll (Dec 25, 2006)

When I did mine, and have been asked to go to friends homes and do draft sealing for them, I use DAP foam in the can, that is water clean up. Then just place the foam gasket inside the plate, place back on the outlet.

As for around windows & doors, same thing with the DAP foam. We have retro-fit windows, and I got tired of the drafts coming through them. Took the moldings off, and found out that whoever installed them, used very little insulation around the edges.

I also use the Z style Foam Weatherstripping around entry doors to the outside & garages, on older doors, or doors that are starting to kick out, where there is a gap between the edge of the door and the installed weatherstripping in the frame. Helps a lot to stop drafts.

It is surprising after you start sealing gaps, how much warmer the home is.


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## gregzoll (Dec 25, 2006)

Gary, after we removed the old chimney for the old Octopus furnace and draft water heater out of the roof, patched the hole, I have seen our humidity go up in the attic. I am going to have to get up there and put in baffles along the roof edge, and probably look at doing something with the Bath Fart Fan, since that is what is my possible culprit.

RH was lower up in the attic before the Chimney came down, so just making that one change in the roof, changed air movement through that space.


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## bluefoxicy (Nov 5, 2012)

Gary in WA said:


> "My house gets negative pressure from home air blowing out the chimney."--------------- isn't that expensive to heat?


It's a standard 1991 furnace design: the input air for the blast furnace comes from the basement. You can reach in and touch the burners if you want, even roast marshmallows on them or use them to light cigarettes.

Newer designs run an intake pipe through the wall to draw in outside air, loop it past the blast furnace, then eject it out the chimney.



> you are confusing a double-sided vapor barrier with vapor permeable drywall (50perms) and plywood sheathing (10perms/OSB=2perms) which do let moisture out in a vapor form.


I coated the entire wall with closed-cell polyurethane spray foam. Like so.


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## Gary in WA (Mar 11, 2009)

Enclosing the furnace in a room with its own supply air could only help your heating bill, IMO. An added benefit of SPF is air-sealing. Why was the lap siding on the wall, the boards will move with the changes in humidity of the seasons with that thickness of foam. (Unless you filled the wall after video). I saw some air gaps between boards that will only get worse, is that an exterior wall?

The foam on the roof sheathing requires more thickness than you added to prevent condensation and eliminate the ventilation there-- see the map;http://www.buildingscience.com/documents/published-articles/pa-crash-course-in-roof-venting Or did you make more passes later?

Gary


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