Sealing electrical wiring ceiling air barrier penetrations
Sealing electrical wiring ceiling air barrier penetrations
Turns out our electricians failed to comprehend what we meant when we said no drilling into the ceiling air barrier OSB or top plates… Our carpenters rabbited channels into the ceiling strapping to put wiring through… But instead they chose to go through the attic and come down, cutting like 10 holes in our precious ceiling air barrier. Apparently there was “no other way” to get the wiring into these interior partition walls (the interior walls are being built after the slab is done).
This is very annoying, but perhaps it is not a big deal. In my mind it’s a HUGE DEAL because we specifically said to avoid doing this and explained where they could run wiring.
Now that we’ve got all these holes, what is the best way to seal them?
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Replies
Have you considered Prosco Air Dam (caulk/fluid applied air/weather barrier)? One sausage tube would be more than enough I'd imagine for those penetrations.
I wonder if fire sealants/caulk (the red stuff - 3M, DAP, etc) is vapor permeable or not.
Dustin,
Considering the tiny amount of the membrane they will be covering, I don't think permeability matters.
I'd use Big Stretch, or tape.
I would recommend some Zip Stretch Tape. That stuff is really flexible and gummy! Cut it into smaller strips and wrap the wire penetrations — you can do a few layers if you need, getting wider and wider.
You might want to use fire caulk first, especially if there's an inspection coming up before your final blower door test.
Thanks! GBA is not letting me upload a photo unfortunately, it just loads endlessly. I’m thinking it might be pretty hard to get tape into these spots which you can see if the photo would attach. Liquid might be easier to get the nozzle in the tight spaces.
Interesting how this type of thing violates OBC part 9 (I think) yet building inspectors don’t even check this because by the time they come back next, all the electrical holes in the attic will be covered. Virtually all electricians seem used to running most wiring through the attic without any thought of sealing the holes they make.
Izzza,
It is a code violation, but sealing penetrations is on the GC not the electrician, as was making sure they used alternate routes for the wiring if that's what you wanted.