Air sealed electrical boxes?

[Innovate1]

I need to ask some local people if this is enforced but thought I would get some general input here...

My plans have a detail "Continuous Air Barrier Detail" that shows caulking of the drywall to the plates, plates to the floor, etc. It also has a note "Electrical boxes caulked, glued, or gasketed to gyp board, caulk @ wire holes and penetrations."

How is this normally done? I know that boxes with flanges and gaskets are available but I have only seen them on line and doubt they are used much. What's the easiest/cost effective way to do this (if I have to do it)?

 

[Kevin Essiambre]

Those plastic boxes with the flanges are common. I know them as R-2000 boxes where I am.

What they are requesting would be using acoustic sealant to plug any possible openings in the vapor barrier.

Another way to do it is with your normal metal boxes and a plastic vapor boot. You seal every opening with acoustic sealant inbthe plastic, and when done properly, every hole through the top or bottom plates into heated walls (e.g., from attic to interior wall). Seal every wire entering a vapor boot (or those plastic boxes). Seal the vapor boot (or plastic box) to the vapor barrier. Basically everything will be airtight.

Unless you mean something else.

Sent from my SM-G920W8 using Tapatalk

 

[DC73]

Here are a couple of options:

https://www.greenbuildingadvisor.com/article/an-easy-way-to-seal-electrical-boxes

https://www.finehomebuilding.com/2019/04/10/easy-to-air-seal-electrical-box

You might be able to use a bit of spray foam on the backside of each box before drywall is installed to close up any openings and then caulk the front of each box to the drywall once installed.

DC

 

[jkeyser14]

You can get the foam gasketed boxes at the big box stores near me. An electrical supply house should definitepy have them toom

 

[ard]

I need to ask some local people if this is enforced but thought I would get some general input here...

My plans have a detail "Continuous Air Barrier Detail" that shows caulking of the drywall to the plates, plates to the floor, etc. It also has a note "Electrical boxes caulked, glued, or gasketed to gyp board, caulk @ wire holes and penetrations."

How is this normally done? I know that boxes with flanges and gaskets are available but I have only seen them on line and doubt they are used much. What's the easiest/cost effective way to do this (if I have to do it)?

who drew the plans...why are you following those plans...who 'owns' the job...

 

[tonyciambrone]

https://www.amazon.com/dp/B018WQ4D7O/?tag=atomicindus08-20

Not cheap but they are good

 

[couch67]

If you can, stay away from the plastic foamed boxes. They are flimsy and in the end not sealed. Stick with your favourite metal box and include a formed vapour barrier behind it to get the air seal.

 

[DieselNut88]

In the commercial world there are plemum rated boxes. Which have knockouts but they are different than standard boxes. You can also buy gasketed covers. Seems overkill for a residential application.

 

[Bert_]

Some expanding foam is what I did in my own house. Don't see it done much but I wouldn't skip it.

 

[Innovate1]

If you can, stay away from the plastic foamed boxes. They are flimsy and in the end not sealed. Stick with your favourite metal box and include a formed vapour barrier behind it to get the air seal.

I used plastic boxes in my whole house and haven't had any issues. They aren't as sturdy as the metal ones so perhaps I should use metal ones in the garage? But I wasn't doing any air sealing - just the cheap standard blue ones from Lowes/HD.

 

[CKS1955]

Some expanding foam is what I did in my own house. Don't see it done much but I wouldn't skip it.

I did the same.

Jay

 

[couch67]

I used plastic boxes in my whole house and haven't had any issues. They aren't as sturdy as the metal ones so perhaps I should use metal ones in the garage? But I wasn't doing any air sealing - just the cheap standard blue ones from Lowes/HD.

I think the quality varies. Years ago I used plastic boxes in various parts of the house while renovating. Tried a few different makes, and all just seem to be flimsy. Questionable holding power for plugs, I've had a few of the 6/32 threads let go in the shop, leaving the plug loose. You may have different experience but I've never had an issue with metal boxes. Just a bit more work to seal though.

 

[Innovate1]

Was just looking at Lowes. They had some plastic boxes with foam around the wire entry points and a flange with foam for the drywall. About $2.50 for a basic box vs. $0.45 for an unsealed basic box. Not terrible and I think I only need them in the exterior walls. Spray foam is pretty easy though.