I’m getting ready to insulate my attic, and I’m trying to seal openings first. I’ve the Taunton Press book on insulating and weatherizing, which is very helpful, but it doesn’t say anything about what to do with electrical boxes in the ceilings, for ceiling light fixtures and smoke detectors.
My house is all conduit and metal boxes, if that makes a difference.
Can I use low-e foam around the boxes to seal gaps? What about on the top of the box; do I need to leave the tops alone for heat dissipation?
Replies
You can seal around the "backside" of any of the boxes.
However, if you have can lights you aren't suppose to have insulation around them closer than 3" (I think that is the number) unless they are speced as IC - insulation contact.
And even in IC can's I don't thing that it is good to have foam directly on them. But I have not see anything definite on that.
You can build boxes around can lights.
Backside - does that mean the top and sides if the box is in the ceiling?
Yes.
Idea I had for sealing boxes (haven't tried it yet) is to run duct seal through a pasta machine to make a thin sheet (maybe 1/4" thick), then form that around the box.
Don't tell yer wife
She bought the machine for working with polymer clay, so no biggie.
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