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Community and Q&A

Building box around non-IC rated recessed lights?

FrankFulton | Posted in General Questions on

We just discovered that the house we purchased has non-IC rated recessed lights in contact with rock wool insulation. We have attic access and are increasing insulation (blowing additional cellulose over rockwool).

Can we simply build airtight foam boxes (with sufficient space) around the non-IC rated lights, then blow the additional cellulosee? This way, we’d just swap out the bulbs for LED bulbs and call it a day.

Thank you.

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  1. user-2310254 | | #1

    Drywall would be safer since someone else may install a different type of bulb down the road. Here is a detail that shows how the box should be assembled.

  2. GBA Editor
    Martin Holladay | | #2

    According to the most recent advice, it's dangerous to install an airtight box above a recessed night that isn't IC-rated, because these older fixtures lack a thermal switch. Temperature measurements show that adding an airtight box can lead to dangerously high temperatures and the possibility of a fire. (Older fixtures depended on airflow through the fixture to prevent the fixture from overheating.)

    For a thorough discussion of the issue, see Recessed can lights.

  3. redbera | | #3

    I'm considering simply caulking/sealing a all in one LED insert fixture with trim (see pic) to the ceiling and plugging into the existing IC rated recessed fixture. It will make replacement difficult after it inevitably goes bad, but they're rated for 10-15yrs and it sure would beat installing a air tight box over the can light in the attic.


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