I am cutting holes in the ceiling to install IC-rated recessed lights and I accidentally slit into the brown paper lining of the underside of the fiberglass insulation. Do I need to repair the cuts in this vapor barrier? If so, how do I make the repair?

  • 1
    always try to maintain the integrity of the paper. I found duct tape works well for this type of repair. – ojait Nov 27 '15 at 15:57

If you are installing IC rated lights an are worried about the paper, I would be concerned about the rest of the insulation that surrounds the light.

Typically when I set a "new work" style rough in I cut the drywall bigger than the light rough in by a few inches on either side up to the joists that will support the light. Yes I may cut the paper, but the larger cut in the drywall helps me address the cut and other issues.

"Remodelers" IC rough ins are a different matter.

Once the light is wired in, I add another 4'section or 2 centered over the area where the light will go, after the light is secured in place I cut the paper and the insulation to the light. You can tape the cuts in the paper if you like, and it may improve the performance of the vapor barrier.

The reason why I detail this, is if you have not cut the insulation other than the incidental cut during the time the drywall is cut, I am led to think the insulation is simply pushed up to make way for the light to go in. Doing this raises the insulation above the neighboring pieces and the R-value is diminished drastically in these ares where this happens. This is the meaning behind my opening statement.

  • I'm a little confused by what you're saying. Are you saying you would add an additional piece of insulation centered over the area where the light is pushed into the ceiling? Even though the remodel lights I'm using are IC-rated, would the extra insulation directly on top of the lamp trap too much heat and create a fire hazard? – Ethan N Nov 28 '15 at 8:00
  • As mentioned, the remodel lights are a different issue, since they require a hole only large enough to set the light in with no repair of the sheetrock, usually the insulation is cut the same way the sheetrock is so the insulation fits snug around the fixture. I would check the specs to see if insulation can go over it, if it can and you can add it through the 4 or 6" hole that is cut in the drywall, I would do so. Only if it is not a hazard, the specs of the light should fill you in on that. – Jack Nov 28 '15 at 9:02

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