My attic currently has 4" of blown cellulose insulation (to the top of the 2x4 joists). I plan on sealing air leaks and adding R-38 batts. The home was built in 1977 in zone 5.

Should I remove the cellulose and use faced batts or should I top with unfaced? Is there anything else I'm missing?

  • 1
    Why aren't you blowing more cellulose? A continuous blanket usually beats all those seams in terms of performance, and cellulose is cheap.
    – isherwood
    Jul 23, 2018 at 20:36
  • How much harder is it to do wiring work in the attic after insulation is blown in? I’ve a number of someday projects that I’d prefer to not have to do before insulating.
    – John K
    Jul 24, 2018 at 1:43
  • I wouldn't say it's harder at all. Moving some cellulose aside and then flipping it back in place when you're done is easier than refitting a bunch of batts like a puzzle.
    – isherwood
    Jul 24, 2018 at 12:18

1 Answer 1


I would leave the cellulose in place and use unfaced batts so moisture is not trapped. A couple extra inches over the top would help reduce the heat from conducting through the wood.

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