What insulation is recommended when adding more?
Jeff writes from Stanhope, New Jersey: “I want to reinsulate my attic which already contains R30 blown insulation. I do not want to use blown insulation I would like to use R25/R30 rolled insulation. Which insulation would work best for this installment, faced, unfaced, plastic wrapped?” Answer: The recommendation when adding attic insulation is always to use “unfaced” insulation. You will be putting the new insulation on top of existing insulation and you don’t want a second vapor barrier in the middle of your insulation. If there was no insulation in the attic you could install insulation with a vapor retarder and place it toward the warm side in heating climates – in your case on the bottom of the insulation in the attic. Since you have insulation in the attic, there is presumably already a vapor barrier in place under the insulation and a second one is not needed. If the ventilation is sufficient – such as with a vented soffit and full ridge vent – some counties do not require a va
