Asa writes from Clover, South Carolina: "I have a new home and I am considering how best to floor a ventilated attic for storage, which currently has 13" blown insulation over 2x8 floor joists. Can I compress the insulation by placing flooring directly over the existing insulation and reducing the current height 5 inches without a significant reduction of R value, or do I need to remove the blown insulation and replace with rolled. Also, just wondering if OSB offers any significant insulation properties, and if so is it possible to remove blown insulation to the top of the rafters and then floor, or will this not offer enough insulation (R value)."

Answer: Compressing the insulation will reduce the R-value and oriented strand board (OSB) does not have a significant R-value.

You should consider insulating the attic rafters and walls if there is significant storage in your attic. There is information on the Owens Corning website about insulating for a finished attic.