Mikr writes from Plaistow, New Hampshire: "I just purchased a home. Attic insulation was installed along the roof sheathing to the peak between the roof 2x6"s. There is central air equipment in the attic. There is also insulation between the ceiling joists. Is this correct?"

Answer: If the attic is heated and/or air conditioned, what you describe is OK. There should be a 1" air space between the insulation and the roof deck to allow for ventilation. Insulation between the ceiling joists should help with noise control but will not improve thermal efficiency.

If the attic is not heated or air conditioned the roof deck does not need to be insulated, just the floor of the attic.