Well, nowadays I'm seeing on TV, and in houses I've
visited, insulation between the rafters in, as I've stated,
attic used only as storage(the Christmas tree, luggage,
unused toys awaiting tag sale, etc).
Even on 'THIS OLD HOUSE' in an episode featuring a
'Net Zero' energy project, the roof consists of no less
than three layers of styrofoam insulation and vapor
barriers, the final roof planking, another barrier, and
finally, the shingles A total of 20" of insulation BELOW
So I guess techniques are changing. But I continue to
recommend the old fashioned way - NO insulation under
the rafters of an attic where only the Samsonite family,
and Barbie & Ken, reside.