I recently bought a home in the DFW area. I will be blowing in 30 bags of cellulose to add 6 inches of blown insulation to the attic floor. I have considered either setting a foil radiant barrier over the insulation or fitting 3/4in aluminum foil-lined foam board between my rafters. I would not have them pressed up against the plywood. I planned on fitting them between rafters on the bottom side giving about 4-5 inches of air space between the foam board and roofing. My question is: Would installing the reflective foam board have the same or more insulation benefits as having the sheets of foil barrier laid on the blown insulation? Any additional thoughts would be great. I could use some help insulation this 25 year old house. Thanks

MiggySWA