Everybody that owns a house should probably do this and I'm sending this hoping someone notices. Foil sided insulation board laid over existing roof decking, foil up. 2 x 4's laid flat on insulation board over joists and screwed down. Another layer of decking, paper and shingles over 2x4's. Creates a vented cavity that draws air from bottom out through a ridge vent. The foil radiation barrier radiates it's heat into this vented cavity also. 2" thick P Iso insulation board is R12 could go to R25 or more. Keeps the asphalt shingles cooler as well so last longer. You can figure out the details from my drawings. Bug shields are easy to install or replace. It's a one-time thing as the shingles can be replaced over and over without doing anything extra afterward. Cheap and easy-can be performed by roofers/carpenters of average skill. I'll do mine it the fall as an experiment and work out the bugs. This design is a modification of GAF's vented insulation roof board, just quicker and better. Nobody wants to work in a hot attic but they might be more inclined to with this and do a better job up there too-I know Takes a load off the A/C. Might look kinda cool, too-like a double fat roof. Pass it around-it's free.