I know this doesn't have much to do with the original topic but out of the 4 attics I have been in since Saturday (during afternoon inspections), 2 had the radiant barrier (foil type) in them and I could definitely tell a difference in the attic temperatures between those with the barrier and those without. All houses were similar in age and construction and the ones with the barrier were noticeably cooler judging by my sweat meter (shirt saturation ). I have yet to see the silver paint type unless you count the houses that had previous fires.

Eric