Insulation question is foil iso board OK?

New to the forum, but have been lurking a long time, thank you to all, I have learned so much on this site.Fixing a cathedral ceiling (2x8s)it was filled with fiberglass,r19, insulation and no room for air movement,I have some 1 1/2" iso board with foil on both sides My plan is to put a three layers sandwich, 4 1/2" in each cavity, is the foil OK or is that going to create condensation, the cathedral roof space empties into the full stand up attic which has full ridgevents. I am in central fl