Remove radiant insulation first that causing a lot of condensation problems. For cathedral celling the best is spray foam insulation. you will never have any problem again or you can use this high dense insulation however you need to have enough intake vents (more sq ft area than outtake vent area). And enough r value for your region. If your rafters are 2x6 or 2x8 that might be not enough. Also use air tide light so warm air will not travel to attic space.