A system for protecting building penetrations is disclosed. The system can include a screen comprising flexible, strong fabric-like material suitable for resisting high winds, driving rain, and wind-driven missiles. The screen can further include loops sewn, or otherwise manufactured, into the span sides of the screen. The system can further include one or more retention channels having an internal hem rod. The loops in the screens can slide over the hem rod to guide and retain the screen in the retention channels. The hem rod can include a tapered end and a loop opener to facilitate the loops sliding over the end of the hem rod. The system can further include an enclosure for housing a take-up roll and a powered or manual rotating system. The system can include a deflection device to enable the screen to unroll off the take-up roll smoothly and vertically.