Abstract: A ventilating device for a roof having a vent opening includes a cover for a vent opening in the roof. The cover defines vent passages for communicating the vent opening to ambient atmosphere. A moveable member mounted adjacent to the passages is moveable from an open or inactive position permitting communication through the passages to an active or closed position in which the moveable member closes the passage to restrain entry of wind driven rain and or snow into the passages. The moveable members are returned to their inactive or open position by the resiliency of the material from which the moveable members are made and/or by the force of gravity.

Abstract: A ventilated cap system for use on a ridge of a roof which includes an expandable utility cap to seal over a variably expanding metal roof. In one form a top cap may snap lock over the utility cap for slidable attachment thereto when exposed to deforming forces such as snow or ice. The top cap prevents deformation of the underlying utility cap. Roof panel clips permit uneven thermal expansion between metal panel members.