A vent for a building has a cover attached to a base. The base has an aperture permitting gas to pass. A moisture directing means on an underside of the cover directs moisture move under the influence of gravity to fall outside of the aperture. The cover may include a slanted side wall portion, with the aperture positioned with its center displaced from the center of the cover toward the slanted side. The base may include a pair of moisture deflecting features along at least a portion of one of the nonslope sides to prevent moisture flowing along the base from within an area on the base covered by the cover to outside of the covered area at the nonslope sides. The base may also include a water deflecting ridge on its underside positioned between a downslope edge and the aperture to deflect water away.