12 meet at and may be attached to a ridge pole 14 which extends between the end walls of the building the roof deck 18 typically comprising plywood or other suitable panels make up the outer sheathing of the building the roof deck 18 is secured to the rafters 12 and extends to the end walls shingles 20 may be nailed to the roof deck 18 to finish the sloping portions of the roof in accordance with conventional construction practices conventional cap shingles 22 may then be installed in overlapping fashion to cover the peak of the roof above the ridge pole 14 a slot 26 is provided along the length of the peak of the exemplary roof construction 10 to provide a passageway for venting air between the underlying attic area and the ambient atmosphere the ends of the slot 26 are spaced from the opposite ends of peak as seen in fig1 this spacing may typically be on the order of six inches in accordance with the present invention as will be more fully discussed a vent designated generally by the reference v is interposed between the cap shingles 22 and the underlying portions of the roof construction 10 still referring to fig1 the vent v has a web 1 with a longitudinal medial hinge 2 which divides the web 1 lengthwise into a pair of identical portions 1a and 1b capable of being disposed at a dihedral angle relative to one another each web portion such as the web portion 1a has a plurality of frusto conical spacer elements 3 4 5 6 disposed in parallel longitudinal rows a b c d.