Adjustable roof vent

An adjustable passive vent for venting a building enclosure having an opening in a roof portion, said adjustable passive vent comprising:

• a vent structure comprising:
• a collar;
• a vent body attached to said collar, said vent body having a cover, and at least one gas permeable screen positioned between said cover and said collar, said at least one gas permeable screen being sized, shaped and positioned to prevent objects from passing into said vent structure;
• a base pivotally attached to said vent structure at one end and being attachable to said roof portion at the other end, said base comprising:
• a lower attachment structure for attaching said base to said roof portion over said opening;
• an aperture through said lower attachment structure to permit gas to pass in to and out of said opening in said roof portion through said base;
• and
• a wall surrounding said aperture having a pair of opposed curvilinear wall sections configured to fit into said collar;
• a pair of pivot joints pivotally attaching said aperture surrounding wall to said collar, said pivot joints defining a pivot axis about which said vent structure pivots along a range of angles relative to said base, said collar being sized and shaped to overlap portions of said aperture surrounding wall to maintain a continuous wall between said collar and said aperture surrounding wall along said range of angles;
• at least one means to secure said vent structure in one of said range of angles relative to said base;
• and
• said adjustable passive vent defining a gas passageway from said at least one gas permeable screen to said aperture, to permit said gas to pass in to and out of said building enclosure through said adjustable passive vent;
• wherein said adjustable passive vent may be adjusted for mounting on roof portions with different slopes.