Abstract: An improved roll-up closure utilizing a flexible cover selected from a material suitable to effect the type of closure sought. The cover is at least as wide as the portal to be covered and is typically longer than the portal. Each lateral margin of the cover has a strip of hook or loop fastener material affixed thereto, with the complementary strip affixed to either the respective lateral margin defining the portal or to a "floating" edge of an elongated strip of flexible material attached at its opposite edge to the respective lateral margin. A first end of the cover is rigidly affixed across a first margin of the portal. The opposite end of the cover can be upturned about a transverse rod and connected to a take-up roller mounted adjacent the first margin of the portal, or it can be attached to the rod such that as the cover is raised or lowered, the cover is wound or unwound around the rod. Channel members prevent movement of the rod in a direction normal to the plane of the portal.