What is a Fly Roof? How To Build a Flying Roof
Part of: "Best Ways To Cool Your Home."
A fly roof (or flying roof) functions as a parasol by blocking sun or other weather without trapping heated air in or against the main structure.
Another function is to vent the interior of the structure, such as a fly roof over industrial "smoke stacks" or the more familiar chimney cap (rain cap) on residential homes. A fly roof is like a chimney cap over the entire house.
The fly roof can use heat convection, solar chimney effects, stack effects, venturi effects, and evaporative cooling (e.g. swamp cooler, a.k.a. desert cooler) as part of an air-conditioning system.
You can get a partial effect by installing radiant barriers under the roof, insulating below the attic floor, and installing attic vents. Imagine if the entire attic walls were vents or screens.
A "double roof" essentially uses a fly roof, sometimes to create ducting between parallel roofs.
Here are some fly roofs and a retractable roof: