Chimney Cap 4 Description: A simple chimney cap or fireplace flue shown above in a natural unsealed copper that will develop its own patina over time with exposure to the elements. see also Chimney Cap 7 A custom copper chimney cover with attractive standing seams on its roof. Copper mesh, internal steel frame. Chimney Caps: What’s that all about? Chimney Cap 1 Lattice copper cap for a chimney or fireplace flue cover. Hammered copper, steel mesh. Chimney Cap 2 Custom copper cap for a chimney or fireplace cap with decorative copper elements. Chimney Cap 3 Custom copper chimney cap flue cover with decorative wavy copper bars. Chimney Cap 5 Custom sealed hammered copper chimney cap finished in medium copper.