Single flue chimney caps are installed when only a single chimney flue is present or when the need to accommodate a gas appliance chimney cap is necessary. While single flue caps do not provide as much protection to the chimney top as multi-flue caps, they do provide sufficient protection against water, animal, and debris intrusion. Single flue chimney caps are installed by stainless steel pressure screws to the chimney flue tile or fastened to the chimney top with stainless steel masonry anchors.