Metal shingle roofing offers unique beauty by providing depth and detail that is unmatched by other types of metal roofing. The formation of the products creates an air gap between the metal and the roof deck on a structure. That air gap is very beneficial as it becomes a thermal break to stop conductive heat transfer. In other words, the surface of your roof may get very warm to the touch under the hot summer sun but the airspace beneath the metal prevents that heat from conducting to the roof deck and on into the attic and home.
If areas of a roof may have frequent or heavy foot traffic, such as to paint a dormer or clean a chimney, metal roofing manufacturers sometimes offer optional foam inserts that are specially contoured to fill up the air space with high density expanded polystyrene. Because metal shingles can be walked upon even without the inserts and because metal roofing maintains its walkability even as it ages, many metal shingle roofs are installed without any foam inserts beneath the panels. For some homes, though, inserts are used to create easy to walk paths on the roof. On some homes, especially oftentimes those in areas prone to severe hail or heavy snow, the homeowners opt for inserts over their entire roof. A conversation with your contractor will help determine what is most appropriate for you and your roof.