Green Retrofitting, Part Two: Cool Metal Roofing

July 12, 2017

Blue metal roof on an industrial building.

This is part two in an ongoing series that will explore ways in which facilities can affordably retrofit to recoup energy costs and help the environment. This month we are focusing on cool metal roofing.


Metal roofs have been used for decades to provide superior protection from the elements and they have a longer life than other types of roofs. Cool metal roofs are a subset of metal roofs that offer high solar reflectance as well as high infrared emittance. These types of roofs include unpainted metal, pre-painted metal, and granular-coated metal, and are available in a variety of finishes, colors, textures, and profiles.


Traditional bitumen and tar and gravel roofs have a low albedo (reflectance measurement) often as low as .1, so they absorb up to 80% of the heat they receive from the sun, and transfer much of that energy to the building’s interior. Thanks to cool metal roofing’s reflective and emittance properties, the EPA estimates these products can save a facility as much as 40% in cooling costs.


Other advantages of cool metal roofs:


  • Durability. Metal roofs offer a long life, with warranties lasting 20-50 years.
  • Fire Resistance. Many metal roof systems have been tested to meet Class A, B, and C fire ratings.
  • Wind Resistance. Most metal roof panels offer interlocking or active fastening, which allows them to pass very severe wind and uplift tests.
  • Sustainability. These products typically have a minimum recycled content of 25% and are 100% recyclable at the end of their life.
  • Installation. Metal roofs can be installed directly over your existing roof in most cases, eliminating tear-off costs and minimizing interruption to your daily business activities.
  • Solar ready. Standing seam metal roofs make it easy to attach solar panels, should your facility ever decide to go solar.


There are two basic types of cool metal roofs: structural and non-structural. Structural roofs attach directly to purlins or lathe boards; non-structural roofs require a solid substrate beneath it, typically plywood, oriented strand board, or a metal roof deck. Cool metal roofs also come in low-slope (below a pitch of 3:12) or high-slope (with a pitch greater than 3:12) options.


Cool metal roofs don’t just make economic sense. They also come in many colors and patterns, and can be formed into a wide variety of functional profiles, enhancing the aesthetic design of almost any facility.


For more information on cool metal roofs, or help in deciding if metal roofs are right for your facility, contact Vanguard Resources.