A greater standing seam might be created to ensure it might be installed making use of fasteners that are concealed and permit the panels some area for movement. G90 (bare minimum) galvanized steel and strong aluminum with PVDF coatings (go through the trade names Kynar five hundred or Hylar 5000) http://abcroofingsupply31864.tribunablog.com/the-ultimate-guide-to-affordable-roofing-11631108