This is a 70,000 square foot metal roof on a petroleum company.  This roof experienced high intensity heat from a building fire below from several years prior.  The extreme heat melted the grommets around the screws causing it to leak.  Seams were leaking from where the roof had been repaired over the years.  Metal roof was power washed.  All penetrations were inspected and treated with trowel grade silicone.  Primer was applied in designated areas of the roof.  All screw heads were inspected, tightened as needed and pre treated with trowel grade silicone before applying 22 mils of silicone to the entire roof.