We have a 20 yr old 26 gauge sheet metal roof (factory blue paint that's really faded) in good condition.  No leaks, hail damage or injury.  A few screws need to be siliconed and run back in, but otherwise good.
  We are thinking of giving it a good wash, either power wash or soapy brush and rinse and then painting over with something that's more reflective. This is S Texas, so heat is the major factor.
  I've seen aluminum type paints and some "special" thicker goo that is supposed to be really reflective.  Anyone tried such a product and can advise me?   Any comment appreciated.  TIA.  Stetts