Purple spots appear on the underside of a new patio cover (GAF roof) when it rains. Both the roofer and a GAF inspector can't figure out what is causing it. They appear in one area of the cover. This same area was getting green spots with rain after their first installation (it leaked and they had to replace it) Now they are purple, many more and much bigger. Time after time this roofer has had to come back to "fix" things that weren't done properly since the initial installation of
the house and patio cover roofs 1 1/2 years ago. Does anyone know what could be causing the spots and what needs to be done to fix it?
Commented on Mar 15, 2012
It could be the paint. There is a new paint for ceilings that goes on purple and dries white
so you can tell where you've painted, I found out the hard way that when it gets wet again it turns to purple.