12-31-2012, 09:57 AM
It's red algae and some mold thrown in for good measure. It forms on TPO because is it such a cool roof material. The color reflects so much heat that it stays moist much longer than any other roofing here making it ideal for algae to bloom. One good solution (true for any roof mold, algae or lichen problems) is to install a zinc strip (available many places online) at the top edge of the roof. The rain water releases tiny amounts of zinc which will prohibit growth on the roof. Some asphalt shingles are manufactured with tiny bits of zinc in them for this very reason.
But if that doesn't work, my best guess is aliens. And for that problem, there is no where to run or hide!
But if that doesn't work, my best guess is aliens. And for that problem, there is no where to run or hide!