Metal Roof Splotches


was out bidding a metal roof last night. What customer claims to be oxidation in white/beige splatter covers the roof at random and in a grid pattern. Claims it just appeared slowly after he had painters using same/similar color to paint siding. Close to the siding on roof is about a foot of the paint but the entire roof has splatter in a grid like pattern. And it appeared slowly after the paint job. Not immediately. Laid down some roof mix which i knew wouldn’t do anything though it did make the paint bleed some. Threw on some gutter grenade and brushed it after a swell and the “paint” lifted but left the underlying metal shiny. I am gonna walk away from doing this roof but any thoughts on what it could be?


Looks to me like the remains of a previous coating after it has broken down then hit with high pressure , it has then aged some more and has become covered with algae. It doesn’t look like overspray from spray painting siding.
What can cause grid effect is overlaps when roof was sprayed .
The paint used on roof may not have been rated for exterior use that is why it has broken down to that extent, some scammers use interior paint/whatever they can get their hands on.


Makes sense. I’m avoiding it. No sense in trying things out again there. Just was looking for an answer/explanation for the customer. Thanks Aussie!

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