rusty or yellowish on stucco

[Peter Louis]

Hi Guys:

What is that rusty or yellowish on stucco below crawl vent? the crawl is heated.

Thank you

Peter

[John Kogel]

Could be dog pee. Don't worry about it.

[Peter Louis]

Thank you, Possible. My thought is the poor stucco finish & high humidity around vent, which caused rusty spots from metal mesh or vent screen, is it possible?

[Eric Barker]

Around here it'd most likely be due to iron from well water that is sprayed onto the siding from a yard sprinkler.