I painted my house last summer and painstakingly scraped and sanded where needed. I put a layer of oil based primer on the sanded areas and caulked where the siding had gaps. I finished the whole thing with a coat of Sherwin Williams latex, Duration paint.
Sometime during late winter, Ohio, I noticed a good number of brown streaks going down the vertical side of the house. It has a tar color quality and it ran fromm several siding boards all the way to the bottom of the house.
I have no idea what this could be or how it happened. Does anyone have any advice?