| What you think is tar might be dark mildew stains. I've seen that a lot, and our old house had them. I bought some special cleaner for it, applied with a garden sprayer, but it didn't do much for them. I next tried some good old Clorox (applied the same way) and it took most of the stains off (I rinsed with a hose). I can't remember if I diluted it with water or not, but it's worth a try. |