I don't think the guys from the south will see much of this, I have seen a handful last year and nothing worked. I am talking about the black streaks { soot ? } left behind by wood stoves or the oil burner pipe.Some say it is caused by the burner not being properly " tuned " These stains will not come out with Apple sause or any stain removers I have tried. I have seen it on split levels as well, dropping down to the lower roofs. It looks just like black algae streaks but it is not.Keep your eye out for this problem, if you dont notify the customer before hand you will look real stupid when you are done....I know I've been there. If anyone else has delt with this problem or has a solution it will help us colder states out for sure.
Make a thick paste of Oxygenated bleach in high concentration applied specifically to affected area, then low pressure rinse?
Maybe a solution of muriatic acid and water, test on a very small inconspicuous area and wash/rinse with clear water quickly after application so as not to damage the shingle but just remove the offending stains.
BE CAREFUL with the acid applying overhead or from a ladder as it can cause severe burns to eyes and skin. Wear proper protective eyewaer and cover exposed face and skin where applicable.
Believe it or not we do run into that problem down here on chimney's. People love to start fires in their fire place every time the temps get down to 45-50 deg. Hahaha! Normally what we do to remove the creosote is to saturate the area with a good strong house wash mix and then spray it down with a butyl based sodium hydroxide. Most of the time it will require a little bit of brushing. Rinse and repeat as necessary. It will come off. I wish I had pics of the ones we've done during Roof Cleaning but I don't....Note to self: Self, get pics of this. LOL... Good Luck!
I was just reading again what you guys posted.I did't mention that the streaks from the soot are on the roof, a large pattern streaking down on the shingles. Do you think the solutions you mentioned are a good idea for asphalt shingles?
Yes! The mix I mentioned above will take it off the Shingle Roof. You may have to do a little lite rinsing and re-apply a second coat to be sure but it will work. Good Luck!!!