Originally Posted by oldslowchevy
it was very hard to tell what color it really was and once done it wasn't prefect but i was able to go about 90-95% of the roof to match the rest of the shingles
I've never seen anything take kreosote off of shingles. I've tried a lot of products myself to remove stains from roofs. Bleach, tire cleaner, Dawn, Simple Green works about as well as anything if you let it soak for a while first. That's hard to do when the sun is up and the roof is drying as fast as you can spray it on. If you find something that works, let us know. Be careful with bleach and other cleaners, you will streak up the fascia boards and gutters before you know it. I found this out the hard way.
Tom in KY, I didn't dilute anything, but now I know to lay a towel on the roof below where I'm working!