This topic caught my eye because I just spent this entire weekend ripping & re-roofing most of my house (no time to do the other half). Had to replace 4 sheets of rotted, moldy plywood... boy ,was THAT fun!
I just finished an hour ago - - my back & right shoulder are KILLING me! Not to many friends to help due to Chrismas coming..... What a pain
in the ass!! I wish I had the cash to pay someone to do it for me!
Anyways, my old man had some stains on light colored shingles on his house. He used a pressure washer (on LOW pressure, obviously) with a solution of bleach & water. Those 20 year old shingles looked like they were just installed! Worked great!
I don't know why your getting stains from your chimney. My chimney is barely holding up (after 150 yrs!!) & I have no stains whatsoever. But, I have black (well, now charcoal colored) shingles. Is it a masonary or a stainless steel chimney?