Looks like bits of moss and lichen to me,....especially with the trees in close proximity. It's natural for it to stay on there for a little while after it's dead. Moss and lichen have much more body than the typical black streaking. It will turn white first then turn brown as it dries and falls off over time. You have to be very careful if you try and manually remove it with any type of force, it will more often than not leave an exposed patch of asphalt where the moss or lichen was.
Really is easier to tell the customer it should've been sprayed a long time ago and not let it get to it's current stage. Then tell them it's in yours and there best interest to just let it fall off naturally over time,...and it will.
Sometimes you can remove it and it ill look ok,....but if you start and strart seeing black asphalt without the granules,...I'd stop.
jeff thank you for the reply. i feel a lot better now after all this great help. yea im just going to let the rain do all the work. it hasnt rained yet but i hope it will soon. when i went back over there its all brown and looks all balled up like its going to fall off easy. but when i pulled on a few spots it felt like it was still attach to the roof. but im just going to see what happens after a few rains. thank you again for all your help.
Yea, the moss will go away with time,....but if you remove it physically the black exposed spots will always be there. Don't ever take the blame for these roofs not being able to be cleaned "instantly". Simple as this,...it's the customers fault for not addressing the issue before it gets to bad,... whether they were aware of what to do about it or not. Always explain that these moss and lichen jobs can't be done to a finished product on the same day,...they take time. Otherwise you're just asking for trouble.
The Sun actually does about as much as the rain does. The Sun makes it brittle and will just begin to fall away.
Jeff
-- Edited by Raystown Roof Cleaning Central PA 1-800-236-0322 on Sunday 21st of March 2010 12:12:52 PM