Trees can cause a myriad of problems when they are too near, or hanging over, roofs. Sometimes the damage is pretty apparent: Like when the big branch blows in the wind and rips or breaks shingles off. Perhaps more devastating long-term, because homeowners do not pick up on it, is the roof that is shaded by trees all the time and, as a result of that, moss and fungus take over. Typically, when that is the case, the tree also sheds needles or leaves down on the roof leaving organic debris. When that occurs, the best thing to do is to prune the tree back, so it is no longer over the roof. If you cannot bear to do that, then trim it so it is at least 10' above the roof. You should clean a roof of debris and apply commercially available moss killers as needed. If you let the moss grow, that will drastically shorten the life of any roof.
Thanks for stopping by.
Steven L. Smith