Instructions for best way to remove moss from roof in Western Oregon
Hello and thanks for your question!
There are physical controls, and chemical controls. Only the physical controls are able to prevent moss growth in the future.
Physical controls: http://bryophytes.science.oregonstate.edu/page23.htm
Chemical controls: http://bryophytes.science.oregonstate.edu/page24.htm
After reading about your options, please feel free to reach out with follow-up questions. If you choose to use a pesticide (moss killer), be sure to read the label directions and follow them closely.
All the best, Kaci Buhl