I am a new homeowner and my home has a asphalt composite shingles. I live in seattle and because of the wet weather we have here, I have moss growth on my roof. I am trying to hire a roof cleaning company to take care of it. While most roof cleaning companies say they use Zinc Sulphate based moss prevention, I have one company that uses "
ATCO Shakelast roof preservative". From what I researched it is a Copper naphthenate based product. The vendor says this kind of moss prevention will be good for anywhere between 3 to 7 years. While I like the sound of it, I couldn't find much details about it and not sure if its a common approach for a composite roof.