I had my roof treated 2 years ago. I have been delighted with the result. There is a house on the hill above me, I was on their deck looking down on my own roof and 3 neighbours all in a row. All the other roofs had a lot of moss, but mine looked great. I know people don’t want to pay, as it more expensive than just getting the moss removed. However, the moss comes back quickly. I tell everyone I am pleased with your treatment. I only wish I had had it done sooner. It is a great product.