The title says it all. I have a 1926 house in Northern IN with the original Cement Asbestos Roof on it, I am not sure of the pitch but it is appears to be pretty standard. Previous owners have painted it, I have owned the house for 11 years so the last last coat is at least that old. It has moss growing on it, so I plan to pressure wash then bleach (capturing wash in buckets at downspouts to save landscaping) and rinse as prep. But what product should i coat with. I am considering a opaque cement deck stain with the thought that it was designed for more vertical application meaning it should take more direct sun and standing water. Any suggestions welcome.