Hello, I have a few questions and not sure what product I should be using. I purchased a home three years ago which has an EPDM roof. It was in need of a good cleaning and had a lot of algae on it. I want to coat the roof and take care of it. The roof is app: 15 years old. I know at some point I will need a new one, but until that time, I want to do this. Should I be using the butyl liquid rubber or RV Roof Magic for RV's? I do not have the exact roof measurements, but my home is 1279 sq. ft. The roof is not torch down if that helps at all. Do I need to use the primer beforehand? Thank you for your time and feedback.