How old is your roof now? How bad is it? If your roof is not cracked or split and you just want to maintain it a coating maybe the right thing to do. EPDM roofs are made in layers, the top layer is white and will slough off with time and show the black layer underneath. Any acrylic coating will slow this process down. I coated my roof in 2006 with a gallon of Koolseal that a friend gave me when he bought a new MH with a FG roof. It really could have used 2 coats but I only had enough for one coat. It looked good for about 5 years and it began to slough off. The roof is now 22 years old and still has some of the coating left,so it has extended my roof for another 10 years. Another friend has a 22 year old EPDM roof that was never coated and is completely black because the top white layer has worn away. Based on my experience I would buy the 5 gallon bucket put 2 coats on then as it begins to slough off maybe every 5 years or so clean well and add another coat. $99 is a good price for 5 gals. Do they recommend a primer? Some of the cheaper acrylic or latex coatings warn about applying it where standing water can be a problem. I have looked into several products like this (Black Jack, Henry's) and have always been referred to a technical person to answer these type's of questions.
