GacoFlex A48 single-component, high-build, acrylic roof coating can be applied up to 80 wet mils thick in a single pass. The manufacturer says the coating, which can be applied for maintenance over most existing roof substrates, offers a long roof life, strong adhesion, high tensile strength, and reflectivity. The water-based solution is zinc-free, contains zero VOCs, and can be sprayed from a standard acrylic spray system. It is resistant to rain as soon as 30 minutes after application and cures fully in about eight hours, according to the manufacturer. gaco.com