I used a swimming pool type membrane paint on sealer . Left it two days to set etc . Then painted over with acrylic water bassed high sun resistant paint . Two Coates 6 moths apart looks like new . The membrane is put on just in case there's any leaks in original rubber covering . It also breaks down a little leaving white stripes down lower section pain . Since painting roof . We don't have any issues . I must say it seems cooler too . I used full gloss .. IMO it resists dust and dirt better and easier to wash . I have some bees wax I'm going to put over it soon to keep water etc off so it's way easier to clean ..

You only need 5 litres .https://www.ebay.com.au/itm/111482668336