I have about an inch 1/2 of water on flat roof(asphalt)?

Most flat roofs have a drain, its normally a requirement, but I dont know that particulars of the roof in question. If this is a residence and its a small overhang roof without drainage, it will eventually leak, I dont care what its made out of. Throwing more stuff on top of it isn't going to make any difference, in fact it may make it worse. If its exposed now and the water evaporates quickly then its not as big a worry, if not then it should be resurfaced.