what i used was a garage floor epoxy paint from home depot to paint my bus. its only about $22 gallon around here. i only needed 2 gallons, one white, one black, to paint my bus (short bus) all i did was wash it with a good dish soap using bundles of steel wool instead of a sponge to remove all waxes, tar, etc. then after it dried i just used a roller to apply. it took 3 coats, and take your time! the finish is great. exactly what i wanted. i used a cloth roller because i wanted a "textured" finish, but i used a foam roller on the whole roof and it worked great, nice, smooth, and shiny. they will color the garage epoxies any color you want also. i kept the roof paint a bright white, but the rest i went with a kind of semi-gloss charcoal black. with this too, it creates a nice a hardened finish for the paint. we used to paint the equipment and trailers for our fire department with it as well. hope this helps!