I need to replace the semi-flat roof on my garage and need some affordable, diy options. It has had several layers of cheap roll roofing on it that haven't held up. I am going to tear off the entire roof, nail up new rafters and put down plywood. What are my best roofing options? My biggest obstacle is that I share the garage with a neighbor who doesn't want to spend much money on it. A professionally installed rubber membrane roof isn't an option. Thanks for any help.