Hi Jason, I have used Modified, (torch down) roofing on my patios for years. It looks just like roll roofing, but you can either use a torch to heat the underside up so the tar melts and it lays down like you hot mopped the roof, or just use roof nails. I did both patios in 1995 and they still look great. (Now try to get roll roofing to last even half that long).
I have done roofs out at Orange Empire, as well as some of the roofs in Chama and Sublette with the material and it is very pliable to boot. Looks historic and lasts 2 to 3 times as long = win.