Tin roofs generally last 40 to 70 years and shingled asphalt roofs roughly 20 years. Tin roofs have seams which allow panels to be attached with a clamp which is an easier and cheaper installation method, without drilling holes in your roof.   Asphalt roofs require a simple standard penetrating mount that is easy to install. Flat roofs can have tilt up brackets to keep the panels at a 30-degree angle. Tile roofs can have solar installed but need more work to cut or remove tiles for the mounts.