A roof plumber repairer is responsible for installing, repairing, and maintaining plumbing systems on roofs. This can include installing and repairing gutters, downpipes, and roof flashings, as well as ensuring proper drainage and water flow on roofs. Roof plumbers may also work on rainwater collection systems, such as rainwater tanks and filtration systems. Additionally, they may be involved in waterproofing roofs and preventing leaks. Overall, the role of a roof plumber is to ensure that the plumbing systems on a roof are functioning properly and effectively.