If the cause of a leak is a hole in a roof flashing, or a dislodged joint, you can repair it by yourself. If the damage is severe, however, replacing the flashing with a new one is the best solution to the leak in the roof. For holes, you can patch them with epoxy compound. For dislodged joints, you need roof cement or slater’s cement to re-attach them. Finish the project by caulking the base joints. Use roof caulk specifically for this purpose.