One of the most important safety tools youll need is a good pair of rubber soled shoes. For a shingle roof, once you find the leak look for damage, a cracked or missing shingle may just need replacing. If no damage can be seen you will need to call a professional. To repair curled back shingle, use asphalt roof cement. In the summer a curled back shingle can to easily straighten out, but in the winter a shingle can become brittle. To soften a cold brittle shingle, careful use a propane torch with a flame-spreader nozzle. Apply heat only to soften, not until it catches fire. Once flatten apply roof cement generously to the bottom and edges and press firmly into place.