The answer to 'why is my flashing worn out' is that flashing typically becomes worn out due to exposure to the elements over time. Flashing is the metal or plastic material used around roof penetrations, edges, and joints to prevent water leaks. Over the years, the flashing can deteriorate from UV radiation, weather, and physical wear, leading to cracks, gaps, and holes that allow water to seep in.
Common symptoms of worn-out flashing include water stains, mold growth, and visible damage or gaps around chimneys, vents, and roof edges. The best solution is to have the worn flashing replaced by a professional roofing contractor, as improper flashing installation or repair can lead to major water damage.