The answer to 'why is my flashing leaking' is that flashing can leak for several common reasons, including improper installation, damage or deterioration, and sealant failure. Flashing is the thin metal or rubberized material installed around roof penetrations, edges, and transitions to prevent water from seeping into the home.
Some of the most common causes of flashing leaks include: nails or screws that are loose or missing, cracks or holes in the flashing material, deteriorated sealants, and improper overlap or installation. Symptoms of a flashing leak can include water stains, mold growth, and rotting wood around the affected area.