The answer to 'what causes flashing' is flashing is a thin metal strip used to prevent water leaks at roof joints, edges, and penetrations. Flashing is typically made of aluminum, galvanized steel, or other corrosion-resistant metals and is installed around chimneys, skylights, dormers, and other areas where the roof meets a vertical surface. Proper installation of flashing is critical to ensure a watertight roof and prevent costly water damage.
Flashing can fail for several reasons, including poor installation, corrosion, physical damage, or improper maintenance. Over time, flashing can become loose, cracked, or detached, allowing water to seep through and cause leaks. Regular inspections and timely repairs are essential to maintain the integrity of your roof's flashing and prevent water intrusion.