Flashing is usually thin sheets of aluminum or galvanized steel. Many professional roofers will fashion their own from sheet metal. Flashing is installed over joints in the roof & wall construction. Possible areas are valleys, chimneys, dormers, windows, pipes, skylights, porches, decks and edges.
New flashing often installed with a new roof. If flashing deteriorates or comes loose is can cause severe damage to your home. It is important to make sure it is installed properly to avoid unnecessary damage.