Roof Flashing

Flashing refers to materials installed along roof joints or angles such as roof valleys to prevent the penetration of water into roofing materials. It is generally made of galvanized metals for outdoor durability, or aluminum for flexibility. There are several different shapes and sizes of flashing, most of which form some kind of V or L-shape. Special attention should be paid to the areas that need flashing as they are the most susceptible to water leaks in a roofing system.


Flashing can normally be found in roof valleys where two roof planes meet, at the base of the chimney where roofing materials meet up with the brick, and the bases of vent fans. If your home has dormers, the base of the dormer wall and the roof deck meeting up to it are also areas of importance. The purpose of flashing is to direct water from these vulnerable areas down and out onto the main roofing materials where leaks are less likely.