What is the purpose of using step flashing in roofing?

The purpose of using step flashing in roofing is primarily to redirect water away from vulnerable areas, particularly at the junction of a sloped roof and a wall. Step flashing consists of individual pieces of metal that are bent into an L shape and installed in overlapping layers. This design allows water flowing down the roof to be diverted away from the wall and off the roof, reducing the risk of leaks and water damage surrounding the intersection.

The effectiveness of step flashing comes from its ability to create a watertight seal at critical points, ensuring that any moisture is channeled away from the structure rather than allowing it to seep behind the wall or into the building. This is crucial in maintaining the integrity of the roofing system and protecting the home from potential damage due to water infiltration.

Other options, such as providing a decorative finish, improving insulation value, or supporting structural beams, do not accurately reflect the primary function of step flashing in roofing applications. Step flashing's design and installation are specifically targeted toward managing water runoff and safeguarding vulnerable areas of a roof system.