What is the primary function of flashing in a roofing system?

The primary function of flashing in a roofing system is to prevent water seepage. Flashing is typically made from metal or other waterproof materials and is strategically installed at joints, seams, and around protrusions such as vents, chimneys, and skylights. By directing water away from these vulnerable areas, flashing plays a crucial role in waterproofing the roof and protecting the underlying structures from moisture damage, which can lead to mold, rot, and structural issues. This is essential for maintaining the integrity and longevity of the roofing system.

While insulation, aesthetic appeal, and supporting roofing materials can be important aspects of a roofing system, none serve the primary purpose of preventing water intrusion as effectively as flashing does.