What is placed around a chimney to prevent leaks?

Flashing is a crucial component in roofing and chimney construction that is designed to prevent water leaks. It consists of thin pieces of metal that are strategically installed around a chimney to direct water away from the structure. When properly installed, flashing helps create a watertight seal where the chimney intersects with the roof. This is essential because the junction between these elements is often a point where water can enter if not adequately protected.

While caulk can be used to seal smaller gaps, it is not the primary material for preventing leaks around a chimney; it acts more as a supplementary sealant. Gutters are designed to channel rainwater off the roof and away from the building, but they do not specifically address the joint between the roof and chimney. Sealants may also help with waterproofing but do not serve the same structural purpose as flashing, which is specifically designed for this application. Therefore, flashing is the most effective solution for preventing leaks around chimneys.