What part of the flashing system is attached to the chimney when flashing around a masonry chimney?

The part of the flashing system that is attached to the chimney when flashing around a masonry chimney is cap flashing. Cap flashing is designed to prevent water from penetrating through the joint where the chimney meets the roofline. It covers the top of the chimney and directs water away from the chimney sides, guiding it onto the roof surface below.

Cap flashing is essential because it provides a watertight seal at the highest point of the chimney, which is vulnerable to weather exposure. By effectively directing water away, it protects the chimney structure itself and helps to prevent leaks into the home.

Other types of flashing, such as base flashing and step flashing, serve different purposes. Base flashing is usually applied at the base of vertical surfaces, while step flashing is used at the intersections of sloped roofs and vertical walls. Counter flashing is installed above other types of flashing to cover their edges and prevent water from getting underneath. Understanding the specific function of each flashing type helps ensure effective waterproofing and the longevity of roofing installations.