What are the two types of flashings that should protect roof-wall interfaces?

The correct answer focuses on the essential types of flashings needed to protect roof-wall interfaces effectively. Flashing is crucial in preventing water intrusion, especially at vulnerable points where different building elements meet, such as where a roof intersects with a wall.

Base flashing is installed at the base of a wall and acts as the primary defense against water that travels down the wall, directing it away from the structure. Counter-flashing, on the other hand, is typically installed over the base flashing to provide an additional layer of protection. It helps to direct water away from the building and ensures that any water that might bypass the counter-flashing is still managed effectively by the base flashing.

Together, base and counter-flashing form a robust waterproofing system at roof-wall interfaces, which is critical for the longevity and integrity of the roofing system. Understanding these components and their roles helps ensure that roof installations are done correctly to stave off moisture issues that could lead to significant structural damage over time.