What is required for barriers to form an effective membrane in a building?

For barriers in a building to form an effective membrane, they must be continuous and properly integrated throughout the structure to ensure a watertight and air-tight envelope. The key concept here is the continuity of the barrier from various critical points, such as the top of the foundation to the underside of the roof sheathing or deck. This continuous application prevents moisture intrusion, reduces energy loss, and helps manage air flow within the building.

The first choice emphasizes the requirement for continuity from the foundation to the roof sheathing, which is crucial for preventing water infiltration and maintaining climate control within the building. The second choice focuses on the connection from the foundation to the underside of the deck, which serves a similar purpose but may not cover all aspects of the building's envelope. The third choice expands this idea further by including different structural components like the floor and ceiling assemblies, emphasizing the importance of continuity between these areas.

Since each of these choices highlights an important element of effective barrier installation within a building, selecting all of them recognizes the full spectrum of conditions required for a properly functioning membrane. Thus, the comprehensive understanding that all these barriers should ideally be continuous throughout defines why the correct response includes all of the previously mentioned requirements.