In terms of Firestop Penetrations, which of the following is defined as an opening that pierces one side of an assembly?

The concept of a Firestop Penetration involves understanding how various openings in building assemblies can impact fire safety. The correct choice, which describes an opening that pierces one side of an assembly, is defined as a Membrane Penetration.

Membrane penetrations are openings that traverse a fire-resistance-rated assembly, such as walls or floors, allowing cables, pipes, or ductwork to pass through. The key aspect here is that these penetrations occur within the membrane of a fire-rated barrier and are critical in maintaining the integrity of that fire-resistance rating. Proper firestopping is necessary to restore the fire-resistance rating and prevent the spread of fire and smoke through these openings.

In contrast, through penetrations involve openings that extend through the entire thickness of the assembly, while a fire partition is a vertical assembly designed to restrict the spread of fire. A curtain wall refers to a non-structural outer covering of a building, typically made of glass or other lightweight materials, which does not contribute to fire resistance in the context of penetrations.

Understanding these definitions helps ensure compliance with fire safety regulations and contributes to building safety design.