Which of the following is NOT a factor in selecting a firestop system?

Selecting a firestop system involves careful consideration of various factors that directly impact fire containment and safety. One critical factor is the fire-rated assembly, which signifies the specific rating a building element has in terms of its fire-resistance capabilities. This rating helps determine the appropriate firestop system to use based on the level of protection needed.

The penetrating item is also a crucial factor, as it pertains to what is penetrating the fire-rated assembly. Different items, such as pipes or cables, require tailored firestop solutions based on their materials and fire performance characteristics.

The annular space refers to the gap between the penetrating item and the surrounding construction. This spacing must be accounted for in the design of the firestop system, as it influences the effectiveness of the firestop material in preventing the spread of fire and smoke.

The length of time the building has been standing does not generally affect the selection of a firestop system. Firestop systems are designed to perform in accordance with the current standards and conditions, regardless of the age of the building. Therefore, it is the other elements—fire-rated assembly, penetrating item, and annular space—that are essential to consider in the decision-making process for firestop system selection.