Which type of firestop requires verification of approved installation methods by the manufacturer?

The correct answer highlights that through-penetration systems are particularly sensitive to installation methods due to the nature of how they function. These systems are designed to prevent the passage of fire, smoke, and hot gases through openings created when pipes, cables, or other items penetrate walls, floors, or ceilings. Because this type of firestop is installed around penetrating items, ensuring compliance with the manufacturer's installation guidelines is critical.

Improper installation can lead to vulnerabilities in the fire-resistive barrier, diminishing its effectiveness and potentially leading to fire spread. Therefore, verifying approved installation methods as described by the manufacturer is vital for maintaining the integrity of the firestop system in these cases.

While other firestop types may have installation requirements, through-penetration systems require a higher level of scrutiny to ensure that they are installed correctly to meet fire safety standards and regulations.