According to special provisions, a building must be separated with a horizontal assembly having a minimum fire-resistance rating of how many hours?

The correct answer indicates that a building must feature a horizontal assembly with a minimum fire-resistance rating of 3 hours due to specific safety regulations and building codes aimed at reducing fire hazards and protecting occupants. A 3-hour rating provides significant time for occupants to evacuate and for fire services to respond before the structural integrity of the building is compromised.

In the context of commercial buildings, this requirement often applies to mixed-use scenarios or structures where different occupancies might pose varied fire risks. This level of fire resistance is crucial in ensuring that a fire in one area does not quickly spread to other areas, thereby affording additional time to implement safety measures and ensure the protection of life and property.

Understanding the implications of fire-resistance ratings and how they enhance safety measures is key for a building inspector. This rating not only determines the materials and construction methods used but also aligns with broader fire safety provisions to mitigate risk effectively.