Ontario Building Code Practice Exam

Which of the following is not a requirement for a fire-rated ceiling assembly in an industrial building?

1. Non-combustible materials

2. Labeled with a fire rating

3. Continuous from wall to wall

4. Minimum thickness of 75 mm

The correct answer is: Minimum thickness of 75 mm

The requirement for a fire-rated ceiling assembly in an industrial building includes the use of non-combustible materials, proper labeling indicating the fire rating, and a design that ensures continuity from wall to wall. These elements are essential for maintaining the integrity and effectiveness of the fire protection system. Non-combustible materials are crucial since they help prevent the spread of flames and smoke between different compartments of the building. Labeled fire ratings provide crucial information about the fire-resistance capabilities of the materials, ensuring compliance with standards and regulations. Continuity from wall to wall is vital to limit potential fire spread, as gaps or interruptions can compromise the assembly's performance during a fire event. The minimum thickness of 75 mm, however, is not a standard requirement for fire-rated ceilings. Fire-rated assemblies may have various thickness requirements depending on the specific materials used and the rating needed, but 75 mm does not universally apply to all fire-rated ceiling assemblies. Therefore, this aspect is not a general requirement in accordance with the Ontario Building Code.