Ontario Building Code Practice Exam

Which of the following is not a requirement for a fire-rated enclosure in a commercial building?

1. Non-combustible materials

2. Labeled with a fire rating

3. Continuous from floor to underside of roof sheathing

4. Minimum thickness of 50 mm

The correct answer is: Minimum thickness of 50 mm

A requirement for a fire-rated enclosure in a commercial building is that it must be made of non-combustible materials, labeled with a fire rating, and continuous from floor to underside of roof sheathing. The minimum thickness of 50 mm is not a requirement for a fire-rated enclosure, making option D the correct answer. It is important for a fire-rated enclosure to be made of non-combustible materials to prevent the spread of fire, labeled with a fire rating for easy identification, and continuous from floor to roof to ensure complete containment of the fire. While a minimum thickness can contribute to the structural integrity and durability of the enclosure, it is not a necessary requirement.