Ontario Building Code Practice Exam

Which of the following is not a requirement for a fire-rated wall assembly in a high-rise building?

1. Non-combustible materials

2. Labeled with a fire rating

3. Continuous from floor to underside of roof sheathing

4. Minimum thickness of 75 mm

The correct answer is: Minimum thickness of 75 mm

Building codes typically require fire-rated wall assemblies in high-rise buildings to be made of non-combustible materials, to be labeled with a fire rating, and to be continuous from the floor to the underside of the roof sheathing. However, there is no specific minimum thickness requirement for fire-rated walls in high-rise buildings. Thickness may vary depending on the specific materials and fire rating used. This is why option D, "Minimum thickness of 75 mm," is not a requirement for a fire-rated wall assembly in a high-rise building.