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 50 mm

The correct answer is: Minimum thickness of 50 mm

Fire-rated wall assemblies are specifically designed to prevent the spread of fire in high-rise buildings. Therefore, all of the other options listed are requirements for a fire-rated wall assembly in a high-rise building. Non-combustible materials and a fire rating label are necessary to ensure that the wall can withstand high temperatures and flames. The wall must also be continuous from the floor to the underside of the roof sheathing, preventing any gaps that could allow a fire to spread. The minimum thickness of a fire-rated wall assembly can vary based on building codes and regulations, but it is not a specific requirement for a high-rise building. Therefore, the correct answer is D.