Ontario Building Code Practice Exam

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

1. Labeled with a fire rating

2. Non-combustible materials

3. Continuous from floor to underside of roof sheathing

4. Minimum thickness of 75 mm

The correct answer is: Minimum thickness of 75 mm

A fire-rated column assembly is a structural element designed to resist the spread of fire and provide structural support in a commercial building. As such, it must meet certain requirements to ensure its effectiveness. Option D, minimum thickness of 75 mm, is not a requirement for a fire-rated column assembly. This is because there are other factors that determine the fire resistance of a column, such as the materials used and the method of construction. Option A, being labeled with a fire rating, is a requirement to communicate the level of fire resistance to building occupants and authorities. Option B, non-combustible materials, is a key requirement for the column to withstand high temperatures and prevent the spread of fire. Option C, being continuous from floor to underside of roof sheathing, is also necessary to prevent the fire from spreading through any gaps or breaks in the assembly. Thus, option D does not align with the general requirements for a fire-rated column assembly.