Ontario Building Code Practice Exam

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

1. Labeled with a fire rating

2. Non-combustible materials

3. Minimum thickness of 75 mm

4. Continuous from floor to underside of roof sheathing

The correct answer is: Minimum thickness of 75 mm

Minimum thickness of 75 mm is not a specific requirement for a fire-rated beam assembly in a commercial building. While a fire-rated beam must be labeled with a fire rating and made with non-combustible materials, the thickness can vary depending on the design and needs of the building. For example, a beam might have a fire rating of 2 hours, but the minimum thickness may be more or less than 75 mm depending on the building's design. Additionally, the option about the beam being continuous from floor to underside of roof sheathing is also a requirement for a fire-rated beam assembly. This option is important because it ensures that there are no gaps or breaks in the fire-resistant barrier created by the beam.