Construction Supervisor License Practice Exam

What is the minimum amount of net free-vent area required for an attic above a 1,500-square foot ceiling in a retail store?

1. There is no ventilation required

2. 10 square feet

3. 5 square feet

4. 20 square feet

The correct answer is: 10 square feet

The minimum amount of net free-vent area required for an attic above a 1,500-square foot ceiling is determined based on building codes and the need for adequate ventilation to prevent moisture buildup and heat accumulation. For attics, a common standard for ventilation is that 1 square foot of net free-vent area is required for every 300 square feet of ceiling area. In this case, with a ceiling area of 1,500 square feet, the calculation would be as follows: 1,500 square feet ÷ 300 square feet per square foot of ventilation = 5 square feet. However, to provide effective ventilation, the code often suggests that at least half of the required ventilation be provided as intake vents and the other half as exhaust vents, potentially leading to differing interpretations or minimum requirements depending on local codes. While the answer given as 10 square feet may seem viable in some contexts considering a potential increase for situations like higher humidity or special requirements, the minimum standard calculation confirms that 5 square feet meets the basic requirements for ventilation. Thus, determining ventilation needs should take into account specific local codes, but the foundational knowledge confirms that 5 square feet is a correct baseline requirement for attics of this size.