Chimney Safety Institute of America (CSIA) Certification Practice Test

What is the minimum height that a natural draft chimney must extend above a parapet wall within 10 feet?

1. 1 foot

2. 2 feet

3. 3 feet

4. 4 feet

The correct answer is: 2 feet

The minimum height that a natural draft chimney must extend above a parapet wall within 10 feet is 2 feet. This requirement is established to ensure proper draft and to minimize the potential for downdrafts or the reentry of exhaust gases into the building. Natural draft chimneys rely on the difference in temperature between the flue gases and the ambient air to create a draft. If a chimney is not sufficiently tall above obstructions like parapet walls, it can obstruct airflow and adversely affect the chimney's performance. A height of 2 feet above a parapet wall ensures that the chimney's exit is adequately elevated to provide an unobstructed path for the flue gases to escape safely, contributing to better ventilation and improved safety. By adhering to this height requirement, it helps prevent issues such as smoke backdrafts that can pose safety hazards. Thus, maintaining a minimum of 2 feet above nearby structures is a critical aspect of chimney safety and functionality.