If a roof ridge is closer than 10 feet to a chimney, the stack should be ____ feet higher?

In this scenario, the correct answer indicates that the chimney should be at least 2 feet higher than the roof ridge if the ridge is less than 10 feet away from the chimney. This requirement is based on general guidelines for the proper installation and placement of chimneys to ensure efficient operation and safety.

Chimneys need to be adequately positioned to prevent exhaust gases from directly impacting the performance of vents, especially from nearby structures like roofs. If a chimney's height is insufficient in relation to the roof ridge, there is an increased risk of downdrafts, which can cause smoke or gases to enter the living space, creating health hazards. Additionally, proper chimney height helps mitigate issues like creosote buildup and inefficient combustion.

Therefore, maintaining a height differential of at least 2 feet over the closer roof elements helps promote better ventilation, protects structural integrity, and enhances safety within the home. These considerations underscore the importance of adhering to established guidelines for chimney and roof system interactions.