When eave or cornice vents are installed, what is the minimum air space required between the insulation and the roof sheathing at the vent location?

The correct minimum air space required between the insulation and the roof sheathing at the vent location is 1 inch. This space is critical for ensuring proper ventilation in the attic, which helps in maintaining the performance and longevity of the roofing system. Proper air circulation is essential to prevent moisture buildup, which can lead to mold growth and degrade insulation effectiveness.

Maintaining a 1-inch air gap allows for sufficient airflow to enter through eave or cornice vents and exit through ridge vents, facilitating the exchange of air that regulates temperature and humidity levels in the attic space. This balance is vital in preventing overheating during the summer months and ice dam formation in winter, contributing to the overall efficiency of the roof system.

The other options, while valid considerations, do not meet the standard requirement for effective air circulation. For instance, options with less than 1 inch may restrict airflow, while those with more than 1 inch might not necessarily contribute to improved ventilation but can complicate insulation installation or lead to increased energy costs. Therefore, 1 inch is established as the optimal minimum distance to achieve effective ventilation without compromising insulation performance.