California Residential Inspector Practice Exam

What is the minimum clearance required between insulation and roof sheathing for enclosed attics or rafter spaces with eave vents?

1. 1/2 inch

2. 1 inch

3. 2 inches

4. 3 inches

The correct answer is: 1 inch

The minimum clearance required between insulation and roof sheathing in enclosed attics or rafter spaces that have eave vents is established primarily for ventilation purposes. Having a minimum clearance of 1 inch allows for proper airflow within the attic space, helping to prevent moisture accumulation and subsequent problems like mold growth and wood deterioration. Adequate ventilation is essential in these areas to maintain the overall health of the structure, especially in climates prone to temperature fluctuations and moisture buildup. By maintaining this clearance, homeowners and inspectors ensure that insulation does not block airflow from the eave vents, allowing cool air to enter and warm, moist air to escape. This balance of airflow helps to regulate attic temperatures and moisture levels, which can prolong the life of roofing materials and the structural elements of the home. The other options suggest greater clearances, which are not necessary and could unnecessarily reduce the amount of insulation that can be installed, potentially decreasing energy efficiency.