What is the minimum distance required between insulation and the roof sheathing?

In residential construction, it is crucial to maintain proper ventilation and prevent moisture buildup in attics and roof spaces. The minimum distance required between insulation and the roof sheathing is established to ensure that air can circulate adequately. This distance helps to reduce the risk of moisture accumulation, which can lead to mold growth and deterioration of materials.

Having a gap of at least 1 inch allows enough space for air to flow, which is essential for maintaining an effective ventilation system in the attic. This ventilation helps regulate temperatures, particularly in hot weather, thus preventing overheating and promoting an overall healthier environment for the building structure.

If the insulation were too close to the roof sheathing, it could trap heat and moisture, increasing the likelihood of insulation degradation and structural damage over time. This requirement is based on ensuring not just energy efficiency, but also the longevity and safety of the building.