What is the minimum space required between insulation and roof-deck sheathing?

The minimum space required between insulation and roof-deck sheathing is 1 inch. This space is critical for allowing adequate ventilation and preventing moisture buildup in the roof assembly. Adequate airflow helps to manage the temperature and humidity levels in the attic or roof space, reducing the risk of condensation that could lead to mold growth and damage to roofing materials.

Having that 1-inch gap ensures that air can circulate freely, which is especially important in climates that experience significant fluctuations in temperature or humidity. Proper airflow also contributes to the overall effectiveness of the insulation system, promoting energy efficiency in the home.

This specific measurement is generally referenced in building codes and guidelines concerning attic ventilation and insulation installation practices. It’s essential for homeowners and contractors to adhere to this requirement to maintain the integrity of the roof system and prevent potential structural issues arising from trapped moisture.