What is installed below the roof sheathing in the Combination Method?

In the Combination Method of insulation, air-permeable insulation is installed below the roof sheathing. This approach takes advantage of the properties of air-permeable materials, allowing some airflow while still providing effective thermal resistance. This component is crucial for managing moisture control and ventilation in roofing assemblies.

Air-permeable insulation enables the building to breathe while also helping to reduce heat loss in colder months. It works together with other insulation systems to create a balanced environment that mitigates condensation risks and enhances overall energy efficiency.

The choice of air-permeable insulation in this method supports both insulation and ventilation strategies, ensuring that any moisture that may develop in the roof assembly can escape without compromising the thermal performance of the roof.