Final answer:
Maintaining ventilated airflow between sheathing and insulation is essential for effective insulation and healthy air turnover.
Step-by-step explanation:
You have to maintain a ventilated airflow between the bottom of the sheathing and the insulation. Air acts as a good insulator due to its poor conductivity, and it is helpful to prevent heat transfer through convection when sealed within a space like within the walls or window panes.
In the context of home construction, ventilation which allows for a controlled amount of airflow works to keep insulation effective while also allowing the house to 'breathe,' facilitating the necessary air turnover for a healthy indoor environment.
Furthermore, measures such as weather stripping and caulking improve the insulation and energy efficiency of a house by reducing air infiltration, which is the unintentional introduction of outside air into the building.