Which of these is not a likely indicator of inadequate ventilation in a steep slope roofing system?

The presence of moisture on the top surface of the deck is typically not directly attributed to inadequate ventilation in a steep slope roofing system. Inadequate ventilation is more commonly linked to issues that result from trapped moisture within the insulation or living space, as well as the build-up of heat and humidity.

Other indicators of poor ventilation, such as moisture in the insulation, ice dams forming, and mold growth in upper areas, all stem from the inability of moist air to escape effectively. Moisture in the insulation suggests that humidity has penetrated and accumulated, potentially leading to deterioration. Ice dams occur when warm air in the attic melts snow on the roof, which then refreezes at the eaves due to cooler air, pointing to poor airflow. Similarly, mold growth is often the result of persistent moisture and lack of airflow, a direct consequence of inadequate ventilation.

In contrast, moisture on the top surface of the deck can be influenced by external factors, such as poor roofing material installation, weather conditions, or inadequate drainage systems, and does not unequivocally indicate a ventilation problem. Thus, this characteristic is less likely to be a sign of ventilation inadequacy compared to the other options listed.