Which of these is a common risk associated with nail base insulation on steep slope roof assemblies?

Nail base insulation on steep slope roof assemblies is particularly susceptible to the risk of condensation or moisture accumulation. This happens because the insulation can create a thermal barrier that may trap warm, humid air underneath the roofing materials, especially if there is insufficient ventilation in the roof assembly. When the warm air rises and comes into contact with the cooler roof surface, condensation can form, leading to moisture accumulation. This accumulation can, over time, result in significant damage, including mold growth, deterioration of roofing materials, and even structural issues if not addressed promptly.

Other options either do not pertain to the common risks associated with nail base insulation or describe benefits rather than risks. For instance, structural failure generally is not linked to nail base insulation itself unless it is improperly installed or if the underlying structure is compromised. Increased insulation value and reduced weight on the roof are beneficial aspects of using nail base insulation, contributing positively to energy efficiency and load considerations rather than highlighting any risks involved.