What is a potential problem of using rigid board insulation in low slope roofing systems?

The correct answer highlights a significant concern associated with the use of rigid board insulation in low slope roofing systems. One of the primary challenges with rigid board insulation is its potential to create a scenario where moisture can become trapped within the roofing assembly.

In low slope roofing systems, water drainage can be less effective, and if there is an accumulation of humidity or condensation, it may not be able to escape efficiently. When rigid board insulation doesn't allow for adequate ventilation or if it's improperly installed without consideration of moisture management, condensation can form on the underside of the roof membrane.

This trapped moisture can lead to several issues, including reduced insulation performance, potential mold growth, and damage to the roofing materials and structure over time. This is particularly problematic since the insulation needs to function effectively in preventing heat loss or gain while also managing moisture levels.

Understanding this potential for condensation reinforces the need for careful design and planning when installing low slope roofing systems, ensuring that proper ventilation and moisture control strategies are implemented alongside the insulation.