What issue can arise from using nail-base insulation?

Using nail-base insulation can lead to moisture buildup for several reasons. This type of insulation often has a rigid board with a layer designed for attachment to the roof deck. If not installed properly or if there are gaps around the edges, moisture from the environment or from the interior spaces can become trapped between the insulation board and the roof deck. This trapped moisture may lead to mold growth, deterioration of roofing materials, and damage to the building structure over time.

Furthermore, if the nail-base insulation does not provide proper drainage or if ventilation is insufficient, condensation can accumulate. This scenario is particularly common in climates with high humidity or where there are significant temperature differences between indoor and outdoor environments. Addressing the installation and ensuring that there are adequate ventilation pathways are essential to prevent moisture-related issues.

In contrast, the other issues listed, such as increased thermal resistance, excessive weight, and poor ventilation, either do not specifically result from nail-base insulation or are not as directly linked to the immediate installation concerns typically associated with this type of product. While those factors are worth considering in general roofing practices, moisture buildup remains a more critical and direct concern when using this insulation method.