At what moisture content can drywall cover wall cavities with insulation?

The correct answer is based on the recommended conditions for installing drywall over insulated wall cavities. When installing drywall, it is crucial that the moisture content of the materials involved—particularly the insulation and framing—remains at a level that minimizes the risk of mold growth and structural damage.

A moisture content up to 19% is generally considered acceptable for wall insulation when covered with drywall. This level helps ensure that the drywall adheres properly and reduces the chance of moisture-related issues. Higher moisture levels can lead to problems like mold growth, which can not only damage the structure but also pose health risks to occupants.

Lower moisture contents (12% and 15%) are generally ideal; however, 19% is recognized as the maximum threshold before the risk of moisture-related issues becomes significant, making it the best choice among the given options for practical applications in residential construction. 22% is too high and would indicate that the materials are not in a suitable condition for installation.