Dew point-related condensation risk can be mitigated by

• A. Improved interior lighting
• B. More attic insulation only
• C. Using more permeable drywall
• D. Vapor retarders placement, air sealing, and continuous insulation

Answer: (D)

Controlling dew point-related condensation hinges on managing how moisture moves through and how temperatures are maintained across the building envelope. Condensation happens when moist indoor air meets a surface that’s cooled enough for its water vapor to condense. The best way to mitigate this is to reduce moisture diffusion into wall and attic assemblies, prevent uncontrolled air leakage, and minimize cold spots where dew point can be reached.

Vapor retarders placed correctly limit how much moisture can diffuse from the interior into wall cavities. Air sealing stops warm, humid indoor air from leaking into hidden spaces. Continuous insulation reduces thermal bridging, which creates cold spots and lowers surface temperatures beneath the dew point. Together, these measures keep moisture from reaching susceptible surfaces and keep interior surfaces warm enough to stay above the dew point.

Interior lighting has no direct effect on moisture transport or surface temperatures. Adding attic insulation alone doesn’t address gaps or diffusion paths and won’t prevent condensation if leaks and diffusion are still present. Making drywall more permeable would actually allow more moisture to migrate into assemblies, increasing the risk of condensation.