What provides both moisture control and thermal barrier in an EIFS system?

In an Exterior Insulation and Finish System (EIFS), the insulation plays a crucial role in providing both moisture control and thermal barriers. The insulation material is typically installed on the exterior side of the wall, which helps to keep the interior of the building warm in winter and cool in summer, thus serving as an effective thermal barrier.

Furthermore, insulation materials used in EIFS often have moisture-resistant properties. They help to manage moisture penetration by creating an environment that minimizes the chances of condensation that could lead to mold and decay within the wall assembly. This dual function of providing thermal resistance while also controlling moisture is essential for maintaining the overall integrity and energy efficiency of the building.

Other options do not provide both functions as effectively: exterior cladding primarily serves as a protective layer against the elements, while vapor barriers focus mainly on preventing moisture vapor from passing through, but they do not contribute to insulation. Foam board is a type of insulation, but it does not inherently provide moisture control without additional protective layers. Therefore, insulation stands out as the component in an EIFS system that effectively combines both moisture control and thermal insulation benefits.