Hygrothermal performance assessment of ICF walls with different moisture control strategies and wall designs

The initial high moisture content of concrete and the low vapor permeability of insulation layers on both sides of the concrete complicate the drying process of Insulated Concrete Forms (ICF). In order to facilitate the moisture transport and enhance the drying process, diffierent moisture control strategies and wall designs can be implemented. The application of an air and vapor barrier is one of the most common moisture control strategies. In this paper, the impact of vapor permeance of an air and vapor barriers on the hygrothermal performance of an ICF wall in three diffierent cold and wet climates is examined using a validated Heat-Air-Moisture transfer model. The hygrothermal performance of an ICF wall assembly with diffierent types of barriers and locations in the wall system for several wall designs is investigated. Results indicate that a smaller thickness of insulation on the outside facilitates removing the moisture towards the outside and installing low permeance air/vapor barrier systems on the outside prohibits drying and drives the moisture to the inside. Our findings also show that with the proper selection of insulation thickness and vapor control strategy moisture-related problems can be avoided.