How should a wall cavity be designed regarding moisture?

Designing a wall cavity to dry toward at least one side is crucial for managing moisture effectively. This approach allows any moisture that enters the cavity to escape, reducing the risk of mold growth, wood rot, and compromise to the structural integrity of the building. By ensuring that the wall cavity can dry toward at least one side—generally the exterior or an interior space that can accommodate drying—the design promotes moisture control and helps to maintain a healthier indoor environment.

In contrast, keeping the wall cavity completely sealed is ineffective because it prevents any moisture that might accumulate from escaping, leading to potential build-up that can cause long-term damage. Trapping moisture is counterproductive as it creates an environment conducive to mold and deterioration. Similarly, eliminating all airflow restricts the natural movement of air, which is essential for moisture management. Proper airflow combined with a design that allows for drying can significantly enhance the durability and safety of the building structure.