Which type of wall is preferred in areas with severe weather exposure for maximum rain penetration resistance?

The preferred type of wall for areas with severe weather exposure, designed to provide maximum resistance to rain penetration, is the cavity wall. Cavity walls consist of two parallel walls with a gap or cavity between them, which helps to direct water away from the interior of the building.

This design creates a barrier that prevents moisture from transferring through the outer layer to the inner layer. The cavity can allow for the drainage of any water that does enter the wall system, helping to ensure that it does not reach the insulation or the interior spaces of the building. Additionally, cavity walls can accommodate various weatherproofing techniques, such as flashing or weep holes, further enhancing their protective capabilities against rain.

In contrast, retaining walls are primarily designed to hold back soil, and while they can be built to resist water pressure, they are not specifically aimed at preventing rain penetration. Load-bearing walls support vertical loads of a structure, and their design is more focused on strength rather than weather resistance. Shear walls are designed to resist lateral forces, such as wind or earthquakes, and are also not primarily intended for rainwater management. Therefore, cavity walls are considered the most effective choice in regions vulnerable to heavy rain.