In which cavity walls are best suited against head dust rain or light?

Cavity walls are best suited against heavy rain, as their design creates a barrier that reduces water penetration. The outer leaf of the wall acts as a shield, while the cavity allows any moisture that does get through to drain away. Additionally, these walls provide insulation and help to prevent dampness, making them effective in various weather conditions. However, they may not offer significant advantages against light, as their primary function is moisture control rather than light blockage.