In cavity walls, the inner leaf handles the structural and physical requirements, such as heat storage and sound insulation, while the outer leaf primarily offers weather protection. Thermal insulation between the two leaves is designed to ensure a favourable temperature profile inside the wall, reducing heat losses in winter and avoiding overheating in the summer. XPS insulation boards are favoured as core insulation in cavity wall insulation projects because they meet all the requirements specified in the relevant industry norms for properties such as:
- Compressive strength.
- Water resistance
- Tensile strength.
- Dimensional stability