Cavity Wall Insulation

Cavity wall insulation is a thermal insulation system in which insulation material is installed within the cavity between the inner and outer leaves of a wall assembly. The primary function of this system is to reduce conductive heat transfer through external walls while maintaining the structural performance of the wall.

By placing insulation inside the cavity, a continuous thermal resistance layer is formed that limits heat flow from the exterior environment into the building. This improves indoor thermal comfort, reduces cooling energy demand, and enhances overall building energy efficiency.

Polystyrene products are commonly used for cavity wall applications due to its lightweight nature, stable thermal performance, low water absorption, and ease of handling.

In a typical cavity wall insulation system, XPS / EPS  insulation boards or  beads are positioned between the inner blockwork and the external masonry or cladding leaf. The insulation layer acts as a thermal barrier while the wall leaves provide structural capacity and weather protection.