What is Partial-Fill Cavity Insulation?

Definition

Partial-fill cavity insulation involves fitting PIR boards to the inner leaf of a wall, leaving a small air gap behind the outer leaf and the PIR boards. It’s ideal for walls where space is constrained or for retrofit projects.

Benefits

• Energy Efficiency: Improves U-values while avoiding thick wall build-ups.
  
• Moisture Management: An air gap allows moisture to escape, reducing the risk of condensation.
  
• Flexibility: Suitable for retrofit and limited-space projects.
  

Applications

• ECO/CW boards are designed for partial-fill applications.
  
• Works with drylining systems, such as Safe-R or Thin-R, for added internal insulation.
  
• Suitable for residential and commercial properties, including older builds.
  

Best Practice Tips

• Maintain consistent air gaps for proper moisture ventilation.
  
• Combine with VCLs and high-performance plasterboards for optimal thermal efficiency.
  
• Ensure careful board alignment to minimise thermal bridging.