WHL SURVEYING & ENGINEERING CASE STUDY
Intrusive Investigation of Cavity Wall Insulation Performance
WHL Surveying & Engineering was instructed to undertake an intrusive investigation of cavity wall insulation at a recently constructed detached dwelling following reports of cold spots and draughts.
Scope of Work
The scope included creating localised inspection openings to external walls, removing sections of internal plasterboard, inspecting insulation within the garage ceiling void, and undertaking thermal imaging to assess thermal performance. The objective was to determine the type, quality, and adequacy of insulation installed and its compliance with current Building Regulations.
Findings
Intrusive inspections revealed that the cavity walls contained loose-fill insulation only, within cavities measuring approximately 85–100mm in depth, with no rigid insulation present on the inner leaf. This configuration is unlikely to meet current thermal performance requirements and may allow settlement, voids, and moisture bridging over time. Internal inspections confirmed the absence of rigid insulation behind plasterboard on external walls, while insulation within the garage ceiling void and lantern room floor appeared inconsistent. Thermal imaging identified widespread cold spots to walls and around openings, confirming reduced thermal performance. Blocked weep holes were also observed, increasing the risk of moisture retention within the cavity.
Recommendations
It was recommended that the developer be engaged to provide documentation confirming insulation specifications and compliance with Building Regulations. Further in-situ thermal performance testing was advised to verify actual U-values. If compliance cannot be demonstrated, remedial works may include removal of external brickwork to access the cavity, replacement with compliant insulation systems, and reinstatement of the façade with appropriate cavity detailing. Supplementary internal insulation may be considered where necessary, followed by post-remediation thermal imaging and air leakage testing to confirm improved performance and eliminate cold bridging.
Contact Us
For more information about our structural design and drawing services, please contact WHL Surveying & Engineering. We’re here to help with innovative solutions for your projects.