Eh? Are you talking about retro-fitting or building with proprietary cavity batts etc?
The main culprits are poor workmanship i.e. cavity snots etc.
Retro fitted. Often fitted in unsuitable homes.
![www.gov.uk](https://www.gov.uk/assets/static/govuk-opengraph-image-03837e1cec82f217cf32514635a13c879b8c400ae3b1c207c5744411658c7635.png)
Cavity wall insulation (CWI): consumer guide to issues arising from installations
Guidance for householders who suspect they have had faulty cavity wall insulation installed at their properties, or have been contacted by a claims management company.