How to document cavity wall insulation so it never gets questioned
4 min read
Cavity insulation is the classic example of work that disappears within days and gets questioned for years. A short, disciplined photo routine as the wall goes up removes the risk entirely.
Photograph in lifts, not at the end
Capture each lift of insulation as it is installed. Once the outer leaf is up, nothing behind it can be proven by photograph.
Show the joints and the fit
Aim for images that show boards or batts butted tightly with no gaps, correctly clipped, and fully filling the designed cavity width.
Include the product packaging or label at least once per plot so the specification is evidenced.
Cover the weak points
Reveals, cills, lintels, floor and roof junctions and service penetrations are where heat and water actually get through — and where inspectors look first.
Cavity trays, weep holes and closers deserve their own photographs.
Attach the record to the stage
File the photos against the external walls and cavity insulation stage for that plot, with location and time attached, and share the stage with building control for sign-off.