What needs to be clarified
Locate the haze relative to the glass surfaces and assess indications of insulating glass seal failure, distinguishing cavity moisture from surface condensation before deciding whether any replacement is justified.
Materials to prepare
- Glazing specification and photographs linking unit markings to the window
- Photographs under different conditions and a log of the patch’s appearance
- Specialist access to safely reachable surfaces and glazing details
What to compare
A specialist observes the patch from different directions and records its surface location, using safe cleaning of accessible faces for comparison. Record temperature and humidity; inspect accessible unit edges, drainage and support against system documentation. If removal is needed, agree it while preserving evidence; do not drill the sealed cavity for testing.
Possible outcome of the analysis
Possible results include a haze location diagram and assessment of supported explanations; further edge-seal examination, work on the glass unit or observation in colder weather is specified separately.
Limits of the conclusions
A photograph does not prove seal failure. Cavity moisture does not automatically establish a manufacturing cause; timing and installation effects require additional evidence about the particular unit.