Water appears at a window’s lower corner in driving rain

If water appears after rain, glazing may be blamed. Suppose it happens with one wind direction, starts by the frame, and earlier testing only wetted glass without observing drainage, perimeter joints or first droplets indoors.

What needs to be clarified

Locate water paths, separating window drainage and external junctions, through agreed repeatable testing before considering whole-window replacement.

Materials to prepare

Window drainage drawing and installation joint detail
First-trace photos with rain duration, date and wind direction
Specialist access to internal and external observation zones

What to compare

Map traces and initial moisture; inspect accessible seals, drainage and perimeter. A specialist tests agreed zones sequentially with controlled exposure, recording first-water timing and location. Document conditions, applied pressure and unobserved cavities; protect finishes against further damage.

Possible outcome of the analysis

A water-path diagram and zone protocol may assess explanations and specify targeted opening or further testing where the route remains concealed.

Limits of the conclusions

Simple wetting cannot reproduce every driving-rain condition. One dry trial cannot exclude concealed moisture; frame-side water does not prove defective glazing.