Double Glazed Window Cracked Inside [hot] May 2026

You don’t usually hear it happen. There’s no smash of baseball-bat glass, no howl of wind, no obvious intruder. You simply glance at the living room window one morning and see it: a thin, silvery line, or perhaps a web of fractures, snaking across the inner surface of the glass.

You touch the pane. It’s smooth. The crack is on the inside—but between the two sheets of glass. double glazed window cracked inside

Your window frame expands and contracts at a different rate than the glass. If the installer used too little glazing tape or overtightened the retaining beads, the frame pinches the IGU. Over a few seasons of expansion, the inner pane, which has less flexibility than the outer (being further from the external buffer), gives way. You don’t usually hear it happen