Can double glazing spontaneously crack?

[Stu]

There's a window in my house that has developed a long crack to the inside pane. No one is admitting hitting the window, and I kind of believe them.* So, can a window spontaneously crack?

*previously on a different window I tried with all my might to break a double glazed window with a brick and failed.

Yes, if there's a load on it. It could suggest structural problems in the house

[Luckypants]

Yes - most likely caused by stresses in the sealed unit from time of manufacture or stress induced during mounting in the frame. These can take a while cause a crack as heating/cooling cycles of CH or solar gain cause minute flexes in the glass.

No doubt someone will be along to tell me my 20yo information is out of date very soon.

Anything can 'spontaneously' crack, even after years of good service.

[SoulKiss]

Told you should have put a baffle in that can........

[dizzyblonde]

yes, a big gust of wind can crack it, especially if it is a large one like mine here

My parents had two inside panes of double glazing go on one cold morning....because the house was warm and outside was very cold the glass just gave!!!!

Mate my parents had exactly the same thing. We had a few large panes of double glazing which have an awning over the patio behind them. A strong heat form the sun caused a shadow over half of the window and the temp difference made a huge crack appear. I think it is temp differences maybe that did it for you?

Does sound like a manufacturing fault or increase load from structural failure above; undersized lintol have been typical failures in the past. Generally double glazing panels when correctly fitted are very hard to break compared to a single glazed unit due to the air space between the panes.

Originally Posted by lily

My parents had two inside panes of double glazing go on one cold morning....because the house was warm and outside was very cold the glass just gave!!!!

Originally Posted by Warthog

Mate my parents had exactly the same thing. We had a few large panes of double glazing which have an awning over the patio behind them. A strong heat form the sun caused a shadow over half of the window and the temp difference made a huge crack appear. I think it is temp differences maybe that did it for you?

I would have expected there to be more to it than that as the glass itself should easily withstand such temperature changes. Sounds like a badly fitted unit (too tight a fit?) where the frame has expanded without sufficient room for expansion? Scary!