[?] Any glazing experts care to comment on glass breakage.

[Dave Chapman]

The inside glass of a double-glazed panel in our locked and unoccupied conservatory has spontaneously shattered (the fourth panel to do it in the 4 years since the conservatory was installed).

Fortunately (?) this time the glass granules didn't all fall out but stayed in place so that I could take pictures of the shattered window and post them here :-

and here's a close-up of the 'epicentre' ....

I'd be most interested to hear from any glazing experts who, after viewing the two pictures, may be able to explain the possible reason for this latest failure.

Any suggestions about the best course of action that I can take with the manufacturer of the conservatory in order to try and get them to try and eliminate any further failures will also be much appreciated.

All sensible responses will be most welcome.

TIA - Dave.

[Jabba]

Dave Chapman wrote

This bloke claims to have investigated the issue

[Andy Burns]

Presumably the panels are not openers, so they don't need to be packed (toed-and-heeled) particularly tight? WHat time of year was the conservatory installed, what time of year have they each shattered?

Got any polaroid sunglasses and a sheet of polarising film (from a dead LCD screen perhaps)?

see if you can see stress patterns in the remaining panes with the polarising sheet on one side and you with the glasses on the other side?

[Dave Chapman]

Conservatory was installed August 2010 1st shattered window panel October 2012 2nd shattered window panel November 2012 3rd shattered window panel July 2013 Latest shattered window panel July 2014

All failed panels (to date) are non-openers. I'll try to find some polaroid material to follow up your suggestion.

Many thanks for your response Andy.

- Dave.

[Andy Burns]

Doesn't really fit my theory that it might have been installed in cold weather and wedged tight, and then they all shattered in hot weather, having expanded - can't count the July ones and ignore the Oct/Nov ones.

[Brian Gaff]

A guy who lives in Richmond was on a phone in a while ago and was convinced it was aircraft doing it, but if that was the case, why not the outside pane? Brian

[soup]

Is it toughened/tempered glass?

Maybe a Nickel sulphide 'inclusion'. However to have one is a long shot(glass manufacturers are pretty hot on weeding out these), but occasionally a sheet of toughened glass with an NiS inclusion gets out)[1], to have four in a row is pretty much unheard off.

[1] 1 sheet for the green house shattered as I moved it, G.H. supplier was pretty adamant I must have done something as NiS inclusions, that get through all QA tests, are so rare, however I was convinced I hadn't struck the edge[2] or anything like that and was supplied FOC with a replacement. [2] Apparently T glass is very strong normally but the edge is really weak (G.H. suppliers show six men standing on a sheet of T glass: but if anything dunts the edge sheet can (and does) shatter).

[Dave Chapman]

They are all TOUGHENED glass panels.

- Dave.

[Peter Crosland]

Most likely thing is a bird strike.

[Dave Chapman]

INSIDE the conservatory, with nothing to show on the outside? I think that rather unlikely.

>

[Tim Lamb]

In message , Dave Chapman writes

We had a Duck go through the toughened glass of my sister's new greenhouse. Wandered in and then took the easy way out!

[harryagain]

[harryagain]

Very interesting. You notice when this issue comes up it's always a conservatory. (Extremes of temperature) So the temperature difference theory seems to hold.

[Johny B Good]

What? You mean it found your dad's service revolver and blew its brains out?

[Sorry, couldn't resist - this is such a busy news group and I've been 'playing catch up' on the news this past week]

[Tim Lamb]

In message , Johny B Good writes

Farming was a reserved occupation.

I expect the Duck thought processes followed the... if it looks like sky, it must be sky....error.

You haven't missed anything much.