Spontaneous shattering of patio door glass.

If it's toughened glass this just sometimes happens - same as it does with toughened glass once used on cars.

Insurance should cover it.

Was it the fixed door or the moving one? It might be subsidence and the fixed door coming under slowly increasing stress and the eventually shattering. if it's the moving door then it can't be that becuase it would get stiff first.

i've seen this happe nat work and it is very alarmning - a big bang and then a pile of granules of glass. Sometimes they stay intact but turn to a mosaic of small fragments.

Robert

Known phenomenon with toughened glass. Check out

Yes that looks about right. Although I guess the window is the same age as the house ~20 years, a bit older than expected for this type of fault.

In message , RobertL writes

I've also seen this happen but to some poor guy who was entering a bank, he was left with a pile of granules around his ankles and holding a rather heavy brushed stainless steel door handle... Would have been cruel of me to laugh at his obvious shock and bemusement, so I did.

I saw that happen to a car window once. The door had been left open and no-one was near it and nothing was touching it. The window just shattered all of a sudden.

We were somewhere around Barstow, on the edge of the desert, when the drugs began to take hold. I remember chunkyoldcortina saying something like:

When I was a lad I saw that happen to a parked dustcart windscreen. Nobody was near it and the crew were amazed at it shattering all of a sudden. 'Course it might have had something to do with my mate's unerring catapult aim.